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FFmpeg/libavformat/ffmdec.c

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  1. /*

  2.  * FFM (ffserver live feed) demuxer

  3.  * Copyright (c) 2001 Fabrice Bellard

  4.  *

  5.  * This file is part of FFmpeg.

  6.  *

  7.  * FFmpeg is free software; you can redistribute it and/or

  8.  * modify it under the terms of the GNU Lesser General Public

  9.  * License as published by the Free Software Foundation; either

  10.  * version 2.1 of the License, or (at your option) any later version.

  11.  *

  12.  * FFmpeg is distributed in the hope that it will be useful,

  13.  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  14.  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

  15.  * Lesser General Public License for more details.

  16.  *

  17.  * You should have received a copy of the GNU Lesser General Public

  18.  * License along with FFmpeg; if not, write to the Free Software

  19.  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

  20.  */

  21. 

  22. #include <stdint.h>

  23. 

  24. #include "libavutil/internal.h"

  25. #include "libavutil/intreadwrite.h"

  26. #include "libavutil/intfloat.h"

  27. #include "libavutil/opt.h"

  28. #include "libavutil/avassert.h"

  29. #include "libavutil/avstring.h"

  30. #include "libavutil/pixdesc.h"

  31. #include "avformat.h"

  32. #include "internal.h"

  33. #include "ffm.h"

  34. #include "avio_internal.h"

  35. 

  36. static int ffm_is_avail_data(AVFormatContext *s, int size)

  37. {

  38.     FFMContext *ffm = s->priv_data;

  39.     int64_t pos, avail_size;

  40.     int len;

  41. 

  42.     len = ffm->packet_end - ffm->packet_ptr;

  43.     if (size <= len)

  44.         return 1;

  45.     pos = avio_tell(s->pb);

  46.     if (!ffm->write_index) {

  47.         if (pos == ffm->file_size)

  48.             return AVERROR_EOF;

  49.         avail_size = ffm->file_size - pos;

  50.     } else {

  51.     if (pos == ffm->write_index) {

  52.         /* exactly at the end of stream */

  53.         return AVERROR(EAGAIN);

  54.     } else if (pos < ffm->write_index) {

  55.         avail_size = ffm->write_index - pos;

  56.     } else {

  57.         avail_size = (ffm->file_size - pos) + (ffm->write_index - FFM_PACKET_SIZE);

  58.     }

  59.     }

  60.     avail_size = (avail_size / ffm->packet_size) * (ffm->packet_size - FFM_HEADER_SIZE) + len;

  61.     if (size <= avail_size)

  62.         return 1;

  63.     else

  64.         return AVERROR(EAGAIN);

  65. }

  66. 

  67. static int ffm_resync(AVFormatContext *s, int state)

  68. {

  69.     av_log(s, AV_LOG_ERROR, "resyncing\n");

  70.     while (state != PACKET_ID) {

  71.         if (avio_feof(s->pb)) {

  72.             av_log(s, AV_LOG_ERROR, "cannot find FFM syncword\n");

  73.             return -1;

  74.         }

  75.         state = (state << 8) | avio_r8(s->pb);

  76.     }

  77.     return 0;

  78. }

  79. 

  80. /* first is true if we read the frame header */

  81. static int ffm_read_data(AVFormatContext *s,

  82.                          uint8_t *buf, int size, int header)

  83. {

  84.     FFMContext *ffm = s->priv_data;

  85.     AVIOContext *pb = s->pb;

  86.     int len, fill_size, size1, frame_offset, id;

  87.     int64_t last_pos = -1;

  88. 

  89.     size1 = size;

  90.     while (size > 0) {

  91.     redo:

  92.         len = ffm->packet_end - ffm->packet_ptr;

  93.         if (len < 0)

  94.             return -1;

  95.         if (len > size)

  96.             len = size;

  97.         if (len == 0) {

  98.             if (avio_tell(pb) == ffm->file_size)

  99.                 avio_seek(pb, ffm->packet_size, SEEK_SET);

  100.     retry_read:

  101.             if (pb->buffer_size != ffm->packet_size) {

  102.                 int64_t tell = avio_tell(pb);

  103.                 int ret = ffio_set_buf_size(pb, ffm->packet_size);

  104.                 if (ret < 0)

  105.                     return ret;

  106.                 avio_seek(pb, tell, SEEK_SET);

  107.             }

  108.             id = avio_rb16(pb); /* PACKET_ID */

  109.             if (id != PACKET_ID) {

  110.                 if (ffm_resync(s, id) < 0)

  111.                     return -1;

  112.                 last_pos = avio_tell(pb);

