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  1. /*
  2.  * Matroska muxer
  3.  * Copyright (c) 2007 David Conrad
  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 "avc.h"
  23. #include "avformat.h"
  24. #include "avio_internal.h"
  25. #include "avlanguage.h"
  26. #include "flacenc.h"
  27. #include "internal.h"
  28. #include "isom.h"
  29. #include "matroska.h"
  30. #include "riff.h"
  31. #include "subtitles.h"
  32. #include "wv.h"
  33.  
  34. #include "libavutil/avstring.h"
  35. #include "libavutil/dict.h"
  36. #include "libavutil/intfloat.h"
  37. #include "libavutil/intreadwrite.h"
  38. #include "libavutil/lfg.h"
  39. #include "libavutil/mathematics.h"
  40. #include "libavutil/opt.h"
  41. #include "libavutil/random_seed.h"
  42. #include "libavutil/samplefmt.h"
  43. #include "libavutil/sha.h"
  44.  
  45. #include "libavcodec/xiph.h"
  46. #include "libavcodec/mpeg4audio.h"
  47. #include "libavcodec/internal.h"
  48.  
  49. typedef struct ebml_master {
  50.     int64_t         pos;                ///< absolute offset in the file where the master's elements start
  51.     int             sizebytes;          ///< how many bytes were reserved for the size
  52. } ebml_master;
  53.  
  54. typedef struct mkv_seekhead_entry {
  55.     unsigned int    elementid;
  56.     uint64_t        segmentpos;
  57. } mkv_seekhead_entry;
  58.  
  59. typedef struct mkv_seekhead {
  60.     int64_t                 filepos;
  61.     int64_t                 segment_offset;     ///< the file offset to the beginning of the segment
  62.     int                     reserved_size;      ///< -1 if appending to file
  63.     int                     max_entries;
  64.     mkv_seekhead_entry      *entries;
  65.     int                     num_entries;
  66. } mkv_seekhead;
  67.  
  68. typedef struct {
  69.     uint64_t        pts;
  70.     int             tracknum;
  71.     int64_t         cluster_pos;        ///< file offset of the cluster containing the block
  72.     int64_t         relative_pos;       ///< relative offset from the position of the cluster containing the block
  73.     int64_t         duration;           ///< duration of the block according to time base
  74. } mkv_cuepoint;
  75.  
  76. typedef struct {
  77.     int64_t         segment_offset;
  78.     mkv_cuepoint    *entries;
  79.     int             num_entries;
  80. } mkv_cues;
  81.  
  82. typedef struct {
  83.     int             write_dts;
  84.     int             has_cue;
  85. } mkv_track;
  86.  
  87. #define MODE_MATROSKAv2 0x01
  88. #define MODE_WEBM       0x02
  89.  
  90. typedef struct MatroskaMuxContext {
  91.     const AVClass  *class;
  92.     int             mode;
  93.     AVIOContext   *dyn_bc;
  94.     ebml_master     segment;
  95.     int64_t         segment_offset;
  96.     ebml_master     cluster;
  97.     int64_t         cluster_pos;        ///< file offset of the current cluster
  98.     int64_t         cluster_pts;
  99.     int64_t         duration_offset;
  100.     int64_t         duration;
  101.     mkv_seekhead    *main_seekhead;
  102.     mkv_cues        *cues;
  103.     mkv_track       *tracks;
  104.  
  105.     AVPacket        cur_audio_pkt;
  106.  
  107.     int have_attachments;
  108.  
  109.     int reserve_cues_space;
  110.     int cluster_size_limit;
  111.     int64_t cues_pos;
  112.     int64_t cluster_time_limit;
  113.  
  114.     uint32_t chapter_id_offset;
  115.     int wrote_chapters;
  116. } MatroskaMuxContext;
  117.  
  118.  
  119. /** 2 bytes * 3 for EBML IDs, 3 1-byte EBML lengths, 8 bytes for 64 bit
  120.  * offset, 4 bytes for target EBML ID */
  121. #define MAX_SEEKENTRY_SIZE 21
  122.  
  123. /** per-cuepoint-track - 5 1-byte EBML IDs, 5 1-byte EBML sizes, 4
  124.  * 8-byte uint max */
  125. #define MAX_CUETRACKPOS_SIZE 42
  126.  
  127. /** per-cuepoint - 2 1-byte EBML IDs, 2 1-byte EBML sizes, 8-byte uint max */
  128. #define MAX_CUEPOINT_SIZE(num_tracks) 12 + MAX_CUETRACKPOS_SIZE*num_tracks
  129.  
  130. /** Seek preroll value for opus */
  131. #define OPUS_SEEK_PREROLL 80000000
  132.  
  133.  
  134. static int ebml_id_size(unsigned int id)
  135. {
  136.     return (av_log2(id+1)-1)/7+1;
  137. }
  138.  
  139. static void put_ebml_id(AVIOContext *pb, unsigned int id)
  140. {
  141.     int i = ebml_id_size(id);
  142.     while (i--)
  143.         avio_w8(pb, (uint8_t)(id >> (i*8)));
  144. }
  145.  
  146. /**
  147.  * Write an EBML size meaning "unknown size".
  148.  *
  149.  * @param bytes The number of bytes the size should occupy (maximum: 8).
  150.  */
  151. static void put_ebml_size_unknown(AVIOContext *pb, int bytes)
  152. {
  153.     av_assert0(bytes <= 8);
  154.     avio_w8(pb, 0x1ff >> bytes);
  155.     ffio_fill(pb, 0xff, bytes - 1);
  156. }
  157.  
  158. /**
  159.  * Calculate how many bytes are needed to represent a given number in EBML.
  160.  */
  161. static int ebml_num_size(uint64_t num)
  162. {
  163.     int bytes = 1;
  164.     while ((num+1) >> bytes*7) bytes++;
  165.     return bytes;
  166. }
  167.  
  168. /**
  169.  * Write a number in EBML variable length format.
  170.  *
  171.  * @param bytes The number of bytes that need to be used to write the number.
  172.  *              If zero, any number of bytes can be used.
  173.  */
  174. static void put_ebml_num(AVIOContext *pb, uint64_t num, int bytes)
  175. {
  176.     int i, needed_bytes = ebml_num_size(num);
  177.  
  178.     // sizes larger than this are currently undefined in EBML
  179.     av_assert0(num < (1ULL<<56)-1);
  180.  
  181.     if (bytes == 0)
  182.         // don't care how many bytes are used, so use the min
  183.         bytes = needed_bytes;
  184.     // the bytes needed to write the given size would exceed the bytes
  185.     // that we need to use, so write unknown size. This shouldn't happen.
  186.     av_assert0(bytes >= needed_bytes);
  187.  
  188.     num |= 1ULL << bytes*7;
  189.     for (i = bytes - 1; i >= 0; i--)
  190.         avio_w8(pb, (uint8_t)(num >> i*8));
  191. }
  192.  
  193. static void put_ebml_uint(AVIOContext *pb, unsigned int elementid, uint64_t val)
  194. {
  195.     int i, bytes = 1;
  196.     uint64_t tmp = val;
  197.     while (tmp>>=8) bytes++;
  198.  
  199.     put_ebml_id(pb, elementid);
  200.     put_ebml_num(pb, bytes, 0);
  201.     for (i = bytes - 1; i >= 0; i--)
  202.         avio_w8(pb, (uint8_t)(val >> i*8));
  203. }
  204.  
  205. static void put_ebml_float(AVIOContext *pb, unsigned int elementid, double val)
  206. {
  207.     put_ebml_id(pb, elementid);
  208.     put_ebml_num(pb, 8, 0);
  209.     avio_wb64(pb, av_double2int(val));
  210. }
  211.  
  212. static void put_ebml_binary(AVIOContext *pb, unsigned int elementid,
  213.                             const void *buf, int size)
  214. {
  215.     put_ebml_id(pb, elementid);
  216.     put_ebml_num(pb, size, 0);
  217.     avio_write(pb, buf, size);
  218. }
  219.  
  220. static void put_ebml_string(AVIOContext *pb, unsigned int elementid, const char *str)
  221. {
  222.     put_ebml_binary(pb, elementid, str, strlen(str));
  223. }
  224.  
  225. /**
  226.  * Write a void element of a given size. Useful for reserving space in
  227.  * the file to be written to later.
  228.  *
  229.  * @param size The number of bytes to reserve, which must be at least 2.
  230.  */
  231. static void put_ebml_void(AVIOContext *pb, uint64_t size)
  232. {
  233.     int64_t currentpos = avio_tell(pb);
  234.  
  235.     av_assert0(size >= 2);
  236.  
  237.     put_ebml_id(pb, EBML_ID_VOID);
  238.     // we need to subtract the length needed to store the size from the
  239.     // size we need to reserve so 2 cases, we use 8 bytes to store the
  240.     // size if possible, 1 byte otherwise
  241.     if (size < 10)
  242.         put_ebml_num(pb, size-1, 0);
  243.     else
  244.         put_ebml_num(pb, size-9, 8);
  245.     ffio_fill(pb, 0, currentpos + size - avio_tell(pb));
  246. }
  247.  
  248. static ebml_master start_ebml_master(AVIOContext *pb, unsigned int elementid, uint64_t expectedsize)
  249. {
  250.     int bytes = expectedsize ? ebml_num_size(expectedsize) : 8;
  251.     put_ebml_id(pb, elementid);
  252.     put_ebml_size_unknown(pb, bytes);
  253.     return (ebml_master){ avio_tell(pb), bytes };
  254. }
  255.  
  256. static void end_ebml_master(AVIOContext *pb, ebml_master master)
  257. {
  258.     int64_t pos = avio_tell(pb);
  259.  
  260.     if (avio_seek(pb, master.pos - master.sizebytes, SEEK_SET) < 0)
  261.         return;
  262.     put_ebml_num(pb, pos - master.pos, master.sizebytes);
  263.     avio_seek(pb, pos, SEEK_SET);
  264. }
  265.  
  266. static void put_xiph_size(AVIOContext *pb, int size)
  267. {
  268.     ffio_fill(pb, 255, size / 255);
  269.     avio_w8(pb, size % 255);
  270. }
  271.  
  272. /**
  273.  * Initialize a mkv_seekhead element to be ready to index level 1 Matroska
  274.  * elements. If a maximum number of elements is specified, enough space
  275.  * will be reserved at the current file location to write a seek head of
  276.  * that size.
  277.  *
  278.  * @param segment_offset The absolute offset to the position in the file
  279.  *                       where the segment begins.
