| 
							- /*
 -  * various utility functions for use within Libav
 -  * Copyright (c) 2000, 2001, 2002 Fabrice Bellard
 -  *
 -  * This file is part of Libav.
 -  *
 -  * Libav is free software; you can redistribute it and/or
 -  * modify it under the terms of the GNU Lesser General Public
 -  * License as published by the Free Software Foundation; either
 -  * version 2.1 of the License, or (at your option) any later version.
 -  *
 -  * Libav is distributed in the hope that it will be useful,
 -  * but WITHOUT ANY WARRANTY; without even the implied warranty of
 -  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 -  * Lesser General Public License for more details.
 -  *
 -  * You should have received a copy of the GNU Lesser General Public
 -  * License along with Libav; if not, write to the Free Software
 -  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 -  */
 - 
 - #undef NDEBUG
 - #include <assert.h>
 - #include <stdarg.h>
 - #include <stdint.h>
 - 
 - #include "config.h"
 - 
 - #include "libavutil/avassert.h"
 - #include "libavutil/avstring.h"
 - #include "libavutil/dict.h"
 - #include "libavutil/internal.h"
 - #include "libavutil/mathematics.h"
 - #include "libavutil/opt.h"
 - #include "libavutil/parseutils.h"
 - #include "libavutil/pixdesc.h"
 - #include "libavutil/time.h"
 - 
 - #include "libavcodec/bytestream.h"
 - #include "libavcodec/internal.h"
 - 
 - #include "audiointerleave.h"
 - #include "avformat.h"
 - #include "avio_internal.h"
 - #include "id3v2.h"
 - #include "internal.h"
 - #include "metadata.h"
 - #if CONFIG_NETWORK
 - #include "network.h"
 - #endif
 - #include "riff.h"
 - #include "url.h"
 - 
 - /**
 -  * @file
 -  * various utility functions for use within Libav
 -  */
 - 
 - unsigned avformat_version(void)
 - {
 -     return LIBAVFORMAT_VERSION_INT;
 - }
 - 
 - const char *avformat_configuration(void)
 - {
 -     return LIBAV_CONFIGURATION;
 - }
 - 
 - const char *avformat_license(void)
 - {
 - #define LICENSE_PREFIX "libavformat license: "
 -     return LICENSE_PREFIX LIBAV_LICENSE + sizeof(LICENSE_PREFIX) - 1;
 - }
 - 
 - /* an arbitrarily chosen "sane" max packet size -- 50M */
 - #define SANE_CHUNK_SIZE (50000000)
 - 
 - /* Read the data in sane-sized chunks and append to pkt.
 -  * Return the number of bytes read or an error. */
 - static int append_packet_chunked(AVIOContext *s, AVPacket *pkt, int size)
 - {
 -     int64_t chunk_size = size;
 -     int64_t orig_pos   = pkt->pos; // av_grow_packet might reset pos
 -     int orig_size      = pkt->size;
 -     int ret = 0;
 - 
 -     do {
 -         int prev_size = pkt->size;
 -         int read_size;
 - 
 -         /* When the caller requests a lot of data, limit it to the amount
 -          * left in file or SANE_CHUNK_SIZE when it is not known. */
 -         if (size > SANE_CHUNK_SIZE) {
 -             int64_t filesize = avio_size(s) - avio_tell(s);
 -             chunk_size = FFMAX(filesize, SANE_CHUNK_SIZE);
 -         }
 -         read_size = FFMIN(size, chunk_size);
 - 
 -         ret = av_grow_packet(pkt, read_size);
 -         if (ret < 0)
 -             break;
 - 
 -         ret = avio_read(s, pkt->data + prev_size, read_size);
 -         if (ret != read_size) {
 -             av_shrink_packet(pkt, prev_size + FFMAX(ret, 0));
 -             break;
 -         }
 - 
 -         size -= read_size;
 -     } while (size > 0);
 - 
 -     pkt->pos = orig_pos;
 -     if (!pkt->size)
 -         av_free_packet(pkt);
 -     return pkt->size > orig_size ? pkt->size - orig_size : ret;
 - }
 - 
 - int av_get_packet(AVIOContext *s, AVPacket *pkt, int size)
 - {
 -     av_init_packet(pkt);
 -     pkt->data = NULL;
 -     pkt->size = 0;
 -     pkt->pos  = avio_tell(s);
 - 
 -     return append_packet_chunked(s, pkt, size);
 - }
 - 
 - int av_append_packet(AVIOContext *s, AVPacket *pkt, int size)
 - {
 -     if (!pkt->size)
 -         return av_get_packet(s, pkt, size);
 -     return append_packet_chunked(s, pkt, size);
 - }
 - 
 - int av_filename_number_test(const char *filename)
 - {
 -     char buf[1024];
 -     return filename &&
 -            (av_get_frame_filename(buf, sizeof(buf), filename, 1) >= 0);
 - }
 - 
 - AVInputFormat *av_probe_input_format2(AVProbeData *pd, int is_opened,
 -                                       int *score_max)
 - {
 -     AVProbeData lpd = *pd;
 -     AVInputFormat *fmt1 = NULL, *fmt;
 -     int score, id3 = 0;
 - 
 -     if (lpd.buf_size > 10 && ff_id3v2_match(lpd.buf, ID3v2_DEFAULT_MAGIC)) {
 -         int id3len = ff_id3v2_tag_len(lpd.buf);
 -         if (lpd.buf_size > id3len + 16) {
 -             lpd.buf      += id3len;
 -             lpd.buf_size -= id3len;
 -         }
 -         id3 = 1;
 -     }
 - 
 -     fmt = NULL;
 -     while ((fmt1 = av_iformat_next(fmt1))) {
 -         if (!is_opened == !(fmt1->flags & AVFMT_NOFILE))
 -             continue;
 -         score = 0;
 -         if (fmt1->read_probe) {
 -             score = fmt1->read_probe(&lpd);
 -         } else if (fmt1->extensions) {
 -             if (av_match_ext(lpd.filename, fmt1->extensions))
 -                 score = AVPROBE_SCORE_EXTENSION;
 -         }
 -         if (score > *score_max) {
 -             *score_max = score;
 -             fmt        = fmt1;
 -         } else if (score == *score_max)
 -             fmt = NULL;
 -     }
 - 
 -     // A hack for files with huge id3v2 tags -- try to guess by file extension.
 -     if (!fmt && is_opened && *score_max < AVPROBE_SCORE_EXTENSION / 2) {
 -         while ((fmt = av_iformat_next(fmt)))
 -             if (fmt->extensions &&
 -                 av_match_ext(lpd.filename, fmt->extensions)) {
 -                 *score_max = AVPROBE_SCORE_EXTENSION / 2;
 -                 break;
 -             }
 -     }
 - 
 -     if (!fmt && id3 && *score_max < AVPROBE_SCORE_EXTENSION / 2 - 1) {
 -         while ((fmt = av_iformat_next(fmt)))
 -             if (fmt->extensions && av_match_ext("mp3", fmt->extensions)) {
 -                 *score_max = AVPROBE_SCORE_EXTENSION / 2 - 1;
 -                 break;
 -             }
 -     }
 - 
 -     return fmt;
 - }
 - 
 - AVInputFormat *av_probe_input_format(AVProbeData *pd, int is_opened)
 - {
 -     int score = 0;
 -     return av_probe_input_format2(pd, is_opened, &score);
 - }
 - 
 - static int set_codec_from_probe_data(AVFormatContext *s, AVStream *st,
 -                                      AVProbeData *pd, int score)
 - {
 -     static const struct {
 -         const char *name;
 -         enum AVCodecID id;
 -         enum AVMediaType type;
 -     } fmt_id_type[] = {
 -         { "aac",       AV_CODEC_ID_AAC,        AVMEDIA_TYPE_AUDIO },
 -         { "ac3",       AV_CODEC_ID_AC3,        AVMEDIA_TYPE_AUDIO },
 -         { "dts",       AV_CODEC_ID_DTS,        AVMEDIA_TYPE_AUDIO },
 -         { "eac3",      AV_CODEC_ID_EAC3,       AVMEDIA_TYPE_AUDIO },
 -         { "h264",      AV_CODEC_ID_H264,       AVMEDIA_TYPE_VIDEO },
 -         { "latm",      AV_CODEC_ID_AAC_LATM,   AVMEDIA_TYPE_AUDIO },
 -         { "m4v",       AV_CODEC_ID_MPEG4,      AVMEDIA_TYPE_VIDEO },
 -         { "mp3",       AV_CODEC_ID_MP3,        AVMEDIA_TYPE_AUDIO },
 -         { "mpegvideo", AV_CODEC_ID_MPEG2VIDEO, AVMEDIA_TYPE_VIDEO },
 -         { 0 }
 -     };
 -     AVInputFormat *fmt = av_probe_input_format2(pd, 1, &score);
 - 
 -     if (fmt) {
 -         int i;
 -         av_log(s, AV_LOG_DEBUG,
 -                "Probe with size=%d, packets=%d detected %s with score=%d\n",
 -                pd->buf_size, MAX_PROBE_PACKETS - st->probe_packets,
 -                fmt->name, score);
 -         for (i = 0; fmt_id_type[i].name; i++) {
 -             if (!strcmp(fmt->name, fmt_id_type[i].name)) {
 -                 st->codec->codec_id   = fmt_id_type[i].id;
 -                 st->codec->codec_type = fmt_id_type[i].type;
 -                 break;
 -             }
 -         }
 -     }
 -     return !!fmt;
 - }
 - 
 - /************************************************************/
 - /* input media file */
 - 
 - /** size of probe buffer, for guessing file type from file contents */
 - #define PROBE_BUF_MIN 2048
 - #define PROBE_BUF_MAX (1 << 20)
 - 
 - int av_probe_input_buffer(AVIOContext *pb, AVInputFormat **fmt,
 -                           const char *filename, void *logctx,
 -                           unsigned int offset, unsigned int max_probe_size)
 - {
 -     AVProbeData pd = { filename ? filename : "" };
 -     uint8_t *buf = NULL;
 -     int ret = 0, probe_size;
 - 
 -     if (!max_probe_size)
 -         max_probe_size = PROBE_BUF_MAX;
 -     else if (max_probe_size > PROBE_BUF_MAX)
 -         max_probe_size = PROBE_BUF_MAX;
 -     else if (max_probe_size < PROBE_BUF_MIN)
 -         return AVERROR(EINVAL);
 - 
 -     if (offset >= max_probe_size)
 -         return AVERROR(EINVAL);
 -     avio_skip(pb, offset);
 -     max_probe_size -= offset;
 - 
 -     for (probe_size = PROBE_BUF_MIN; probe_size <= max_probe_size && !*fmt;
 -          probe_size = FFMIN(probe_size << 1,
 -                             FFMAX(max_probe_size, probe_size + 1))) {
 -         int score = probe_size < max_probe_size ? AVPROBE_SCORE_MAX / 4 : 0;
 - 
 -         /* Read probe data. */
 -         if ((ret = av_reallocp(&buf, probe_size + AVPROBE_PADDING_SIZE)) < 0)
 -             return ret;
 -         if ((ret = avio_read(pb, buf + pd.buf_size,
 -                              probe_size - pd.buf_size)) < 0) {
 -             /* Fail if error was not end of file, otherwise, lower score. */
 -             if (ret != AVERROR_EOF) {
 -                 av_free(buf);
 -                 return ret;
 -             }
 -             score = 0;
 -             ret   = 0;          /* error was end of file, nothing read */
 -         }
 -         pd.buf_size += ret;
 -         pd.buf       = buf;
 - 
 -         memset(pd.buf + pd.buf_size, 0, AVPROBE_PADDING_SIZE);
 - 
 -         /* Guess file format. */
 -         *fmt = av_probe_input_format2(&pd, 1, &score);
 -         if (*fmt) {
 -             /* This can only be true in the last iteration. */
 -             if (score <= AVPROBE_SCORE_MAX / 4) {
 -                 av_log(logctx, AV_LOG_WARNING,
 -                        "Format detected only with low score of %d, "
 -                        "misdetection possible!\n", score);
 -             } else
 -                 av_log(logctx, AV_LOG_DEBUG,
 -                        "Probed with size=%d and score=%d\n", probe_size, score);
 -         }
 -     }
 - 
 -     if (!*fmt) {
 -         av_free(buf);
 -         return AVERROR_INVALIDDATA;
 -     }
 - 
 -     /* Rewind. Reuse probe buffer to avoid seeking. */
 -     if ((ret = ffio_rewind_with_probe_data(pb, buf, pd.buf_size)) < 0)
 -         av_free(buf);
 - 
 -     return ret;
 - }
 - 
 - /* Open input file and probe the format if necessary. */
 - static int init_input(AVFormatContext *s, const char *filename,
 -                       AVDictionary **options)
 - {
 -     int ret;
 -     AVProbeData pd = { filename, NULL, 0 };
 - 
 -     if (s->pb) {
 -         s->flags |= AVFMT_FLAG_CUSTOM_IO;
 -         if (!s->iformat)
 -             return av_probe_input_buffer(s->pb, &s->iformat, filename,
 -                                          s, 0, s->probesize);
 -         else if (s->iformat->flags & AVFMT_NOFILE)
 -             return AVERROR(EINVAL);
 -         return 0;
 -     }
 - 
 -     if ((s->iformat && s->iformat->flags & AVFMT_NOFILE) ||
 -         (!s->iformat && (s->iformat = av_probe_input_format(&pd, 0))))
 -         return 0;
 - 
 -     if ((ret = avio_open2(&s->pb, filename, AVIO_FLAG_READ,
 -                           &s->interrupt_callback, options)) < 0)
 -         return ret;
 -     if (s->iformat)
 -         return 0;
 -     return av_probe_input_buffer(s->pb, &s->iformat, filename,
 -                                  s, 0, s->probesize);
 - }
 - 
 - static AVPacket *add_to_pktbuf(AVPacketList **packet_buffer, AVPacket *pkt,
 -                                AVPacketList **plast_pktl)
 - {
 -     AVPacketList *pktl = av_mallocz(sizeof(AVPacketList));
 -     if (!pktl)
 -         return NULL;
 - 
 -     if (*packet_buffer)
 -         (*plast_pktl)->next = pktl;
 -     else
 -         *packet_buffer = pktl;
 - 
 -     /* Add the packet in the buffered packet list. */
 -     *plast_pktl = pktl;
 -     pktl->pkt   = *pkt;
 -     return &pktl->pkt;
 - }
 - 
 - static int queue_attached_pictures(AVFormatContext *s)
 - {
 -     int i;
 -     for (i = 0; i < s->nb_streams; i++)
 -         if (s->streams[i]->disposition & AV_DISPOSITION_ATTACHED_PIC &&
 -             s->streams[i]->discard < AVDISCARD_ALL) {
 -             AVPacket copy = s->streams[i]->attached_pic;
 -             copy.buf = av_buffer_ref(copy.buf);
 -             if (!copy.buf)
 -                 return AVERROR(ENOMEM);
 - 
 -             add_to_pktbuf(&s->raw_packet_buffer, ©,
 -                           &s->raw_packet_buffer_end);
 -         }
 -     return 0;
 - }
 - 
 - int avformat_open_input(AVFormatContext **ps, const char *filename,
 -                         AVInputFormat *fmt, AVDictionary **options)
 - {
 -     AVFormatContext *s = *ps;
 -     int ret = 0;
 -     AVDictionary *tmp = NULL;
 -     ID3v2ExtraMeta *id3v2_extra_meta = NULL;
 - 
 -     if (!s && !(s = avformat_alloc_context()))
 -         return AVERROR(ENOMEM);
 -     if (fmt)
 -         s->iformat = fmt;
 - 
 -     if (options)
 -         av_dict_copy(&tmp, *options, 0);
 - 
 -     if ((ret = av_opt_set_dict(s, &tmp)) < 0)
 -         goto fail;
 - 
 -     if ((ret = init_input(s, filename, &tmp)) < 0)
 -         goto fail;
 - 
 -     /* Check filename in case an image number is expected. */
 -     if (s->iformat->flags & AVFMT_NEEDNUMBER) {
 -         if (!av_filename_number_test(filename)) {
 -             ret = AVERROR(EINVAL);
 -             goto fail;
 -         }
 -     }
 - 
 -     s->duration = s->start_time = AV_NOPTS_VALUE;
 -     av_strlcpy(s->filename, filename ? filename : "", sizeof(s->filename));
 - 
 -     /* Allocate private data. */
 -     if (s->iformat->priv_data_size > 0) {
 -         if (!(s->priv_data = av_mallocz(s->iformat->priv_data_size))) {
 -             ret = AVERROR(ENOMEM);
 -             goto fail;
 -         }
 -         if (s->iformat->priv_class) {
 -             *(const AVClass **) s->priv_data = s->iformat->priv_class;
 -             av_opt_set_defaults(s->priv_data);
 -             if ((ret = av_opt_set_dict(s->priv_data, &tmp)) < 0)
 -                 goto fail;
 -         }
 -     }
 - 
 -     /* e.g. AVFMT_NOFILE formats will not have a AVIOContext */
 -     if (s->pb)
 -         ff_id3v2_read(s, ID3v2_DEFAULT_MAGIC, &id3v2_extra_meta);
 - 
 -     if (s->iformat->read_header)
 -         if ((ret = s->iformat->read_header(s)) < 0)
 -             goto fail;
 - 
 -     if (id3v2_extra_meta &&
 -         (ret = ff_id3v2_parse_apic(s, &id3v2_extra_meta)) < 0)
 -         goto fail;
 -     ff_id3v2_free_extra_meta(&id3v2_extra_meta);
 - 
 -     if ((ret = queue_attached_pictures(s)) < 0)
 -         goto fail;
 - 
 -     if (s->pb && !s->data_offset)
 -         s->data_offset = avio_tell(s->pb);
 - 
 -     s->raw_packet_buffer_remaining_size = RAW_PACKET_BUFFER_SIZE;
 - 
 -     if (options) {
 -         av_dict_free(options);
 -         *options = tmp;
 -     }
 -     *ps = s;
 -     return 0;
 - 
 - fail:
 -     ff_id3v2_free_extra_meta(&id3v2_extra_meta);
 -     av_dict_free(&tmp);
 -     if (s->pb && !(s->flags & AVFMT_FLAG_CUSTOM_IO))
 -         avio_close(s->pb);
 -     avformat_free_context(s);
 -     *ps = NULL;
 -     return ret;
 - }
 - 
 - /*******************************************************/
 - 
 - static int probe_codec(AVFormatContext *s, AVStream *st, const AVPacket *pkt)
 - {
 -     if (st->codec->codec_id == AV_CODEC_ID_PROBE) {
 -         AVProbeData *pd = &st->probe_data;
 -         av_log(s, AV_LOG_DEBUG, "probing stream %d\n", st->index);
