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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/imgutils.h"

  25. #include "libavutil/internal.h"

  26. #include "libavutil/intreadwrite.h"

  27. #include "libavutil/intfloat.h"

  28. #include "libavutil/opt.h"

  29. #include "libavutil/avassert.h"

  30. #include "libavutil/avstring.h"

  31. #include "libavutil/pixdesc.h"

  32. #include "libavcodec/internal.h"

  33. #include "avformat.h"

  34. #include "internal.h"

  35. #include "ffm.h"

  36. #include "avio_internal.h"

  37. 

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

  39. {

  40.     FFMContext *ffm = s->priv_data;

  41.     int64_t pos, avail_size;

  42.     ptrdiff_t len;

  43. 

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

  45.     if (size <= len)

  46.         return 1;

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

  48.     if (!ffm->write_index) {

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

  50.             return AVERROR_EOF;

  51.         avail_size = ffm->file_size - pos;

  52.     } else {

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

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

  55.         if (ffm->server_attached)

  56.             return AVERROR(EAGAIN);

  57.         else

  58.             return AVERROR_INVALIDDATA;

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

  60.         avail_size = ffm->write_index - pos;

  61.     } else {

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

  63.     }

  64.     }

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

  66.     if (size <= avail_size)

  67.         return 1;

  68.     else if (ffm->server_attached)

  69.         return AVERROR(EAGAIN);

  70.     else

  71.         return AVERROR_INVALIDDATA;

  72. }

  73. 

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

  75. {

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

  77.     while (state != PACKET_ID) {

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

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

  80.             return -1;

  81.         }

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

  83.     }

  84.     return 0;

  85. }

  86. 

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

  88. static int ffm_read_data(AVFormatContext *s,

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

  90. {

  91.     FFMContext *ffm = s->priv_data;

  92.     AVIOContext *pb = s->pb;

  93.     int fill_size, size1, frame_offset;

  94.     uint32_t id;

  95.     ptrdiff_t len;

  96.     int64_t last_pos = -1;

  97. 

  98.     size1 = size;

  99.     while (size > 0) {

  100.     redo:

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

  102.         if (len < 0)

  103.             return -1;

  104.         if (len > size)

  105.             len = size;

  106.         if (len == 0) {

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

  108.                 if (ffm->server_attached) {

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

  110.                 } else

  111.                     return AVERROR_EOF;

  112.             }

  113.     retry_read:

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

  115.                 int64_t tell = avio_tell(pb);

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

  117.                 if (ret < 0)

  118.                     return ret;

  119.                 avio_seek(pb, tell, SEEK_SET);

  120.             }

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

  122.             if (id != PACKET_ID) {

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

  124.                     return -1;

  125.                 last_pos = avio_tell(pb);

  126.             }

  127.             fill_size = avio_rb16(pb);

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

  129.             frame_offset = avio_rb16(pb);

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

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

  132.                 return -1;

  133.             }

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

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

  136.                handle it specifically */

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

  138.                 if (!frame_offset) {

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

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

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

  142.                         seekback = FFMAX(seekback, 0);

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

  144.                         goto retry_read;

  145.                     }

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

  147.                     return 0;

  148.                 }

  149.                 ffm->first_packet = 0;

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

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

  152.                     return -1;

  153.                 }

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

  155.                 if (!header)

  156.                     break;

  157.             } else {

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

  159.             }

  160.             goto redo;

  161.         }

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

  163.         buf += len;

  164.         ffm->packet_ptr += len;

  165.         size -= len;

  166.         header = 0;

  167.     }

  168.     return size1 - size;

  169. }

  170. 

  171. /* ensure that actual seeking happens between FFM_PACKET_SIZE

  172.    and file_size - FFM_PACKET_SIZE */

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

  174. {

  175.     FFMContext *ffm = s->priv_data;

  176.     AVIOContext *pb = s->pb;

  177.     int64_t pos;

  178. 

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

  180.     pos = FFMAX(pos, FFM_PACKET_SIZE);

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

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

  183. }

  184. 

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

  186. {

  187.     AVIOContext *pb = s->pb;

  188.     int64_t dts;

  189. 

  190.     ffm_seek1(s, pos);

  191.     avio_skip(pb, 4);

  192.     dts = avio_rb64(pb);

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

  194.     return dts;

  195. }

  196. 