  280.  * @param numelements The maximum number of elements that will be indexed
  281.  *                    by this seek head, 0 if unlimited.
  282.  */
  283. static mkv_seekhead * mkv_start_seekhead(AVIOContext *pb, int64_t segment_offset, int numelements)
  284. {
  285.     mkv_seekhead *new_seekhead = av_mallocz(sizeof(mkv_seekhead));
  286.     if (new_seekhead == NULL)
  287.         return NULL;
  288.  
  289.     new_seekhead->segment_offset = segment_offset;
  290.  
  291.     if (numelements > 0) {
  292.         new_seekhead->filepos = avio_tell(pb);
  293.         // 21 bytes max for a seek entry, 10 bytes max for the SeekHead ID
  294.         // and size, and 3 bytes to guarantee that an EBML void element
  295.         // will fit afterwards
  296.         new_seekhead->reserved_size = numelements * MAX_SEEKENTRY_SIZE + 13;
  297.         new_seekhead->max_entries = numelements;
  298.         put_ebml_void(pb, new_seekhead->reserved_size);
  299.     }
  300.     return new_seekhead;
  301. }
  302.  
  303. static int mkv_add_seekhead_entry(mkv_seekhead *seekhead, unsigned int elementid, uint64_t filepos)
  304. {
  305.     mkv_seekhead_entry *entries = seekhead->entries;
  306.  
  307.     // don't store more elements than we reserved space for
  308.     if (seekhead->max_entries > 0 && seekhead->max_entries <= seekhead->num_entries)
  309.         return -1;
  310.  
  311.     entries = av_realloc_array(entries, seekhead->num_entries + 1, sizeof(mkv_seekhead_entry));
  312.     if (entries == NULL)
  313.         return AVERROR(ENOMEM);
  314.     seekhead->entries = entries;
  315.  
  316.     seekhead->entries[seekhead->num_entries].elementid    = elementid;
  317.     seekhead->entries[seekhead->num_entries++].segmentpos = filepos - seekhead->segment_offset;
  318.  
  319.     return 0;
  320. }
  321.  
  322. /**
  323.  * Write the seek head to the file and free it. If a maximum number of
  324.  * elements was specified to mkv_start_seekhead(), the seek head will
  325.  * be written at the location reserved for it. Otherwise, it is written
  326.  * at the current location in the file.
  327.  *
  328.  * @return The file offset where the seekhead was written,
  329.  * -1 if an error occurred.
  330.  */
  331. static int64_t mkv_write_seekhead(AVIOContext *pb, mkv_seekhead *seekhead)
  332. {
  333.     ebml_master metaseek, seekentry;
  334.     int64_t currentpos;
  335.     int i;
  336.  
  337.     currentpos = avio_tell(pb);
  338.  
  339.     if (seekhead->reserved_size > 0) {
  340.         if (avio_seek(pb, seekhead->filepos, SEEK_SET) < 0) {
  341.             currentpos = -1;
  342.             goto fail;
  343.         }
  344.     }
  345.  
  346.     metaseek = start_ebml_master(pb, MATROSKA_ID_SEEKHEAD, seekhead->reserved_size);
  347.     for (i = 0; i < seekhead->num_entries; i++) {
  348.         mkv_seekhead_entry *entry = &seekhead->entries[i];
  349.  
  350.         seekentry = start_ebml_master(pb, MATROSKA_ID_SEEKENTRY, MAX_SEEKENTRY_SIZE);
  351.  
  352.         put_ebml_id(pb, MATROSKA_ID_SEEKID);
  353.         put_ebml_num(pb, ebml_id_size(entry->elementid), 0);
  354.         put_ebml_id(pb, entry->elementid);
  355.  
  356.         put_ebml_uint(pb, MATROSKA_ID_SEEKPOSITION, entry->segmentpos);
  357.         end_ebml_master(pb, seekentry);
  358.     }
  359.     end_ebml_master(pb, metaseek);
  360.  
  361.     if (seekhead->reserved_size > 0) {
  362.         uint64_t remaining = seekhead->filepos + seekhead->reserved_size - avio_tell(pb);
  363.         put_ebml_void(pb, remaining);
  364.         avio_seek(pb, currentpos, SEEK_SET);
  365.  
  366.         currentpos = seekhead->filepos;
  367.     }
  368. fail:
  369.     av_freep(&seekhead->entries);
  370.     av_free(seekhead);
  371.  
  372.     return currentpos;
  373. }
  374.  
  375. static mkv_cues * mkv_start_cues(int64_t segment_offset)
  376. {
  377.     mkv_cues *cues = av_mallocz(sizeof(mkv_cues));
  378.     if (cues == NULL)
  379.         return NULL;
  380.  
  381.     cues->segment_offset = segment_offset;
  382.     return cues;
  383. }
  384.  
  385. static int mkv_add_cuepoint(mkv_cues *cues, int stream, int64_t ts, int64_t cluster_pos, int64_t relative_pos,
  386.                             int64_t duration)
  387. {
  388.     mkv_cuepoint *entries = cues->entries;
  389.  
  390.     if (ts < 0)
  391.         return 0;
  392.  
  393.     entries = av_realloc_array(entries, cues->num_entries + 1, sizeof(mkv_cuepoint));
  394.     if (entries == NULL)
  395.         return AVERROR(ENOMEM);
  396.     cues->entries = entries;
  397.  
  398.     cues->entries[cues->num_entries].pts           = ts;
  399.     cues->entries[cues->num_entries].tracknum      = stream + 1;
  400.     cues->entries[cues->num_entries].cluster_pos   = cluster_pos - cues->segment_offset;
  401.     cues->entries[cues->num_entries].relative_pos  = relative_pos;
  402.     cues->entries[cues->num_entries++].duration    = duration;
  403.  
  404.     return 0;
  405. }
  406.  
  407. static int64_t mkv_write_cues(AVIOContext *pb, mkv_cues *cues, mkv_track *tracks, int num_tracks)
  408. {
  409.     ebml_master cues_element;
  410.     int64_t currentpos;
  411.     int i, j;
  412.  
  413.     currentpos = avio_tell(pb);
  414.     cues_element = start_ebml_master(pb, MATROSKA_ID_CUES, 0);
  415.  
  416.     for (i = 0; i < cues->num_entries; i++) {
  417.         ebml_master cuepoint, track_positions;
  418.         mkv_cuepoint *entry = &cues->entries[i];
  419.         uint64_t pts = entry->pts;
  420.  
  421.         cuepoint = start_ebml_master(pb, MATROSKA_ID_POINTENTRY, MAX_CUEPOINT_SIZE(num_tracks));
  422.         put_ebml_uint(pb, MATROSKA_ID_CUETIME, pts);
  423.  
  424.         // put all the entries from different tracks that have the exact same
  425.         // timestamp into the same CuePoint
  426.         for (j = 0; j < num_tracks; j++)
  427.             tracks[j].has_cue = 0;
  428.         for (j = 0; j < cues->num_entries - i && entry[j].pts == pts; j++) {
  429.             int tracknum = entry[j].tracknum - 1;
  430.             av_assert0(tracknum>=0 && tracknum<num_tracks);
  431.             if (tracks[tracknum].has_cue)
  432.                 continue;
  433.             tracks[tracknum].has_cue = 1;
  434.             track_positions = start_ebml_master(pb, MATROSKA_ID_CUETRACKPOSITION, MAX_CUETRACKPOS_SIZE);
  435.             put_ebml_uint(pb, MATROSKA_ID_CUETRACK           , entry[j].tracknum   );
  436.             put_ebml_uint(pb, MATROSKA_ID_CUECLUSTERPOSITION , entry[j].cluster_pos);
  437.             put_ebml_uint(pb, MATROSKA_ID_CUERELATIVEPOSITION, entry[j].relative_pos);
  438.             if (entry[j].duration != -1)
  439.                 put_ebml_uint(pb, MATROSKA_ID_CUEDURATION    , entry[j].duration);
  440.             end_ebml_master(pb, track_positions);
  441.         }
  442.         i += j - 1;
  443.         end_ebml_master(pb, cuepoint);
  444.     }
  445.     end_ebml_master(pb, cues_element);
  446.  
  447.     return currentpos;
  448. }
  449.  
  450. static int put_xiph_codecpriv(AVFormatContext *s, AVIOContext *pb, AVCodecContext *codec)
  451. {
  452.     uint8_t *header_start[3];
  453.     int header_len[3];
  454.     int first_header_size;
  455.     int j;
  456.  
  457.     if (codec->codec_id == AV_CODEC_ID_VORBIS)
  458.         first_header_size = 30;
  459.     else
  460.         first_header_size = 42;
  461.  
  462.     if (avpriv_split_xiph_headers(codec->extradata, codec->extradata_size,
  463.                               first_header_size, header_start, header_len) < 0) {
  464.         av_log(s, AV_LOG_ERROR, "Extradata corrupt.\n");
  465.         return -1;
  466.     }
  467.  
  468.     avio_w8(pb, 2);                    // number packets - 1
  469.     for (j = 0; j < 2; j++) {
  470.         put_xiph_size(pb, header_len[j]);
  471.     }
  472.     for (j = 0; j < 3; j++)
  473.         avio_write(pb, header_start[j], header_len[j]);
  474.  
  475.     return 0;
  476. }
  477.  
  478. static int put_wv_codecpriv(AVIOContext *pb, AVCodecContext *codec)
  479. {
  480.     if (codec->extradata && codec->extradata_size == 2)
  481.         avio_write(pb, codec->extradata, 2);
  482.     else
  483.         avio_wl16(pb, 0x403); // fallback to the version mentioned in matroska specs
  484.     return 0;
  485. }
  486.  
  487. static void get_aac_sample_rates(AVFormatContext *s, AVCodecContext *codec, int *sample_rate, int *output_sample_rate)
  488. {
  489.     MPEG4AudioConfig mp4ac;
  490.  
  491.     if (avpriv_mpeg4audio_get_config(&mp4ac, codec->extradata,
  492.                                      codec->extradata_size * 8, 1) < 0) {
  493.         av_log(s, AV_LOG_WARNING, "Error parsing AAC extradata, unable to determine samplerate.\n");
  494.         return;
  495.     }
  496.  
  497.     *sample_rate        = mp4ac.sample_rate;
  498.     *output_sample_rate = mp4ac.ext_sample_rate;
  499. }
  500.  