 -         --st->probe_packets;
 - 
 -         if (pkt) {
 -             int err;
 -             if ((err = av_reallocp(&pd->buf, pd->buf_size + pkt->size +
 -                                    AVPROBE_PADDING_SIZE)) < 0)
 -                 return err;
 -             memcpy(pd->buf + pd->buf_size, pkt->data, pkt->size);
 -             pd->buf_size += pkt->size;
 -             memset(pd->buf + pd->buf_size, 0, AVPROBE_PADDING_SIZE);
 -         } else {
 -             st->probe_packets = 0;
 -             if (!pd->buf_size) {
 -                 av_log(s, AV_LOG_ERROR,
 -                        "nothing to probe for stream %d\n", st->index);
 -                 return 0;
 -             }
 -         }
 - 
 -         if (!st->probe_packets ||
 -             av_log2(pd->buf_size) != av_log2(pd->buf_size - pkt->size)) {
 -             set_codec_from_probe_data(s, st, pd, st->probe_packets > 0
 -                                                  ? AVPROBE_SCORE_MAX / 4 : 0);
 -             if (st->codec->codec_id != AV_CODEC_ID_PROBE) {
 -                 pd->buf_size = 0;
 -                 av_freep(&pd->buf);
 -                 av_log(s, AV_LOG_DEBUG, "probed stream %d\n", st->index);
 -             }
 -         }
 -     }
 -     return 0;
 - }
 - 
 - int ff_read_packet(AVFormatContext *s, AVPacket *pkt)
 - {
 -     int ret, i, err;
 -     AVStream *st;
 - 
 -     for (;;) {
 -         AVPacketList *pktl = s->raw_packet_buffer;
 - 
 -         if (pktl) {
 -             *pkt = pktl->pkt;
 -             st   = s->streams[pkt->stream_index];
 -             if (st->codec->codec_id != AV_CODEC_ID_PROBE ||
 -                 !st->probe_packets ||
 -                 s->raw_packet_buffer_remaining_size < pkt->size) {
 -                 AVProbeData *pd;
 -                 if (st->probe_packets)
 -                     if ((err = probe_codec(s, st, NULL)) < 0)
 -                         return err;
 -                 pd = &st->probe_data;
 -                 av_freep(&pd->buf);
 -                 pd->buf_size = 0;
 -                 s->raw_packet_buffer                 = pktl->next;
 -                 s->raw_packet_buffer_remaining_size += pkt->size;
 -                 av_free(pktl);
 -                 return 0;
 -             }
 -         }
 - 
 -         pkt->data = NULL;
 -         pkt->size = 0;
 -         av_init_packet(pkt);
 -         ret = s->iformat->read_packet(s, pkt);
 -         if (ret < 0) {
 -             if (!pktl || ret == AVERROR(EAGAIN))
 -                 return ret;
 -             for (i = 0; i < s->nb_streams; i++) {
 -                 st = s->streams[i];
 -                 if (st->probe_packets)
 -                     if ((err = probe_codec(s, st, NULL)) < 0)
 -                         return err;
 -             }
 -             continue;
 -         }
 - 
 -         if ((s->flags & AVFMT_FLAG_DISCARD_CORRUPT) &&
 -             (pkt->flags & AV_PKT_FLAG_CORRUPT)) {
 -             av_log(s, AV_LOG_WARNING,
 -                    "Dropped corrupted packet (stream = %d)\n",
 -                    pkt->stream_index);
 -             av_free_packet(pkt);
 -             continue;
 -         }
 - 
 -         st = s->streams[pkt->stream_index];
 - 
 -         switch (st->codec->codec_type) {
 -         case AVMEDIA_TYPE_VIDEO:
 -             if (s->video_codec_id)
 -                 st->codec->codec_id = s->video_codec_id;
 -             break;
 -         case AVMEDIA_TYPE_AUDIO:
 -             if (s->audio_codec_id)
 -                 st->codec->codec_id = s->audio_codec_id;
 -             break;
 -         case AVMEDIA_TYPE_SUBTITLE:
 -             if (s->subtitle_codec_id)
 -                 st->codec->codec_id = s->subtitle_codec_id;
 -             break;
 -         }
 - 
 -         if (!pktl && (st->codec->codec_id != AV_CODEC_ID_PROBE ||
 -                       !st->probe_packets))
 -             return ret;
 - 
 -         add_to_pktbuf(&s->raw_packet_buffer, pkt, &s->raw_packet_buffer_end);
 -         s->raw_packet_buffer_remaining_size -= pkt->size;
 - 
 -         if ((err = probe_codec(s, st, pkt)) < 0)
 -             return err;
 -     }
 - }
 - 
 - /**********************************************************/
 - 
 - /**
 -  * Get the number of samples of an audio frame. Return -1 on error.
 -  */
 - int ff_get_audio_frame_size(AVCodecContext *enc, int size, int mux)
 - {
 -     int frame_size;
 - 
 -     /* give frame_size priority if demuxing */
 -     if (!mux && enc->frame_size > 1)
 -         return enc->frame_size;
 - 
 -     if ((frame_size = av_get_audio_frame_duration(enc, size)) > 0)
 -         return frame_size;
 - 
 -     /* Fall back on using frame_size if muxing. */
 -     if (enc->frame_size > 1)
 -         return enc->frame_size;
 - 
 -     return -1;
 - }
 - 
 - /**
 -  * Return the frame duration in seconds. Return 0 if not available.
 -  */
 - void ff_compute_frame_duration(int *pnum, int *pden, AVStream *st,
 -                                AVCodecParserContext *pc, AVPacket *pkt)
 - {
 -     int frame_size;
 - 
 -     *pnum = 0;
 -     *pden = 0;
 -     switch (st->codec->codec_type) {
 -     case AVMEDIA_TYPE_VIDEO:
 -         if (st->avg_frame_rate.num) {
 -             *pnum = st->avg_frame_rate.den;
 -             *pden = st->avg_frame_rate.num;
 -         } else if (st->time_base.num * 1000LL > st->time_base.den) {
 -             *pnum = st->time_base.num;
 -             *pden = st->time_base.den;
 -         } else if (st->codec->time_base.num * 1000LL > st->codec->time_base.den) {
 -             *pnum = st->codec->time_base.num;
 -             *pden = st->codec->time_base.den;
 -             if (pc && pc->repeat_pict) {
 -                 if (*pnum > INT_MAX / (1 + pc->repeat_pict))
 -                     *pden /= 1 + pc->repeat_pict;
 -                 else
 -                     *pnum *= 1 + pc->repeat_pict;
 -             }
 -             /* If this codec can be interlaced or progressive then we need
 -              * a parser to compute duration of a packet. Thus if we have
 -              * no parser in such case leave duration undefined. */
 -             if (st->codec->ticks_per_frame > 1 && !pc)
 -                 *pnum = *pden = 0;
 -         }
 -         break;
 -     case AVMEDIA_TYPE_AUDIO:
 -         frame_size = ff_get_audio_frame_size(st->codec, pkt->size, 0);
 -         if (frame_size <= 0 || st->codec->sample_rate <= 0)
 -             break;
 -         *pnum = frame_size;
 -         *pden = st->codec->sample_rate;
 -         break;
 -     default:
 -         break;
 -     }
 - }
 - 
 - static int is_intra_only(enum AVCodecID id)
 - {
 -     const AVCodecDescriptor *d = avcodec_descriptor_get(id);
 -     if (!d)
 -         return 0;
 -     if (d->type == AVMEDIA_TYPE_VIDEO && !(d->props & AV_CODEC_PROP_INTRA_ONLY))
 -         return 0;
 -     return 1;
 - }
 - 
 - static void update_initial_timestamps(AVFormatContext *s, int stream_index,
 -                                       int64_t dts, int64_t pts)
 - {
 -     AVStream *st       = s->streams[stream_index];
 -     AVPacketList *pktl = s->packet_buffer;
 - 
 -     if (st->first_dts != AV_NOPTS_VALUE ||
 -         dts           == AV_NOPTS_VALUE ||
 -         st->cur_dts   == AV_NOPTS_VALUE)
 -         return;
 - 
 -     st->first_dts = dts - st->cur_dts;
 -     st->cur_dts   = dts;
 - 
 -     for (; pktl; pktl = pktl->next) {
 -         if (pktl->pkt.stream_index != stream_index)
 -             continue;
 -         // FIXME: think more about this check
 -         if (pktl->pkt.pts != AV_NOPTS_VALUE && pktl->pkt.pts == pktl->pkt.dts)
 -             pktl->pkt.pts += st->first_dts;
 - 
 -         if (pktl->pkt.dts != AV_NOPTS_VALUE)
 -             pktl->pkt.dts += st->first_dts;
 - 
 -         if (st->start_time == AV_NOPTS_VALUE && pktl->pkt.pts != AV_NOPTS_VALUE)
 -             st->start_time = pktl->pkt.pts;
 -     }
 -     if (st->start_time == AV_NOPTS_VALUE)
 -         st->start_time = pts;
 - }
 - 
 - static void update_initial_durations(AVFormatContext *s, AVStream *st,
 -                                      int stream_index, int duration)
 - {
 -     AVPacketList *pktl = s->packet_buffer;
 -     int64_t cur_dts    = 0;
 - 
 -     if (st->first_dts != AV_NOPTS_VALUE) {
 -         cur_dts = st->first_dts;
 -         for (; pktl; pktl = pktl->next) {
 -             if (pktl->pkt.stream_index == stream_index) {
 -                 if (pktl->pkt.pts != pktl->pkt.dts  ||
 -                     pktl->pkt.dts != AV_NOPTS_VALUE ||
 -                     pktl->pkt.duration)
 -                     break;
 -                 cur_dts -= duration;
 -             }
 -         }
 -         pktl          = s->packet_buffer;
 -         st->first_dts = cur_dts;
 -     } else if (st->cur_dts)
 -         return;
 - 
 -     for (; pktl; pktl = pktl->next) {
 -         if (pktl->pkt.stream_index != stream_index)
 -             continue;
 -         if (pktl->pkt.pts == pktl->pkt.dts  &&
 -             pktl->pkt.dts == AV_NOPTS_VALUE &&
 -             !pktl->pkt.duration) {
 -             pktl->pkt.dts = cur_dts;
 -             if (!st->codec->has_b_frames)
 -                 pktl->pkt.pts = cur_dts;
 -             cur_dts += duration;
 -             if (st->codec->codec_type != AVMEDIA_TYPE_AUDIO)
 -                 pktl->pkt.duration = duration;
 -         } else
 -             break;
 -     }
 -     if (st->first_dts == AV_NOPTS_VALUE)
 -         st->cur_dts = cur_dts;
 - }
 - 
 - static void compute_pkt_fields(AVFormatContext *s, AVStream *st,
 -                                AVCodecParserContext *pc, AVPacket *pkt)
 - {
 -     int num, den, presentation_delayed, delay, i;
 -     int64_t offset;
 - 
 -     if (s->flags & AVFMT_FLAG_NOFILLIN)
 -         return;
 - 
 -     if ((s->flags & AVFMT_FLAG_IGNDTS) && pkt->pts != AV_NOPTS_VALUE)
 -         pkt->dts = AV_NOPTS_VALUE;
 - 
 -     /* do we have a video B-frame ? */
 -     delay = st->codec->has_b_frames;
 -     presentation_delayed = 0;
 - 
 -     /* XXX: need has_b_frame, but cannot get it if the codec is
 -      *  not initialized */
 -     if (delay &&
 -         pc && pc->pict_type != AV_PICTURE_TYPE_B)
 -         presentation_delayed = 1;
 - 
 -     if (pkt->pts != AV_NOPTS_VALUE && pkt->dts != AV_NOPTS_VALUE &&
 -         st->pts_wrap_bits < 63 &&
 -         pkt->dts - (1LL << (st->pts_wrap_bits - 1)) > pkt->pts) {
 -         pkt->dts -= 1LL << st->pts_wrap_bits;
 -     }
 - 
 -     /* Some MPEG-2 in MPEG-PS lack dts (issue #171 / input_file.mpg).
 -      * We take the conservative approach and discard both.
 -      * Note: If this is misbehaving for an H.264 file, then possibly
 -      * presentation_delayed is not set correctly. */
 -     if (delay == 1 && pkt->dts == pkt->pts &&
 -         pkt->dts != AV_NOPTS_VALUE && presentation_delayed) {
 -         av_log(s, AV_LOG_DEBUG, "invalid dts/pts combination\n");
 -         pkt->dts = pkt->pts = AV_NOPTS_VALUE;
 -     }
 - 
 -     if (pkt->duration == 0 && st->codec->codec_type != AVMEDIA_TYPE_AUDIO) {
 -         ff_compute_frame_duration(&num, &den, st, pc, pkt);
 -         if (den && num) {
 -             pkt->duration = av_rescale_rnd(1, num * (int64_t) st->time_base.den,
 -                                            den * (int64_t) st->time_base.num,
 -                                            AV_ROUND_DOWN);
 - 
 -             if (pkt->duration != 0 && s->packet_buffer)
 -                 update_initial_durations(s, st, pkt->stream_index,
 -                                          pkt->duration);
 -         }
 -     }
 - 
 -     /* Correct timestamps with byte offset if demuxers only have timestamps
 -      * on packet boundaries */
 -     if (pc && st->need_parsing == AVSTREAM_PARSE_TIMESTAMPS && pkt->size) {
 -         /* this will estimate bitrate based on this frame's duration and size */
 -         offset = av_rescale(pc->offset, pkt->duration, pkt->size);
 -         if (pkt->pts != AV_NOPTS_VALUE)
 -             pkt->pts += offset;
 -         if (pkt->dts != AV_NOPTS_VALUE)
 -             pkt->dts += offset;
 -     }
 - 
 -     /* This may be redundant, but it should not hurt. */
 -     if (pkt->dts != AV_NOPTS_VALUE &&
 -         pkt->pts != AV_NOPTS_VALUE &&
 -         pkt->pts > pkt->dts)
 -         presentation_delayed = 1;
 - 
 -     av_dlog(NULL,
 -             "IN delayed:%d pts:%"PRId64", dts:%"PRId64" "
 -             "cur_dts:%"PRId64" st:%d pc:%p\n",
 -             presentation_delayed, pkt->pts, pkt->dts, st->cur_dts,
 -             pkt->stream_index, pc);
 -     /* Interpolate PTS and DTS if they are not present. We skip H.264
 -      * currently because delay and has_b_frames are not reliably set. */
 -     if ((delay == 0 || (delay == 1 && pc)) &&
 -         st->codec->codec_id != AV_CODEC_ID_H264) {
 -         if (presentation_delayed) {
 -             /* DTS = decompression timestamp */
 -             /* PTS = presentation timestamp */
 -             if (pkt->dts == AV_NOPTS_VALUE)
 -                 pkt->dts = st->last_IP_pts;
 -             update_initial_timestamps(s, pkt->stream_index, pkt->dts, pkt->pts);
 -             if (pkt->dts == AV_NOPTS_VALUE)
 -                 pkt->dts = st->cur_dts;
 - 
 -             /* This is tricky: the dts must be incremented by the duration
 -              * of the frame we are displaying, i.e. the last I- or P-frame. */
 -             if (st->last_IP_duration == 0)
 -                 st->last_IP_duration = pkt->duration;
 -             if (pkt->dts != AV_NOPTS_VALUE)
 -                 st->cur_dts = pkt->dts + st->last_IP_duration;
 -             st->last_IP_duration = pkt->duration;
 -             st->last_IP_pts      = pkt->pts;
 -             /* Cannot compute PTS if not present (we can compute it only
 -              * by knowing the future. */
 -         } else if (pkt->pts != AV_NOPTS_VALUE ||
 -                    pkt->dts != AV_NOPTS_VALUE ||
 -                    pkt->duration              ||
 -                    st->codec->codec_type == AVMEDIA_TYPE_AUDIO) {
 -             int duration = pkt->duration;
 -             if (!duration && st->codec->codec_type == AVMEDIA_TYPE_AUDIO) {
 -                 ff_compute_frame_duration(&num, &den, st, pc, pkt);
 -                 if (den && num) {
 -                     duration = av_rescale_rnd(1,
 -                                               num * (int64_t) st->time_base.den,
 -                                               den * (int64_t) st->time_base.num,
 -                                               AV_ROUND_DOWN);
 -                     if (duration != 0 && s->packet_buffer)
 -                         update_initial_durations(s, st, pkt->stream_index,
 -                                                  duration);
 -                 }
 -             }
 - 
 -             if (pkt->pts != AV_NOPTS_VALUE || pkt->dts != AV_NOPTS_VALUE ||
 -                 duration) {
 -                 /* presentation is not delayed : PTS and DTS are the same */
 -                 if (pkt->pts == AV_NOPTS_VALUE)
 -                     pkt->pts = pkt->dts;
 -                 update_initial_timestamps(s, pkt->stream_index, pkt->pts,
 -                                           pkt->pts);
 -                 if (pkt->pts == AV_NOPTS_VALUE)
 -                     pkt->pts = st->cur_dts;
 -                 pkt->dts = pkt->pts;
 -                 if (pkt->pts != AV_NOPTS_VALUE)
 -                     st->cur_dts = pkt->pts + duration;
 -             }
 -         }
 -     }
 - 
 -     if (pkt->pts != AV_NOPTS_VALUE && delay <= MAX_REORDER_DELAY) {
 -         st->pts_buffer[0] = pkt->pts;
 -         for (i = 0; i<delay && st->pts_buffer[i] > st->pts_buffer[i + 1]; i++)
 -             FFSWAP(int64_t, st->pts_buffer[i], st->pts_buffer[i + 1]);
 -         if (pkt->dts == AV_NOPTS_VALUE)
 -             pkt->dts = st->pts_buffer[0];
 -         // We skipped it above so we try here.