  113.             }

  114.             fill_size = avio_rb16(pb);

  115.             ffm->dts = avio_rb64(pb);

  116.             frame_offset = avio_rb16(pb);

  117.             avio_read(pb, ffm->packet, ffm->packet_size - FFM_HEADER_SIZE);

  118.             if (ffm->packet_size < FFM_HEADER_SIZE + fill_size || frame_offset < 0) {

  119.                 return -1;

  120.             }

  121.             ffm->packet_end = ffm->packet + (ffm->packet_size - FFM_HEADER_SIZE - fill_size);

  122.             /* if first packet or resynchronization packet, we must

  123.                handle it specifically */

  124.             if (ffm->first_packet || (frame_offset & 0x8000)) {

  125.                 if (!frame_offset) {

  126.                     /* This packet has no frame headers in it */

  127.                     if (avio_tell(pb) >= ffm->packet_size * 3LL) {

  128.                         int64_t seekback = FFMIN(ffm->packet_size * 2LL, avio_tell(pb) - last_pos);

  129.                         seekback = FFMAX(seekback, 0);

  130.                         avio_seek(pb, -seekback, SEEK_CUR);

  131.                         goto retry_read;

  132.                     }

  133.                     /* This is bad, we cannot find a valid frame header */

  134.                     return 0;

  135.                 }

  136.                 ffm->first_packet = 0;

  137.                 if ((frame_offset & 0x7fff) < FFM_HEADER_SIZE) {

  138.                     ffm->packet_end = ffm->packet_ptr;

  139.                     return -1;

  140.                 }

  141.                 ffm->packet_ptr = ffm->packet + (frame_offset & 0x7fff) - FFM_HEADER_SIZE;

  142.                 if (!header)

  143.                     break;

  144.             } else {

  145.                 ffm->packet_ptr = ffm->packet;

  146.             }

  147.             goto redo;

  148.         }

  149.         memcpy(buf, ffm->packet_ptr, len);

  150.         buf += len;

  151.         ffm->packet_ptr += len;

  152.         size -= len;

  153.         header = 0;

  154.     }

  155.     return size1 - size;

  156. }

  157. 

  158. /* ensure that actual seeking happens between FFM_PACKET_SIZE

  159.    and file_size - FFM_PACKET_SIZE */

  160. static int64_t ffm_seek1(AVFormatContext *s, int64_t pos1)

  161. {

  162.     FFMContext *ffm = s->priv_data;

  163.     AVIOContext *pb = s->pb;

  164.     int64_t pos;

  165. 

  166.     pos = FFMIN(pos1, ffm->file_size - FFM_PACKET_SIZE);

  167.     pos = FFMAX(pos, FFM_PACKET_SIZE);

  168.     ff_dlog(s, "seek to %"PRIx64" -> %"PRIx64"\n", pos1, pos);

  169.     return avio_seek(pb, pos, SEEK_SET);

  170. }

  171. 

  172. static int64_t get_dts(AVFormatContext *s, int64_t pos)

  173. {

  174.     AVIOContext *pb = s->pb;

  175.     int64_t dts;

  176. 

  177.     ffm_seek1(s, pos);

  178.     avio_skip(pb, 4);

  179.     dts = avio_rb64(pb);

  180.     ff_dlog(s, "dts=%0.6f\n", dts / 1000000.0);

  181.     return dts;

  182. }

  183. 

  184. static void adjust_write_index(AVFormatContext *s)

  185. {

  186.     FFMContext *ffm = s->priv_data;

  187.     AVIOContext *pb = s->pb;

  188.     int64_t pts;

  189.     //int64_t orig_write_index = ffm->write_index;

  190.     int64_t pos_min, pos_max;

  191.     int64_t pts_start;

  192.     int64_t ptr = avio_tell(pb);

  193. 

  194. 

  195.     pos_min = 0;

  196.     pos_max = ffm->file_size - 2 * FFM_PACKET_SIZE;

  197. 

  198.     pts_start = get_dts(s, pos_min);

  199. 

  200.     pts = get_dts(s, pos_max);

  201. 

  202.     if (pts - 100000 > pts_start)

  203.         goto end;

  204. 

  205.     ffm->write_index = FFM_PACKET_SIZE;

  206. 

  207.     pts_start = get_dts(s, pos_min);

  208. 

  209.     pts = get_dts(s, pos_max);

  210. 

  211.     if (pts - 100000 <= pts_start) {

  212.         while (1) {

  213.             int64_t newpos;

  214.             int64_t newpts;

  215. 

  216.             newpos = ((pos_max + pos_min) / (2 * FFM_PACKET_SIZE)) * FFM_PACKET_SIZE;

  217. 