  501. static int mkv_write_codecprivate(AVFormatContext *s, AVIOContext *pb, AVCodecContext *codec, int native_id, int qt_id)
  502. {
  503.     AVIOContext *dyn_cp;
  504.     uint8_t *codecpriv;
  505.     int ret, codecpriv_size;
  506.  
  507.     ret = avio_open_dyn_buf(&dyn_cp);
  508.     if(ret < 0)
  509.         return ret;
  510.  
  511.     if (native_id) {
  512.         if (codec->codec_id == AV_CODEC_ID_VORBIS || codec->codec_id == AV_CODEC_ID_THEORA)
  513.             ret = put_xiph_codecpriv(s, dyn_cp, codec);
  514.         else if (codec->codec_id == AV_CODEC_ID_FLAC)
  515.             ret = ff_flac_write_header(dyn_cp, codec, 1);
  516.         else if (codec->codec_id == AV_CODEC_ID_WAVPACK)
  517.             ret = put_wv_codecpriv(dyn_cp, codec);
  518.         else if (codec->codec_id == AV_CODEC_ID_H264)
  519.             ret = ff_isom_write_avcc(dyn_cp, codec->extradata, codec->extradata_size);
  520.         else if (codec->codec_id == AV_CODEC_ID_ALAC) {
  521.             if (codec->extradata_size < 36) {
  522.                 av_log(s, AV_LOG_ERROR,
  523.                        "Invalid extradata found, ALAC expects a 36-byte "
  524.                        "QuickTime atom.");
  525.                 ret = AVERROR_INVALIDDATA;
  526.             } else
  527.                 avio_write(dyn_cp, codec->extradata + 12,
  528.                                    codec->extradata_size - 12);
  529.         }
  530.         else if (codec->extradata_size && codec->codec_id != AV_CODEC_ID_TTA)
  531.             avio_write(dyn_cp, codec->extradata, codec->extradata_size);
  532.     } else if (codec->codec_type == AVMEDIA_TYPE_VIDEO) {
  533.         if (qt_id) {
  534.             if (!codec->codec_tag)
  535.                 codec->codec_tag = ff_codec_get_tag(ff_codec_movvideo_tags, codec->codec_id);
  536.             if (codec->extradata_size)
  537.                 avio_write(dyn_cp, codec->extradata, codec->extradata_size);
  538.         } else {
  539.             if (!codec->codec_tag)
  540.                 codec->codec_tag = ff_codec_get_tag(ff_codec_bmp_tags, codec->codec_id);
  541.             if (!codec->codec_tag) {
  542.                 av_log(s, AV_LOG_ERROR, "No bmp codec tag found for codec %s\n",
  543.                        avcodec_get_name(codec->codec_id));
  544.                 ret = AVERROR(EINVAL);
  545.             }
  546.  
  547.             ff_put_bmp_header(dyn_cp, codec, ff_codec_bmp_tags, 0);
  548.         }
  549.  
  550.     } else if (codec->codec_type == AVMEDIA_TYPE_AUDIO) {
  551.         unsigned int tag;
  552.         tag = ff_codec_get_tag(ff_codec_wav_tags, codec->codec_id);
  553.         if (!tag) {
  554.             av_log(s, AV_LOG_ERROR, "No wav codec tag found for codec %s\n",
  555.                    avcodec_get_name(codec->codec_id));
  556.             ret = AVERROR(EINVAL);
  557.         }
  558.         if (!codec->codec_tag)
  559.             codec->codec_tag = tag;
  560.  
  561.         ff_put_wav_header(dyn_cp, codec);
  562.     }
  563.  
  564.     codecpriv_size = avio_close_dyn_buf(dyn_cp, &codecpriv);
  565.     if (codecpriv_size)
  566.         put_ebml_binary(pb, MATROSKA_ID_CODECPRIVATE, codecpriv, codecpriv_size);
  567.     av_free(codecpriv);
  568.     return ret;
  569. }
  570.  
  571. static int mkv_write_tracks(AVFormatContext *s)
  572. {
  573.     MatroskaMuxContext *mkv = s->priv_data;
  574.     AVIOContext *pb = s->pb;
  575.     ebml_master tracks;
  576.     int i, j, ret, default_stream_exists = 0;
  577.  
  578.     ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_TRACKS, avio_tell(pb));
  579.     if (ret < 0) return ret;
  580.  
  581.     tracks = start_ebml_master(pb, MATROSKA_ID_TRACKS, 0);
  582.     for (i = 0; i < s->nb_streams; i++) {
  583.         AVStream *st = s->streams[i];
  584.         default_stream_exists |= st->disposition & AV_DISPOSITION_DEFAULT;
  585.     }
  586.     for (i = 0; i < s->nb_streams; i++) {
  587.         AVStream *st = s->streams[i];
  588.         AVCodecContext *codec = st->codec;
  589.         ebml_master subinfo, track;
  590.         int native_id = 0;
  591.         int qt_id = 0;
  592.         int bit_depth = av_get_bits_per_sample(codec->codec_id);
  593.         int sample_rate = codec->sample_rate;
  594.         int output_sample_rate = 0;
  595.         AVDictionaryEntry *tag;
  596.  
  597.         if (codec->codec_type == AVMEDIA_TYPE_ATTACHMENT) {
  598.             mkv->have_attachments = 1;
  599.             continue;
  600.         }
  601.  
  602.         if (!bit_depth)
  603.             bit_depth = av_get_bytes_per_sample(codec->sample_fmt) << 3;
  604.         if (!bit_depth)
  605.             bit_depth = codec->bits_per_coded_sample;
  606.  
  607.         if (codec->codec_id == AV_CODEC_ID_AAC)
  608.             get_aac_sample_rates(s, codec, &sample_rate, &output_sample_rate);
  609.  
  610.         track = start_ebml_master(pb, MATROSKA_ID_TRACKENTRY, 0);
  611.         put_ebml_uint (pb, MATROSKA_ID_TRACKNUMBER     , i + 1);
  612.         put_ebml_uint (pb, MATROSKA_ID_TRACKUID        , i + 1);
  613.         put_ebml_uint (pb, MATROSKA_ID_TRACKFLAGLACING , 0);    // no lacing (yet)
  614.  
  615.         if ((tag = av_dict_get(st->metadata, "title", NULL, 0)))
  616.             put_ebml_string(pb, MATROSKA_ID_TRACKNAME, tag->value);
  617.         tag = av_dict_get(st->metadata, "language", NULL, 0);
  618.         if (mkv->mode != MODE_WEBM || codec->codec_id != AV_CODEC_ID_WEBVTT) {
  619.             put_ebml_string(pb, MATROSKA_ID_TRACKLANGUAGE, tag ? tag->value:"und");
  620.         } else if (tag && tag->value) {
  621.             put_ebml_string(pb, MATROSKA_ID_TRACKLANGUAGE, tag->value);
  622.         }
  623.  
  624.         // The default value for TRACKFLAGDEFAULT is 1, so add element
  625.         // if we need to clear it.
  626.         if (default_stream_exists && !(st->disposition & AV_DISPOSITION_DEFAULT))
  627.             put_ebml_uint(pb, MATROSKA_ID_TRACKFLAGDEFAULT, !!(st->disposition & AV_DISPOSITION_DEFAULT));
  628.  
  629.         if (st->disposition & AV_DISPOSITION_FORCED)
  630.             put_ebml_uint(pb, MATROSKA_ID_TRACKFLAGFORCED, 1);
  631.  
  632.         if (mkv->mode == MODE_WEBM && codec->codec_id == AV_CODEC_ID_WEBVTT) {
  633.             const char *codec_id;
  634.             if (st->disposition & AV_DISPOSITION_CAPTIONS) {
  635.                 codec_id = "D_WEBVTT/CAPTIONS";
  636.                 native_id = MATROSKA_TRACK_TYPE_SUBTITLE;
  637.             } else if (st->disposition & AV_DISPOSITION_DESCRIPTIONS) {
  638.                 codec_id = "D_WEBVTT/DESCRIPTIONS";
  639.                 native_id = MATROSKA_TRACK_TYPE_METADATA;
  640.             } else if (st->disposition & AV_DISPOSITION_METADATA) {
  641.                 codec_id = "D_WEBVTT/METADATA";
  642.                 native_id = MATROSKA_TRACK_TYPE_METADATA;
  643.             } else {
  644.                 codec_id = "D_WEBVTT/SUBTITLES";
  645.                 native_id = MATROSKA_TRACK_TYPE_SUBTITLE;
  646.             }
  647.             put_ebml_string(pb, MATROSKA_ID_CODECID, codec_id);
  648.         } else {
  649.             // look for a codec ID string specific to mkv to use,
  650.             // if none are found, use AVI codes
  651.             for (j = 0; ff_mkv_codec_tags[j].id != AV_CODEC_ID_NONE; j++) {
  652.                 if (ff_mkv_codec_tags[j].id == codec->codec_id) {
  653.                     put_ebml_string(pb, MATROSKA_ID_CODECID, ff_mkv_codec_tags[j].str);
  654.                     native_id = 1;
  655.                     break;
  656.                 }
  657.             }
  658.         }
  659.  
  660.         if (codec->codec_id == AV_CODEC_ID_OPUS) {
  661.             uint64_t codec_delay =av_rescale_q(codec->delay,
  662.                                                (AVRational){1, codec->sample_rate},
  663.                                                (AVRational){1, 1000000000});
  664.             put_ebml_uint(pb, MATROSKA_ID_CODECDELAY, codec_delay);
  665.             put_ebml_uint(pb, MATROSKA_ID_SEEKPREROLL, OPUS_SEEK_PREROLL);
  666.  
  667.         }
  668.  
  669.         if (mkv->mode == MODE_WEBM && !(codec->codec_id == AV_CODEC_ID_VP8 ||
  670.                                         codec->codec_id == AV_CODEC_ID_VP9 ||
  671.                                       ((codec->codec_id == AV_CODEC_ID_OPUS)&&(codec->strict_std_compliance <= FF_COMPLIANCE_EXPERIMENTAL)) ||
  672.                                         codec->codec_id == AV_CODEC_ID_VORBIS ||
  673.                                         codec->codec_id == AV_CODEC_ID_WEBVTT)) {
  674.             av_log(s, AV_LOG_ERROR,
  675.                    "Only VP8,VP9 video and Vorbis,Opus(experimental, use -strict -2) audio and WebVTT subtitles are supported for WebM.\n");
  676.             return AVERROR(EINVAL);
  677.         }
  678.  