 -         if (st->codec->codec_id == AV_CODEC_ID_H264)
 -             // This should happen on the first packet
 -             update_initial_timestamps(s, pkt->stream_index, pkt->dts, pkt->pts);
 -         if (pkt->dts > st->cur_dts)
 -             st->cur_dts = pkt->dts;
 -     }
 - 
 -     av_dlog(NULL,
 -             "OUTdelayed:%d/%d pts:%"PRId64", dts:%"PRId64" cur_dts:%"PRId64"\n",
 -             presentation_delayed, delay, pkt->pts, pkt->dts, st->cur_dts);
 - 
 -     /* update flags */
 -     if (is_intra_only(st->codec->codec_id))
 -         pkt->flags |= AV_PKT_FLAG_KEY;
 -     if (pc)
 -         pkt->convergence_duration = pc->convergence_duration;
 - }
 - 
 - static void free_packet_buffer(AVPacketList **pkt_buf, AVPacketList **pkt_buf_end)
 - {
 -     while (*pkt_buf) {
 -         AVPacketList *pktl = *pkt_buf;
 -         *pkt_buf = pktl->next;
 -         av_free_packet(&pktl->pkt);
 -         av_freep(&pktl);
 -     }
 -     *pkt_buf_end = NULL;
 - }
 - 
 - /**
 -  * Parse a packet, add all split parts to parse_queue.
 -  *
 -  * @param pkt Packet to parse, NULL when flushing the parser at end of stream.
 -  */
 - static int parse_packet(AVFormatContext *s, AVPacket *pkt, int stream_index)
 - {
 -     AVPacket out_pkt = { 0 }, flush_pkt = { 0 };
 -     AVStream *st = s->streams[stream_index];
 -     uint8_t *data = pkt ? pkt->data : NULL;
 -     int size      = pkt ? pkt->size : 0;
 -     int ret = 0, got_output = 0;
 - 
 -     if (!pkt) {
 -         av_init_packet(&flush_pkt);
 -         pkt        = &flush_pkt;
 -         got_output = 1;
 -     }
 - 
 -     while (size > 0 || (pkt == &flush_pkt && got_output)) {
 -         int len;
 - 
 -         av_init_packet(&out_pkt);
 -         len = av_parser_parse2(st->parser, st->codec,
 -                                &out_pkt.data, &out_pkt.size, data, size,
 -                                pkt->pts, pkt->dts, pkt->pos);
 - 
 -         pkt->pts = pkt->dts = AV_NOPTS_VALUE;
 -         /* increment read pointer */
 -         data += len;
 -         size -= len;
 - 
 -         got_output = !!out_pkt.size;
 - 
 -         if (!out_pkt.size)
 -             continue;
 - 
 -         if (pkt->side_data) {
 -             out_pkt.side_data       = pkt->side_data;
 -             out_pkt.side_data_elems = pkt->side_data_elems;
 -             pkt->side_data          = NULL;
 -             pkt->side_data_elems    = 0;
 -         }
 - 
 -         /* set the duration */
 -         out_pkt.duration = 0;
 -         if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO) {
 -             if (st->codec->sample_rate > 0) {
 -                 out_pkt.duration =
 -                     av_rescale_q_rnd(st->parser->duration,
 -                                      (AVRational) { 1, st->codec->sample_rate },
 -                                      st->time_base,
 -                                      AV_ROUND_DOWN);
 -             }
 -         }
 - 
 -         out_pkt.stream_index = st->index;
 -         out_pkt.pts          = st->parser->pts;
 -         out_pkt.dts          = st->parser->dts;
 -         out_pkt.pos          = st->parser->pos;
 - 
 -         if (st->parser->key_frame == 1 ||
 -             (st->parser->key_frame == -1 &&
 -              st->parser->pict_type == AV_PICTURE_TYPE_I))
 -             out_pkt.flags |= AV_PKT_FLAG_KEY;
 - 
 -         compute_pkt_fields(s, st, st->parser, &out_pkt);
 - 
 -         if ((s->iformat->flags & AVFMT_GENERIC_INDEX) &&
 -             out_pkt.flags & AV_PKT_FLAG_KEY) {
 -             ff_reduce_index(s, st->index);
 -             av_add_index_entry(st, st->parser->frame_offset, out_pkt.dts,
 -                                0, 0, AVINDEX_KEYFRAME);
 -         }
 - 
 -         if (out_pkt.data == pkt->data && out_pkt.size == pkt->size) {
 -             out_pkt.buf = pkt->buf;
 -             pkt->buf    = NULL;
 - #if FF_API_DESTRUCT_PACKET
 - FF_DISABLE_DEPRECATION_WARNINGS
 -             out_pkt.destruct = pkt->destruct;
 -             pkt->destruct = NULL;
 - FF_ENABLE_DEPRECATION_WARNINGS
 - #endif
 -         }
 -         if ((ret = av_dup_packet(&out_pkt)) < 0)
 -             goto fail;
 - 
 -         if (!add_to_pktbuf(&s->parse_queue, &out_pkt, &s->parse_queue_end)) {
 -             av_free_packet(&out_pkt);
 -             ret = AVERROR(ENOMEM);
 -             goto fail;
 -         }
 -     }
 - 
 -     /* end of the stream => close and free the parser */
 -     if (pkt == &flush_pkt) {
 -         av_parser_close(st->parser);
 -         st->parser = NULL;
 -     }
 - 
 - fail:
 -     av_free_packet(pkt);
 -     return ret;
 - }
 - 
 - static int read_from_packet_buffer(AVPacketList **pkt_buffer,
 -                                    AVPacketList **pkt_buffer_end,
 -                                    AVPacket      *pkt)
 - {
 -     AVPacketList *pktl;
 -     av_assert0(*pkt_buffer);
 -     pktl        = *pkt_buffer;
 -     *pkt        = pktl->pkt;
 -     *pkt_buffer = pktl->next;
 -     if (!pktl->next)
 -         *pkt_buffer_end = NULL;
 -     av_freep(&pktl);
 -     return 0;
 - }
 - 
 - static int read_frame_internal(AVFormatContext *s, AVPacket *pkt)
 - {
 -     int ret = 0, i, got_packet = 0;
 - 
 -     av_init_packet(pkt);
 - 
 -     while (!got_packet && !s->parse_queue) {
 -         AVStream *st;
 -         AVPacket cur_pkt;
 - 
 -         /* read next packet */
 -         ret = ff_read_packet(s, &cur_pkt);
 -         if (ret < 0) {
 -             if (ret == AVERROR(EAGAIN))
 -                 return ret;
 -             /* flush the parsers */
 -             for (i = 0; i < s->nb_streams; i++) {
 -                 st = s->streams[i];
 -                 if (st->parser && st->need_parsing)
 -                     parse_packet(s, NULL, st->index);
 -             }
 -             /* all remaining packets are now in parse_queue =>
 -              * really terminate parsing */
 -             break;
 -         }
 -         ret = 0;
 -         st  = s->streams[cur_pkt.stream_index];
 - 
 -         if (cur_pkt.pts != AV_NOPTS_VALUE &&
 -             cur_pkt.dts != AV_NOPTS_VALUE &&
 -             cur_pkt.pts < cur_pkt.dts) {
 -             av_log(s, AV_LOG_WARNING,
 -                    "Invalid timestamps stream=%d, pts=%"PRId64", "
 -                    "dts=%"PRId64", size=%d\n",
 -                    cur_pkt.stream_index, cur_pkt.pts,
 -                    cur_pkt.dts, cur_pkt.size);
 -         }
 -         if (s->debug & FF_FDEBUG_TS)
 -             av_log(s, AV_LOG_DEBUG,
 -                    "ff_read_packet stream=%d, pts=%"PRId64", dts=%"PRId64", "
 -                    "size=%d, duration=%d, flags=%d\n",
 -                    cur_pkt.stream_index, cur_pkt.pts, cur_pkt.dts,
 -                    cur_pkt.size, cur_pkt.duration, cur_pkt.flags);
 - 
 -         if (st->need_parsing && !st->parser && !(s->flags & AVFMT_FLAG_NOPARSE)) {
 -             st->parser = av_parser_init(st->codec->codec_id);
 -             if (!st->parser)
 -                 /* no parser available: just output the raw packets */
 -                 st->need_parsing = AVSTREAM_PARSE_NONE;
 -             else if (st->need_parsing == AVSTREAM_PARSE_HEADERS)
 -                 st->parser->flags |= PARSER_FLAG_COMPLETE_FRAMES;
 -             else if (st->need_parsing == AVSTREAM_PARSE_FULL_ONCE)
 -                 st->parser->flags |= PARSER_FLAG_ONCE;
 -         }
 - 
 -         if (!st->need_parsing || !st->parser) {
 -             /* no parsing needed: we just output the packet as is */
 -             *pkt = cur_pkt;
 -             compute_pkt_fields(s, st, NULL, pkt);
 -             if ((s->iformat->flags & AVFMT_GENERIC_INDEX) &&
 -                 (pkt->flags & AV_PKT_FLAG_KEY) && pkt->dts != AV_NOPTS_VALUE) {
 -                 ff_reduce_index(s, st->index);
 -                 av_add_index_entry(st, pkt->pos, pkt->dts,
 -                                    0, 0, AVINDEX_KEYFRAME);
 -             }
 -             got_packet = 1;
 -         } else if (st->discard < AVDISCARD_ALL) {
 -             if ((ret = parse_packet(s, &cur_pkt, cur_pkt.stream_index)) < 0)
 -                 return ret;
 -         } else {
 -             /* free packet */
 -             av_free_packet(&cur_pkt);
 -         }
 -     }
 - 
 -     if (!got_packet && s->parse_queue)
 -         ret = read_from_packet_buffer(&s->parse_queue, &s->parse_queue_end, pkt);
 - 
 -     if (s->debug & FF_FDEBUG_TS)
 -         av_log(s, AV_LOG_DEBUG,
 -                "read_frame_internal stream=%d, pts=%"PRId64", dts=%"PRId64", "
 -                "size=%d, duration=%d, flags=%d\n",
 -                pkt->stream_index, pkt->pts, pkt->dts,
 -                pkt->size, pkt->duration, pkt->flags);
 - 
 -     return ret;
 - }
 - 
 - int av_read_frame(AVFormatContext *s, AVPacket *pkt)
 - {
 -     const int genpts = s->flags & AVFMT_FLAG_GENPTS;
 -     int eof = 0;
 - 
 -     if (!genpts)
 -         return s->packet_buffer
 -                ? read_from_packet_buffer(&s->packet_buffer,
 -                                          &s->packet_buffer_end, pkt)
 -                : read_frame_internal(s, pkt);
 - 
 -     for (;;) {
 -         int ret;
 -         AVPacketList *pktl = s->packet_buffer;
 - 
 -         if (pktl) {
 -             AVPacket *next_pkt = &pktl->pkt;
 - 
 -             if (next_pkt->dts != AV_NOPTS_VALUE) {
 -                 int wrap_bits = s->streams[next_pkt->stream_index]->pts_wrap_bits;
 -                 while (pktl && next_pkt->pts == AV_NOPTS_VALUE) {
 -                     if (pktl->pkt.stream_index == next_pkt->stream_index &&
 -                         (av_compare_mod(next_pkt->dts, pktl->pkt.dts, 2LL << (wrap_bits - 1)) < 0) &&
 -                          av_compare_mod(pktl->pkt.pts, pktl->pkt.dts, 2LL << (wrap_bits - 1))) {
 -                         // not B-frame
 -                         next_pkt->pts = pktl->pkt.dts;
 -                     }
 -                     pktl = pktl->next;
 -                 }
 -                 pktl = s->packet_buffer;
 -             }
 - 
 -             /* read packet from packet buffer, if there is data */
 -             if (!(next_pkt->pts == AV_NOPTS_VALUE &&
 -                   next_pkt->dts != AV_NOPTS_VALUE && !eof))
 -                 return read_from_packet_buffer(&s->packet_buffer,
 -                                                &s->packet_buffer_end, pkt);
 -         }
 - 
 -         ret = read_frame_internal(s, pkt);
 -         if (ret < 0) {
 -             if (pktl && ret != AVERROR(EAGAIN)) {
 -                 eof = 1;
 -                 continue;
 -             } else
 -                 return ret;
 -         }
 - 
 -         if (av_dup_packet(add_to_pktbuf(&s->packet_buffer, pkt,
 -                                         &s->packet_buffer_end)) < 0)
 -             return AVERROR(ENOMEM);
 -     }
 - }
 - 
 - /* XXX: suppress the packet queue */
 - static void flush_packet_queue(AVFormatContext *s)
 - {
 -     free_packet_buffer(&s->parse_queue,       &s->parse_queue_end);
 -     free_packet_buffer(&s->packet_buffer,     &s->packet_buffer_end);
 -     free_packet_buffer(&s->raw_packet_buffer, &s->raw_packet_buffer_end);
 - 
 -     s->raw_packet_buffer_remaining_size = RAW_PACKET_BUFFER_SIZE;
 - }
 - 
 - /*******************************************************/
 - /* seek support */
 - 
 - int av_find_default_stream_index(AVFormatContext *s)
 - {
 -     int first_audio_index = -1;
 -     int i;
 -     AVStream *st;
 - 
 -     if (s->nb_streams <= 0)
 -         return -1;
 -     for (i = 0; i < s->nb_streams; i++) {
 -         st = s->streams[i];
 -         if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO &&
 -             !(st->disposition & AV_DISPOSITION_ATTACHED_PIC)) {
 -             return i;
 -         }
 -         if (first_audio_index < 0 &&
 -             st->codec->codec_type == AVMEDIA_TYPE_AUDIO)
 -             first_audio_index = i;
 -     }
 -     return first_audio_index >= 0 ? first_audio_index : 0;
 - }
 - 
 - /** Flush the frame reader. */
 - void ff_read_frame_flush(AVFormatContext *s)
 - {
 -     AVStream *st;
 -     int i, j;
 - 
 -     flush_packet_queue(s);
 - 
 -     /* Reset read state for each stream. */
 -     for (i = 0; i < s->nb_streams; i++) {
 -         st = s->streams[i];
 - 
 -         if (st->parser) {
 -             av_parser_close(st->parser);
 -             st->parser = NULL;
 -         }
 -         st->last_IP_pts = AV_NOPTS_VALUE;
 -         /* We set the current DTS to an unspecified origin. */
 -         st->cur_dts     = AV_NOPTS_VALUE;
 - 
 -         st->probe_packets = MAX_PROBE_PACKETS;
 - 
 -         for (j = 0; j < MAX_REORDER_DELAY + 1; j++)
 -             st->pts_buffer[j] = AV_NOPTS_VALUE;
 -     }
 - }
 - 
 - void ff_update_cur_dts(AVFormatContext *s, AVStream *ref_st, int64_t timestamp)
 - {
 -     int i;
 - 
 -     for (i = 0; i < s->nb_streams; i++) {
 -         AVStream *st = s->streams[i];
 - 
 -         st->cur_dts =
 -             av_rescale(timestamp,
 -                        st->time_base.den * (int64_t) ref_st->time_base.num,
 -                        st->time_base.num * (int64_t) ref_st->time_base.den);
 -     }
 - }
 - 
 - void ff_reduce_index(AVFormatContext *s, int stream_index)
 - {
 -     AVStream *st             = s->streams[stream_index];
 -     unsigned int max_entries = s->max_index_size / sizeof(AVIndexEntry);
 - 
 -     if ((unsigned) st->nb_index_entries >= max_entries) {
 -         int i;
 -         for (i = 0; 2 * i < st->nb_index_entries; i++)
 -             st->index_entries[i] = st->index_entries[2 * i];
 -         st->nb_index_entries = i;
 -     }
 - }
 - 
 - int ff_add_index_entry(AVIndexEntry **index_entries,
 -                        int *nb_index_entries,
 -                        unsigned int *index_entries_allocated_size,
 -                        int64_t pos, int64_t timestamp,
 -                        int size, int distance, int flags)
 - {
 -     AVIndexEntry *entries, *ie;
 -     int index;
 - 
 -     if ((unsigned) *nb_index_entries + 1 >= UINT_MAX / sizeof(AVIndexEntry))
 -         return -1;
 - 
 -     entries = av_fast_realloc(*index_entries,
 -                               index_entries_allocated_size,
 -                               (*nb_index_entries + 1) *
 -                               sizeof(AVIndexEntry));
 -     if (!entries)
 -         return -1;
 - 
 -     *index_entries = entries;
 - 
 -     index = ff_index_search_timestamp(*index_entries, *nb_index_entries,
 -                                       timestamp, AVSEEK_FLAG_ANY);
 - 
 -     if (index < 0) {
 -         index = (*nb_index_entries)++;
 -         ie    = &entries[index];
 -         assert(index == 0 || ie[-1].timestamp < timestamp);
 -     } else {
 -         ie = &entries[index];
 -         if (ie->timestamp != timestamp) {
 -             if (ie->timestamp <= timestamp)
 -                 return -1;
 -             memmove(entries + index + 1, entries + index,
 -                     sizeof(AVIndexEntry) * (*nb_index_entries - index));
 -             (*nb_index_entries)++;
 -         } else if (ie->pos == pos && distance < ie->min_distance)
 -             // do not reduce the distance
 -             distance = ie->min_distance;
 -     }
 - 
 -     ie->pos          = pos;
 -     ie->timestamp    = timestamp;
 -     ie->min_distance = distance;
 -     ie->size         = size;
 -     ie->flags        = flags;
 - 
 -     return index;
 - }
 - 
 - int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp,
 -                        int size, int distance, int flags)
 - {
 -     return ff_add_index_entry(&st->index_entries, &st->nb_index_entries,
 -                               &st->index_entries_allocated_size, pos,
 -                               timestamp, size, distance, flags);
 - }
 - 
 - int ff_index_search_timestamp(const AVIndexEntry *entries, int nb_entries,
 -                               int64_t wanted_timestamp, int flags)
 - {
 -     int a, b, m;
 -     int64_t timestamp;
 - 
 -     a = -1;
 -     b = nb_entries;
 - 
 -     // Optimize appending index entries at the end.