  197. static void adjust_write_index(AVFormatContext *s)

  198. {

  199.     FFMContext *ffm = s->priv_data;

  200.     AVIOContext *pb = s->pb;

  201.     int64_t pts;

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

  203.     int64_t pos_min, pos_max;

  204.     int64_t pts_start;

  205.     int64_t ptr = avio_tell(pb);

  206. 

  207. 

  208.     pos_min = 0;

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

  210. 

  211.     pts_start = get_dts(s, pos_min);

  212. 

  213.     pts = get_dts(s, pos_max);

  214. 

  215.     if (pts - 100000 > pts_start)

  216.         goto end;

  217. 

  218.     ffm->write_index = FFM_PACKET_SIZE;

  219. 

  220.     pts_start = get_dts(s, pos_min);

  221. 

  222.     pts = get_dts(s, pos_max);

  223. 

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

  225.         while (1) {

  226.             int64_t newpos;

  227.             int64_t newpts;

  228. 

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

  230. 

  231.             if (newpos == pos_min)

  232.                 break;

  233. 

  234.             newpts = get_dts(s, newpos);

  235. 

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

  237.                 pos_max = newpos;

  238.                 pts = newpts;

  239.             } else {

  240.                 pos_min = newpos;

  241.             }

  242.         }

  243.         ffm->write_index += pos_max;

  244.     }

  245. 

  246.  end:

  247.     avio_seek(pb, ptr, SEEK_SET);

  248. }

  249. 

  250. 

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

  252. {

  253.     int ret;

  254.     size_t newsize;

  255.     av_assert0(conf && st);

  256.     if (!*conf)

  257.         return 0;

  258.     if (!st->recommended_encoder_configuration) {

  259.         st->recommended_encoder_configuration = *conf;

  260.         *conf = 0;

  261.         return 0;

  262.     }

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

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

  265.         return ret;

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

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

  268.     av_freep(conf);

  269.     return 0;

  270. }

  271. 

  272. #define VALIDATE_PARAMETER(parameter, name, check) {                              \

  273.     if (check) {                                                                  \

  274.         av_log(s, AV_LOG_ERROR, "Invalid " name " %d\n", codecpar->parameter);   \

  275.         ret = AVERROR_INVALIDDATA;                                                \

  276.         goto fail;                                                                \

  277.     }                                                                             \

  278. }

  279. 

  280. static int ffm2_read_header(AVFormatContext *s)

  281. {

  282.     FFMContext *ffm = s->priv_data;

  283.     AVStream *st = NULL;

  284.     AVIOContext *pb = s->pb;

  285.     AVCodecContext *dummy_codec = NULL;

  286.     AVCodecParameters *codecpar = NULL;

  287.     const AVCodecDescriptor *codec_desc;

  288.     int ret;

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

  290.     AVCodec *enc;

  291.     char *buffer;

  292. 

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

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

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

  296.                ffm->packet_size, FFM_PACKET_SIZE);

  297.         ret = AVERROR_INVALIDDATA;

  298.         goto fail;

  299.     }

  300. 

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

  302.     /* get also filesize */

  303.     if (pb->seekable & AVIO_SEEKABLE_NORMAL) {

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

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

  306.             adjust_write_index(s);

  307.     } else {

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

  309.     }

  310.     dummy_codec = avcodec_alloc_context3(NULL);

  311. 

  312.     while(!avio_feof(pb)) {

  313.         unsigned id = avio_rb32(pb);

  314.         unsigned size = avio_rb32(pb);

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

  316.         char rc_eq_buf[128];

  317.         int flags;

  318. 

  319.         if(!id)

  320.             break;

  321. 

  322.         switch(id) {

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

  324.             if (f_main++) {

  325.                 ret = AVERROR(EINVAL);

  326.                 goto fail;

  327.             }

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

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

  330.             break;

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

  332.             f_cprv = f_stvi = f_stau = 0;

  333.             st = avformat_new_stream(s, NULL);

  334.             if (!st) {

  335.                 ret = AVERROR(ENOMEM);

  336.                 goto fail;

  337.             }

  338. 

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

  340. 