  218.             if (newpos == pos_min)

  219.                 break;

  220. 

  221.             newpts = get_dts(s, newpos);

  222. 

  223.             if (newpts - 100000 <= pts) {

  224.                 pos_max = newpos;

  225.                 pts = newpts;

  226.             } else {

  227.                 pos_min = newpos;

  228.             }

  229.         }

  230.         ffm->write_index += pos_max;

  231.     }

  232. 

  233.  end:

  234.     avio_seek(pb, ptr, SEEK_SET);

  235. }

  236. 

  237. 

  238. static int ffm_close(AVFormatContext *s)

  239. {

  240.     int i;

  241. 

  242.     for (i = 0; i < s->nb_streams; i++)

  243.         av_freep(&s->streams[i]->codec->rc_eq);

  244. 

  245.     return 0;

  246. }

  247. 

  248. static int ffm_append_recommended_configuration(AVStream *st, char **conf)

  249. {

  250.     int ret;

  251.     size_t newsize;

  252.     av_assert0(conf && st);

  253.     if (!*conf)

  254.         return 0;

  255.     if (!st->recommended_encoder_configuration) {

  256.         st->recommended_encoder_configuration = *conf;

  257.         *conf = 0;

  258.         return 0;

  259.     }

  260.     newsize = strlen(*conf) + strlen(st->recommended_encoder_configuration) + 2;

  261.     if ((ret = av_reallocp(&st->recommended_encoder_configuration, newsize)) < 0)

  262.         return ret;

  263.     av_strlcat(st->recommended_encoder_configuration, ",", newsize);

  264.     av_strlcat(st->recommended_encoder_configuration, *conf, newsize);

  265.     av_freep(conf);

  266.     return 0;

  267. }

  268. 

  269. static int ffm2_read_header(AVFormatContext *s)

  270. {

  271.     FFMContext *ffm = s->priv_data;

  272.     AVStream *st;

  273.     AVIOContext *pb = s->pb;

  274.     AVCodecContext *codec;

  275.     const AVCodecDescriptor *codec_desc;

  276.     int ret;

  277.     int f_main = 0, f_cprv = -1, f_stvi = -1, f_stau = -1;

  278.     AVCodec *enc;

  279.     char *buffer;

  280. 

  281.     ffm->packet_size = avio_rb32(pb);

  282.     if (ffm->packet_size != FFM_PACKET_SIZE) {

  283.         av_log(s, AV_LOG_ERROR, "Invalid packet size %d, expected size was %d\n",

  284.                ffm->packet_size, FFM_PACKET_SIZE);

  285.         ret = AVERROR_INVALIDDATA;

  286.         goto fail;

  287.     }

  288. 

  289.     ffm->write_index = avio_rb64(pb);

  290.     /* get also filesize */

  291.     if (pb->seekable) {

  292.         ffm->file_size = avio_size(pb);

  293.         if (ffm->write_index && 0)

  294.             adjust_write_index(s);

  295.     } else {

  296.         ffm->file_size = (UINT64_C(1) << 63) - 1;

  297.     }

  298. 

  299.     while(!avio_feof(pb)) {

  300.         unsigned id = avio_rb32(pb);

  301.         unsigned size = avio_rb32(pb);

  302.         int64_t next = avio_tell(pb) + size;

  303.         char rc_eq_buf[128];

  304. 

  305.         if(!id)

  306.             break;

  307. 

  308.         switch(id) {

  309.         case MKBETAG('M', 'A', 'I', 'N'):

  310.             if (f_main++) {

  311.                 ret = AVERROR(EINVAL);

  312.                 goto fail;

  313.             }

  314.             avio_rb32(pb); /* nb_streams */

  315.             avio_rb32(pb); /* total bitrate */

  316.             break;

  317.         case MKBETAG('C', 'O', 'M', 'M'):

  318.             f_cprv = f_stvi = f_stau = 0;

  319.             st = avformat_new_stream(s, NULL);

  320.             if (!st) {

  321.                 ret = AVERROR(ENOMEM);

  322.                 goto fail;

  323.             }

  324. 

  325.             avpriv_set_pts_info(st, 64, 1, 1000000);

  326. 