 -     if (b && entries[b - 1].timestamp < wanted_timestamp)
 -         a = b - 1;
 - 
 -     while (b - a > 1) {
 -         m         = (a + b) >> 1;
 -         timestamp = entries[m].timestamp;
 -         if (timestamp >= wanted_timestamp)
 -             b = m;
 -         if (timestamp <= wanted_timestamp)
 -             a = m;
 -     }
 -     m = (flags & AVSEEK_FLAG_BACKWARD) ? a : b;
 - 
 -     if (!(flags & AVSEEK_FLAG_ANY))
 -         while (m >= 0 && m < nb_entries &&
 -                !(entries[m].flags & AVINDEX_KEYFRAME))
 -             m += (flags & AVSEEK_FLAG_BACKWARD) ? -1 : 1;
 - 
 -     if (m == nb_entries)
 -         return -1;
 -     return m;
 - }
 - 
 - int av_index_search_timestamp(AVStream *st, int64_t wanted_timestamp, int flags)
 - {
 -     return ff_index_search_timestamp(st->index_entries, st->nb_index_entries,
 -                                      wanted_timestamp, flags);
 - }
 - 
 - int ff_seek_frame_binary(AVFormatContext *s, int stream_index,
 -                          int64_t target_ts, int flags)
 - {
 -     AVInputFormat *avif = s->iformat;
 -     int64_t av_uninit(pos_min), av_uninit(pos_max), pos, pos_limit;
 -     int64_t ts_min, ts_max, ts;
 -     int index;
 -     int64_t ret;
 -     AVStream *st;
 - 
 -     if (stream_index < 0)
 -         return -1;
 - 
 -     av_dlog(s, "read_seek: %d %"PRId64"\n", stream_index, target_ts);
 - 
 -     ts_max =
 -     ts_min = AV_NOPTS_VALUE;
 -     pos_limit = -1; // GCC falsely says it may be uninitialized.
 - 
 -     st = s->streams[stream_index];
 -     if (st->index_entries) {
 -         AVIndexEntry *e;
 - 
 -         /* FIXME: Whole function must be checked for non-keyframe entries in
 -          * index case, especially read_timestamp(). */
 -         index = av_index_search_timestamp(st, target_ts,
 -                                           flags | AVSEEK_FLAG_BACKWARD);
 -         index = FFMAX(index, 0);
 -         e     = &st->index_entries[index];
 - 
 -         if (e->timestamp <= target_ts || e->pos == e->min_distance) {
 -             pos_min = e->pos;
 -             ts_min  = e->timestamp;
 -             av_dlog(s, "using cached pos_min=0x%"PRIx64" dts_min=%"PRId64"\n",
 -                     pos_min, ts_min);
 -         } else {
 -             assert(index == 0);
 -         }
 - 
 -         index = av_index_search_timestamp(st, target_ts,
 -                                           flags & ~AVSEEK_FLAG_BACKWARD);
 -         assert(index < st->nb_index_entries);
 -         if (index >= 0) {
 -             e = &st->index_entries[index];
 -             assert(e->timestamp >= target_ts);
 -             pos_max   = e->pos;
 -             ts_max    = e->timestamp;
 -             pos_limit = pos_max - e->min_distance;
 -             av_dlog(s, "using cached pos_max=0x%"PRIx64" pos_limit=0x%"PRIx64
 -                     " dts_max=%"PRId64"\n", pos_max, pos_limit, ts_max);
 -         }
 -     }
 - 
 -     pos = ff_gen_search(s, stream_index, target_ts, pos_min, pos_max, pos_limit,
 -                         ts_min, ts_max, flags, &ts, avif->read_timestamp);
 -     if (pos < 0)
 -         return -1;
 - 
 -     /* do the seek */
 -     if ((ret = avio_seek(s->pb, pos, SEEK_SET)) < 0)
 -         return ret;
 - 
 -     ff_update_cur_dts(s, st, ts);
 - 
 -     return 0;
 - }
 - 
 - int64_t ff_gen_search(AVFormatContext *s, int stream_index, int64_t target_ts,
 -                       int64_t pos_min, int64_t pos_max, int64_t pos_limit,
 -                       int64_t ts_min, int64_t ts_max,
 -                       int flags, int64_t *ts_ret,
 -                       int64_t (*read_timestamp)(struct AVFormatContext *, int,
 -                                                 int64_t *, int64_t))
 - {
 -     int64_t pos, ts;
 -     int64_t start_pos, filesize;
 -     int no_change;
 - 
 -     av_dlog(s, "gen_seek: %d %"PRId64"\n", stream_index, target_ts);
 - 
 -     if (ts_min == AV_NOPTS_VALUE) {
 -         pos_min = s->data_offset;
 -         ts_min  = read_timestamp(s, stream_index, &pos_min, INT64_MAX);
 -         if (ts_min == AV_NOPTS_VALUE)
 -             return -1;
 -     }
 - 
 -     if (ts_max == AV_NOPTS_VALUE) {
 -         int step = 1024;
 -         filesize = avio_size(s->pb);
 -         pos_max  = filesize - 1;
 -         do {
 -             pos_max -= step;
 -             ts_max   = read_timestamp(s, stream_index, &pos_max,
 -                                       pos_max + step);
 -             step    += step;
 -         } while (ts_max == AV_NOPTS_VALUE && pos_max >= step);
 -         if (ts_max == AV_NOPTS_VALUE)
 -             return -1;
 - 
 -         for (;;) {
 -             int64_t tmp_pos = pos_max + 1;
 -             int64_t tmp_ts  = read_timestamp(s, stream_index,
 -                                              &tmp_pos, INT64_MAX);
 -             if (tmp_ts == AV_NOPTS_VALUE)
 -                 break;
 -             ts_max  = tmp_ts;
 -             pos_max = tmp_pos;
 -             if (tmp_pos >= filesize)
 -                 break;
 -         }
 -         pos_limit = pos_max;
 -     }
 - 
 -     if (ts_min > ts_max)
 -         return -1;
 -     else if (ts_min == ts_max)
 -         pos_limit = pos_min;
 - 
 -     no_change = 0;
 -     while (pos_min < pos_limit) {
 -         av_dlog(s, "pos_min=0x%"PRIx64" pos_max=0x%"PRIx64" dts_min=%"PRId64
 -                 " dts_max=%"PRId64"\n", pos_min, pos_max, ts_min, ts_max);
 -         assert(pos_limit <= pos_max);
 - 
 -         if (no_change == 0) {
 -             int64_t approximate_keyframe_distance = pos_max - pos_limit;
 -             // interpolate position (better than dichotomy)
 -             pos = av_rescale(target_ts - ts_min, pos_max - pos_min,
 -                              ts_max - ts_min) +
 -                   pos_min - approximate_keyframe_distance;
 -         } else if (no_change == 1) {
 -             // bisection if interpolation did not change min / max pos last time
 -             pos = (pos_min + pos_limit) >> 1;
 -         } else {
 -             /* linear search if bisection failed, can only happen if there
 -              * are very few or no keyframes between min/max */
 -             pos = pos_min;
 -         }
 -         if (pos <= pos_min)
 -             pos = pos_min + 1;
 -         else if (pos > pos_limit)
 -             pos = pos_limit;
 -         start_pos = pos;
 - 
 -         // May pass pos_limit instead of -1.
 -         ts = read_timestamp(s, stream_index, &pos, INT64_MAX);
 -         if (pos == pos_max)
 -             no_change++;
 -         else
 -             no_change = 0;
 -         av_dlog(s, "%"PRId64" %"PRId64" %"PRId64" / %"PRId64" %"PRId64" %"PRId64
 -                 " target:%"PRId64" limit:%"PRId64" start:%"PRId64" noc:%d\n",
 -                 pos_min, pos, pos_max, ts_min, ts, ts_max, target_ts,
 -                 pos_limit, start_pos, no_change);
 -         if (ts == AV_NOPTS_VALUE) {
 -             av_log(s, AV_LOG_ERROR, "read_timestamp() failed in the middle\n");
 -             return -1;
 -         }
 -         assert(ts != AV_NOPTS_VALUE);
 -         if (target_ts <= ts) {
 -             pos_limit = start_pos - 1;
 -             pos_max   = pos;
 -             ts_max    = ts;
 -         }
 -         if (target_ts >= ts) {
 -             pos_min = pos;
 -             ts_min  = ts;
 -         }
 -     }
 - 
 -     pos     = (flags & AVSEEK_FLAG_BACKWARD) ? pos_min : pos_max;
 -     ts      = (flags & AVSEEK_FLAG_BACKWARD) ? ts_min  : ts_max;
 -     pos_min = pos;
 -     ts_min  = read_timestamp(s, stream_index, &pos_min, INT64_MAX);
 -     pos_min++;
 -     ts_max = read_timestamp(s, stream_index, &pos_min, INT64_MAX);
 -     av_dlog(s, "pos=0x%"PRIx64" %"PRId64"<=%"PRId64"<=%"PRId64"\n",
 -             pos, ts_min, target_ts, ts_max);
 -     *ts_ret = ts;
 -     return pos;
 - }
 - 
 - static int seek_frame_byte(AVFormatContext *s, int stream_index,
 -                            int64_t pos, int flags)
 - {
 -     int64_t pos_min, pos_max;
 - 
 -     pos_min = s->data_offset;
 -     pos_max = avio_size(s->pb) - 1;
 - 
 -     if (pos < pos_min)
 -         pos = pos_min;
 -     else if (pos > pos_max)
 -         pos = pos_max;
 - 
 -     avio_seek(s->pb, pos, SEEK_SET);
 - 
 -     return 0;
 - }
 - 
 - static int seek_frame_generic(AVFormatContext *s, int stream_index,
 -                               int64_t timestamp, int flags)
 - {
 -     int index;
 -     int64_t ret;
 -     AVStream *st;
 -     AVIndexEntry *ie;
 - 
 -     st = s->streams[stream_index];
 - 
 -     index = av_index_search_timestamp(st, timestamp, flags);
 - 
 -     if (index < 0 && st->nb_index_entries &&
 -         timestamp < st->index_entries[0].timestamp)
 -         return -1;
 - 
 -     if (index < 0 || index == st->nb_index_entries - 1) {
 -         AVPacket pkt;
 - 
 -         if (st->nb_index_entries) {
 -             assert(st->index_entries);
 -             ie = &st->index_entries[st->nb_index_entries - 1];
 -             if ((ret = avio_seek(s->pb, ie->pos, SEEK_SET)) < 0)
 -                 return ret;
 -             ff_update_cur_dts(s, st, ie->timestamp);
 -         } else {
 -             if ((ret = avio_seek(s->pb, s->data_offset, SEEK_SET)) < 0)
 -                 return ret;
 -         }
 -         for (;;) {
 -             int read_status;
 -             do {
 -                 read_status = av_read_frame(s, &pkt);
 -             } while (read_status == AVERROR(EAGAIN));
 -             if (read_status < 0)
 -                 break;
 -             av_free_packet(&pkt);
 -             if (stream_index == pkt.stream_index)
 -                 if ((pkt.flags & AV_PKT_FLAG_KEY) && pkt.dts > timestamp)
 -                     break;
 -         }
 -         index = av_index_search_timestamp(st, timestamp, flags);
 -     }
 -     if (index < 0)
 -         return -1;
 - 
 -     ff_read_frame_flush(s);
 -     if (s->iformat->read_seek)
 -         if (s->iformat->read_seek(s, stream_index, timestamp, flags) >= 0)
 -             return 0;
 -     ie = &st->index_entries[index];
 -     if ((ret = avio_seek(s->pb, ie->pos, SEEK_SET)) < 0)
 -         return ret;
 -     ff_update_cur_dts(s, st, ie->timestamp);
 - 
 -     return 0;
 - }
 - 
 - static int seek_frame_internal(AVFormatContext *s, int stream_index,
 -                                int64_t timestamp, int flags)
 - {
 -     int ret;
 -     AVStream *st;
 - 
 -     if (flags & AVSEEK_FLAG_BYTE) {
 -         if (s->iformat->flags & AVFMT_NO_BYTE_SEEK)
 -             return -1;
 -         ff_read_frame_flush(s);
 -         return seek_frame_byte(s, stream_index, timestamp, flags);
 -     }
 - 
 -     if (stream_index < 0) {
 -         stream_index = av_find_default_stream_index(s);
 -         if (stream_index < 0)
 -             return -1;
 - 
 -         st = s->streams[stream_index];
 -         /* timestamp for default must be expressed in AV_TIME_BASE units */
 -         timestamp = av_rescale(timestamp, st->time_base.den,
 -                                AV_TIME_BASE * (int64_t) st->time_base.num);
 -     }
 - 
 -     /* first, we try the format specific seek */
 -     if (s->iformat->read_seek) {
 -         ff_read_frame_flush(s);
 -         ret = s->iformat->read_seek(s, stream_index, timestamp, flags);
 -     } else
 -         ret = -1;
 -     if (ret >= 0)
 -         return 0;
 - 
 -     if (s->iformat->read_timestamp &&
 -         !(s->iformat->flags & AVFMT_NOBINSEARCH)) {
 -         ff_read_frame_flush(s);
 -         return ff_seek_frame_binary(s, stream_index, timestamp, flags);
 -     } else if (!(s->iformat->flags & AVFMT_NOGENSEARCH)) {
 -         ff_read_frame_flush(s);
 -         return seek_frame_generic(s, stream_index, timestamp, flags);
 -     } else
 -         return -1;
 - }
 - 
 - int av_seek_frame(AVFormatContext *s, int stream_index,
 -                   int64_t timestamp, int flags)
 - {
 -     int ret = seek_frame_internal(s, stream_index, timestamp, flags);
 - 
 -     if (ret >= 0)
 -         ret = queue_attached_pictures(s);
 - 
 -     return ret;
 - }
 - 
 - int avformat_seek_file(AVFormatContext *s, int stream_index, int64_t min_ts,
 -                        int64_t ts, int64_t max_ts, int flags)
 - {
 -     if (min_ts > ts || max_ts < ts)
 -         return -1;
 - 
 -     if (s->iformat->read_seek2) {
 -         int ret;
 -         ff_read_frame_flush(s);
 -         ret = s->iformat->read_seek2(s, stream_index, min_ts,
 -                                      ts, max_ts, flags);
 - 
 -         if (ret >= 0)
 -             ret = queue_attached_pictures(s);
 -         return ret;
 -     }
 - 
 -     if (s->iformat->read_timestamp) {
 -         // try to seek via read_timestamp()
 -     }
 - 
 -     // Fall back on old API if new is not implemented but old is.
 -     // Note the old API has somewhat different semantics.
 -     if (s->iformat->read_seek || 1)
 -         return av_seek_frame(s, stream_index, ts,
 -                              flags | ((uint64_t) ts - min_ts >
 -                                       (uint64_t) max_ts - ts
 -                                       ? AVSEEK_FLAG_BACKWARD : 0));
 - 
 -     // try some generic seek like seek_frame_generic() but with new ts semantics
 - }
 - 
 - /*******************************************************/
 - 
 - /**
 -  * Return TRUE if the stream has accurate duration in any stream.
 -  *
 -  * @return TRUE if the stream has accurate duration for at least one component.
 -  */
 - static int has_duration(AVFormatContext *ic)
 - {
 -     int i;
 -     AVStream *st;
 - 
 -     for (i = 0; i < ic->nb_streams; i++) {
 -         st = ic->streams[i];
 -         if (st->duration != AV_NOPTS_VALUE)
 -             return 1;
 -     }
 -     if (ic->duration != AV_NOPTS_VALUE)
 -         return 1;
 -     return 0;
 - }
 - 
 - /**
 -  * Estimate the stream timings from the one of each components.
 -  *
 -  * Also computes the global bitrate if possible.