  341.             codecpar = st->codecpar;

  342.             /* generic info */

  343.             codecpar->codec_id = avio_rb32(pb);

  344.             codec_desc = avcodec_descriptor_get(codecpar->codec_id);

  345.             if (!codec_desc) {

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

  347.                 codecpar->codec_id = AV_CODEC_ID_NONE;

  348.                 ret = AVERROR_INVALIDDATA;

  349.                 goto fail;

  350.             }

  351.             codecpar->codec_type = avio_r8(pb);

  352.             if (codecpar->codec_type != codec_desc->type) {

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

  354.                        codec_desc->type, codecpar->codec_type);

  355.                 codecpar->codec_id = AV_CODEC_ID_NONE;

  356.                 codecpar->codec_type = AVMEDIA_TYPE_UNKNOWN;

  357.                 ret = AVERROR_INVALIDDATA;

  358.                 goto fail;

  359.             }

  360.             codecpar->bit_rate = avio_rb32(pb);

  361.             if (codecpar->bit_rate < 0) {

  362.                 av_log(s, AV_LOG_ERROR, "Invalid bit rate %"PRId64"\n", codecpar->bit_rate);

  363.                 ret = AVERROR_INVALIDDATA;

  364.                 goto fail;

  365.             }

  366.             flags = avio_rb32(pb);

  367. #if FF_API_LAVF_AVCTX

  368. FF_DISABLE_DEPRECATION_WARNINGS

  369.             st->codec->flags = flags;

  370. FF_ENABLE_DEPRECATION_WARNINGS

  371. #endif

  372.             avio_rb32(pb); // flags2

  373.             avio_rb32(pb); // debug

  374.             if (flags & AV_CODEC_FLAG_GLOBAL_HEADER) {

  375.                 int size = avio_rb32(pb);

  376.                 if (size < 0 || size >= FF_MAX_EXTRADATA_SIZE) {

  377.                     av_log(s, AV_LOG_ERROR, "Invalid extradata size %d\n", size);

  378.                     ret = AVERROR_INVALIDDATA;

  379.                     goto fail;

  380.                 }

  381.                 codecpar->extradata = av_mallocz(size + AV_INPUT_BUFFER_PADDING_SIZE);

  382.                 if (!codecpar->extradata) {

  383.                     ret = AVERROR(ENOMEM);

  384.                     goto fail;

  385.                 }

  386.                 codecpar->extradata_size = size;

  387.                 avio_read(pb, codecpar->extradata, size);

  388.             }

  389.             break;

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

  391.             if (f_stvi++ || codecpar->codec_type != AVMEDIA_TYPE_VIDEO) {

  392.                 ret = AVERROR(EINVAL);

  393.                 goto fail;

  394.             }

  395.             avio_rb32(pb); // time_base.num

  396.             avio_rb32(pb); // time_base.den

  397.             codecpar->width = avio_rb16(pb);

  398.             codecpar->height = avio_rb16(pb);

  399.             ret = av_image_check_size(codecpar->width, codecpar->height, 0, s);

  400.             if (ret < 0)

  401.                 goto fail;

  402.             avio_rb16(pb); // gop_size

  403.             codecpar->format = avio_rb32(pb);

  404.             if (!av_pix_fmt_desc_get(codecpar->format)) {

  405.                 av_log(s, AV_LOG_ERROR, "Invalid pix fmt id: %d\n", codecpar->format);

  406.                 codecpar->format = AV_PIX_FMT_NONE;

  407.                 ret = AVERROR_INVALIDDATA;

  408.                 goto fail;

  409.             }

  410.             avio_r8(pb);   // qmin

  411.             avio_r8(pb);   // qmax

  412.             avio_r8(pb);   // max_qdiff

  413.             avio_rb16(pb); // qcompress / 10000.0

  414.             avio_rb16(pb); // qblur / 10000.0

  415.             avio_rb32(pb); // bit_rate_tolerance

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

  417. 