  327.             codec = st->codec;

  328.             /* generic info */

  329.             codec->codec_id = avio_rb32(pb);

  330.             codec_desc = avcodec_descriptor_get(codec->codec_id);

  331.             if (!codec_desc) {

  332.                 av_log(s, AV_LOG_ERROR, "Invalid codec id: %d\n", codec->codec_id);

  333.                 codec->codec_id = AV_CODEC_ID_NONE;

  334.                 goto fail;

  335.             }

  336.             codec->codec_type = avio_r8(pb);

  337.             if (codec->codec_type != codec_desc->type) {

  338.                 av_log(s, AV_LOG_ERROR, "Codec type mismatch: expected %d, found %d\n",

  339.                        codec_desc->type, codec->codec_type);

  340.                 codec->codec_id = AV_CODEC_ID_NONE;

  341.                 codec->codec_type = AVMEDIA_TYPE_UNKNOWN;

  342.                 goto fail;

  343.             }

  344.             codec->bit_rate = avio_rb32(pb);

  345.             codec->flags = avio_rb32(pb);

  346.             codec->flags2 = avio_rb32(pb);

  347.             codec->debug = avio_rb32(pb);

  348.             if (codec->flags & AV_CODEC_FLAG_GLOBAL_HEADER) {

  349.                 if (ff_get_extradata(codec, pb, avio_rb32(pb)) < 0)

  350.                     return AVERROR(ENOMEM);

  351.             }

  352.             break;

  353.         case MKBETAG('S', 'T', 'V', 'I'):

  354.             if (f_stvi++ || codec->codec_type != AVMEDIA_TYPE_VIDEO) {

  355.                 ret = AVERROR(EINVAL);

  356.                 goto fail;

  357.             }

  358.             codec->time_base.num = avio_rb32(pb);

  359.             codec->time_base.den = avio_rb32(pb);

  360.             if (codec->time_base.num <= 0 || codec->time_base.den <= 0) {

  361.                 av_log(s, AV_LOG_ERROR, "Invalid time base %d/%d\n",

  362.                        codec->time_base.num, codec->time_base.den);

  363.                 ret = AVERROR_INVALIDDATA;

  364.                 goto fail;

  365.             }

  366.             codec->width = avio_rb16(pb);

  367.             codec->height = avio_rb16(pb);

  368.             codec->gop_size = avio_rb16(pb);

  369.             codec->pix_fmt = avio_rb32(pb);

  370.             if (!av_pix_fmt_desc_get(codec->pix_fmt)) {

  371.                 av_log(s, AV_LOG_ERROR, "Invalid pix fmt id: %d\n", codec->pix_fmt);

  372.                 codec->pix_fmt = AV_PIX_FMT_NONE;

  373.                 goto fail;

  374.             }

  375.             codec->qmin = avio_r8(pb);

  376.             codec->qmax = avio_r8(pb);

  377.             codec->max_qdiff = avio_r8(pb);

  378.             codec->qcompress = avio_rb16(pb) / 10000.0;

  379.             codec->qblur = avio_rb16(pb) / 10000.0;

  380.             codec->bit_rate_tolerance = avio_rb32(pb);

  381.             avio_get_str(pb, INT_MAX, rc_eq_buf, sizeof(rc_eq_buf));

  382.             codec->rc_eq = av_strdup(rc_eq_buf);

  383.             codec->rc_max_rate = avio_rb32(pb);

  384.             codec->rc_min_rate = avio_rb32(pb);

  385.             codec->rc_buffer_size = avio_rb32(pb);

  386.             codec->i_quant_factor = av_int2double(avio_rb64(pb));

  387.             codec->b_quant_factor = av_int2double(avio_rb64(pb));

  388.             codec->i_quant_offset = av_int2double(avio_rb64(pb));

  389.             codec->b_quant_offset = av_int2double(avio_rb64(pb));

  390.             codec->dct_algo = avio_rb32(pb);

  391.             codec->strict_std_compliance = avio_rb32(pb);

  392.             codec->max_b_frames = avio_rb32(pb);

  393.             codec->mpeg_quant = avio_rb32(pb);

  394.             codec->intra_dc_precision = avio_rb32(pb);

  395.             codec->me_method = avio_rb32(pb);

  396.             codec->mb_decision = avio_rb32(pb);

  397.             codec->nsse_weight = avio_rb32(pb);

  398.             codec->frame_skip_cmp = avio_rb32(pb);

  399.             codec->rc_buffer_aggressivity = av_int2double(avio_rb64(pb));

  400.             codec->codec_tag = avio_rb32(pb);

  401.             codec->thread_count = avio_r8(pb);

  402.             codec->coder_type = avio_rb32(pb);

  403.             codec->me_cmp = avio_rb32(pb);

  404.             codec->me_subpel_quality = avio_rb32(pb);

  405.             codec->me_range = avio_rb32(pb);

  406.             codec->keyint_min = avio_rb32(pb);

