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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 "avformat.h"

  31. #include "internal.h"

  32. #include "ffm.h"

  33. #include "avio_internal.h"

  34. 

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

  36. {

  37.     FFMContext *ffm = s->priv_data;

  38.     int64_t pos, avail_size;

  39.     ptrdiff_t len;

  40. 

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

  42.     if (size <= len)

  43.         return 1;

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

  45.     if (!ffm->write_index) {

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

  47.             return AVERROR_EOF;

  48.         avail_size = ffm->file_size - pos;

  49.     } else {

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

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

  52.         if (ffm->server_attached)

  53.             return AVERROR(EAGAIN);

  54.         else

  55.             return AVERROR_INVALIDDATA;

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

  57.         avail_size = ffm->write_index - pos;

  58.     } else {

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

  60.     }

  61.     }

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

  63.     if (size <= avail_size)

  64.         return 1;

  65.     else if (ffm->server_attached)

  66.         return AVERROR(EAGAIN);

  67.     else

  68.         return AVERROR_INVALIDDATA;

  69. }

  70. 

  71. static int ffm_resync(AVFormatContext *s, uint32_t state)

  72. {

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

  74.     while (state != PACKET_ID) {

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

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

  77.             return -1;

  78.         }

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

  80.     }

  81.     return 0;

  82. }

  83. 

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

  85. static int ffm_read_data(AVFormatContext *s,

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

  87. {

  88.     FFMContext *ffm = s->priv_data;

  89.     AVIOContext *pb = s->pb;

  90.     int fill_size, size1, frame_offset;

  91.     uint32_t id;

  92.     ptrdiff_t len;

  93.     int64_t last_pos = -1;

  94. 

  95.     size1 = size;

  96.     while (size > 0) {

  97.     redo:

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

  99.         if (len < 0)

  100.             return -1;

  101.         if (len > size)

  102.             len = size;

  103.         if (len == 0) {

  104.             if (avio_tell(pb) == ffm->file_size) {

  105.                 if (ffm->server_attached) {

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

  107.                 } else

  108.                     return AVERROR_EOF;

  109.             }

  110.     retry_read:

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

  112.                 int64_t tell = avio_tell(pb);

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

  114.                 if (ret < 0)

  115.                     return ret;

  116.                 avio_seek(pb, tell, SEEK_SET);

  117.             }

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

  119.             if (id != PACKET_ID) {

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

  121.                     return -1;

  122.                 last_pos = avio_tell(pb);

  123.             }

  124.             fill_size = avio_rb16(pb);

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

  126.             frame_offset = avio_rb16(pb);

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

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

  129.                 return -1;

  130.             }

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

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

  133.                handle it specifically */

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

  135.                 if (!frame_offset) {

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

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

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

  139.                         seekback = FFMAX(seekback, 0);

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

  141.                         goto retry_read;

  142.                     }

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

  144.                     return 0;

  145.                 }

  146.                 ffm->first_packet = 0;

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

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

  149.                     return -1;

  150.                 }

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

  152.                 if (!header)

  153.                     break;

  154.             } else {

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

  156.             }

  157.             goto redo;

  158.         }

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

  160.         buf += len;

  161.         ffm->packet_ptr += len;

  162.         size -= len;

  163.         header = 0;

  164.     }

  165.     return size1 - size;

  166. }

  167. 

  168. /* ensure that actual seeking happens between FFM_PACKET_SIZE

  169.    and file_size - FFM_PACKET_SIZE */

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

  171. {

  172.     FFMContext *ffm = s->priv_data;

  173.     AVIOContext *pb = s->pb;

  174.     int64_t pos;

  175. 

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

  177.     pos = FFMAX(pos, FFM_PACKET_SIZE);

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

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

  180. }

  181. 

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

  183. {

  184.     AVIOContext *pb = s->pb;

  185.     int64_t dts;

  186. 

  187.     ffm_seek1(s, pos);

  188.     avio_skip(pb, 4);

  189.     dts = avio_rb64(pb);

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

  191.     return dts;

  192. }

  193. 

  194. static void adjust_write_index(AVFormatContext *s)

  195. {

  196.     FFMContext *ffm = s->priv_data;

  197.     AVIOContext *pb = s->pb;

  198.     int64_t pts;

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

  200.     int64_t pos_min, pos_max;

  201.     int64_t pts_start;

  202.     int64_t ptr = avio_tell(pb);

  203. 

  204. 

  205.     pos_min = 0;

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

  207. 

  208.     pts_start = get_dts(s, pos_min);

  209. 