  418.             avio_rb32(pb); // rc_max_rate

  419.             avio_rb32(pb); // rc_min_rate

  420.             avio_rb32(pb); // rc_buffer_size

  421.             avio_rb64(pb); // i_quant_factor

  422.             avio_rb64(pb); // b_quant_factor

  423.             avio_rb64(pb); // i_quant_offset

  424.             avio_rb64(pb); // b_quant_offset

  425.             avio_rb32(pb); // dct_algo

  426.             avio_rb32(pb); // strict_std_compliance

  427.             avio_rb32(pb); // max_b_frames

  428.             avio_rb32(pb); // mpeg_quant

  429.             avio_rb32(pb); // intra_dc_precision

  430.             avio_rb32(pb); // me_method

  431.             avio_rb32(pb); // mb_decision

  432.             avio_rb32(pb); // nsse_weight

  433.             avio_rb32(pb); // frame_skip_cmp

  434.             avio_rb64(pb); // rc_buffer_aggressivity

  435.             codecpar->codec_tag = avio_rb32(pb);

  436.             avio_r8(pb);   // thread_count

  437.             avio_rb32(pb); // coder_type

  438.             avio_rb32(pb); // me_cmp

  439.             avio_rb32(pb); // me_subpel_quality

  440.             avio_rb32(pb); // me_range

  441.             avio_rb32(pb); // keyint_min

  442.             avio_rb32(pb); // scenechange_threshold

  443.             avio_rb32(pb); // b_frame_strategy

  444.             avio_rb64(pb); // qcompress

  445.             avio_rb64(pb); // qblur

  446.             avio_rb32(pb); // max_qdiff

  447.             avio_rb32(pb); // refs

  448.             break;

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

  450.             if (f_stau++ || codecpar->codec_type != AVMEDIA_TYPE_AUDIO) {

  451.                 ret = AVERROR(EINVAL);

  452.                 goto fail;

  453.             }

  454.             codecpar->sample_rate = avio_rb32(pb);

  455.             VALIDATE_PARAMETER(sample_rate, "sample rate",        codecpar->sample_rate < 0)

  456.             codecpar->channels = avio_rl16(pb);

  457.             VALIDATE_PARAMETER(channels,    "number of channels", codecpar->channels < 0)

  458.             codecpar->frame_size = avio_rl16(pb);

  459.             VALIDATE_PARAMETER(frame_size,  "frame size",         codecpar->frame_size < 0)

  460.             break;

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

  462.             if (f_cprv++) {

  463.                 ret = AVERROR(EINVAL);

  464.                 goto fail;

  465.             }

  466.             enc = avcodec_find_encoder(codecpar->codec_id);

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

  468.                 buffer = av_malloc(size + 1);

  469.                 if (!buffer) {

  470.                     ret = AVERROR(ENOMEM);

  471.                     goto fail;

  472.                 }

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

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

  475.                     goto fail;

  476.             }

  477.             break;

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

  479.             if (f_stvi++ || !size || codecpar->codec_type != AVMEDIA_TYPE_VIDEO) {

  480.                 ret = AVERROR(EINVAL);

  481.                 goto fail;

  482.             }

  483.             buffer = av_malloc(size);

  484.             if (!buffer) {

  485.                 ret = AVERROR(ENOMEM);

  486.                 goto fail;

  487.             }

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

  489.             // The lack of AVOptions support in AVCodecParameters makes this back and forth copying needed

  490.             avcodec_parameters_to_context(dummy_codec, codecpar);

  491.             av_set_options_string(dummy_codec, buffer, "=", ",");

  492.             avcodec_parameters_from_context(codecpar, dummy_codec);

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

  494.                 goto fail;

  495.             break;

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

  497.             if (f_stau++ || !size || codecpar->codec_type != AVMEDIA_TYPE_AUDIO) {

  498.                 ret = AVERROR(EINVAL);

  499.                 goto fail;

  500.             }

  501.             buffer = av_malloc(size);

  502.             if (!buffer) {

  503.                 ret = AVERROR(ENOMEM);

  504.                 goto fail;

  505.             }

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

  507.             // The lack of AVOptions support in AVCodecParameters makes this back and forth copying needed

  508.             avcodec_parameters_to_context(dummy_codec, codecpar);

  509.             av_set_options_string(dummy_codec, buffer, "=", ",");

  510.             avcodec_parameters_from_context(codecpar, dummy_codec);

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

  512.                 goto fail;

  513.             break;

  514.         }

  515.         avio_seek(pb, next, SEEK_SET);

  516.     }

  517. 

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

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

  520.         avio_r8(pb);

  521. 