  407.             codec->scenechange_threshold = avio_rb32(pb);

  408.             codec->b_frame_strategy = avio_rb32(pb);

  409.             codec->qcompress = av_int2double(avio_rb64(pb));

  410.             codec->qblur = av_int2double(avio_rb64(pb));

  411.             codec->max_qdiff = avio_rb32(pb);

  412.             codec->refs = avio_rb32(pb);

  413.             break;

  414.         case MKBETAG('S', 'T', 'A', 'U'):

  415.             if (f_stau++ || codec->codec_type != AVMEDIA_TYPE_AUDIO) {

  416.                 ret = AVERROR(EINVAL);

  417.                 goto fail;

  418.             }

  419.             codec->sample_rate = avio_rb32(pb);

  420.             codec->channels = avio_rl16(pb);

  421.             codec->frame_size = avio_rl16(pb);

  422.             break;

  423.         case MKBETAG('C', 'P', 'R', 'V'):

  424.             if (f_cprv++) {

  425.                 ret = AVERROR(EINVAL);

  426.                 goto fail;

  427.             }

  428.             enc = avcodec_find_encoder(codec->codec_id);

  429.             if (enc && enc->priv_data_size && enc->priv_class) {

  430.                 buffer = av_malloc(size + 1);

  431.                 if (!buffer) {

  432.                     ret = AVERROR(ENOMEM);

  433.                     goto fail;

  434.                 }

  435.                 avio_get_str(pb, size, buffer, size + 1);

  436.                 if ((ret = ffm_append_recommended_configuration(st, &buffer)) < 0)

  437.                     goto fail;

  438.             }

  439.             break;

  440.         case MKBETAG('S', '2', 'V', 'I'):

  441.             if (f_stvi++ || !size || codec->codec_type != AVMEDIA_TYPE_VIDEO) {

  442.                 ret = AVERROR(EINVAL);

  443.                 goto fail;

  444.             }

  445.             buffer = av_malloc(size);

  446.             if (!buffer) {

  447.                 ret = AVERROR(ENOMEM);

  448.                 goto fail;

  449.             }

  450.             avio_get_str(pb, INT_MAX, buffer, size);

  451.             av_set_options_string(codec, buffer, "=", ",");

  452.             if ((ret = ffm_append_recommended_configuration(st, &buffer)) < 0)

  453.                 goto fail;

  454.             break;

  455.         case MKBETAG('S', '2', 'A', 'U'):

  456.             if (f_stau++ || !size || codec->codec_type != AVMEDIA_TYPE_AUDIO) {

  457.                 ret = AVERROR(EINVAL);

  458.                 goto fail;

  459.             }

  460.             buffer = av_malloc(size);

  461.             if (!buffer) {

  462.                 ret = AVERROR(ENOMEM);

  463.                 goto fail;

  464.             }

  465.             avio_get_str(pb, INT_MAX, buffer, size);

  466.             av_set_options_string(codec, buffer, "=", ",");

  467.             if ((ret = ffm_append_recommended_configuration(st, &buffer)) < 0)

  468.                 goto fail;

  469.             break;

  470.         }

  471.         avio_seek(pb, next, SEEK_SET);

  472.     }

  473. 

  474.     /* get until end of block reached */

  475.     while ((avio_tell(pb) % ffm->packet_size) != 0 && !pb->eof_reached)

  476.         avio_r8(pb);

  477. 

  478.     /* init packet demux */

  479.     ffm->packet_ptr = ffm->packet;

  480.     ffm->packet_end = ffm->packet;

  481.     ffm->frame_offset = 0;

  482.     ffm->dts = 0;

  483.     ffm->read_state = READ_HEADER;

  484.     ffm->first_packet = 1;

  485.     return 0;

  486.  fail:

  487.     ffm_close(s);

  488.     return ret;

  489. }

  490. 

  491. static int ffm_read_header(AVFormatContext *s)

  492. {

  493.     FFMContext *ffm = s->priv_data;

  494.     AVStream *st;

  495.     AVIOContext *pb = s->pb;

  496.     AVCodecContext *codec;

  497.     const AVCodecDescriptor *codec_desc;

  498.     int i, nb_streams;

  499.     uint32_t tag;

  500. 

  501.     /* header */

  502.     tag = avio_rl32(pb);

  503.     if (tag == MKTAG('F', 'F', 'M', '2'))

  504.         return ffm2_read_header(s);

  505.     if (tag != MKTAG('F', 'F', 'M', '1'))

  506.         goto fail;

  507.     ffm->packet_size = avio_rb32(pb);

  508.     if (ffm->packet_size != FFM_PACKET_SIZE)

  509.         goto fail;

  510.     ffm->write_index = avio_rb64(pb);

  511.     /* get also filesize */

  512.     if (pb->seekable) {

  513.         ffm->file_size = avio_size(pb);

  514.         if (ffm->write_index && 0)

  515.             adjust_write_index(s);

  516.     } else {

  517.         ffm->file_size = (UINT64_C(1) << 63) - 1;

  518.     }

  519. 