  210.     pts = get_dts(s, pos_max);

  211. 

  212.     if (pts - 100000 > pts_start)

  213.         goto end;

  214. 

  215.     ffm->write_index = FFM_PACKET_SIZE;

  216. 

  217.     pts_start = get_dts(s, pos_min);

  218. 

  219.     pts = get_dts(s, pos_max);

  220. 

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

  222.         while (1) {

  223.             int64_t newpos;

  224.             int64_t newpts;

  225. 

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

  227. 

  228.             if (newpos == pos_min)

  229.                 break;

  230. 

  231.             newpts = get_dts(s, newpos);

  232. 

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

  234.                 pos_max = newpos;

  235.                 pts = newpts;

  236.             } else {

  237.                 pos_min = newpos;

  238.             }

  239.         }

  240.         ffm->write_index += pos_max;

  241.     }

  242. 

  243.  end:

  244.     avio_seek(pb, ptr, SEEK_SET);

  245. }

  246. 

  247. 

  248. static int ffm_close(AVFormatContext *s)

  249. {

  250.     int i;

  251. 

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

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

  254. 

  255.     return 0;

  256. }

  257. 

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

  259. {

  260.     int ret;

  261.     size_t newsize;

  262.     av_assert0(conf && st);

  263.     if (!*conf)

  264.         return 0;

  265.     if (!st->recommended_encoder_configuration) {

  266.         st->recommended_encoder_configuration = *conf;

  267.         *conf = 0;

  268.         return 0;

  269.     }

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

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

  272.         return ret;

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

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

  275.     av_freep(conf);

  276.     return 0;

  277. }

  278. 

  279. static int ffm2_read_header(AVFormatContext *s)

  280. {

  281.     FFMContext *ffm = s->priv_data;

  282.     AVStream *st;

  283.     AVIOContext *pb = s->pb;

  284.     AVCodecContext *codec;

  285.     const AVCodecDescriptor *codec_desc;

  286.     int ret;

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

  288.     AVCodec *enc;

  289.     char *buffer;

  290. 

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

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

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

  294.                ffm->packet_size, FFM_PACKET_SIZE);

  295.         ret = AVERROR_INVALIDDATA;

  296.         goto fail;

  297.     }

  298. 

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

  300.     /* get also filesize */

  301.     if (pb->seekable) {

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

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

  304.             adjust_write_index(s);

  305.     } else {

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

  307.     }

  308. 

  309.     while(!avio_feof(pb)) {

  310.         unsigned id = avio_rb32(pb);

  311.         unsigned size = avio_rb32(pb);

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

  313.         char rc_eq_buf[128];

  314. 

  315.         if(!id)

  316.             break;

  317. 

  318.         switch(id) {

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

  320.             if (f_main++) {

  321.                 ret = AVERROR(EINVAL);

  322.                 goto fail;

  323.             }

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

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

  326.             break;

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

  328.             f_cprv = f_stvi = f_stau = 0;

  329.             st = avformat_new_stream(s, NULL);

  330.             if (!st) {

  331.                 ret = AVERROR(ENOMEM);

  332.                 goto fail;

  333.             }

  334. 

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

  336. 

  337.             codec = st->codec;

  338.             /* generic info */

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

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

  341.             if (!codec_desc) {

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

  343.                 codec->codec_id = AV_CODEC_ID_NONE;

  344.                 goto fail;

  345.             }

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

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

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

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

  350.                 codec->codec_id = AV_CODEC_ID_NONE;

  351.                 codec->codec_type = AVMEDIA_TYPE_UNKNOWN;

  352.                 goto fail;

  353.             }

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

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

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

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

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

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

  360.                     return AVERROR(ENOMEM);

  361.             }

  362.             break;

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

  364.             if (f_stvi++) {

  365.                 ret = AVERROR(EINVAL);

  366.                 goto fail;

  367.             }

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

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

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

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

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

  373.                 ret = AVERROR_INVALIDDATA;

  374.                 goto fail;

  375.             }

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

  418.             break;

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

  420.             if (f_stau++) {

  421.                 ret = AVERROR(EINVAL);

  422.                 goto fail;

  423.             }

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

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

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

  427.             break;

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

  429.             if (f_cprv++) {

  430.                 ret = AVERROR(EINVAL);

  431.                 goto fail;

  432.             }

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

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

  435.                 buffer = av_malloc(size + 1);

  436.                 if (!buffer) {

  437.                     ret = AVERROR(ENOMEM);