  679.         switch (codec->codec_type) {
  680.             case AVMEDIA_TYPE_VIDEO:
  681.                 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_VIDEO);
  682.                 if(st->avg_frame_rate.num && st->avg_frame_rate.den && 1.0/av_q2d(st->avg_frame_rate) > av_q2d(codec->time_base))
  683.                     put_ebml_uint(pb, MATROSKA_ID_TRACKDEFAULTDURATION, 1E9/av_q2d(st->avg_frame_rate));
  684.                 else
  685.                     put_ebml_uint(pb, MATROSKA_ID_TRACKDEFAULTDURATION, av_q2d(codec->time_base)*1E9);
  686.  
  687.                 if (!native_id &&
  688.                       ff_codec_get_tag(ff_codec_movvideo_tags, codec->codec_id) &&
  689.                     (!ff_codec_get_tag(ff_codec_bmp_tags,   codec->codec_id)
  690.                      || codec->codec_id == AV_CODEC_ID_SVQ1
  691.                      || codec->codec_id == AV_CODEC_ID_SVQ3
  692.                      || codec->codec_id == AV_CODEC_ID_CINEPAK))
  693.                     qt_id = 1;
  694.  
  695.                 if (qt_id)
  696.                     put_ebml_string(pb, MATROSKA_ID_CODECID, "V_QUICKTIME");
  697.                 else if (!native_id) {
  698.                     // if there is no mkv-specific codec ID, use VFW mode
  699.                     put_ebml_string(pb, MATROSKA_ID_CODECID, "V_MS/VFW/FOURCC");
  700.                     mkv->tracks[i].write_dts = 1;
  701.                 }
  702.  
  703.                 subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKVIDEO, 0);
  704.                 // XXX: interlace flag?
  705.                 put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELWIDTH , codec->width);
  706.                 put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELHEIGHT, codec->height);
  707.  
  708.                 if ((tag = av_dict_get(st->metadata, "stereo_mode", NULL, 0)) ||
  709.                     (tag = av_dict_get( s->metadata, "stereo_mode", NULL, 0))) {
  710.                     // save stereo mode flag
  711.                     uint64_t st_mode = MATROSKA_VIDEO_STEREO_MODE_COUNT;
  712.  
  713.                     for (j=0; j<MATROSKA_VIDEO_STEREO_MODE_COUNT; j++)
  714.                         if (!strcmp(tag->value, ff_matroska_video_stereo_mode[j])){
  715.                             st_mode = j;
  716.                             break;
  717.                         }
  718.  
  719.                     if ((mkv->mode == MODE_WEBM && st_mode > 3 && st_mode != 11)
  720.                         || st_mode >= MATROSKA_VIDEO_STEREO_MODE_COUNT) {
  721.                         av_log(s, AV_LOG_ERROR,
  722.                                "The specified stereo mode is not valid.\n");
  723.                         return AVERROR(EINVAL);
  724.                     } else
  725.                         put_ebml_uint(pb, MATROSKA_ID_VIDEOSTEREOMODE, st_mode);
  726.                 }
  727.  
  728.                 if ((tag = av_dict_get(st->metadata, "alpha_mode", NULL, 0)) ||
  729.                     (tag = av_dict_get( s->metadata, "alpha_mode", NULL, 0)) ||
  730.                     (codec->pix_fmt == AV_PIX_FMT_YUVA420P)) {
  731.                     put_ebml_uint(pb, MATROSKA_ID_VIDEOALPHAMODE, 1);
  732.                 }
  733.  
  734.                 if (st->sample_aspect_ratio.num) {
  735.                     int64_t d_width = av_rescale(codec->width, st->sample_aspect_ratio.num, st->sample_aspect_ratio.den);
  736.                     if (d_width > INT_MAX) {
  737.                         av_log(s, AV_LOG_ERROR, "Overflow in display width\n");
  738.                         return AVERROR(EINVAL);
  739.                     }
  740.                     put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYWIDTH , d_width);
  741.                     put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYHEIGHT, codec->height);
  742.                 }
  743.  
  744.                 if (codec->codec_id == AV_CODEC_ID_RAWVIDEO) {
  745.                     uint32_t color_space = av_le2ne32(codec->codec_tag);
  746.                     put_ebml_binary(pb, MATROSKA_ID_VIDEOCOLORSPACE, &color_space, sizeof(color_space));
  747.                 }
  748.                 end_ebml_master(pb, subinfo);
  749.                 break;
  750.  
  751.             case AVMEDIA_TYPE_AUDIO:
  752.                 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_AUDIO);
  753.  
  754.                 if (!native_id)
  755.                     // no mkv-specific ID, use ACM mode
  756.                     put_ebml_string(pb, MATROSKA_ID_CODECID, "A_MS/ACM");
  757.  
  758.                 subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKAUDIO, 0);
  759.                 put_ebml_uint  (pb, MATROSKA_ID_AUDIOCHANNELS    , codec->channels);
  760.                 put_ebml_float (pb, MATROSKA_ID_AUDIOSAMPLINGFREQ, sample_rate);
  761.                 if (output_sample_rate)
  762.                     put_ebml_float(pb, MATROSKA_ID_AUDIOOUTSAMPLINGFREQ, output_sample_rate);
  763.                 if (bit_depth)
  764.                     put_ebml_uint(pb, MATROSKA_ID_AUDIOBITDEPTH, bit_depth);
  765.                 end_ebml_master(pb, subinfo);
  766.                 break;
  767.  
  768.             case AVMEDIA_TYPE_SUBTITLE:
  769.                 if (!native_id) {
  770.                     av_log(s, AV_LOG_ERROR, "Subtitle codec %d is not supported.\n", codec->codec_id);
  771.                     return AVERROR(ENOSYS);
  772.                 }
  773.  
  774.                 if (mkv->mode != MODE_WEBM || codec->codec_id != AV_CODEC_ID_WEBVTT)
  775.                     native_id = MATROSKA_TRACK_TYPE_SUBTITLE;
  776.  
  777.                 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, native_id);
  778.                 break;
  779.             default:
  780.                 av_log(s, AV_LOG_ERROR, "Only audio, video, and subtitles are supported for Matroska.\n");
  781.                 return AVERROR(EINVAL);
  782.         }
  783.  
  784.         if (mkv->mode != MODE_WEBM || codec->codec_id != AV_CODEC_ID_WEBVTT) {
  785.             ret = mkv_write_codecprivate(s, pb, codec, native_id, qt_id);
  786.             if (ret < 0) return ret;
  787.         }
  788.  
  789.         end_ebml_master(pb, track);
  790.  
  791.         // ms precision is the de-facto standard timescale for mkv files
  792.         avpriv_set_pts_info(st, 64, 1, 1000);
  793.     }
  794.     end_ebml_master(pb, tracks);
  795.     return 0;
  796. }
  797.  
  798. static int mkv_write_chapters(AVFormatContext *s)
  799. {
  800.     MatroskaMuxContext *mkv = s->priv_data;
  801.     AVIOContext *pb = s->pb;
  802.     ebml_master chapters, editionentry;
  803.     AVRational scale = {1, 1E9};
  804.     int i, ret;
  805.  
  806.     if (!s->nb_chapters || mkv->wrote_chapters)
  807.         return 0;
  808.  
  809.     ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_CHAPTERS, avio_tell(pb));
  810.     if (ret < 0) return ret;
  811.  
  812.     chapters     = start_ebml_master(pb, MATROSKA_ID_CHAPTERS    , 0);
  813.     editionentry = start_ebml_master(pb, MATROSKA_ID_EDITIONENTRY, 0);
  814.     put_ebml_uint(pb, MATROSKA_ID_EDITIONFLAGDEFAULT, 1);
  815.     put_ebml_uint(pb, MATROSKA_ID_EDITIONFLAGHIDDEN , 0);
  816.     for (i = 0; i < s->nb_chapters; i++) {
  817.         ebml_master chapteratom, chapterdisplay;
  818.         AVChapter *c     = s->chapters[i];
  819.         AVDictionaryEntry *t = NULL;
  820.  
  821.         chapteratom = start_ebml_master(pb, MATROSKA_ID_CHAPTERATOM, 0);
  822.         put_ebml_uint(pb, MATROSKA_ID_CHAPTERUID, c->id + mkv->chapter_id_offset);
  823.         put_ebml_uint(pb, MATROSKA_ID_CHAPTERTIMESTART,
  824.                       av_rescale_q(c->start, c->time_base, scale));
  825.         put_ebml_uint(pb, MATROSKA_ID_CHAPTERTIMEEND,
  826.                       av_rescale_q(c->end,   c->time_base, scale));
  827.         put_ebml_uint(pb, MATROSKA_ID_CHAPTERFLAGHIDDEN , 0);
  828.         put_ebml_uint(pb, MATROSKA_ID_CHAPTERFLAGENABLED, 1);
  829.         if ((t = av_dict_get(c->metadata, "title", NULL, 0))) {
  830.             chapterdisplay = start_ebml_master(pb, MATROSKA_ID_CHAPTERDISPLAY, 0);
  831.             put_ebml_string(pb, MATROSKA_ID_CHAPSTRING, t->value);
  832.             put_ebml_string(pb, MATROSKA_ID_CHAPLANG  , "und");
  833.             end_ebml_master(pb, chapterdisplay);
  834.         }
  835.         end_ebml_master(pb, chapteratom);
  836.     }
  837.     end_ebml_master(pb, editionentry);
  838.     end_ebml_master(pb, chapters);
  839.  
  840.     mkv->wrote_chapters = 1;
  841.     return 0;
  842. }
  843.  
  844. static void mkv_write_simpletag(AVIOContext *pb, AVDictionaryEntry *t)
  845. {
  846.     uint8_t *key = av_strdup(t->key);
  847.     uint8_t *p   = key;
  848.     const uint8_t *lang = NULL;
  849.     ebml_master tag;
  850.  
  851.     if ((p = strrchr(p, '-')) &&
  852.         (lang = av_convert_lang_to(p + 1, AV_LANG_ISO639_2_BIBL)))
  853.         *p = 0;
  854.  
  855.     p = key;
  856.     while (*p) {
  857.         if (*p == ' ')
  858.             *p = '_';
  859.         else if (*p >= 'a' && *p <= 'z')
  860.             *p -= 'a' - 'A';
  861.         p++;
  862.     }
  863.  