 -  */
 - static void update_stream_timings(AVFormatContext *ic)
 - {
 -     int64_t start_time, start_time1, end_time, end_time1;
 -     int64_t duration, duration1, filesize;
 -     int i;
 -     AVStream *st;
 - 
 -     start_time = INT64_MAX;
 -     end_time   = INT64_MIN;
 -     duration   = INT64_MIN;
 -     for (i = 0; i < ic->nb_streams; i++) {
 -         st = ic->streams[i];
 -         if (st->start_time != AV_NOPTS_VALUE && st->time_base.den) {
 -             start_time1 = av_rescale_q(st->start_time, st->time_base,
 -                                        AV_TIME_BASE_Q);
 -             start_time  = FFMIN(start_time, start_time1);
 -             if (st->duration != AV_NOPTS_VALUE) {
 -                 end_time1 = start_time1 +
 -                             av_rescale_q(st->duration, st->time_base,
 -                                          AV_TIME_BASE_Q);
 -                 end_time = FFMAX(end_time, end_time1);
 -             }
 -         }
 -         if (st->duration != AV_NOPTS_VALUE) {
 -             duration1 = av_rescale_q(st->duration, st->time_base,
 -                                      AV_TIME_BASE_Q);
 -             duration  = FFMAX(duration, duration1);
 -         }
 -     }
 -     if (start_time != INT64_MAX) {
 -         ic->start_time = start_time;
 -         if (end_time != INT64_MIN)
 -             duration = FFMAX(duration, end_time - start_time);
 -     }
 -     if (duration != INT64_MIN) {
 -         ic->duration = duration;
 -         if (ic->pb && (filesize = avio_size(ic->pb)) > 0)
 -             /* compute the bitrate */
 -             ic->bit_rate = (double) filesize * 8.0 * AV_TIME_BASE /
 -                            (double) ic->duration;
 -     }
 - }
 - 
 - static void fill_all_stream_timings(AVFormatContext *ic)
 - {
 -     int i;
 -     AVStream *st;
 - 
 -     update_stream_timings(ic);
 -     for (i = 0; i < ic->nb_streams; i++) {
 -         st = ic->streams[i];
 -         if (st->start_time == AV_NOPTS_VALUE) {
 -             if (ic->start_time != AV_NOPTS_VALUE)
 -                 st->start_time = av_rescale_q(ic->start_time, AV_TIME_BASE_Q,
 -                                               st->time_base);
 -             if (ic->duration != AV_NOPTS_VALUE)
 -                 st->duration = av_rescale_q(ic->duration, AV_TIME_BASE_Q,
 -                                             st->time_base);
 -         }
 -     }
 - }
 - 
 - static void estimate_timings_from_bit_rate(AVFormatContext *ic)
 - {
 -     int64_t filesize, duration;
 -     int i;
 -     AVStream *st;
 - 
 -     /* if bit_rate is already set, we believe it */
 -     if (ic->bit_rate <= 0) {
 -         int bit_rate = 0;
 -         for (i = 0; i < ic->nb_streams; i++) {
 -             st = ic->streams[i];
 -             if (st->codec->bit_rate > 0) {
 -                 if (INT_MAX - st->codec->bit_rate < bit_rate) {
 -                     bit_rate = 0;
 -                     break;
 -                 }
 -                 bit_rate += st->codec->bit_rate;
 -             }
 -         }
 -         ic->bit_rate = bit_rate;
 -     }
 - 
 -     /* if duration is already set, we believe it */
 -     if (ic->duration == AV_NOPTS_VALUE &&
 -         ic->bit_rate != 0) {
 -         filesize = ic->pb ? avio_size(ic->pb) : 0;
 -         if (filesize > 0) {
 -             for (i = 0; i < ic->nb_streams; i++) {
 -                 st       = ic->streams[i];
 -                 duration = av_rescale(8 * filesize, st->time_base.den,
 -                                       ic->bit_rate *
 -                                       (int64_t) st->time_base.num);
 -                 if (st->duration == AV_NOPTS_VALUE)
 -                     st->duration = duration;
 -             }
 -         }
 -     }
 - }
 - 
 - #define DURATION_MAX_READ_SIZE 250000
 - #define DURATION_MAX_RETRY 3
 - 
 - /* only usable for MPEG-PS streams */
 - static void estimate_timings_from_pts(AVFormatContext *ic, int64_t old_offset)
 - {
 -     AVPacket pkt1, *pkt = &pkt1;
 -     AVStream *st;
 -     int read_size, i, ret;
 -     int64_t end_time;
 -     int64_t filesize, offset, duration;
 -     int retry = 0;
 - 
 -     /* flush packet queue */
 -     flush_packet_queue(ic);
 - 
 -     for (i = 0; i < ic->nb_streams; i++) {
 -         st = ic->streams[i];
 -         if (st->start_time == AV_NOPTS_VALUE && st->first_dts == AV_NOPTS_VALUE)
 -             av_log(st->codec, AV_LOG_WARNING,
 -                    "start time is not set in estimate_timings_from_pts\n");
 - 
 -         if (st->parser) {
 -             av_parser_close(st->parser);
 -             st->parser = NULL;
 -         }
 -     }
 - 
 -     /* estimate the end time (duration) */
 -     /* XXX: may need to support wrapping */
 -     filesize = ic->pb ? avio_size(ic->pb) : 0;
 -     end_time = AV_NOPTS_VALUE;
 -     do {
 -         offset = filesize - (DURATION_MAX_READ_SIZE << retry);
 -         if (offset < 0)
 -             offset = 0;
 - 
 -         avio_seek(ic->pb, offset, SEEK_SET);
 -         read_size = 0;
 -         for (;;) {
 -             if (read_size >= DURATION_MAX_READ_SIZE << (FFMAX(retry - 1, 0)))
 -                 break;
 - 
 -             do {
 -                 ret = ff_read_packet(ic, pkt);
 -             } while (ret == AVERROR(EAGAIN));
 -             if (ret != 0)
 -                 break;
 -             read_size += pkt->size;
 -             st         = ic->streams[pkt->stream_index];
 -             if (pkt->pts != AV_NOPTS_VALUE &&
 -                 (st->start_time != AV_NOPTS_VALUE ||
 -                  st->first_dts  != AV_NOPTS_VALUE)) {
 -                 duration = end_time = pkt->pts;
 -                 if (st->start_time != AV_NOPTS_VALUE)
 -                     duration -= st->start_time;
 -                 else
 -                     duration -= st->first_dts;
 -                 if (duration < 0)
 -                     duration += 1LL << st->pts_wrap_bits;
 -                 if (duration > 0) {
 -                     if (st->duration == AV_NOPTS_VALUE || st->duration < duration)
 -                         st->duration = duration;
 -                 }
 -             }
 -             av_free_packet(pkt);
 -         }
 -     } while (end_time == AV_NOPTS_VALUE &&
 -              filesize > (DURATION_MAX_READ_SIZE << retry) &&
 -              ++retry <= DURATION_MAX_RETRY);
 - 
 -     fill_all_stream_timings(ic);
 - 
 -     avio_seek(ic->pb, old_offset, SEEK_SET);
 -     for (i = 0; i < ic->nb_streams; i++) {
 -         st              = ic->streams[i];
 -         st->cur_dts     = st->first_dts;
 -         st->last_IP_pts = AV_NOPTS_VALUE;
 -     }
 - }
 - 
 - static void estimate_timings(AVFormatContext *ic, int64_t old_offset)
 - {
 -     int64_t file_size;
 - 
 -     /* get the file size, if possible */
 -     if (ic->iformat->flags & AVFMT_NOFILE) {
 -         file_size = 0;
 -     } else {
 -         file_size = avio_size(ic->pb);
 -         file_size = FFMAX(0, file_size);
 -     }
 - 
 -     if ((!strcmp(ic->iformat->name, "mpeg") ||
 -          !strcmp(ic->iformat->name, "mpegts")) &&
 -         file_size && ic->pb->seekable) {
 -         /* get accurate estimate from the PTSes */
 -         estimate_timings_from_pts(ic, old_offset);
 -     } else if (has_duration(ic)) {
 -         /* at least one component has timings - we use them for all
 -          * the components */
 -         fill_all_stream_timings(ic);
 -     } else {
 -         av_log(ic, AV_LOG_WARNING,
 -                "Estimating duration from bitrate, this may be inaccurate\n");
 -         /* less precise: use bitrate info */
 -         estimate_timings_from_bit_rate(ic);
 -     }
 -     update_stream_timings(ic);
 - 
 -     {
 -         int i;
 -         AVStream av_unused *st;
 -         for (i = 0; i < ic->nb_streams; i++) {
 -             st = ic->streams[i];
 -             av_dlog(ic, "%d: start_time: %0.3f duration: %0.3f\n", i,
 -                     (double) st->start_time / AV_TIME_BASE,
 -                     (double) st->duration   / AV_TIME_BASE);
 -         }
 -         av_dlog(ic,
 -                 "stream: start_time: %0.3f duration: %0.3f bitrate=%d kb/s\n",
 -                 (double) ic->start_time / AV_TIME_BASE,
 -                 (double) ic->duration   / AV_TIME_BASE,
 -                 ic->bit_rate / 1000);
 -     }
 - }
 - 
 - static int has_codec_parameters(AVStream *st)
 - {
 -     AVCodecContext *avctx = st->codec;
 -     int val;
 - 
 -     switch (avctx->codec_type) {
 -     case AVMEDIA_TYPE_AUDIO:
 -         val = avctx->sample_rate && avctx->channels;
 -         if (st->info->found_decoder >= 0 &&
 -             avctx->sample_fmt == AV_SAMPLE_FMT_NONE)
 -             return 0;
 -         break;
 -     case AVMEDIA_TYPE_VIDEO:
 -         val = avctx->width;
 -         if (st->info->found_decoder >= 0 && avctx->pix_fmt == AV_PIX_FMT_NONE)
 -             return 0;
 -         break;
 -     default:
 -         val = 1;
 -         break;
 -     }
 -     return avctx->codec_id != AV_CODEC_ID_NONE && val != 0;
 - }
 - 
 - static int has_decode_delay_been_guessed(AVStream *st)
 - {
 -     return st->codec->codec_id != AV_CODEC_ID_H264 ||
 -            st->info->nb_decoded_frames >= 6;
 - }
 - 
 - /* returns 1 or 0 if or if not decoded data was returned, or a negative error */
 - static int try_decode_frame(AVStream *st, AVPacket *avpkt,
 -                             AVDictionary **options)
 - {
 -     const AVCodec *codec;
 -     int got_picture = 1, ret = 0;
 -     AVFrame *frame = av_frame_alloc();
 -     AVPacket pkt = *avpkt;
 - 
 -     if (!frame)
 -         return AVERROR(ENOMEM);
 - 
 -     if (!avcodec_is_open(st->codec) && !st->info->found_decoder) {
 -         AVDictionary *thread_opt = NULL;
 - 
 -         codec = st->codec->codec ? st->codec->codec
 -                                  : avcodec_find_decoder(st->codec->codec_id);
 - 
 -         if (!codec) {
 -             st->info->found_decoder = -1;
 -             ret                     = -1;
 -             goto fail;
 -         }
 - 
 -         /* Force thread count to 1 since the H.264 decoder will not extract
 -          * SPS and PPS to extradata during multi-threaded decoding. */
 -         av_dict_set(options ? options : &thread_opt, "threads", "1", 0);
 -         ret = avcodec_open2(st->codec, codec, options ? options : &thread_opt);
 -         if (!options)
 -             av_dict_free(&thread_opt);
 -         if (ret < 0) {
 -             st->info->found_decoder = -1;
 -             goto fail;
 -         }
 -         st->info->found_decoder = 1;
 -     } else if (!st->info->found_decoder)
 -         st->info->found_decoder = 1;
 - 
 -     if (st->info->found_decoder < 0) {
 -         ret = -1;
 -         goto fail;
 -     }
 - 
 -     while ((pkt.size > 0 || (!pkt.data && got_picture)) &&
 -            ret >= 0 &&
 -            (!has_codec_parameters(st) || !has_decode_delay_been_guessed(st) ||
 -             (!st->codec_info_nb_frames &&
 -              st->codec->codec->capabilities & CODEC_CAP_CHANNEL_CONF))) {
 -         got_picture = 0;
 -         switch (st->codec->codec_type) {
 -         case AVMEDIA_TYPE_VIDEO:
 -             ret = avcodec_decode_video2(st->codec, frame,
 -                                         &got_picture, &pkt);
 -             break;
 -         case AVMEDIA_TYPE_AUDIO:
 -             ret = avcodec_decode_audio4(st->codec, frame, &got_picture, &pkt);
 -             break;
 -         default:
 -             break;
 -         }
 -         if (ret >= 0) {
 -             if (got_picture)
 -                 st->info->nb_decoded_frames++;
 -             pkt.data += ret;
 -             pkt.size -= ret;
 -             ret       = got_picture;
 -         }
 -     }
 - 
 - fail:
 -     av_frame_free(&frame);
 -     return ret;
 - }
 - 
 - unsigned int ff_codec_get_tag(const AVCodecTag *tags, enum AVCodecID id)
 - {
 -     while (tags->id != AV_CODEC_ID_NONE) {
 -         if (tags->id == id)
 -             return tags->tag;
 -         tags++;
 -     }
 -     return 0;
 - }
 - 
 - enum AVCodecID ff_codec_get_id(const AVCodecTag *tags, unsigned int tag)
 - {
 -     int i;
 -     for (i = 0; tags[i].id != AV_CODEC_ID_NONE; i++)
 -         if (tag == tags[i].tag)
 -             return tags[i].id;
 -     for (i = 0; tags[i].id != AV_CODEC_ID_NONE; i++)
 -         if (avpriv_toupper4(tag) == avpriv_toupper4(tags[i].tag))
 -             return tags[i].id;
 -     return AV_CODEC_ID_NONE;
 - }
 - 
 - enum AVCodecID ff_get_pcm_codec_id(int bps, int flt, int be, int sflags)
 - {
 -     if (flt) {
 -         switch (bps) {
 -         case 32:
 -             return be ? AV_CODEC_ID_PCM_F32BE : AV_CODEC_ID_PCM_F32LE;
 -         case 64:
 -             return be ? AV_CODEC_ID_PCM_F64BE : AV_CODEC_ID_PCM_F64LE;
 -         default:
 -             return AV_CODEC_ID_NONE;
 -         }
 -     } else {
 -         bps >>= 3;
 -         if (sflags & (1 << (bps - 1))) {
 -             switch (bps) {
 -             case 1:
 -                 return AV_CODEC_ID_PCM_S8;
 -             case 2:
 -                 return be ? AV_CODEC_ID_PCM_S16BE : AV_CODEC_ID_PCM_S16LE;
 -             case 3:
 -                 return be ? AV_CODEC_ID_PCM_S24BE : AV_CODEC_ID_PCM_S24LE;
 -             case 4:
 -                 return be ? AV_CODEC_ID_PCM_S32BE : AV_CODEC_ID_PCM_S32LE;
 -             default:
 -                 return AV_CODEC_ID_NONE;
 -             }
 -         } else {
 -             switch (bps) {
 -             case 1:
 -                 return AV_CODEC_ID_PCM_U8;
 -             case 2:
 -                 return be ? AV_CODEC_ID_PCM_U16BE : AV_CODEC_ID_PCM_U16LE;
 -             case 3:
 -                 return be ? AV_CODEC_ID_PCM_U24BE : AV_CODEC_ID_PCM_U24LE;
 -             case 4:
 -                 return be ? AV_CODEC_ID_PCM_U32BE : AV_CODEC_ID_PCM_U32LE;
 -             default:
 -                 return AV_CODEC_ID_NONE;
 -             }
 -         }
 -     }
 - }
 - 
 - unsigned int av_codec_get_tag(const AVCodecTag *const *tags, enum AVCodecID id)
 - {
 -     int i;
 -     for (i = 0; tags && tags[i]; i++) {
 -         int tag = ff_codec_get_tag(tags[i], id);
 -         if (tag)
 -             return tag;
 -     }
 -     return 0;
 - }
 - 
 - enum AVCodecID av_codec_get_id(const AVCodecTag *const *tags, unsigned int tag)
 - {
 -     int i;
 -     for (i = 0; tags && tags[i]; i++) {
 -         enum AVCodecID id = ff_codec_get_id(tags[i], tag);
 -         if (id != AV_CODEC_ID_NONE)
 -             return id;
 -     }
 -     return AV_CODEC_ID_NONE;
 - }
 - 
 - static void compute_chapters_end(AVFormatContext *s)
 - {
 -     unsigned int i, j;
 -     int64_t max_time = s->duration +
 -                        ((s->start_time == AV_NOPTS_VALUE) ? 0 : s->start_time);
 - 
 -     for (i = 0; i < s->nb_chapters; i++)
 -         if (s->chapters[i]->end == AV_NOPTS_VALUE) {
 -             AVChapter *ch = s->chapters[i];
 -             int64_t end = max_time ? av_rescale_q(max_time, AV_TIME_BASE_Q,
 -                                                   ch->time_base)
 -                                    : INT64_MAX;
 - 
 -             for (j = 0; j < s->nb_chapters; j++) {
 -                 AVChapter *ch1     = s->chapters[j];
 -                 int64_t next_start = av_rescale_q(ch1->start, ch1->time_base,
 -                                                   ch->time_base);
 -                 if (j != i && next_start > ch->start && next_start < end)
 -                     end = next_start;
 -             }
 -             ch->end = (end == INT64_MAX) ? ch->start : end;
 -         }
 - }
 - 
 - static int get_std_framerate(int i)
 - {
 -     if (i < 60 * 12)
 -         return (i + 1) * 1001;
 -     else
 -         return ((const int[]) { 24, 30, 60, 12, 15 })[i - 60 * 12] * 1000 * 12;
 - }
 - 
 - int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options)
 - {
 -     int i, count, ret, read_size, j;
 -     AVStream *st;
 -     AVPacket pkt1, *pkt;
 -     int64_t old_offset  = avio_tell(ic->pb);
 -     // new streams might appear, no options for those
 -     int orig_nb_streams = ic->nb_streams;
 - 
 -     for (i = 0; i < ic->nb_streams; i++) {
 -         const AVCodec *codec;
 -         AVDictionary *thread_opt = NULL;
 -         st = ic->streams[i];
 - 
 -         // only for the split stuff
 -         if (!st->parser && !(ic->flags & AVFMT_FLAG_NOPARSE)) {
 -             st->parser = av_parser_init(st->codec->codec_id);
 -             if (st->need_parsing == AVSTREAM_PARSE_HEADERS && st->parser)
 -                 st->parser->flags |= PARSER_FLAG_COMPLETE_FRAMES;
 -         }
 -         codec = st->codec->codec ? st->codec->codec
 -                                  : avcodec_find_decoder(st->codec->codec_id);
 - 
 -         /* Force thread count to 1 since the H.264 decoder will not extract
 -          * SPS and PPS to extradata during multi-threaded decoding. */
 -         av_dict_set(options ? &options[i] : &thread_opt, "threads", "1", 0);
 - 
 -         /* Ensure that subtitle_header is properly set. */
 -         if (st->codec->codec_type == AVMEDIA_TYPE_SUBTITLE
 -             && codec && !st->codec->codec)
 -             avcodec_open2(st->codec, codec,
 -                           options ? &options[i] : &thread_opt);
 - 
 -         // Try to just open decoders, in case this is enough to get parameters.