  522.     /* init packet demux */

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

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

  525.     ffm->frame_offset = 0;

  526.     ffm->dts = 0;

  527.     ffm->read_state = READ_HEADER;

  528.     ffm->first_packet = 1;

  529.     avcodec_free_context(&dummy_codec);

  530.     return 0;

  531.  fail:

  532.     avcodec_free_context(&dummy_codec);

  533.     return ret;

  534. }

  535. 

  536. static int ffm_read_header(AVFormatContext *s)

  537. {

  538.     FFMContext *ffm = s->priv_data;

  539.     AVStream *st;

  540.     AVIOContext *pb = s->pb;

  541.     AVCodecContext *dummy_codec = NULL;

  542.     AVCodecParameters *codecpar;

  543.     const AVCodecDescriptor *codec_desc;

  544.     int i, nb_streams, ret;

  545.     uint32_t tag;

  546. 

  547.     /* header */

  548.     tag = avio_rl32(pb);

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

  550.         return ffm2_read_header(s);

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

  552.         ret = AVERROR_INVALIDDATA;

  553.         goto fail;

  554.     }

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

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

  557.         ret = AVERROR_INVALIDDATA;

  558.         goto fail;

  559.     }

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

  561.     /* get also filesize */

  562.     if (pb->seekable & AVIO_SEEKABLE_NORMAL) {

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

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

  565.             adjust_write_index(s);

  566.     } else {

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

  568.     }

  569.     dummy_codec = avcodec_alloc_context3(NULL);

  570. 

  571.     nb_streams = avio_rb32(pb);

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

  573.     /* read each stream */

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

  575.         char rc_eq_buf[128];

  576.         int flags;

  577. 

  578.         st = avformat_new_stream(s, NULL);

  579.         if (!st) {

  580.             ret = AVERROR(ENOMEM);

  581.             goto fail;

  582.         }

  583. 

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

  585. 

  586.         codecpar = st->codecpar;

  587.         /* generic info */

  588.         codecpar->codec_id = avio_rb32(pb);

  589.         codec_desc = avcodec_descriptor_get(codecpar->codec_id);

  590.         if (!codec_desc) {

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

  592.             codecpar->codec_id = AV_CODEC_ID_NONE;

  593.             ret = AVERROR_INVALIDDATA;

  594.             goto fail;

  595.         }

  596.         codecpar->codec_type = avio_r8(pb); /* codec_type */

  597.         if (codecpar->codec_type != codec_desc->type) {

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

  599.                    codec_desc->type, codecpar->codec_type);

  600.             codecpar->codec_id = AV_CODEC_ID_NONE;

  601.             codecpar->codec_type = AVMEDIA_TYPE_UNKNOWN;

  602.             ret = AVERROR_INVALIDDATA;

  603.             goto fail;

  604.         }

  605.         codecpar->bit_rate = avio_rb32(pb);

  606.         if (codecpar->bit_rate < 0) {

  607.             av_log(s, AV_LOG_WARNING, "Invalid bit rate %"PRId64"\n", codecpar->bit_rate);

  608.             ret = AVERROR_INVALIDDATA;

  609.             goto fail;

  610.         }

  611.         flags = avio_rb32(pb);

  612. #if FF_API_LAVF_AVCTX

  613. FF_DISABLE_DEPRECATION_WARNINGS

  614.             st->codec->flags = flags;

  615. FF_ENABLE_DEPRECATION_WARNINGS

  616. #endif

  617.         avio_rb32(pb); // flags2

  618.         avio_rb32(pb); // debug

  619.         /* specific info */

  620.         switch(codecpar->codec_type) {

  621.         case AVMEDIA_TYPE_VIDEO:

  622.             avio_rb32(pb); // time_base.num

  623.             avio_rb32(pb); // time_base.den

  624.             codecpar->width = avio_rb16(pb);

  625.             codecpar->height = avio_rb16(pb);

  626.             if ((ret = av_image_check_size(codecpar->width, codecpar->height, 0, s)) < 0)

  627.                 goto fail;

  628.             avio_rb16(pb); // gop_size

  629.             codecpar->format = avio_rb32(pb);