  864.     tag = start_ebml_master(pb, MATROSKA_ID_SIMPLETAG, 0);
  865.     put_ebml_string(pb, MATROSKA_ID_TAGNAME, key);
  866.     if (lang)
  867.         put_ebml_string(pb, MATROSKA_ID_TAGLANG, lang);
  868.     put_ebml_string(pb, MATROSKA_ID_TAGSTRING, t->value);
  869.     end_ebml_master(pb, tag);
  870.  
  871.     av_freep(&key);
  872. }
  873.  
  874. static int mkv_write_tag(AVFormatContext *s, AVDictionary *m, unsigned int elementid,
  875.                          unsigned int uid, ebml_master *tags)
  876. {
  877.     MatroskaMuxContext *mkv = s->priv_data;
  878.     ebml_master tag, targets;
  879.     AVDictionaryEntry *t = NULL;
  880.     int ret;
  881.  
  882.     if (!tags->pos) {
  883.         ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_TAGS, avio_tell(s->pb));
  884.         if (ret < 0) return ret;
  885.  
  886.         *tags = start_ebml_master(s->pb, MATROSKA_ID_TAGS, 0);
  887.     }
  888.  
  889.     tag     = start_ebml_master(s->pb, MATROSKA_ID_TAG,        0);
  890.     targets = start_ebml_master(s->pb, MATROSKA_ID_TAGTARGETS, 0);
  891.     if (elementid)
  892.         put_ebml_uint(s->pb, elementid, uid);
  893.     end_ebml_master(s->pb, targets);
  894.  
  895.     while ((t = av_dict_get(m, "", t, AV_DICT_IGNORE_SUFFIX)))
  896.         if (av_strcasecmp(t->key, "title") && av_strcasecmp(t->key, "stereo_mode"))
  897.             mkv_write_simpletag(s->pb, t);
  898.  
  899.     end_ebml_master(s->pb, tag);
  900.     return 0;
  901. }
  902.  
  903. static int mkv_check_tag(AVDictionary *m)
  904. {
  905.     AVDictionaryEntry *t = NULL;
  906.  
  907.     while ((t = av_dict_get(m, "", t, AV_DICT_IGNORE_SUFFIX)))
  908.         if (av_strcasecmp(t->key, "title") && av_strcasecmp(t->key, "stereo_mode"))
  909.             return 1;
  910.  
  911.     return 0;
  912. }
  913.  
  914. static int mkv_write_tags(AVFormatContext *s)
  915. {
  916.     MatroskaMuxContext *mkv = s->priv_data;
  917.     ebml_master tags = {0};
  918.     int i, ret;
  919.  
  920.     ff_metadata_conv_ctx(s, ff_mkv_metadata_conv, NULL);
  921.  
  922.     if (mkv_check_tag(s->metadata)) {
  923.         ret = mkv_write_tag(s, s->metadata, 0, 0, &tags);
  924.         if (ret < 0) return ret;
  925.     }
  926.  
  927.     for (i = 0; i < s->nb_streams; i++) {
  928.         AVStream *st = s->streams[i];
  929.  
  930.         if (!mkv_check_tag(st->metadata))
  931.             continue;
  932.  
  933.         ret = mkv_write_tag(s, st->metadata, MATROSKA_ID_TAGTARGETS_TRACKUID, i + 1, &tags);
  934.         if (ret < 0) return ret;
  935.     }
  936.  
  937.     for (i = 0; i < s->nb_chapters; i++) {
  938.         AVChapter *ch = s->chapters[i];
  939.  
  940.         if (!mkv_check_tag(ch->metadata))
  941.             continue;
  942.  
  943.         ret = mkv_write_tag(s, ch->metadata, MATROSKA_ID_TAGTARGETS_CHAPTERUID, ch->id + mkv->chapter_id_offset, &tags);
  944.         if (ret < 0) return ret;
  945.     }
  946.  
  947.     if (tags.pos)
  948.         end_ebml_master(s->pb, tags);
  949.     return 0;
  950. }
  951.  
  952. static int mkv_write_attachments(AVFormatContext *s)
  953. {
  954.     MatroskaMuxContext *mkv = s->priv_data;
  955.     AVIOContext *pb = s->pb;
  956.     ebml_master attachments;
  957.     AVLFG c;
  958.     int i, ret;
  959.  
  960.     if (!mkv->have_attachments)
  961.         return 0;
  962.  
  963.     av_lfg_init(&c, av_get_random_seed());
  964.  
  965.     ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_ATTACHMENTS, avio_tell(pb));
  966.     if (ret < 0) return ret;
  967.  
  968.     attachments = start_ebml_master(pb, MATROSKA_ID_ATTACHMENTS, 0);
  969.  
  970.     for (i = 0; i < s->nb_streams; i++) {
  971.         AVStream *st = s->streams[i];
  972.         ebml_master attached_file;
  973.         AVDictionaryEntry *t;
  974.         const char *mimetype = NULL;
  975.         uint64_t fileuid;
  976.  
  977.         if (st->codec->codec_type != AVMEDIA_TYPE_ATTACHMENT)
  978.             continue;
  979.  
  980.         attached_file = start_ebml_master(pb, MATROSKA_ID_ATTACHEDFILE, 0);
  981.  
  982.         if (t = av_dict_get(st->metadata, "title", NULL, 0))
  983.             put_ebml_string(pb, MATROSKA_ID_FILEDESC, t->value);
  984.         if (!(t = av_dict_get(st->metadata, "filename", NULL, 0))) {
  985.             av_log(s, AV_LOG_ERROR, "Attachment stream %d has no filename tag.\n", i);
  986.             return AVERROR(EINVAL);
  987.         }
  988.         put_ebml_string(pb, MATROSKA_ID_FILENAME, t->value);
  989.         if (t = av_dict_get(st->metadata, "mimetype", NULL, 0))
  990.             mimetype = t->value;
  991.         else if (st->codec->codec_id != AV_CODEC_ID_NONE ) {
  992.             int i;
  993.             for (i = 0; ff_mkv_mime_tags[i].id != AV_CODEC_ID_NONE; i++)
  994.                 if (ff_mkv_mime_tags[i].id == st->codec->codec_id) {
  995.                     mimetype = ff_mkv_mime_tags[i].str;
  996.                     break;
  997.                 }
  998.         }
  999.         if (!mimetype) {
  1000.             av_log(s, AV_LOG_ERROR, "Attachment stream %d has no mimetype tag and "
  1001.                                     "it cannot be deduced from the codec id.\n", i);
  1002.             return AVERROR(EINVAL);
  1003.         }
  1004.  
  1005.         if (st->codec->flags & CODEC_FLAG_BITEXACT) {
  1006.             struct AVSHA *sha = av_sha_alloc();
  1007.             uint8_t digest[20];
  1008.             if (!sha)
  1009.                 return AVERROR(ENOMEM);
  1010.             av_sha_init(sha, 160);
  1011.             av_sha_update(sha, st->codec->extradata, st->codec->extradata_size);
  1012.             av_sha_final(sha, digest);
  1013.             av_free(sha);
  1014.             fileuid = AV_RL64(digest);
  1015.         } else {
  1016.             fileuid = av_lfg_get(&c);
  1017.         }
  1018.         av_log(s, AV_LOG_VERBOSE, "Using %.16"PRIx64" for attachment %d\n",
  1019.                fileuid, i);
  1020.  
  1021.         put_ebml_string(pb, MATROSKA_ID_FILEMIMETYPE, mimetype);
  1022.         put_ebml_binary(pb, MATROSKA_ID_FILEDATA, st->codec->extradata, st->codec->extradata_size);
  1023.         put_ebml_uint(pb, MATROSKA_ID_FILEUID, fileuid);
  1024.         end_ebml_master(pb, attached_file);
  1025.     }
  1026.     end_ebml_master(pb, attachments);
  1027.  
  1028.     return 0;
  1029. }
  1030.  
  1031. static int mkv_write_header(AVFormatContext *s)
  1032. {
  1033.     MatroskaMuxContext *mkv = s->priv_data;
  1034.     AVIOContext *pb = s->pb;
  1035.     ebml_master ebml_header, segment_info;
  1036.     AVDictionaryEntry *tag;
  1037.     int ret, i;
  1038.  
  1039.     if (!strcmp(s->oformat->name, "webm")) mkv->mode = MODE_WEBM;
  1040.     else                                   mkv->mode = MODE_MATROSKAv2;
  1041.  
  1042.     if (s->avoid_negative_ts < 0)
  1043.         s->avoid_negative_ts = 1;
  1044.  
  1045.     for (i = 0; i < s->nb_streams; i++)
  1046.         if (s->streams[i]->codec->codec_id == AV_CODEC_ID_ATRAC3 ||
  1047.             s->streams[i]->codec->codec_id == AV_CODEC_ID_COOK ||
  1048.             s->streams[i]->codec->codec_id == AV_CODEC_ID_RA_288 ||
  1049.             s->streams[i]->codec->codec_id == AV_CODEC_ID_SIPR ||
  1050.             s->streams[i]->codec->codec_id == AV_CODEC_ID_RV10 ||
  1051.             s->streams[i]->codec->codec_id == AV_CODEC_ID_RV20) {
  1052.             av_log(s, AV_LOG_ERROR,
  1053.                    "The Matroska muxer does not yet support muxing %s\n",
  1054.                    avcodec_get_name(s->streams[i]->codec->codec_id));
  1055.             return AVERROR_PATCHWELCOME;
  1056.         }
  1057.  
  1058.     mkv->tracks = av_mallocz(s->nb_streams * sizeof(*mkv->tracks));
  1059.     if (!mkv->tracks)
  1060.         return AVERROR(ENOMEM);
  1061.  
  1062.     ebml_header = start_ebml_master(pb, EBML_ID_HEADER, 0);
  1063.     put_ebml_uint   (pb, EBML_ID_EBMLVERSION        ,           1);
  1064.     put_ebml_uint   (pb, EBML_ID_EBMLREADVERSION    ,           1);
  1065.     put_ebml_uint   (pb, EBML_ID_EBMLMAXIDLENGTH    ,           4);
  1066.     put_ebml_uint   (pb, EBML_ID_EBMLMAXSIZELENGTH  ,           8);
  1067.     put_ebml_string (pb, EBML_ID_DOCTYPE            , s->oformat->name);
  1068.     put_ebml_uint   (pb, EBML_ID_DOCTYPEVERSION     ,           4);
  1069.     put_ebml_uint   (pb, EBML_ID_DOCTYPEREADVERSION ,           2);
  1070.     end_ebml_master(pb, ebml_header);
  1071.  