 -         if (!has_codec_parameters(st)) {
 -             if (codec && !st->codec->codec)
 -                 avcodec_open2(st->codec, codec,
 -                               options ? &options[i] : &thread_opt);
 -         }
 -         if (!options)
 -             av_dict_free(&thread_opt);
 -     }
 - 
 -     for (i = 0; i < ic->nb_streams; i++) {
 -         ic->streams[i]->info->fps_first_dts = AV_NOPTS_VALUE;
 -         ic->streams[i]->info->fps_last_dts  = AV_NOPTS_VALUE;
 -     }
 - 
 -     count     = 0;
 -     read_size = 0;
 -     for (;;) {
 -         if (ff_check_interrupt(&ic->interrupt_callback)) {
 -             ret = AVERROR_EXIT;
 -             av_log(ic, AV_LOG_DEBUG, "interrupted\n");
 -             break;
 -         }
 - 
 -         /* check if one codec still needs to be handled */
 -         for (i = 0; i < ic->nb_streams; i++) {
 -             int fps_analyze_framecount = 20;
 - 
 -             st = ic->streams[i];
 -             if (!has_codec_parameters(st))
 -                 break;
 -             /* If the timebase is coarse (like the usual millisecond precision
 -              * of mkv), we need to analyze more frames to reliably arrive at
 -              * the correct fps. */
 -             if (av_q2d(st->time_base) > 0.0005)
 -                 fps_analyze_framecount *= 2;
 -             if (ic->fps_probe_size >= 0)
 -                 fps_analyze_framecount = ic->fps_probe_size;
 -             /* variable fps and no guess at the real fps */
 -             if (!st->avg_frame_rate.num &&
 -                 st->codec_info_nb_frames < fps_analyze_framecount &&
 -                 st->codec->codec_type == AVMEDIA_TYPE_VIDEO)
 -                 break;
 -             if (st->parser && st->parser->parser->split &&
 -                 !st->codec->extradata)
 -                 break;
 -             if (st->first_dts == AV_NOPTS_VALUE &&
 -                 (st->codec->codec_type == AVMEDIA_TYPE_VIDEO ||
 -                  st->codec->codec_type == AVMEDIA_TYPE_AUDIO))
 -                 break;
 -         }
 -         if (i == ic->nb_streams) {
 -             /* NOTE: If the format has no header, then we need to read some
 -              * packets to get most of the streams, so we cannot stop here. */
 -             if (!(ic->ctx_flags & AVFMTCTX_NOHEADER)) {
 -                 /* If we found the info for all the codecs, we can stop. */
 -                 ret = count;
 -                 av_log(ic, AV_LOG_DEBUG, "All info found\n");
 -                 break;
 -             }
 -         }
 -         /* We did not get all the codec info, but we read too much data. */
 -         if (read_size >= ic->probesize) {
 -             ret = count;
 -             av_log(ic, AV_LOG_DEBUG,
 -                    "Probe buffer size limit %d reached\n", ic->probesize);
 -             break;
 -         }
 - 
 -         /* NOTE: A new stream can be added there if no header in file
 -          * (AVFMTCTX_NOHEADER). */
 -         ret = read_frame_internal(ic, &pkt1);
 -         if (ret == AVERROR(EAGAIN))
 -             continue;
 - 
 -         if (ret < 0) {
 -             /* EOF or error*/
 -             AVPacket empty_pkt = { 0 };
 -             int err = 0;
 -             av_init_packet(&empty_pkt);
 - 
 -             /* We could not have all the codec parameters before EOF. */
 -             ret = -1;
 -             for (i = 0; i < ic->nb_streams; i++) {
 -                 st = ic->streams[i];
 - 
 -                 /* flush the decoders */
 -                 if (st->info->found_decoder == 1) {
 -                     do {
 -                         err = try_decode_frame(st, &empty_pkt,
 -                                                (options && i < orig_nb_streams)
 -                                                ? &options[i] : NULL);
 -                     } while (err > 0 && !has_codec_parameters(st));
 -                 }
 - 
 -                 if (err < 0) {
 -                     av_log(ic, AV_LOG_WARNING,
 -                            "decoding for stream %d failed\n", st->index);
 -                 } else if (!has_codec_parameters(st)) {
 -                     char buf[256];
 -                     avcodec_string(buf, sizeof(buf), st->codec, 0);
 -                     av_log(ic, AV_LOG_WARNING,
 -                            "Could not find codec parameters (%s)\n", buf);
 -                 } else {
 -                     ret = 0;
 -                 }
 -             }
 -             break;
 -         }
 - 
 -         if (ic->flags & AVFMT_FLAG_NOBUFFER) {
 -             pkt = &pkt1;
 -         } else {
 -             pkt = add_to_pktbuf(&ic->packet_buffer, &pkt1,
 -                                 &ic->packet_buffer_end);
 -             if ((ret = av_dup_packet(pkt)) < 0)
 -                 goto find_stream_info_err;
 -         }
 - 
 -         read_size += pkt->size;
 - 
 -         st = ic->streams[pkt->stream_index];
 -         if (pkt->dts != AV_NOPTS_VALUE && st->codec_info_nb_frames > 1) {
 -             /* check for non-increasing dts */
 -             if (st->info->fps_last_dts != AV_NOPTS_VALUE &&
 -                 st->info->fps_last_dts >= pkt->dts) {
 -                 av_log(ic, AV_LOG_WARNING,
 -                        "Non-increasing DTS in stream %d: packet %d with DTS "
 -                        "%"PRId64", packet %d with DTS %"PRId64"\n",
 -                        st->index, st->info->fps_last_dts_idx,
 -                        st->info->fps_last_dts, st->codec_info_nb_frames,
 -                        pkt->dts);
 -                 st->info->fps_first_dts =
 -                 st->info->fps_last_dts  = AV_NOPTS_VALUE;
 -             }
 -             /* Check for a discontinuity in dts. If the difference in dts
 -              * is more than 1000 times the average packet duration in the
 -              * sequence, we treat it as a discontinuity. */
 -             if (st->info->fps_last_dts != AV_NOPTS_VALUE &&
 -                 st->info->fps_last_dts_idx > st->info->fps_first_dts_idx &&
 -                 (pkt->dts - st->info->fps_last_dts) / 1000 >
 -                 (st->info->fps_last_dts     - st->info->fps_first_dts) /
 -                 (st->info->fps_last_dts_idx - st->info->fps_first_dts_idx)) {
 -                 av_log(ic, AV_LOG_WARNING,
 -                        "DTS discontinuity in stream %d: packet %d with DTS "
 -                        "%"PRId64", packet %d with DTS %"PRId64"\n",
 -                        st->index, st->info->fps_last_dts_idx,
 -                        st->info->fps_last_dts, st->codec_info_nb_frames,
 -                        pkt->dts);
 -                 st->info->fps_first_dts =
 -                 st->info->fps_last_dts  = AV_NOPTS_VALUE;
 -             }
 - 
 -             /* update stored dts values */
 -             if (st->info->fps_first_dts == AV_NOPTS_VALUE) {
 -                 st->info->fps_first_dts     = pkt->dts;
 -                 st->info->fps_first_dts_idx = st->codec_info_nb_frames;
 -             }
 -             st->info->fps_last_dts     = pkt->dts;
 -             st->info->fps_last_dts_idx = st->codec_info_nb_frames;
 - 
 -             /* check max_analyze_duration */
 -             if (av_rescale_q(pkt->dts - st->info->fps_first_dts, st->time_base,
 -                              AV_TIME_BASE_Q) >= ic->max_analyze_duration) {
 -                 av_log(ic, AV_LOG_WARNING, "max_analyze_duration %d reached\n",
 -                        ic->max_analyze_duration);
 -                 break;
 -             }
 -         }
 -         if (st->parser && st->parser->parser->split && !st->codec->extradata) {
 -             int i = st->parser->parser->split(st->codec, pkt->data, pkt->size);
 -             if (i > 0 && i < FF_MAX_EXTRADATA_SIZE) {
 -                 st->codec->extradata_size = i;
 -                 st->codec->extradata = av_malloc(st->codec->extradata_size +
 -                                                  FF_INPUT_BUFFER_PADDING_SIZE);
 -                 if (!st->codec->extradata)
 -                     return AVERROR(ENOMEM);
 -                 memcpy(st->codec->extradata, pkt->data,
 -                        st->codec->extradata_size);
 -                 memset(st->codec->extradata + i, 0,
 -                        FF_INPUT_BUFFER_PADDING_SIZE);
 -             }
 -         }
 - 
 -         /* If still no information, we try to open the codec and to
 -          * decompress the frame. We try to avoid that in most cases as
 -          * it takes longer and uses more memory. For MPEG-4, we need to
 -          * decompress for QuickTime.
 -          *
 -          * If CODEC_CAP_CHANNEL_CONF is set this will force decoding of at
 -          * least one frame of codec data, this makes sure the codec initializes
 -          * the channel configuration and does not only trust the values from
 -          * the container. */
 -         try_decode_frame(st, pkt,
 -                          (options && i < orig_nb_streams) ? &options[i] : NULL);
 - 
 -         st->codec_info_nb_frames++;
 -         count++;
 -     }
 - 
 -     // close codecs which were opened in try_decode_frame()
 -     for (i = 0; i < ic->nb_streams; i++) {
 -         st = ic->streams[i];
 -         avcodec_close(st->codec);
 -     }
 -     for (i = 0; i < ic->nb_streams; i++) {
 -         st = ic->streams[i];
 -         if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
 -             /* estimate average framerate if not set by demuxer */
 -             if (!st->avg_frame_rate.num &&
 -                 st->info->fps_last_dts != st->info->fps_first_dts) {
 -                 int64_t delta_dts = st->info->fps_last_dts -
 -                                     st->info->fps_first_dts;
 -                 int delta_packets = st->info->fps_last_dts_idx -
 -                                     st->info->fps_first_dts_idx;
 -                 int best_fps      = 0;
 -                 double best_error = 0.01;
 - 
 -                 if (delta_dts     >= INT64_MAX / st->time_base.num ||
 -                     delta_packets >= INT64_MAX / st->time_base.den ||
 -                     delta_dts < 0)
 -                     continue;
 -                 av_reduce(&st->avg_frame_rate.num, &st->avg_frame_rate.den,
 -                           delta_packets * (int64_t) st->time_base.den,
 -                           delta_dts * (int64_t) st->time_base.num, 60000);
 - 
 -                 /* Round guessed framerate to a "standard" framerate if it's
 -                  * within 1% of the original estimate. */
 -                 for (j = 0; j < MAX_STD_TIMEBASES; j++) {
 -                     AVRational std_fps = { get_std_framerate(j), 12 * 1001 };
 -                     double error       = fabs(av_q2d(st->avg_frame_rate) /
 -                                               av_q2d(std_fps) - 1);
 - 
 -                     if (error < best_error) {
 -                         best_error = error;
 -                         best_fps   = std_fps.num;
 -                     }
 -                 }
 -                 if (best_fps)
 -                     av_reduce(&st->avg_frame_rate.num, &st->avg_frame_rate.den,
 -                               best_fps, 12 * 1001, INT_MAX);
 -             }
 -         } else if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO) {
 -             if (!st->codec->bits_per_coded_sample)
 -                 st->codec->bits_per_coded_sample =
 -                     av_get_bits_per_sample(st->codec->codec_id);
 -             // set stream disposition based on audio service type
 -             switch (st->codec->audio_service_type) {
 -             case AV_AUDIO_SERVICE_TYPE_EFFECTS:
 -                 st->disposition = AV_DISPOSITION_CLEAN_EFFECTS;
 -                 break;
 -             case AV_AUDIO_SERVICE_TYPE_VISUALLY_IMPAIRED:
 -                 st->disposition = AV_DISPOSITION_VISUAL_IMPAIRED;
 -                 break;
 -             case AV_AUDIO_SERVICE_TYPE_HEARING_IMPAIRED:
 -                 st->disposition = AV_DISPOSITION_HEARING_IMPAIRED;
 -                 break;
 -             case AV_AUDIO_SERVICE_TYPE_COMMENTARY:
 -                 st->disposition = AV_DISPOSITION_COMMENT;
 -                 break;
 -             case AV_AUDIO_SERVICE_TYPE_KARAOKE:
 -                 st->disposition = AV_DISPOSITION_KARAOKE;
 -                 break;
 -             }
 -         }
 -     }
 - 
 -     estimate_timings(ic, old_offset);
 - 
 -     compute_chapters_end(ic);
 - 
 - find_stream_info_err:
 -     for (i = 0; i < ic->nb_streams; i++) {
 -         ic->streams[i]->codec->thread_count = 0;
 -         av_freep(&ic->streams[i]->info);
 -     }
 -     return ret;
 - }
 - 
 - static AVProgram *find_program_from_stream(AVFormatContext *ic, int s)
 - {
 -     int i, j;
 - 
 -     for (i = 0; i < ic->nb_programs; i++)
 -         for (j = 0; j < ic->programs[i]->nb_stream_indexes; j++)
 -             if (ic->programs[i]->stream_index[j] == s)
 -                 return ic->programs[i];
 -     return NULL;
 - }
 - 
 - int av_find_best_stream(AVFormatContext *ic, enum AVMediaType type,
 -                         int wanted_stream_nb, int related_stream,
 -                         AVCodec **decoder_ret, int flags)
 - {
 -     int i, nb_streams = ic->nb_streams;
 -     int ret = AVERROR_STREAM_NOT_FOUND, best_count = -1;
 -     unsigned *program = NULL;
 -     AVCodec *decoder = NULL, *best_decoder = NULL;
 - 
 -     if (related_stream >= 0 && wanted_stream_nb < 0) {
 -         AVProgram *p = find_program_from_stream(ic, related_stream);
 -         if (p) {
 -             program    = p->stream_index;
 -             nb_streams = p->nb_stream_indexes;
 -         }
 -     }
 -     for (i = 0; i < nb_streams; i++) {
 -         int real_stream_index = program ? program[i] : i;
 -         AVStream *st          = ic->streams[real_stream_index];
 -         AVCodecContext *avctx = st->codec;
 -         if (avctx->codec_type != type)
 -             continue;
 -         if (wanted_stream_nb >= 0 && real_stream_index != wanted_stream_nb)
 -             continue;
 -         if (st->disposition & (AV_DISPOSITION_HEARING_IMPAIRED |
 -                                AV_DISPOSITION_VISUAL_IMPAIRED))
 -             continue;
 -         if (decoder_ret) {
 -             decoder = avcodec_find_decoder(st->codec->codec_id);
 -             if (!decoder) {
 -                 if (ret < 0)
 -                     ret = AVERROR_DECODER_NOT_FOUND;
 -                 continue;
 -             }
 -         }
 -         if (best_count >= st->codec_info_nb_frames)
 -             continue;
 -         best_count   = st->codec_info_nb_frames;
 -         ret          = real_stream_index;
 -         best_decoder = decoder;
 -         if (program && i == nb_streams - 1 && ret < 0) {
 -             program    = NULL;
 -             nb_streams = ic->nb_streams;
 -             /* no related stream found, try again with everything */
 -             i = 0;
 -         }
 -     }
 -     if (decoder_ret)
 -         *decoder_ret = best_decoder;
 -     return ret;
 - }
 - 
 - /*******************************************************/
 - 
 - int av_read_play(AVFormatContext *s)
 - {
 -     if (s->iformat->read_play)
 -         return s->iformat->read_play(s);
 -     if (s->pb)
 -         return avio_pause(s->pb, 0);
 -     return AVERROR(ENOSYS);
 - }
 - 
 - int av_read_pause(AVFormatContext *s)
 - {
 -     if (s->iformat->read_pause)
 -         return s->iformat->read_pause(s);
 -     if (s->pb)
 -         return avio_pause(s->pb, 1);
 -     return AVERROR(ENOSYS);
 - }
 - 
 - void avformat_free_context(AVFormatContext *s)
 - {
 -     int i, j;
 -     AVStream *st;
 - 
 -     av_opt_free(s);
 -     if (s->iformat && s->iformat->priv_class && s->priv_data)
 -         av_opt_free(s->priv_data);
 - 