  630.             if (!av_pix_fmt_desc_get(codecpar->format)) {

  631.                 av_log(s, AV_LOG_ERROR, "Invalid pix fmt id: %d\n", codecpar->format);

  632.                 codecpar->format = AV_PIX_FMT_NONE;

  633.                 ret = AVERROR_INVALIDDATA;

  634.                 goto fail;

  635.             }

  636.             avio_r8(pb);   // qmin

  637.             avio_r8(pb);   // qmax

  638.             avio_r8(pb);   // max_qdiff

  639.             avio_rb16(pb); // qcompress / 10000.0

  640.             avio_rb16(pb); // qblur / 10000.0

  641.             avio_rb32(pb); // bit_rate_tolerance

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

  643. 

  644.             avio_rb32(pb); // rc_max_rate

  645.             avio_rb32(pb); // rc_min_rate

  646.             avio_rb32(pb); // rc_buffer_size

  647.             avio_rb64(pb); // i_quant_factor

  648.             avio_rb64(pb); // b_quant_factor

  649.             avio_rb64(pb); // i_quant_offset

  650.             avio_rb64(pb); // b_quant_offset

  651.             avio_rb32(pb); // dct_algo

  652.             avio_rb32(pb); // strict_std_compliance

  653.             avio_rb32(pb); // max_b_frames

  654.             avio_rb32(pb); // mpeg_quant

  655.             avio_rb32(pb); // intra_dc_precision

  656.             avio_rb32(pb); // me_method

  657.             avio_rb32(pb); // mb_decision

  658.             avio_rb32(pb); // nsse_weight

  659.             avio_rb32(pb); // frame_skip_cmp

  660.             avio_rb64(pb); // rc_buffer_aggressivity

  661.             codecpar->codec_tag = avio_rb32(pb);

  662.             avio_r8(pb);   // thread_count

  663.             avio_rb32(pb); // coder_type

  664.             avio_rb32(pb); // me_cmp

  665.             avio_rb32(pb); // me_subpel_quality

  666.             avio_rb32(pb); // me_range

  667.             avio_rb32(pb); // keyint_min

  668.             avio_rb32(pb); // scenechange_threshold

  669.             avio_rb32(pb); // b_frame_strategy

  670.             avio_rb64(pb); // qcompress

  671.             avio_rb64(pb); // qblur

  672.             avio_rb32(pb); // max_qdiff

  673.             avio_rb32(pb); // refs

  674.             break;

  675.         case AVMEDIA_TYPE_AUDIO:

  676.             codecpar->sample_rate = avio_rb32(pb);

  677.             VALIDATE_PARAMETER(sample_rate, "sample rate",        codecpar->sample_rate < 0)

  678.             codecpar->channels = avio_rl16(pb);

  679.             VALIDATE_PARAMETER(channels,    "number of channels", codecpar->channels < 0)

  680.             codecpar->frame_size = avio_rl16(pb);

  681.             VALIDATE_PARAMETER(frame_size,  "frame size",         codecpar->frame_size < 0)

  682.             break;

  683.         default:

  684.             ret = AVERROR_INVALIDDATA;

  685.             goto fail;

  686.         }

  687.         if (flags & AV_CODEC_FLAG_GLOBAL_HEADER) {

  688.             int size = avio_rb32(pb);

  689.             if (size < 0 || size >= FF_MAX_EXTRADATA_SIZE) {

  690.                 av_log(s, AV_LOG_ERROR, "Invalid extradata size %d\n", size);

  691.                 ret = AVERROR_INVALIDDATA;

  692.                 goto fail;

  693.             }

  694.             codecpar->extradata = av_mallocz(size + AV_INPUT_BUFFER_PADDING_SIZE);

  695.             if (!codecpar->extradata) {

  696.                 ret = AVERROR(ENOMEM);

  697.                 goto fail;

  698.             }

  699.             codecpar->extradata_size = size;

  700.             avio_read(pb, codecpar->extradata, size);

  701.         }

  702.     }

  703. 

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

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

  706.         avio_r8(pb);

  707. 

  708.     /* init packet demux */

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

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

  711.     ffm->frame_offset = 0;

  712.     ffm->dts = 0;

  713.     ffm->read_state = READ_HEADER;

  714.     ffm->first_packet = 1;

  715.     avcodec_free_context(&dummy_codec);

  716.     return 0;

  717.  fail:

  718.     avcodec_free_context(&dummy_codec);

  719.     return ret;

  720. }

  721. 