  1072.     mkv->segment = start_ebml_master(pb, MATROSKA_ID_SEGMENT, 0);
  1073.     mkv->segment_offset = avio_tell(pb);
  1074.  
  1075.     // we write 2 seek heads - one at the end of the file to point to each
  1076.     // cluster, and one at the beginning to point to all other level one
  1077.     // elements (including the seek head at the end of the file), which
  1078.     // isn't more than 10 elements if we only write one of each other
  1079.     // currently defined level 1 element
  1080.     mkv->main_seekhead    = mkv_start_seekhead(pb, mkv->segment_offset, 10);
  1081.     if (!mkv->main_seekhead)
  1082.         return AVERROR(ENOMEM);
  1083.  
  1084.     ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_INFO, avio_tell(pb));
  1085.     if (ret < 0) return ret;
  1086.  
  1087.     segment_info = start_ebml_master(pb, MATROSKA_ID_INFO, 0);
  1088.     put_ebml_uint(pb, MATROSKA_ID_TIMECODESCALE, 1000000);
  1089.     if ((tag = av_dict_get(s->metadata, "title", NULL, 0)))
  1090.         put_ebml_string(pb, MATROSKA_ID_TITLE, tag->value);
  1091.     if (!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT)) {
  1092.         uint32_t segment_uid[4];
  1093.         AVLFG lfg;
  1094.  
  1095.         av_lfg_init(&lfg, av_get_random_seed());
  1096.  
  1097.         for (i = 0; i < 4; i++)
  1098.             segment_uid[i] = av_lfg_get(&lfg);
  1099.  
  1100.         put_ebml_string(pb, MATROSKA_ID_MUXINGAPP , LIBAVFORMAT_IDENT);
  1101.         put_ebml_string(pb, MATROSKA_ID_WRITINGAPP, LIBAVFORMAT_IDENT);
  1102.         put_ebml_binary(pb, MATROSKA_ID_SEGMENTUID, segment_uid, 16);
  1103.     } else {
  1104.         const char *ident = "Lavf";
  1105.         put_ebml_string(pb, MATROSKA_ID_MUXINGAPP , ident);
  1106.         put_ebml_string(pb, MATROSKA_ID_WRITINGAPP, ident);
  1107.     }
  1108.  
  1109.     if (tag = av_dict_get(s->metadata, "creation_time", NULL, 0)) {
  1110.         // Adjust time so it's relative to 2001-01-01 and convert to nanoseconds.
  1111.         int64_t date_utc = (ff_iso8601_to_unix_time(tag->value) - 978307200) * 1000000000;
  1112.         uint8_t date_utc_buf[8];
  1113.         AV_WB64(date_utc_buf, date_utc);
  1114.         put_ebml_binary(pb, MATROSKA_ID_DATEUTC, date_utc_buf, 8);
  1115.     }
  1116.  
  1117.     // reserve space for the duration
  1118.     mkv->duration = 0;
  1119.     mkv->duration_offset = avio_tell(pb);
  1120.     put_ebml_void(pb, 11);                  // assumes double-precision float to be written
  1121.     end_ebml_master(pb, segment_info);
  1122.  
  1123.     ret = mkv_write_tracks(s);
  1124.     if (ret < 0) return ret;
  1125.  
  1126.     for (i = 0; i < s->nb_chapters; i++)
  1127.         mkv->chapter_id_offset = FFMAX(mkv->chapter_id_offset, 1LL - s->chapters[i]->id);
  1128.  
  1129.     if (mkv->mode != MODE_WEBM) {
  1130.         ret = mkv_write_chapters(s);
  1131.         if (ret < 0) return ret;
  1132.  
  1133.         ret = mkv_write_tags(s);
  1134.         if (ret < 0) return ret;
  1135.  
  1136.         ret = mkv_write_attachments(s);
  1137.         if (ret < 0) return ret;
  1138.     }
  1139.  
  1140.     if (!s->pb->seekable)
  1141.         mkv_write_seekhead(pb, mkv->main_seekhead);
  1142.  
  1143.     mkv->cues = mkv_start_cues(mkv->segment_offset);
  1144.     if (mkv->cues == NULL)
  1145.         return AVERROR(ENOMEM);
  1146.  
  1147.     if (pb->seekable && mkv->reserve_cues_space) {
  1148.         mkv->cues_pos = avio_tell(pb);
  1149.         put_ebml_void(pb, mkv->reserve_cues_space);
  1150.     }
  1151.  
  1152.     av_init_packet(&mkv->cur_audio_pkt);
  1153.     mkv->cur_audio_pkt.size = 0;
  1154.     mkv->cluster_pos = -1;
  1155.  
  1156.     avio_flush(pb);
  1157.  
  1158.     // start a new cluster every 5 MB or 5 sec, or 32k / 1 sec for streaming or
  1159.     // after 4k and on a keyframe
  1160.     if (pb->seekable) {
  1161.         if (mkv->cluster_time_limit < 0)
  1162.             mkv->cluster_time_limit = 5000;
  1163.         if (mkv->cluster_size_limit < 0)
  1164.             mkv->cluster_size_limit = 5 * 1024 * 1024;
  1165.     } else {
  1166.         if (mkv->cluster_time_limit < 0)
  1167.             mkv->cluster_time_limit = 1000;
  1168.         if (mkv->cluster_size_limit < 0)
  1169.             mkv->cluster_size_limit = 32 * 1024;
  1170.     }
  1171.  
  1172.     return 0;
  1173. }
  1174.  
  1175. static int mkv_blockgroup_size(int pkt_size)
  1176. {
  1177.     int size = pkt_size + 4;
  1178.     size += ebml_num_size(size);
  1179.     size += 2;              // EBML ID for block and block duration
  1180.     size += 8;              // max size of block duration
  1181.     size += ebml_num_size(size);
  1182.     size += 1;              // blockgroup EBML ID
  1183.     return size;
  1184. }
  1185.  
  1186. static int ass_get_duration(const uint8_t *p)
  1187. {
  1188.     int sh, sm, ss, sc, eh, em, es, ec;
  1189.     uint64_t start, end;
  1190.  
  1191.     if (sscanf(p, "%*[^,],%d:%d:%d%*c%d,%d:%d:%d%*c%d",
  1192.                &sh, &sm, &ss, &sc, &eh, &em, &es, &ec) != 8)
  1193.         return 0;
  1194.     start = 3600000LL*sh + 60000LL*sm + 1000LL*ss + 10LL*sc;
  1195.     end   = 3600000LL*eh + 60000LL*em + 1000LL*es + 10LL*ec;
  1196.     return end - start;
  1197. }
  1198.  
  1199. #if FF_API_ASS_SSA
  1200. static int mkv_write_ass_blocks(AVFormatContext *s, AVIOContext *pb, AVPacket *pkt)
  1201. {
  1202.     MatroskaMuxContext *mkv = s->priv_data;
  1203.     int i, layer = 0, max_duration = 0, size, line_size, data_size = pkt->size;
  1204.     uint8_t *start, *end, *data = pkt->data;
  1205.     ebml_master blockgroup;
  1206.     char buffer[2048];
  1207.  
  1208.     while (data_size) {
  1209.         int duration = ass_get_duration(data);
  1210.         max_duration = FFMAX(duration, max_duration);
  1211.         end = memchr(data, '\n', data_size);
  1212.         size = line_size = end ? end-data+1 : data_size;
  1213.         size -= end ? (end[-1]=='\r')+1 : 0;
  1214.         start = data;
  1215.         for (i=0; i<3; i++, start++)
  1216.             if (!(start = memchr(start, ',', size-(start-data))))
  1217.                 return max_duration;
  1218.         size -= start - data;
  1219.         sscanf(data, "Dialogue: %d,", &layer);
  1220.         i = snprintf(buffer, sizeof(buffer), "%"PRId64",%d,",
  1221.                      s->streams[pkt->stream_index]->nb_frames, layer);
  1222.         size = FFMIN(i+size, sizeof(buffer));
  1223.         memcpy(buffer+i, start, size-i);
  1224.  
  1225.         av_log(s, AV_LOG_DEBUG, "Writing block at offset %" PRIu64 ", size %d, "
  1226.                "pts %" PRId64 ", duration %d\n",
  1227.                avio_tell(pb), size, pkt->pts, duration);
  1228.         blockgroup = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP, mkv_blockgroup_size(size));
  1229.         put_ebml_id(pb, MATROSKA_ID_BLOCK);
  1230.         put_ebml_num(pb, size+4, 0);
  1231.         avio_w8(pb, 0x80 | (pkt->stream_index + 1));     // this assumes stream_index is less than 126
  1232.         avio_wb16(pb, pkt->pts - mkv->cluster_pts);
  1233.         avio_w8(pb, 0);
  1234.         avio_write(pb, buffer, size);
  1235.         put_ebml_uint(pb, MATROSKA_ID_BLOCKDURATION, duration);
  1236.         end_ebml_master(pb, blockgroup);
  1237.  
  1238.         data += line_size;
  1239.         data_size -= line_size;
  1240.     }
  1241.  
  1242.     return max_duration;
  1243. }
  1244. #endif
  1245.  
  1246. static int mkv_strip_wavpack(const uint8_t *src, uint8_t **pdst, int *size)
  1247. {
  1248.     uint8_t *dst;
  1249.     int srclen = *size;
  1250.     int offset = 0;
  1251.     int ret;
  1252.  
  1253.     dst = av_malloc(srclen);
  1254.     if (!dst)
  1255.         return AVERROR(ENOMEM);
  1256.  
  1257.     while (srclen >= WV_HEADER_SIZE) {
  1258.         WvHeader header;
  1259.  
  1260.         ret = ff_wv_parse_header(&header, src);
  1261.         if (ret < 0)
  1262.             goto fail;
  1263.         src    += WV_HEADER_SIZE;
  1264.         srclen -= WV_HEADER_SIZE;
  1265.  
  1266.         if (srclen < header.blocksize) {
  1267.             ret = AVERROR_INVALIDDATA;
  1268.             goto fail;
  1269.         }
  1270.  
  1271.         if (header.initial) {
  1272.             AV_WL32(dst + offset, header.samples);
  1273.             offset += 4;
  1274.         }
  1275.         AV_WL32(dst + offset,     header.flags);
  1276.         AV_WL32(dst + offset + 4, header.crc);
  1277.         offset += 8;
  1278.  
  1279.         if (!(header.initial && header.final)) {
  1280.             AV_WL32(dst + offset, header.blocksize);
  1281.             offset += 4;
  1282.         }
  1283.  