 -     for (i = 0; i < s->nb_streams; i++) {
 -         /* free all data in a stream component */
 -         st = s->streams[i];
 - 
 -         for (j = 0; j < st->nb_side_data; j++)
 -             av_freep(&st->side_data[j].data);
 -         av_freep(&st->side_data);
 -         st->nb_side_data = 0;
 - 
 -         if (st->parser) {
 -             av_parser_close(st->parser);
 -         }
 -         if (st->attached_pic.data)
 -             av_free_packet(&st->attached_pic);
 -         av_dict_free(&st->metadata);
 -         av_freep(&st->probe_data.buf);
 -         av_free(st->index_entries);
 -         av_free(st->codec->extradata);
 -         av_free(st->codec->subtitle_header);
 -         av_free(st->codec);
 -         av_free(st->priv_data);
 -         av_free(st->info);
 -         av_free(st);
 -     }
 -     for (i = s->nb_programs - 1; i >= 0; i--) {
 -         av_dict_free(&s->programs[i]->metadata);
 -         av_freep(&s->programs[i]->stream_index);
 -         av_freep(&s->programs[i]);
 -     }
 -     av_freep(&s->programs);
 -     av_freep(&s->priv_data);
 -     while (s->nb_chapters--) {
 -         av_dict_free(&s->chapters[s->nb_chapters]->metadata);
 -         av_free(s->chapters[s->nb_chapters]);
 -     }
 -     av_freep(&s->chapters);
 -     av_dict_free(&s->metadata);
 -     av_freep(&s->streams);
 -     av_freep(&s->internal);
 -     av_free(s);
 - }
 - 
 - void avformat_close_input(AVFormatContext **ps)
 - {
 -     AVFormatContext *s = *ps;
 -     AVIOContext *pb    = s->pb;
 - 
 -     if ((s->iformat && s->iformat->flags & AVFMT_NOFILE) ||
 -         (s->flags & AVFMT_FLAG_CUSTOM_IO))
 -         pb = NULL;
 - 
 -     flush_packet_queue(s);
 - 
 -     if (s->iformat)
 -         if (s->iformat->read_close)
 -             s->iformat->read_close(s);
 - 
 -     avformat_free_context(s);
 - 
 -     *ps = NULL;
 - 
 -     avio_close(pb);
 - }
 - 
 - AVStream *avformat_new_stream(AVFormatContext *s, AVCodec *c)
 - {
 -     AVStream *st;
 -     int i;
 - 
 -     if (av_reallocp_array(&s->streams, s->nb_streams + 1,
 -                           sizeof(*s->streams)) < 0) {
 -         s->nb_streams = 0;
 -         return NULL;
 -     }
 - 
 -     st = av_mallocz(sizeof(AVStream));
 -     if (!st)
 -         return NULL;
 -     if (!(st->info = av_mallocz(sizeof(*st->info)))) {
 -         av_free(st);
 -         return NULL;
 -     }
 - 
 -     st->codec = avcodec_alloc_context3(c);
 -     if (s->iformat)
 -         /* no default bitrate if decoding */
 -         st->codec->bit_rate = 0;
 -     st->index      = s->nb_streams;
 -     st->start_time = AV_NOPTS_VALUE;
 -     st->duration   = AV_NOPTS_VALUE;
 -     /* we set the current DTS to 0 so that formats without any timestamps
 -      * but durations get some timestamps, formats with some unknown
 -      * timestamps have their first few packets buffered and the
 -      * timestamps corrected before they are returned to the user */
 -     st->cur_dts       = 0;
 -     st->first_dts     = AV_NOPTS_VALUE;
 -     st->probe_packets = MAX_PROBE_PACKETS;
 - 
 -     /* default pts setting is MPEG-like */
 -     avpriv_set_pts_info(st, 33, 1, 90000);
 -     st->last_IP_pts = AV_NOPTS_VALUE;
 -     for (i = 0; i < MAX_REORDER_DELAY + 1; i++)
 -         st->pts_buffer[i] = AV_NOPTS_VALUE;
 - 
 -     st->sample_aspect_ratio = (AVRational) { 0, 1 };
 - 
 -     st->info->fps_first_dts = AV_NOPTS_VALUE;
 -     st->info->fps_last_dts  = AV_NOPTS_VALUE;
 - 
 -     s->streams[s->nb_streams++] = st;
 -     return st;
 - }
 - 
 - AVProgram *av_new_program(AVFormatContext *ac, int id)
 - {
 -     AVProgram *program = NULL;
 -     int i;
 - 
 -     av_dlog(ac, "new_program: id=0x%04x\n", id);
 - 
 -     for (i = 0; i < ac->nb_programs; i++)
 -         if (ac->programs[i]->id == id)
 -             program = ac->programs[i];
 - 
 -     if (!program) {
 -         program = av_mallocz(sizeof(AVProgram));
 -         if (!program)
 -             return NULL;
 -         dynarray_add(&ac->programs, &ac->nb_programs, program);
 -         program->discard = AVDISCARD_NONE;
 -     }
 -     program->id = id;
 - 
 -     return program;
 - }
 - 
 - AVChapter *avpriv_new_chapter(AVFormatContext *s, int id, AVRational time_base,
 -                               int64_t start, int64_t end, const char *title)
 - {
 -     AVChapter *chapter = NULL;
 -     int i;
 - 
 -     for (i = 0; i < s->nb_chapters; i++)
 -         if (s->chapters[i]->id == id)
 -             chapter = s->chapters[i];
 - 
 -     if (!chapter) {
 -         chapter = av_mallocz(sizeof(AVChapter));
 -         if (!chapter)
 -             return NULL;
 -         dynarray_add(&s->chapters, &s->nb_chapters, chapter);
 -     }
 -     av_dict_set(&chapter->metadata, "title", title, 0);
 -     chapter->id        = id;
 -     chapter->time_base = time_base;
 -     chapter->start     = start;
 -     chapter->end       = end;
 - 
 -     return chapter;
 - }
 - 
 - void ff_program_add_stream_index(AVFormatContext *ac, int progid, unsigned idx)
 - {
 -     int i, j;
 -     AVProgram *program = NULL;
 - 
 -     if (idx >= ac->nb_streams) {
 -         av_log(ac, AV_LOG_ERROR, "stream index %d is not valid\n", idx);
 -         return;
 -     }
 - 
 -     for (i = 0; i < ac->nb_programs; i++) {
 -         if (ac->programs[i]->id != progid)
 -             continue;
 -         program = ac->programs[i];
 -         for (j = 0; j < program->nb_stream_indexes; j++)
 -             if (program->stream_index[j] == idx)
 -                 return;
 - 
 -         if (av_reallocp_array(&program->stream_index,
 -                               program->nb_stream_indexes + 1,
 -                               sizeof(*program->stream_index)) < 0) {
 -             program->nb_stream_indexes = 0;
 -             return;
 -         }
 -         program->stream_index[program->nb_stream_indexes++] = idx;
 -         return;
 -     }
 - }
 - 
 - static void print_fps(double d, const char *postfix)
 - {
 -     uint64_t v = lrintf(d * 100);
 -     if (v % 100)
 -         av_log(NULL, AV_LOG_INFO, ", %3.2f %s", d, postfix);
 -     else if (v % (100 * 1000))
 -         av_log(NULL, AV_LOG_INFO, ", %1.0f %s", d, postfix);
 -     else
 -         av_log(NULL, AV_LOG_INFO, ", %1.0fk %s", d / 1000, postfix);
 - }
 - 
 - static void dump_metadata(void *ctx, AVDictionary *m, const char *indent)
 - {
 -     if (m && !(av_dict_count(m) == 1 && av_dict_get(m, "language", NULL, 0))) {
 -         AVDictionaryEntry *tag = NULL;
 - 
 -         av_log(ctx, AV_LOG_INFO, "%sMetadata:\n", indent);
 -         while ((tag = av_dict_get(m, "", tag, AV_DICT_IGNORE_SUFFIX)))
 -             if (strcmp("language", tag->key))
 -                 av_log(ctx, AV_LOG_INFO,
 -                        "%s  %-16s: %s\n", indent, tag->key, tag->value);
 -     }
 - }
 - 
 - /* "user interface" functions */
 - static void dump_stream_format(AVFormatContext *ic, int i,
 -                                int index, int is_output)
 - {
 -     char buf[256];
 -     int flags = (is_output ? ic->oformat->flags : ic->iformat->flags);
 -     AVStream *st = ic->streams[i];
 -     int g = av_gcd(st->time_base.num, st->time_base.den);
 -     AVDictionaryEntry *lang = av_dict_get(st->metadata, "language", NULL, 0);
 -     avcodec_string(buf, sizeof(buf), st->codec, is_output);
 -     av_log(NULL, AV_LOG_INFO, "    Stream #%d.%d", index, i);
 -     /* the pid is an important information, so we display it */
 -     /* XXX: add a generic system */
 -     if (flags & AVFMT_SHOW_IDS)
 -         av_log(NULL, AV_LOG_INFO, "[0x%x]", st->id);
 -     if (lang)
 -         av_log(NULL, AV_LOG_INFO, "(%s)", lang->value);
 -     av_log(NULL, AV_LOG_DEBUG, ", %d, %d/%d", st->codec_info_nb_frames,
 -            st->time_base.num / g, st->time_base.den / g);
 -     av_log(NULL, AV_LOG_INFO, ": %s", buf);
 -     if (st->sample_aspect_ratio.num && // default
 -         av_cmp_q(st->sample_aspect_ratio, st->codec->sample_aspect_ratio)) {
 -         AVRational display_aspect_ratio;
 -         av_reduce(&display_aspect_ratio.num, &display_aspect_ratio.den,
 -                   st->codec->width  * st->sample_aspect_ratio.num,
 -                   st->codec->height * st->sample_aspect_ratio.den,
 -                   1024 * 1024);
 -         av_log(NULL, AV_LOG_INFO, ", PAR %d:%d DAR %d:%d",
 -                st->sample_aspect_ratio.num, st->sample_aspect_ratio.den,
 -                display_aspect_ratio.num, display_aspect_ratio.den);
 -     }
 -     if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
 -         if (st->avg_frame_rate.den && st->avg_frame_rate.num)
 -             print_fps(av_q2d(st->avg_frame_rate), "fps");
 -         if (st->time_base.den && st->time_base.num)
 -             print_fps(1 / av_q2d(st->time_base), "tbn");
 -         if (st->codec->time_base.den && st->codec->time_base.num)
 -             print_fps(1 / av_q2d(st->codec->time_base), "tbc");
 -     }
 -     if (st->disposition & AV_DISPOSITION_DEFAULT)
 -         av_log(NULL, AV_LOG_INFO, " (default)");
 -     if (st->disposition & AV_DISPOSITION_DUB)
 -         av_log(NULL, AV_LOG_INFO, " (dub)");
 -     if (st->disposition & AV_DISPOSITION_ORIGINAL)
 -         av_log(NULL, AV_LOG_INFO, " (original)");
 -     if (st->disposition & AV_DISPOSITION_COMMENT)
 -         av_log(NULL, AV_LOG_INFO, " (comment)");
 -     if (st->disposition & AV_DISPOSITION_LYRICS)
 -         av_log(NULL, AV_LOG_INFO, " (lyrics)");
 -     if (st->disposition & AV_DISPOSITION_KARAOKE)
 -         av_log(NULL, AV_LOG_INFO, " (karaoke)");
 -     if (st->disposition & AV_DISPOSITION_FORCED)
 -         av_log(NULL, AV_LOG_INFO, " (forced)");
 -     if (st->disposition & AV_DISPOSITION_HEARING_IMPAIRED)
 -         av_log(NULL, AV_LOG_INFO, " (hearing impaired)");
 -     if (st->disposition & AV_DISPOSITION_VISUAL_IMPAIRED)
 -         av_log(NULL, AV_LOG_INFO, " (visual impaired)");
 -     if (st->disposition & AV_DISPOSITION_CLEAN_EFFECTS)
 -         av_log(NULL, AV_LOG_INFO, " (clean effects)");
 -     av_log(NULL, AV_LOG_INFO, "\n");
 -     dump_metadata(NULL, st->metadata, "    ");
 - }
 - 
 - void av_dump_format(AVFormatContext *ic, int index,
 -                     const char *url, int is_output)
 - {
 -     int i;
 -     uint8_t *printed = ic->nb_streams ? av_mallocz(ic->nb_streams) : NULL;
 -     if (ic->nb_streams && !printed)
 -         return;
 - 
 -     av_log(NULL, AV_LOG_INFO, "%s #%d, %s, %s '%s':\n",
 -            is_output ? "Output" : "Input",
 -            index,
 -            is_output ? ic->oformat->name : ic->iformat->name,
 -            is_output ? "to" : "from", url);
 -     dump_metadata(NULL, ic->metadata, "  ");
 -     if (!is_output) {
 -         av_log(NULL, AV_LOG_INFO, "  Duration: ");
 -         if (ic->duration != AV_NOPTS_VALUE) {
 -             int hours, mins, secs, us;
 -             secs  = ic->duration / AV_TIME_BASE;
 -             us    = ic->duration % AV_TIME_BASE;
 -             mins  = secs / 60;
 -             secs %= 60;
 -             hours = mins / 60;
 -             mins %= 60;
 -             av_log(NULL, AV_LOG_INFO, "%02d:%02d:%02d.%02d", hours, mins, secs,
 -                    (100 * us) / AV_TIME_BASE);
 -         } else {
 -             av_log(NULL, AV_LOG_INFO, "N/A");
 -         }
 -         if (ic->start_time != AV_NOPTS_VALUE) {
 -             int secs, us;
 -             av_log(NULL, AV_LOG_INFO, ", start: ");
 -             secs = ic->start_time / AV_TIME_BASE;
 -             us   = abs(ic->start_time % AV_TIME_BASE);
 -             av_log(NULL, AV_LOG_INFO, "%d.%06d",
 -                    secs, (int) av_rescale(us, 1000000, AV_TIME_BASE));
 -         }
 -         av_log(NULL, AV_LOG_INFO, ", bitrate: ");
 -         if (ic->bit_rate)
 -             av_log(NULL, AV_LOG_INFO, "%d kb/s", ic->bit_rate / 1000);
 -         else
 -             av_log(NULL, AV_LOG_INFO, "N/A");
 -         av_log(NULL, AV_LOG_INFO, "\n");
 -     }
 -     for (i = 0; i < ic->nb_chapters; i++) {
 -         AVChapter *ch = ic->chapters[i];
 -         av_log(NULL, AV_LOG_INFO, "    Chapter #%d.%d: ", index, i);
 -         av_log(NULL, AV_LOG_INFO,
 -                "start %f, ", ch->start * av_q2d(ch->time_base));
 -         av_log(NULL, AV_LOG_INFO,
 -                "end %f\n", ch->end * av_q2d(ch->time_base));
 - 
 -         dump_metadata(NULL, ch->metadata, "    ");
 -     }
 -     if (ic->nb_programs) {
 -         int j, k, total = 0;
 -         for (j = 0; j < ic->nb_programs; j++) {
 -             AVDictionaryEntry *name = av_dict_get(ic->programs[j]->metadata,
 -                                                   "name", NULL, 0);
 -             av_log(NULL, AV_LOG_INFO, "  Program %d %s\n", ic->programs[j]->id,
 -                    name ? name->value : "");
 -             dump_metadata(NULL, ic->programs[j]->metadata, "    ");
 -             for (k = 0; k < ic->programs[j]->nb_stream_indexes; k++) {
 -                 dump_stream_format(ic, ic->programs[j]->stream_index[k],
 -                                    index, is_output);
 -                 printed[ic->programs[j]->stream_index[k]] = 1;
 -             }
 -             total += ic->programs[j]->nb_stream_indexes;
 -         }
 -         if (total < ic->nb_streams)
 -             av_log(NULL, AV_LOG_INFO, "  No Program\n");
 -     }
 -     for (i = 0; i < ic->nb_streams; i++)
 -         if (!printed[i])
 -             dump_stream_format(ic, i, index, is_output);
 - 
 -     av_free(printed);
 - }
 - 
 - uint64_t ff_ntp_time(void)
 - {
 -     return (av_gettime() / 1000) * 1000 + NTP_OFFSET_US;
 - }
 - 
 - int av_get_frame_filename(char *buf, int buf_size, const char *path, int number)
 - {
 -     const char *p;
 -     char *q, buf1[20], c;
 -     int nd, len, percentd_found;
 - 
 -     q = buf;
 -     p = path;
 -     percentd_found = 0;
 -     for (;;) {
 -         c = *p++;
 -         if (c == '\0')
 -             break;
 -         if (c == '%') {
 -             do {
 -                 nd = 0;
 -                 while (av_isdigit(*p))
 -                     nd = nd * 10 + *p++ - '0';
 -                 c = *p++;
 -             } while (av_isdigit(c));
 - 
 -             switch (c) {
 -             case '%':
 -                 goto addchar;
 -             case 'd':
 -                 if (percentd_found)
 -                     goto fail;
 -                 percentd_found = 1;
 -                 snprintf(buf1, sizeof(buf1), "%0*d", nd, number);
 -                 len = strlen(buf1);
 -                 if ((q - buf + len) > buf_size - 1)
 -                     goto fail;
 -                 memcpy(q, buf1, len);
 -                 q += len;
 -                 break;
 -             default:
 -                 goto fail;
 -             }
 -         } else {
 - addchar:
 -             if ((q - buf) < buf_size - 1)
 -                 *q++ = c;
 -         }
 -     }
 -     if (!percentd_found)
 -         goto fail;
 -     *q = '\0';
 -     return 0;
 - fail:
 -     *q = '\0';
 -     return -1;
 - }
 - 
 - #define HEXDUMP_PRINT(...)                      \
 -     do {                                        \
 -         if (!f)                                 \
 -             av_log(avcl, level, __VA_ARGS__);   \
 -         else                                    \
 -             fprintf(f, __VA_ARGS__);            \
 -     } while (0)
 - 
 - static void hex_dump_internal(void *avcl, FILE *f, int level,
 -                               const uint8_t *buf, int size)
 - {
 -     int len, i, j, c;
 - 
 -     for (i = 0; i < size; i += 16) {
 -         len = size - i;
 -         if (len > 16)
 -             len = 16;
 -         HEXDUMP_PRINT("%08x ", i);
 -         for (j = 0; j < 16; j++) {
 -             if (j < len)
 -                 HEXDUMP_PRINT(" %02x", buf[i + j]);
 -             else