  520.     nb_streams = avio_rb32(pb);

  521.     avio_rb32(pb); /* total bitrate */

  522.     /* read each stream */

  523.     for(i=0;i<nb_streams;i++) {

  524.         char rc_eq_buf[128];

  525. 

  526.         st = avformat_new_stream(s, NULL);

  527.         if (!st)

  528.             goto fail;

  529. 

  530.         avpriv_set_pts_info(st, 64, 1, 1000000);

  531. 

  532.         codec = st->codec;

  533.         /* generic info */

  534.         codec->codec_id = avio_rb32(pb);

  535.         codec_desc = avcodec_descriptor_get(codec->codec_id);

  536.         if (!codec_desc) {

  537.             av_log(s, AV_LOG_ERROR, "Invalid codec id: %d\n", codec->codec_id);

  538.             codec->codec_id = AV_CODEC_ID_NONE;

  539.             goto fail;

  540.         }

  541.         codec->codec_type = avio_r8(pb); /* codec_type */

  542.         if (codec->codec_type != codec_desc->type) {

  543.             av_log(s, AV_LOG_ERROR, "Codec type mismatch: expected %d, found %d\n",

  544.                    codec_desc->type, codec->codec_type);

  545.             codec->codec_id = AV_CODEC_ID_NONE;

  546.             codec->codec_type = AVMEDIA_TYPE_UNKNOWN;

  547.             goto fail;

  548.         }

  549.         codec->bit_rate = avio_rb32(pb);

  550.         codec->flags = avio_rb32(pb);

  551.         codec->flags2 = avio_rb32(pb);

  552.         codec->debug = avio_rb32(pb);

  553.         /* specific info */

  554.         switch(codec->codec_type) {

  555.         case AVMEDIA_TYPE_VIDEO:

  556.             codec->time_base.num = avio_rb32(pb);

  557.             codec->time_base.den = avio_rb32(pb);

  558.             if (codec->time_base.num <= 0 || codec->time_base.den <= 0) {

  559.                 av_log(s, AV_LOG_ERROR, "Invalid time base %d/%d\n",

  560.                        codec->time_base.num, codec->time_base.den);

  561.                 goto fail;

  562.             }

  563.             codec->width = avio_rb16(pb);

  564.             codec->height = avio_rb16(pb);

  565.             codec->gop_size = avio_rb16(pb);

  566.             codec->pix_fmt = avio_rb32(pb);

  567.             if (!av_pix_fmt_desc_get(codec->pix_fmt)) {

  568.                 av_log(s, AV_LOG_ERROR, "Invalid pix fmt id: %d\n", codec->pix_fmt);

  569.                 codec->pix_fmt = AV_PIX_FMT_NONE;

  570.                 goto fail;

  571.             }

  572.             codec->qmin = avio_r8(pb);

  573.             codec->qmax = avio_r8(pb);

  574.             codec->max_qdiff = avio_r8(pb);

  575.             codec->qcompress = avio_rb16(pb) / 10000.0;

  576.             codec->qblur = avio_rb16(pb) / 10000.0;

  577.             codec->bit_rate_tolerance = avio_rb32(pb);

  578.             avio_get_str(pb, INT_MAX, rc_eq_buf, sizeof(rc_eq_buf));

  579.             codec->rc_eq = av_strdup(rc_eq_buf);

  580.             codec->rc_max_rate = avio_rb32(pb);

  581.             codec->rc_min_rate = avio_rb32(pb);

  582.             codec->rc_buffer_size = avio_rb32(pb);

  583.             codec->i_quant_factor = av_int2double(avio_rb64(pb));

  584.             codec->b_quant_factor = av_int2double(avio_rb64(pb));

  585.             codec->i_quant_offset = av_int2double(avio_rb64(pb));

  586.             codec->b_quant_offset = av_int2double(avio_rb64(pb));

  587.             codec->dct_algo = avio_rb32(pb);

  588.             codec->strict_std_compliance = avio_rb32(pb);

  589.             codec->max_b_frames = avio_rb32(pb);

  590.             codec->mpeg_quant = avio_rb32(pb);

  591.             codec->intra_dc_precision = avio_rb32(pb);