  1284.         memcpy(dst + offset, src, header.blocksize);
  1285.         src    += header.blocksize;
  1286.         srclen -= header.blocksize;
  1287.         offset += header.blocksize;
  1288.     }
  1289.  
  1290.     *pdst = dst;
  1291.     *size = offset;
  1292.  
  1293.     return 0;
  1294. fail:
  1295.     av_freep(&dst);
  1296.     return ret;
  1297. }
  1298.  
  1299. static void mkv_write_block(AVFormatContext *s, AVIOContext *pb,
  1300.                             unsigned int blockid, AVPacket *pkt, int flags)
  1301. {
  1302.     MatroskaMuxContext *mkv = s->priv_data;
  1303.     AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
  1304.     uint8_t *data = NULL, *side_data = NULL;
  1305.     int offset = 0, size = pkt->size, side_data_size = 0;
  1306.     int64_t ts = mkv->tracks[pkt->stream_index].write_dts ? pkt->dts : pkt->pts;
  1307.     uint64_t additional_id = 0, discard_padding = 0;
  1308.     ebml_master block_group, block_additions, block_more;
  1309.  
  1310.     av_log(s, AV_LOG_DEBUG, "Writing block at offset %" PRIu64 ", size %d, "
  1311.            "pts %" PRId64 ", dts %" PRId64 ", duration %d, flags %d\n",
  1312.            avio_tell(pb), pkt->size, pkt->pts, pkt->dts, pkt->duration, flags);
  1313.     if (codec->codec_id == AV_CODEC_ID_H264 && codec->extradata_size > 0 &&
  1314.         (AV_RB24(codec->extradata) == 1 || AV_RB32(codec->extradata) == 1))
  1315.         ff_avc_parse_nal_units_buf(pkt->data, &data, &size);
  1316.     else if (codec->codec_id == AV_CODEC_ID_WAVPACK) {
  1317.         int ret = mkv_strip_wavpack(pkt->data, &data, &size);
  1318.         if (ret < 0) {
  1319.             av_log(s, AV_LOG_ERROR, "Error stripping a WavPack packet.\n");
  1320.             return;
  1321.         }
  1322.     } else
  1323.         data = pkt->data;
  1324.  
  1325.     if (codec->codec_id == AV_CODEC_ID_PRORES) {
  1326.         /* Matroska specification requires to remove the first QuickTime atom
  1327.          */
  1328.         size -= 8;
  1329.         offset = 8;
  1330.     }
  1331.  
  1332.     side_data = av_packet_get_side_data(pkt,
  1333.                                         AV_PKT_DATA_SKIP_SAMPLES,
  1334.                                         &side_data_size);
  1335.  
  1336.     if (side_data && side_data_size >= 10) {
  1337.         discard_padding = av_rescale_q(AV_RL32(side_data + 4),
  1338.                                        (AVRational){1, codec->sample_rate},
  1339.                                        (AVRational){1, 1000000000});
  1340.     }
  1341.  
  1342.     side_data = av_packet_get_side_data(pkt,
  1343.                                         AV_PKT_DATA_MATROSKA_BLOCKADDITIONAL,
  1344.                                         &side_data_size);
  1345.     if (side_data) {
  1346.         additional_id = AV_RB64(side_data);
  1347.         side_data += 8;
  1348.         side_data_size -= 8;
  1349.     }
  1350.  
  1351.     if ((side_data_size && additional_id == 1) || discard_padding) {
  1352.         block_group = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP, 0);
  1353.         blockid = MATROSKA_ID_BLOCK;
  1354.     }
  1355.  
  1356.     put_ebml_id(pb, blockid);
  1357.     put_ebml_num(pb, size+4, 0);
  1358.     avio_w8(pb, 0x80 | (pkt->stream_index + 1));     // this assumes stream_index is less than 126
  1359.     avio_wb16(pb, ts - mkv->cluster_pts);
  1360.     avio_w8(pb, flags);
  1361.     avio_write(pb, data + offset, size);
  1362.     if (data != pkt->data)
  1363.         av_free(data);
  1364.  
  1365.     if (discard_padding) {
  1366.         put_ebml_uint(pb, MATROSKA_ID_DISCARDPADDING, discard_padding);
  1367.     }
  1368.  
  1369.     if (side_data_size && additional_id == 1) {
  1370.         block_additions = start_ebml_master(pb, MATROSKA_ID_BLOCKADDITIONS, 0);
  1371.         block_more = start_ebml_master(pb, MATROSKA_ID_BLOCKMORE, 0);
  1372.         put_ebml_uint(pb, MATROSKA_ID_BLOCKADDID, 1);
  1373.         put_ebml_id(pb, MATROSKA_ID_BLOCKADDITIONAL);
  1374.         put_ebml_num(pb, side_data_size, 0);
  1375.         avio_write(pb, side_data, side_data_size);
  1376.         end_ebml_master(pb, block_more);
  1377.         end_ebml_master(pb, block_additions);
  1378.     }
  1379.     if ((side_data_size && additional_id == 1) || discard_padding) {
  1380.         end_ebml_master(pb, block_group);
  1381.     }
  1382. }
  1383.  
  1384. static int srt_get_duration(uint8_t **buf)
  1385. {
  1386.     int i, duration = 0;
  1387.  
  1388.     for (i=0; i<2 && !duration; i++) {
  1389.         int s_hour, s_min, s_sec, s_hsec, e_hour, e_min, e_sec, e_hsec;
  1390.         if (sscanf(*buf, "%d:%2d:%2d%*1[,.]%3d --> %d:%2d:%2d%*1[,.]%3d",
  1391.                    &s_hour, &s_min, &s_sec, &s_hsec,
  1392.                    &e_hour, &e_min, &e_sec, &e_hsec) == 8) {
  1393.             s_min  +=   60*s_hour;      e_min  +=   60*e_hour;
  1394.             s_sec  +=   60*s_min;       e_sec  +=   60*e_min;
  1395.             s_hsec += 1000*s_sec;       e_hsec += 1000*e_sec;
  1396.             duration = e_hsec - s_hsec;
  1397.         }
  1398.         *buf += ff_subtitles_next_line(*buf);
  1399.     }
  1400.     return duration;
  1401. }
  1402.  
  1403. static int mkv_write_srt_blocks(AVFormatContext *s, AVIOContext *pb, AVPacket *pkt)
  1404. {
  1405.     ebml_master blockgroup;
  1406.     AVPacket pkt2 = *pkt;
  1407.     int64_t duration = srt_get_duration(&pkt2.data);
  1408.     pkt2.size -= pkt2.data - pkt->data;
  1409.  
  1410.     blockgroup = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP,
  1411.                                    mkv_blockgroup_size(pkt2.size));
  1412.     mkv_write_block(s, pb, MATROSKA_ID_BLOCK, &pkt2, 0);
  1413.     put_ebml_uint(pb, MATROSKA_ID_BLOCKDURATION, duration);
  1414.     end_ebml_master(pb, blockgroup);
  1415.  
  1416.     return duration;
  1417. }
  1418.  
  1419. static int mkv_write_vtt_blocks(AVFormatContext *s, AVIOContext *pb, AVPacket *pkt)
  1420. {
  1421.     MatroskaMuxContext *mkv = s->priv_data;
  1422.     ebml_master blockgroup;
  1423.     int id_size, settings_size, size;
  1424.     uint8_t *id, *settings;
  1425.     int64_t ts = mkv->tracks[pkt->stream_index].write_dts ? pkt->dts : pkt->pts;
  1426.     const int flags = 0;
  1427.  
  1428.     id_size = 0;
  1429.     id = av_packet_get_side_data(pkt, AV_PKT_DATA_WEBVTT_IDENTIFIER,
  1430.                                  &id_size);
  1431.  
  1432.     settings_size = 0;
  1433.     settings = av_packet_get_side_data(pkt, AV_PKT_DATA_WEBVTT_SETTINGS,
  1434.                                        &settings_size);
  1435.  
  1436.     size = id_size + 1 + settings_size + 1 + pkt->size;
  1437.  
  1438.     av_log(s, AV_LOG_DEBUG, "Writing block at offset %" PRIu64 ", size %d, "
  1439.            "pts %" PRId64 ", dts %" PRId64 ", duration %d, flags %d\n",
  1440.            avio_tell(pb), size, pkt->pts, pkt->dts, pkt->duration, flags);
  1441.  
  1442.     blockgroup = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP, mkv_blockgroup_size(size));
  1443.  
  1444.     put_ebml_id(pb, MATROSKA_ID_BLOCK);
  1445.     put_ebml_num(pb, size+4, 0);
  1446.     avio_w8(pb, 0x80 | (pkt->stream_index + 1));     // this assumes stream_index is less than 126
  1447.     avio_wb16(pb, ts - mkv->cluster_pts);
  1448.     avio_w8(pb, flags);
  1449.     avio_printf(pb, "%.*s\n%.*s\n%.*s", id_size, id, settings_size, settings, pkt->size, pkt->data);
  1450.  
  1451.     put_ebml_uint(pb, MATROSKA_ID_BLOCKDURATION, pkt->duration);
  1452.     end_ebml_master(pb, blockgroup);
  1453.  
  1454.     return pkt->duration;
  1455. }
  1456.  
  1457. static void mkv_flush_dynbuf(AVFormatContext *s)
  1458. {
  1459.     MatroskaMuxContext *mkv = s->priv_data;
  1460.     int bufsize;
  1461.     uint8_t *dyn_buf;
  1462.  
  1463.     if (!mkv->dyn_bc)
  1464.         return;
  1465.  
  1466.     bufsize = avio_close_dyn_buf(mkv->dyn_bc, &dyn_buf);
  1467.     avio_write(s->pb, dyn_buf, bufsize);
  1468.     av_free(dyn_buf);
  1469.     mkv->dyn_bc = NULL;
  1470. }
  1471.  
  1472. static int mkv_write_packet_internal(AVFormatContext *s, AVPacket *pkt)
  1473. {
  1474.     MatroskaMuxContext *mkv = s->priv_data;
  1475.     AVIOContext *pb = s->pb;
  1476.     AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
  1477.     int keyframe = !!(pkt->flags & AV_PKT_FLAG_KEY);
  1478.     int duration = pkt->duration;
  1479.     int ret;
  1480.     int64_t ts = mkv->tracks[pkt->stream_index].write_dts ? pkt->dts : pkt->pts;
  1481.     int64_t relative_packet_pos;
  1482.  