 -                 HEXDUMP_PRINT("   ");
 -         }
 -         HEXDUMP_PRINT(" ");
 -         for (j = 0; j < len; j++) {
 -             c = buf[i + j];
 -             if (c < ' ' || c > '~')
 -                 c = '.';
 -             HEXDUMP_PRINT("%c", c);
 -         }
 -         HEXDUMP_PRINT("\n");
 -     }
 - }
 - 
 - void av_hex_dump(FILE *f, const uint8_t *buf, int size)
 - {
 -     hex_dump_internal(NULL, f, 0, buf, size);
 - }
 - 
 - void av_hex_dump_log(void *avcl, int level, const uint8_t *buf, int size)
 - {
 -     hex_dump_internal(avcl, NULL, level, buf, size);
 - }
 - 
 - static void pkt_dump_internal(void *avcl, FILE *f, int level, AVPacket *pkt,
 -                               int dump_payload, AVRational time_base)
 - {
 -     HEXDUMP_PRINT("stream #%d:\n", pkt->stream_index);
 -     HEXDUMP_PRINT("  keyframe=%d\n", (pkt->flags & AV_PKT_FLAG_KEY) != 0);
 -     HEXDUMP_PRINT("  duration=%0.3f\n", pkt->duration * av_q2d(time_base));
 -     /* DTS is _always_ valid after av_read_frame() */
 -     HEXDUMP_PRINT("  dts=");
 -     if (pkt->dts == AV_NOPTS_VALUE)
 -         HEXDUMP_PRINT("N/A");
 -     else
 -         HEXDUMP_PRINT("%0.3f", pkt->dts * av_q2d(time_base));
 -     /* PTS may not be known if B-frames are present. */
 -     HEXDUMP_PRINT("  pts=");
 -     if (pkt->pts == AV_NOPTS_VALUE)
 -         HEXDUMP_PRINT("N/A");
 -     else
 -         HEXDUMP_PRINT("%0.3f", pkt->pts * av_q2d(time_base));
 -     HEXDUMP_PRINT("\n");
 -     HEXDUMP_PRINT("  size=%d\n", pkt->size);
 -     if (dump_payload)
 -         av_hex_dump(f, pkt->data, pkt->size);
 - }
 - 
 - void av_pkt_dump2(FILE *f, AVPacket *pkt, int dump_payload, AVStream *st)
 - {
 -     pkt_dump_internal(NULL, f, 0, pkt, dump_payload, st->time_base);
 - }
 - 
 - void av_pkt_dump_log2(void *avcl, int level, AVPacket *pkt, int dump_payload,
 -                       AVStream *st)
 - {
 -     pkt_dump_internal(avcl, NULL, level, pkt, dump_payload, st->time_base);
 - }
 - 
 - void av_url_split(char *proto, int proto_size,
 -                   char *authorization, int authorization_size,
 -                   char *hostname, int hostname_size,
 -                   int *port_ptr, char *path, int path_size, const char *url)
 - {
 -     const char *p, *ls, *at, *col, *brk;
 - 
 -     if (port_ptr)
 -         *port_ptr = -1;
 -     if (proto_size > 0)
 -         proto[0] = 0;
 -     if (authorization_size > 0)
 -         authorization[0] = 0;
 -     if (hostname_size > 0)
 -         hostname[0] = 0;
 -     if (path_size > 0)
 -         path[0] = 0;
 - 
 -     /* parse protocol */
 -     if ((p = strchr(url, ':'))) {
 -         av_strlcpy(proto, url, FFMIN(proto_size, p + 1 - url));
 -         p++; /* skip ':' */
 -         if (*p == '/')
 -             p++;
 -         if (*p == '/')
 -             p++;
 -     } else {
 -         /* no protocol means plain filename */
 -         av_strlcpy(path, url, path_size);
 -         return;
 -     }
 - 
 -     /* separate path from hostname */
 -     ls = strchr(p, '/');
 -     if (!ls)
 -         ls = strchr(p, '?');
 -     if (ls)
 -         av_strlcpy(path, ls, path_size);
 -     else
 -         ls = &p[strlen(p)];  // XXX
 - 
 -     /* the rest is hostname, use that to parse auth/port */
 -     if (ls != p) {
 -         /* authorization (user[:pass]@hostname) */
 -         if ((at = strchr(p, '@')) && at < ls) {
 -             av_strlcpy(authorization, p,
 -                        FFMIN(authorization_size, at + 1 - p));
 -             p = at + 1; /* skip '@' */
 -         }
 - 
 -         if (*p == '[' && (brk = strchr(p, ']')) && brk < ls) {
 -             /* [host]:port */
 -             av_strlcpy(hostname, p + 1,
 -                        FFMIN(hostname_size, brk - p));
 -             if (brk[1] == ':' && port_ptr)
 -                 *port_ptr = atoi(brk + 2);
 -         } else if ((col = strchr(p, ':')) && col < ls) {
 -             av_strlcpy(hostname, p,
 -                        FFMIN(col + 1 - p, hostname_size));
 -             if (port_ptr)
 -                 *port_ptr = atoi(col + 1);
 -         } else
 -             av_strlcpy(hostname, p,
 -                        FFMIN(ls + 1 - p, hostname_size));
 -     }
 - }
 - 
 - char *ff_data_to_hex(char *buff, const uint8_t *src, int s, int lowercase)
 - {
 -     int i;
 -     static const char hex_table_uc[16] = { '0', '1', '2', '3',
 -                                            '4', '5', '6', '7',
 -                                            '8', '9', 'A', 'B',
 -                                            'C', 'D', 'E', 'F' };
 -     static const char hex_table_lc[16] = { '0', '1', '2', '3',
 -                                            '4', '5', '6', '7',
 -                                            '8', '9', 'a', 'b',
 -                                            'c', 'd', 'e', 'f' };
 -     const char *hex_table = lowercase ? hex_table_lc : hex_table_uc;
 - 
 -     for (i = 0; i < s; i++) {
 -         buff[i * 2]     = hex_table[src[i] >> 4];
 -         buff[i * 2 + 1] = hex_table[src[i] & 0xF];
 -     }
 - 
 -     return buff;
 - }
 - 
 - int ff_hex_to_data(uint8_t *data, const char *p)
 - {
 -     int c, len, v;
 - 
 -     len = 0;
 -     v   = 1;
 -     for (;;) {
 -         p += strspn(p, SPACE_CHARS);
 -         if (*p == '\0')
 -             break;
 -         c = av_toupper((unsigned char) *p++);
 -         if (c >= '0' && c <= '9')
 -             c = c - '0';
 -         else if (c >= 'A' && c <= 'F')
 -             c = c - 'A' + 10;
 -         else
 -             break;
 -         v = (v << 4) | c;
 -         if (v & 0x100) {
 -             if (data)
 -                 data[len] = v;
 -             len++;
 -             v = 1;
 -         }
 -     }
 -     return len;
 - }
 - 
 - void avpriv_set_pts_info(AVStream *s, int pts_wrap_bits,
 -                          unsigned int pts_num, unsigned int pts_den)
 - {
 -     AVRational new_tb;
 -     if (av_reduce(&new_tb.num, &new_tb.den, pts_num, pts_den, INT_MAX)) {
 -         if (new_tb.num != pts_num)
 -             av_log(NULL, AV_LOG_DEBUG,
 -                    "st:%d removing common factor %d from timebase\n",
 -                    s->index, pts_num / new_tb.num);
 -     } else
 -         av_log(NULL, AV_LOG_WARNING,
 -                "st:%d has too large timebase, reducing\n", s->index);
 - 
 -     if (new_tb.num <= 0 || new_tb.den <= 0) {
 -         av_log(NULL, AV_LOG_ERROR,
 -                "Ignoring attempt to set invalid timebase for st:%d\n",
 -                s->index);
 -         return;
 -     }
 -     s->time_base     = new_tb;
 -     s->pts_wrap_bits = pts_wrap_bits;
 - }
 - 
 - void ff_parse_key_value(const char *str, ff_parse_key_val_cb callback_get_buf,
 -                         void *context)
 - {
 -     const char *ptr = str;
 - 
 -     /* Parse key=value pairs. */
 -     for (;;) {
 -         const char *key;
 -         char *dest = NULL, *dest_end;
 -         int key_len, dest_len = 0;
 - 
 -         /* Skip whitespace and potential commas. */
 -         while (*ptr && (av_isspace(*ptr) || *ptr == ','))
 -             ptr++;
 -         if (!*ptr)
 -             break;
 - 
 -         key = ptr;
 - 
 -         if (!(ptr = strchr(key, '=')))
 -             break;
 -         ptr++;
 -         key_len = ptr - key;
 - 
 -         callback_get_buf(context, key, key_len, &dest, &dest_len);
 -         dest_end = dest + dest_len - 1;
 - 
 -         if (*ptr == '\"') {
 -             ptr++;
 -             while (*ptr && *ptr != '\"') {
 -                 if (*ptr == '\\') {
 -                     if (!ptr[1])
 -                         break;
 -                     if (dest && dest < dest_end)
 -                         *dest++ = ptr[1];
 -                     ptr += 2;
 -                 } else {
 -                     if (dest && dest < dest_end)
 -                         *dest++ = *ptr;
 -                     ptr++;
 -                 }
 -             }
 -             if (*ptr == '\"')
 -                 ptr++;
 -         } else {
 -             for (; *ptr && !(av_isspace(*ptr) || *ptr == ','); ptr++)
 -                 if (dest && dest < dest_end)
 -                     *dest++ = *ptr;
 -         }
 -         if (dest)
 -             *dest = 0;
 -     }
 - }
 - 
 - int ff_find_stream_index(AVFormatContext *s, int id)
 - {
 -     int i;
 -     for (i = 0; i < s->nb_streams; i++)
 -         if (s->streams[i]->id == id)
 -             return i;
 -     return -1;
 - }
 - 
 - int64_t ff_iso8601_to_unix_time(const char *datestr)
 - {
 - #if HAVE_STRPTIME
 -     struct tm time1 = { 0 }, time2 = { 0 };
 -     char *ret1, *ret2;
 -     ret1 = strptime(datestr, "%Y - %m - %d %T", &time1);
 -     ret2 = strptime(datestr, "%Y - %m - %dT%T", &time2);
 -     if (ret2 && !ret1)
 -         return av_timegm(&time2);
 -     else
 -         return av_timegm(&time1);
 - #else
 -     av_log(NULL, AV_LOG_WARNING,
 -            "strptime() unavailable on this system, cannot convert "
 -            "the date string.\n");
 -     return 0;
 - #endif
 - }
 - 
 - int avformat_query_codec(AVOutputFormat *ofmt, enum AVCodecID codec_id,
 -                          int std_compliance)
 - {
 -     if (ofmt) {
 -         if (ofmt->query_codec)
 -             return ofmt->query_codec(codec_id, std_compliance);
 -         else if (ofmt->codec_tag)
 -             return !!av_codec_get_tag(ofmt->codec_tag, codec_id);
 -         else if (codec_id == ofmt->video_codec ||
 -                  codec_id == ofmt->audio_codec ||
 -                  codec_id == ofmt->subtitle_codec)
 -             return 1;
 -     }
 -     return AVERROR_PATCHWELCOME;
 - }
 - 
 - int avformat_network_init(void)
 - {
 - #if CONFIG_NETWORK
 -     int ret;
 -     ff_network_inited_globally = 1;
 -     if ((ret = ff_network_init()) < 0)
 -         return ret;
 -     ff_tls_init();
 - #endif
 -     return 0;
 - }
 - 
 - int avformat_network_deinit(void)
 - {
 - #if CONFIG_NETWORK
 -     ff_network_close();
 -     ff_tls_deinit();
 - #endif
 -     return 0;
 - }
 - 
 - int ff_add_param_change(AVPacket *pkt, int32_t channels,
 -                         uint64_t channel_layout, int32_t sample_rate,
 -                         int32_t width, int32_t height)
 - {
 -     uint32_t flags = 0;
 -     int size = 4;
 -     uint8_t *data;
 -     if (!pkt)
 -         return AVERROR(EINVAL);
 -     if (channels) {
 -         size  += 4;
 -         flags |= AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_COUNT;
 -     }
 -     if (channel_layout) {
 -         size  += 8;
 -         flags |= AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_LAYOUT;
 -     }
 -     if (sample_rate) {
 -         size  += 4;
 -         flags |= AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE;
 -     }
 -     if (width || height) {
 -         size  += 8;
 -         flags |= AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS;
 -     }
 -     data = av_packet_new_side_data(pkt, AV_PKT_DATA_PARAM_CHANGE, size);
 -     if (!data)
 -         return AVERROR(ENOMEM);
 -     bytestream_put_le32(&data, flags);
 -     if (channels)
 -         bytestream_put_le32(&data, channels);
 -     if (channel_layout)
 -         bytestream_put_le64(&data, channel_layout);
 -     if (sample_rate)
 -         bytestream_put_le32(&data, sample_rate);
 -     if (width || height) {
 -         bytestream_put_le32(&data, width);
 -         bytestream_put_le32(&data, height);
 -     }
 -     return 0;
 - }
 - 
 - int ff_generate_avci_extradata(AVStream *st)
 - {
 -     static const uint8_t avci100_1080p_extradata[] = {
 -         // SPS
 -         0x00, 0x00, 0x00, 0x01, 0x67, 0x7a, 0x10, 0x29,
 -         0xb6, 0xd4, 0x20, 0x22, 0x33, 0x19, 0xc6, 0x63,
 -         0x23, 0x21, 0x01, 0x11, 0x98, 0xce, 0x33, 0x19,
 -         0x18, 0x21, 0x02, 0x56, 0xb9, 0x3d, 0x7d, 0x7e,
 -         0x4f, 0xe3, 0x3f, 0x11, 0xf1, 0x9e, 0x08, 0xb8,
 -         0x8c, 0x54, 0x43, 0xc0, 0x78, 0x02, 0x27, 0xe2,
 -         0x70, 0x1e, 0x30, 0x10, 0x10, 0x14, 0x00, 0x00,
 -         0x03, 0x00, 0x04, 0x00, 0x00, 0x03, 0x00, 0xca,
 -         0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 -         // PPS
 -         0x00, 0x00, 0x00, 0x01, 0x68, 0xce, 0x33, 0x48,
 -         0xd0
 -     };
 -     static const uint8_t avci100_1080i_extradata[] = {
 -         // SPS
 -         0x00, 0x00, 0x00, 0x01, 0x67, 0x7a, 0x10, 0x29,
 -         0xb6, 0xd4, 0x20, 0x22, 0x33, 0x19, 0xc6, 0x63,
 -         0x23, 0x21, 0x01, 0x11, 0x98, 0xce, 0x33, 0x19,
 -         0x18, 0x21, 0x03, 0x3a, 0x46, 0x65, 0x6a, 0x65,
 -         0x24, 0xad, 0xe9, 0x12, 0x32, 0x14, 0x1a, 0x26,
 -         0x34, 0xad, 0xa4, 0x41, 0x82, 0x23, 0x01, 0x50,
 -         0x2b, 0x1a, 0x24, 0x69, 0x48, 0x30, 0x40, 0x2e,
 -         0x11, 0x12, 0x08, 0xc6, 0x8c, 0x04, 0x41, 0x28,
 -         0x4c, 0x34, 0xf0, 0x1e, 0x01, 0x13, 0xf2, 0xe0,
 -         0x3c, 0x60, 0x20, 0x20, 0x28, 0x00, 0x00, 0x03,
 -         0x00, 0x08, 0x00, 0x00, 0x03, 0x01, 0x94, 0x00,
 -         // PPS
 -         0x00, 0x00, 0x00, 0x01, 0x68, 0xce, 0x33, 0x48,
 -         0xd0
 -     };
 -     static const uint8_t avci50_1080i_extradata[] = {
 -         // SPS
 -         0x00, 0x00, 0x00, 0x01, 0x67, 0x6e, 0x10, 0x28,
 -         0xa6, 0xd4, 0x20, 0x32, 0x33, 0x0c, 0x71, 0x18,
 -         0x88, 0x62, 0x10, 0x19, 0x19, 0x86, 0x38, 0x8c,
 -         0x44, 0x30, 0x21, 0x02, 0x56, 0x4e, 0x6e, 0x61,
 -         0x87, 0x3e, 0x73, 0x4d, 0x98, 0x0c, 0x03, 0x06,
 -         0x9c, 0x0b, 0x73, 0xe6, 0xc0, 0xb5, 0x18, 0x63,
 -         0x0d, 0x39, 0xe0, 0x5b, 0x02, 0xd4, 0xc6, 0x19,
 -         0x1a, 0x79, 0x8c, 0x32, 0x34, 0x24, 0xf0, 0x16,
 -         0x81, 0x13, 0xf7, 0xff, 0x80, 0x01, 0x80, 0x02,
 -         0x71, 0x80, 0x80, 0x80, 0xa0, 0x00, 0x00, 0x03,
 -         0x00, 0x20, 0x00, 0x00, 0x06, 0x50, 0x80, 0x00,
 -         // PPS
 -         0x00, 0x00, 0x00, 0x01, 0x68, 0xee, 0x31, 0x12,
 -         0x11
 -     };
 -     static const uint8_t avci100_720p_extradata[] = {
 -         // SPS
 -         0x00, 0x00, 0x00, 0x01, 0x67, 0x7a, 0x10, 0x29,
 -         0xb6, 0xd4, 0x20, 0x2a, 0x33, 0x1d, 0xc7, 0x62,
 -         0xa1, 0x08, 0x40, 0x54, 0x66, 0x3b, 0x8e, 0xc5,
 -         0x42, 0x02, 0x10, 0x25, 0x64, 0x2c, 0x89, 0xe8,
 -         0x85, 0xe4, 0x21, 0x4b, 0x90, 0x83, 0x06, 0x95,
 -         0xd1, 0x06, 0x46, 0x97, 0x20, 0xc8, 0xd7, 0x43,
 -         0x08, 0x11, 0xc2, 0x1e, 0x4c, 0x91, 0x0f, 0x01,
 -         0x40, 0x16, 0xec, 0x07, 0x8c, 0x04, 0x04, 0x05,
 -         0x00, 0x00, 0x03, 0x00, 0x01, 0x00, 0x00, 0x03,
 -         0x00, 0x64, 0x84, 0x00, 0x00, 0x00, 0x00, 0x00,
 -         // PPS
 -         0x00, 0x00, 0x00, 0x01, 0x68, 0xce, 0x31, 0x12,
 -         0x11
 -     };
 - 
 -     const uint8_t *data = NULL;
 -     int size            = 0;
 - 
 -     if (st->codec->width == 1920) {
 -         if (st->codec->field_order == AV_FIELD_PROGRESSIVE) {
 -             data = avci100_1080p_extradata;
 -             size = sizeof(avci100_1080p_extradata);
 -         } else {
 -             data = avci100_1080i_extradata;
 -             size = sizeof(avci100_1080i_extradata);
 -         }
 -     } else if (st->codec->width == 1440) {
 -         data = avci50_1080i_extradata;
 -         size = sizeof(avci50_1080i_extradata);
 -     } else if (st->codec->width == 1280) {
 -         data = avci100_720p_extradata;
 -         size = sizeof(avci100_720p_extradata);
 -     }
 - 
 -     if (!size)
 -         return 0;
 - 
 -     av_freep(&st->codec->extradata);
 -     st->codec->extradata_size = 0;
 -     st->codec->extradata      = av_mallocz(size + FF_INPUT_BUFFER_PADDING_SIZE);
 -     if (!st->codec->extradata)
 -         return AVERROR(ENOMEM);
 - 
 -     memcpy(st->codec->extradata, data, size);
 -     st->codec->extradata_size = size;
 - 
 -     return 0;
 - }
 
 
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