  592.             codec->me_method = avio_rb32(pb);

  593.             codec->mb_decision = avio_rb32(pb);

  594.             codec->nsse_weight = avio_rb32(pb);

  595.             codec->frame_skip_cmp = avio_rb32(pb);

  596.             codec->rc_buffer_aggressivity = av_int2double(avio_rb64(pb));

  597.             codec->codec_tag = avio_rb32(pb);

  598.             codec->thread_count = avio_r8(pb);

  599.             codec->coder_type = avio_rb32(pb);

  600.             codec->me_cmp = avio_rb32(pb);

  601.             codec->me_subpel_quality = avio_rb32(pb);

  602.             codec->me_range = avio_rb32(pb);

  603.             codec->keyint_min = avio_rb32(pb);

  604.             codec->scenechange_threshold = avio_rb32(pb);

  605.             codec->b_frame_strategy = avio_rb32(pb);

  606.             codec->qcompress = av_int2double(avio_rb64(pb));

  607.             codec->qblur = av_int2double(avio_rb64(pb));

  608.             codec->max_qdiff = avio_rb32(pb);

  609.             codec->refs = avio_rb32(pb);

  610.             break;

  611.         case AVMEDIA_TYPE_AUDIO:

  612.             codec->sample_rate = avio_rb32(pb);

  613.             codec->channels = avio_rl16(pb);

  614.             codec->frame_size = avio_rl16(pb);

  615.             break;

  616.         default:

  617.             goto fail;

  618.         }

  619.         if (codec->flags & AV_CODEC_FLAG_GLOBAL_HEADER) {

  620.             if (ff_get_extradata(codec, pb, avio_rb32(pb)) < 0)

  621.                 return AVERROR(ENOMEM);

  622.         }

  623.     }

  624. 

  625.     /* get until end of block reached */

  626.     while ((avio_tell(pb) % ffm->packet_size) != 0 && !pb->eof_reached)

  627.         avio_r8(pb);

  628. 

  629.     /* init packet demux */

  630.     ffm->packet_ptr = ffm->packet;

  631.     ffm->packet_end = ffm->packet;

  632.     ffm->frame_offset = 0;

  633.     ffm->dts = 0;

  634.     ffm->read_state = READ_HEADER;

  635.     ffm->first_packet = 1;

  636.     return 0;

  637.  fail:

  638.     ffm_close(s);

  639.     return -1;

  640. }

  641. 

  642. /* return < 0 if eof */

  643. static int ffm_read_packet(AVFormatContext *s, AVPacket *pkt)

  644. {

  645.     int size;

  646.     FFMContext *ffm = s->priv_data;

  647.     int duration, ret;

  648. 

  649.     switch(ffm->read_state) {

  650.     case READ_HEADER:

  651.         if ((ret = ffm_is_avail_data(s, FRAME_HEADER_SIZE+4)) < 0)

  652.             return ret;

  653. 

  654.         ff_dlog(s, "pos=%08"PRIx64" spos=%"PRIx64", write_index=%"PRIx64" size=%"PRIx64"\n",

  655.                avio_tell(s->pb), s->pb->pos, ffm->write_index, ffm->file_size);

  656.         if (ffm_read_data(s, ffm->header, FRAME_HEADER_SIZE, 1) !=

  657.             FRAME_HEADER_SIZE)

  658.             return -1;

  659.         if (ffm->header[1] & FLAG_DTS)

  660.             if (ffm_read_data(s, ffm->header+16, 4, 1) != 4)

  661.                 return -1;

  662.         ffm->read_state = READ_DATA;

  663.         /* fall through */

  664.     case READ_DATA:

  665.         size = AV_RB24(ffm->header + 2);

  666.         if ((ret = ffm_is_avail_data(s, size)) < 0)

  667.             return ret;

  668. 

  669.         duration = AV_RB24(ffm->header + 5);

  670. 

  671.         if (av_new_packet(pkt, size) < 0) {

  672.             return AVERROR(ENOMEM);

  673.         }

  674.         pkt->stream_index = ffm->header[0];

  675.         if ((unsigned)pkt->stream_index >= s->nb_streams) {

  676.             av_log(s, AV_LOG_ERROR, "invalid stream index %d\n", pkt->stream_index);

  677.             av_free_packet(pkt);

  678.             ffm->read_state = READ_HEADER;

  679.             return -1;

  680.         }

  681.         pkt->pos = avio_tell(s->pb);

  682.         if (ffm->header[1] & FLAG_KEY_FRAME)

  683.             pkt->flags |= AV_PKT_FLAG_KEY;

  684. 