  722. /* return < 0 if eof */

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

  724. {

  725.     int size;

  726.     FFMContext *ffm = s->priv_data;

  727.     int duration, ret;

  728. 

  729.     switch(ffm->read_state) {

  730.     case READ_HEADER:

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

  732.             return ret;

  733. 

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

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

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

  737.             FRAME_HEADER_SIZE)

  738.             return -1;

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

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

  741.                 return -1;

  742.         ffm->read_state = READ_DATA;

  743.         /* fall through */

  744.     case READ_DATA:

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

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

  747.             return ret;

  748. 

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

  750. 

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

  752.             return AVERROR(ENOMEM);

  753.         }

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

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

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

  757.             av_packet_unref(pkt);

  758.             ffm->read_state = READ_HEADER;

  759.             return -1;

  760.         }

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

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

  763.             pkt->flags |= AV_PKT_FLAG_KEY;

  764. 

  765.         ffm->read_state = READ_HEADER;

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

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

  768.             av_packet_unref(pkt);

  769.             return -1;

  770.         }

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

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

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

  774.         else

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

  776.         pkt->duration = duration;

  777.         break;

  778.     }

  779.     return 0;

  780. }

  781. 

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

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

  784.    approximative */

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

  786. {

  787.     FFMContext *ffm = s->priv_data;

  788.     int64_t pos_min, pos_max, pos;

  789.     int64_t pts_min, pts_max, pts;

  790.     double pos1;

  791. 

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

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

  794.        dichotomy in typical cases) */

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

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

  797.             pos_min = FFM_PACKET_SIZE;

  798.             pos_max = ffm->write_index - FFM_PACKET_SIZE;

  799.         } else {

  800.             pos_min = ffm->write_index;

  801.             pos_max = ffm->file_size - FFM_PACKET_SIZE;

  802.         }

  803.     } else {

  804.         pos_min = FFM_PACKET_SIZE;

  805.         pos_max = ffm->file_size - FFM_PACKET_SIZE;

  806.     }

  807.     while (pos_min <= pos_max) {

  808.         pts_min = get_dts(s, pos_min);

  809.         pts_max = get_dts(s, pos_max);

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

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

  812.             goto found;

  813.         }

  814.         /* linear interpolation */

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

  816.             (double)(pts_max - pts_min);

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

  818.         if (pos <= pos_min)

  819.             pos = pos_min;

  820.         else if (pos >= pos_max)

  821.             pos = pos_max;

  822.         pts = get_dts(s, pos);

  823.         /* check if we are lucky */

  824.         if (pts == wanted_pts) {

  825.             goto found;

  826.         } else if (pts > wanted_pts) {

  827.             pos_max = pos - FFM_PACKET_SIZE;

  828.         } else {

  829.             pos_min = pos + FFM_PACKET_SIZE;

  830.         }

  831.     }

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

  833. 

  834.  found:

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

  836.         return -1;

  837. 

  838.     /* reset read state */

  839.     ffm->read_state = READ_HEADER;

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

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

  842.     ffm->first_packet = 1;

  843. 

  844.     return 0;

  845. }

  846. 

  847. static int ffm_probe(AVProbeData *p)

  848. {

  849.     if (

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

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

  852.         return AVPROBE_SCORE_MAX + 1;

  853.     return 0;

  854. }

  855. 

  856. static const AVOption options[] = {

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

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

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

  860.     { NULL },

  861. };

  862. 

  863. static const AVClass ffm_class = {

  864.     .class_name = "ffm demuxer",

  865.     .item_name  = av_default_item_name,

  866.     .option     = options,

  867.     .version    = LIBAVUTIL_VERSION_INT,

  868. };

  869. AVInputFormat ff_ffm_demuxer = {

  870.     .name           = "ffm",

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

  872.     .priv_data_size = sizeof(FFMContext),

  873.     .read_probe     = ffm_probe,

  874.     .read_header    = ffm_read_header,

  875.     .read_packet    = ffm_read_packet,

  876.     .read_seek      = ffm_seek,

  877.     .priv_class     = &ffm_class,

  878. };