  438.                     goto fail;

  439.                 }

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

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

  442.                     goto fail;

  443.             }

  444.             break;

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

  446.             if (f_stvi++ || !size) {

  447.                 ret = AVERROR(EINVAL);

  448.                 goto fail;

  449.             }

  450.             buffer = av_malloc(size);

  451.             if (!buffer) {

  452.                 ret = AVERROR(ENOMEM);

  453.                 goto fail;

  454.             }

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

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

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

  458.                 goto fail;

  459.             break;

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

  461.             if (f_stau++ || !size) {

  462.                 ret = AVERROR(EINVAL);

  463.                 goto fail;

  464.             }

  465.             buffer = av_malloc(size);

  466.             if (!buffer) {

  467.                 ret = AVERROR(ENOMEM);

  468.                 goto fail;

  469.             }

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

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

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

  473.                 goto fail;

  474.             break;

  475.         }

  476.         avio_seek(pb, next, SEEK_SET);

  477.     }

  478. 

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

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

  481.         avio_r8(pb);

  482. 

  483.     /* init packet demux */

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

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

  486.     ffm->frame_offset = 0;

  487.     ffm->dts = 0;

  488.     ffm->read_state = READ_HEADER;

  489.     ffm->first_packet = 1;

  490.     return 0;

  491.  fail:

  492.     ffm_close(s);

  493.     return ret;

  494. }

  495. 

  496. static int ffm_read_header(AVFormatContext *s)

  497. {

  498.     FFMContext *ffm = s->priv_data;

  499.     AVStream *st;

  500.     AVIOContext *pb = s->pb;

  501.     AVCodecContext *codec;

  502.     const AVCodecDescriptor *codec_desc;

  503.     int i, nb_streams;

  504.     uint32_t tag;

  505. 

  506.     /* header */

  507.     tag = avio_rl32(pb);

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

  509.         return ffm2_read_header(s);

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

  511.         goto fail;

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

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

  514.         goto fail;

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

  516.     /* get also filesize */

  517.     if (pb->seekable) {

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

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

  520.             adjust_write_index(s);

  521.     } else {

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

  523.     }

  524. 

  525.     nb_streams = avio_rb32(pb);

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

  527.     /* read each stream */

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

  529.         char rc_eq_buf[128];

  530. 

  531.         st = avformat_new_stream(s, NULL);

  532.         if (!st)

  533.             goto fail;

  534. 

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

  536. 

  537.         codec = st->codec;

  538.         /* generic info */

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

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

  541.         if (!codec_desc) {

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

  543.             codec->codec_id = AV_CODEC_ID_NONE;

  544.             goto fail;

  545.         }

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

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

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

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

  550.             codec->codec_id = AV_CODEC_ID_NONE;

  551.             codec->codec_type = AVMEDIA_TYPE_UNKNOWN;

  552.             goto fail;

  553.         }

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

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

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

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

  558.         /* specific info */

  559.         switch(codec->codec_type) {

  560.         case AVMEDIA_TYPE_VIDEO:

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

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

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

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

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

  566.                 goto fail;

  567.             }

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

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

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

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

  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_packet_unref(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_packet_unref(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. static const AVOption options[] = {

  777.     {"server_attached", NULL, offsetof(FFMContext, server_attached), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, AV_OPT_FLAG_EXPORT },

  778.     {"ffm_write_index", NULL, offsetof(FFMContext, write_index), AV_OPT_TYPE_INT64, {.i64 = 0}, 0, INT64_MAX, AV_OPT_FLAG_EXPORT },

  779.     {"ffm_file_size", NULL, offsetof(FFMContext, file_size), AV_OPT_TYPE_INT64, {.i64 = 0}, 0, INT64_MAX, AV_OPT_FLAG_EXPORT },

  780.     { NULL },

  781. };

  782. 

  783. static const AVClass ffm_class = {

  784.     .class_name = "ffm demuxer",

  785.     .item_name  = av_default_item_name,

  786.     .option     = options,

  787.     .version    = LIBAVUTIL_VERSION_INT,

  788. };

  789. AVInputFormat ff_ffm_demuxer = {

  790.     .name           = "ffm",

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

  792.     .priv_data_size = sizeof(FFMContext),

  793.     .read_probe     = ffm_probe,

  794.     .read_header    = ffm_read_header,

  795.     .read_packet    = ffm_read_packet,

  796.     .read_close     = ffm_close,

  797.     .read_seek      = ffm_seek,

  798.     .priv_class     = &ffm_class,

  799. };