  685.         ffm->read_state = READ_HEADER;

  686.         if (ffm_read_data(s, pkt->data, size, 0) != size) {

  687.             /* bad case: desynchronized packet. we cancel all the packet loading */

  688.             av_free_packet(pkt);

  689.             return -1;

  690.         }

  691.         pkt->pts = AV_RB64(ffm->header+8);

  692.         if (ffm->header[1] & FLAG_DTS)

  693.             pkt->dts = pkt->pts - AV_RB32(ffm->header+16);

  694.         else

  695.             pkt->dts = pkt->pts;

  696.         pkt->duration = duration;

  697.         break;

  698.     }

  699.     return 0;

  700. }

  701. 

  702. /* seek to a given time in the file. The file read pointer is

  703.    positioned at or before pts. XXX: the following code is quite

  704.    approximative */

  705. static int ffm_seek(AVFormatContext *s, int stream_index, int64_t wanted_pts, int flags)

  706. {

  707.     FFMContext *ffm = s->priv_data;

  708.     int64_t pos_min, pos_max, pos;

  709.     int64_t pts_min, pts_max, pts;

  710.     double pos1;

  711. 

  712.     ff_dlog(s, "wanted_pts=%0.6f\n", wanted_pts / 1000000.0);

  713.     /* find the position using linear interpolation (better than

  714.        dichotomy in typical cases) */

  715.     if (ffm->write_index && ffm->write_index < ffm->file_size) {

  716.         if (get_dts(s, FFM_PACKET_SIZE) < wanted_pts) {

  717.             pos_min = FFM_PACKET_SIZE;

  718.             pos_max = ffm->write_index - FFM_PACKET_SIZE;

  719.         } else {

  720.             pos_min = ffm->write_index;

  721.             pos_max = ffm->file_size - FFM_PACKET_SIZE;

  722.         }

  723.     } else {

  724.         pos_min = FFM_PACKET_SIZE;

  725.         pos_max = ffm->file_size - FFM_PACKET_SIZE;

  726.     }

  727.     while (pos_min <= pos_max) {

  728.         pts_min = get_dts(s, pos_min);

  729.         pts_max = get_dts(s, pos_max);

  730.         if (pts_min > wanted_pts || pts_max <= wanted_pts) {

  731.             pos = pts_min > wanted_pts ? pos_min : pos_max;

  732.             goto found;

  733.         }

  734.         /* linear interpolation */

  735.         pos1 = (double)(pos_max - pos_min) * (double)(wanted_pts - pts_min) /

  736.             (double)(pts_max - pts_min);

  737.         pos = (((int64_t)pos1) / FFM_PACKET_SIZE) * FFM_PACKET_SIZE;

  738.         if (pos <= pos_min)

  739.             pos = pos_min;

  740.         else if (pos >= pos_max)

  741.             pos = pos_max;

  742.         pts = get_dts(s, pos);

  743.         /* check if we are lucky */

  744.         if (pts == wanted_pts) {

  745.             goto found;

  746.         } else if (pts > wanted_pts) {

  747.             pos_max = pos - FFM_PACKET_SIZE;

  748.         } else {

  749.             pos_min = pos + FFM_PACKET_SIZE;

  750.         }

  751.     }

  752.     pos = (flags & AVSEEK_FLAG_BACKWARD) ? pos_min : pos_max;

  753. 

  754.  found:

  755.     if (ffm_seek1(s, pos) < 0)

  756.         return -1;

  757. 

  758.     /* reset read state */

  759.     ffm->read_state = READ_HEADER;

  760.     ffm->packet_ptr = ffm->packet;

  761.     ffm->packet_end = ffm->packet;

  762.     ffm->first_packet = 1;

  763. 

  764.     return 0;

  765. }

  766. 

  767. static int ffm_probe(AVProbeData *p)

  768. {

  769.     if (

  770.         p->buf[0] == 'F' && p->buf[1] == 'F' && p->buf[2] == 'M' &&

  771.         (p->buf[3] == '1' || p->buf[3] == '2'))

  772.         return AVPROBE_SCORE_MAX + 1;

  773.     return 0;

  774. }

  775. 

  776. AVInputFormat ff_ffm_demuxer = {

  777.     .name           = "ffm",

  778.     .long_name      = NULL_IF_CONFIG_SMALL("FFM (FFserver live feed)"),

  779.     .priv_data_size = sizeof(FFMContext),

  780.     .read_probe     = ffm_probe,

  781.     .read_header    = ffm_read_header,

  782.     .read_packet    = ffm_read_packet,

  783.     .read_close     = ffm_close,

  784.     .read_seek      = ffm_seek,

  785. };