  1483.     if (ts == AV_NOPTS_VALUE) {
  1484.         av_log(s, AV_LOG_ERROR, "Can't write packet with unknown timestamp\n");
  1485.         return AVERROR(EINVAL);
  1486.     }
  1487.  
  1488.     if (!s->pb->seekable) {
  1489.         if (!mkv->dyn_bc) {
  1490.             if ((ret = avio_open_dyn_buf(&mkv->dyn_bc)) < 0) {
  1491.                 av_log(s, AV_LOG_ERROR, "Failed to open dynamic buffer\n");
  1492.                 return ret;
  1493.             }
  1494.         }
  1495.         pb = mkv->dyn_bc;
  1496.     }
  1497.  
  1498.     if (mkv->cluster_pos == -1) {
  1499.         mkv->cluster_pos = avio_tell(s->pb);
  1500.         mkv->cluster = start_ebml_master(pb, MATROSKA_ID_CLUSTER, 0);
  1501.         put_ebml_uint(pb, MATROSKA_ID_CLUSTERTIMECODE, FFMAX(0, ts));
  1502.         mkv->cluster_pts = FFMAX(0, ts);
  1503.     }
  1504.  
  1505.     relative_packet_pos = avio_tell(s->pb) - mkv->cluster.pos;
  1506.  
  1507.     if (codec->codec_type != AVMEDIA_TYPE_SUBTITLE) {
  1508.         mkv_write_block(s, pb, MATROSKA_ID_SIMPLEBLOCK, pkt, keyframe << 7);
  1509. #if FF_API_ASS_SSA
  1510.     } else if (codec->codec_id == AV_CODEC_ID_SSA) {
  1511.         duration = mkv_write_ass_blocks(s, pb, pkt);
  1512. #endif
  1513.     } else if (codec->codec_id == AV_CODEC_ID_SRT) {
  1514.         duration = mkv_write_srt_blocks(s, pb, pkt);
  1515.     } else if (codec->codec_id == AV_CODEC_ID_WEBVTT) {
  1516.         duration = mkv_write_vtt_blocks(s, pb, pkt);
  1517.     } else {
  1518.         ebml_master blockgroup = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP, mkv_blockgroup_size(pkt->size));
  1519.         /* For backward compatibility, prefer convergence_duration. */
  1520.         if (pkt->convergence_duration > 0) {
  1521.             duration = pkt->convergence_duration;
  1522.         }
  1523.         mkv_write_block(s, pb, MATROSKA_ID_BLOCK, pkt, 0);
  1524.         put_ebml_uint(pb, MATROSKA_ID_BLOCKDURATION, duration);
  1525.         end_ebml_master(pb, blockgroup);
  1526.     }
  1527.  
  1528.     if ((codec->codec_type == AVMEDIA_TYPE_VIDEO && keyframe) || codec->codec_type == AVMEDIA_TYPE_SUBTITLE) {
  1529.         ret = mkv_add_cuepoint(mkv->cues, pkt->stream_index, ts, mkv->cluster_pos, relative_packet_pos,
  1530.                                codec->codec_type == AVMEDIA_TYPE_SUBTITLE ? duration : -1);
  1531.         if (ret < 0) return ret;
  1532.     }
  1533.  
  1534.     mkv->duration = FFMAX(mkv->duration, ts + duration);
  1535.     return 0;
  1536. }
  1537.  
  1538. static int mkv_write_packet(AVFormatContext *s, AVPacket *pkt)
  1539. {
  1540.     MatroskaMuxContext *mkv = s->priv_data;
  1541.     int codec_type          = s->streams[pkt->stream_index]->codec->codec_type;
  1542.     int keyframe            = !!(pkt->flags & AV_PKT_FLAG_KEY);
  1543.     int cluster_size;
  1544.     int64_t cluster_time;
  1545.     AVIOContext *pb;
  1546.     int ret;
  1547.  
  1548.     if (mkv->tracks[pkt->stream_index].write_dts)
  1549.         cluster_time = pkt->dts - mkv->cluster_pts;
  1550.     else
  1551.         cluster_time = pkt->pts - mkv->cluster_pts;
  1552.  
  1553.     // start a new cluster every 5 MB or 5 sec, or 32k / 1 sec for streaming or
  1554.     // after 4k and on a keyframe
  1555.     if (s->pb->seekable) {
  1556.         pb = s->pb;
  1557.         cluster_size = avio_tell(pb) - mkv->cluster_pos;
  1558.     } else {
  1559.         pb = mkv->dyn_bc;
  1560.         cluster_size = avio_tell(pb);
  1561.     }
  1562.  
  1563.     if (mkv->cluster_pos != -1 &&
  1564.         (cluster_size > mkv->cluster_size_limit ||
  1565.          cluster_time > mkv->cluster_time_limit ||
  1566.          (codec_type == AVMEDIA_TYPE_VIDEO && keyframe &&
  1567.           cluster_size > 4 * 1024))) {
  1568.         av_log(s, AV_LOG_DEBUG, "Starting new cluster at offset %" PRIu64
  1569.                " bytes, pts %" PRIu64 "dts %" PRIu64 "\n",
  1570.                avio_tell(pb), pkt->pts, pkt->dts);
  1571.         end_ebml_master(pb, mkv->cluster);
  1572.         mkv->cluster_pos = -1;
  1573.         if (mkv->dyn_bc)
  1574.             mkv_flush_dynbuf(s);
  1575.         avio_flush(s->pb);
  1576.     }
  1577.  
  1578.     // check if we have an audio packet cached
  1579.     if (mkv->cur_audio_pkt.size > 0) {
  1580.         ret = mkv_write_packet_internal(s, &mkv->cur_audio_pkt);
  1581.         av_free_packet(&mkv->cur_audio_pkt);
  1582.         if (ret < 0) {
  1583.             av_log(s, AV_LOG_ERROR, "Could not write cached audio packet ret:%d\n", ret);
  1584.             return ret;
  1585.         }
  1586.     }
  1587.  
  1588.     // buffer an audio packet to ensure the packet containing the video
  1589.     // keyframe's timecode is contained in the same cluster for WebM
  1590.     if (codec_type == AVMEDIA_TYPE_AUDIO) {
  1591.         mkv->cur_audio_pkt = *pkt;
  1592.         if (pkt->buf) {
  1593.             mkv->cur_audio_pkt.buf = av_buffer_ref(pkt->buf);
  1594.             ret = mkv->cur_audio_pkt.buf ? 0 : AVERROR(ENOMEM);
  1595.         } else
  1596.             ret = av_dup_packet(&mkv->cur_audio_pkt);
  1597.             if (mkv->cur_audio_pkt.side_data_elems > 0) {
  1598.                 ret = av_copy_packet_side_data(&mkv->cur_audio_pkt, &mkv->cur_audio_pkt);
  1599.             }
  1600.     } else
  1601.         ret = mkv_write_packet_internal(s, pkt);
  1602.     return ret;
  1603. }
  1604.  
  1605. static int mkv_write_flush_packet(AVFormatContext *s, AVPacket *pkt)
  1606. {
  1607.     MatroskaMuxContext *mkv = s->priv_data;
  1608.     AVIOContext *pb;
  1609.     if (s->pb->seekable)
  1610.         pb = s->pb;
  1611.     else
  1612.         pb = mkv->dyn_bc;
  1613.     if (!pkt) {
  1614.         if (mkv->cluster_pos != -1) {
  1615.             av_log(s, AV_LOG_DEBUG, "Flushing cluster at offset %" PRIu64
  1616.                    " bytes\n", avio_tell(pb));
  1617.             end_ebml_master(pb, mkv->cluster);
  1618.             mkv->cluster_pos = -1;
  1619.             if (mkv->dyn_bc)
  1620.                 mkv_flush_dynbuf(s);
  1621.             avio_flush(s->pb);
  1622.         }
  1623.         return 0;
  1624.     }
  1625.     return mkv_write_packet(s, pkt);
  1626. }
  1627.  
  1628. static int mkv_write_trailer(AVFormatContext *s)
  1629. {
  1630.     MatroskaMuxContext *mkv = s->priv_data;
  1631.     AVIOContext *pb = s->pb;
  1632.     int64_t currentpos, cuespos;
  1633.     int ret;
  1634.  
  1635.     // check if we have an audio packet cached
  1636.     if (mkv->cur_audio_pkt.size > 0) {
  1637.         ret = mkv_write_packet_internal(s, &mkv->cur_audio_pkt);
  1638.         av_free_packet(&mkv->cur_audio_pkt);
  1639.         if (ret < 0) {
  1640.             av_log(s, AV_LOG_ERROR, "Could not write cached audio packet ret:%d\n", ret);
  1641.             return ret;
  1642.         }
  1643.     }
  1644.  
  1645.     if (mkv->dyn_bc) {
  1646.         end_ebml_master(mkv->dyn_bc, mkv->cluster);
  1647.         mkv_flush_dynbuf(s);
  1648.     } else if (mkv->cluster_pos != -1) {
  1649.         end_ebml_master(pb, mkv->cluster);
  1650.     }
  1651.  
  1652.     if (mkv->mode != MODE_WEBM) {
  1653.         ret = mkv_write_chapters(s);
  1654.         if (ret < 0) return ret;
  1655.     }
  1656.  
  1657.     if (pb->seekable) {
  1658.         if (mkv->cues->num_entries) {
  1659.             if (mkv->reserve_cues_space) {
  1660.                 int64_t cues_end;
  1661.  
  1662.                 currentpos = avio_tell(pb);
  1663.                 avio_seek(pb, mkv->cues_pos, SEEK_SET);
  1664.  
  1665.                 cuespos = mkv_write_cues(pb, mkv->cues, mkv->tracks, s->nb_streams);
  1666.                 cues_end = avio_tell(pb);
  1667.                 if (cues_end > cuespos + mkv->reserve_cues_space) {
  1668.                     av_log(s, AV_LOG_ERROR, "Insufficient space reserved for cues: %d "
  1669.                            "(needed: %"PRId64").\n", mkv->reserve_cues_space,
  1670.                            cues_end - cuespos);
  1671.                     return AVERROR(EINVAL);
  1672.                 }
  1673.  
  1674.                 if (cues_end < cuespos + mkv->reserve_cues_space)
  1675.                     put_ebml_void(pb, mkv->reserve_cues_space - (cues_end - cuespos));
  1676.  
  1677.                 avio_seek(pb, currentpos, SEEK_SET);
  1678.             } else {
  1679.                 cuespos = mkv_write_cues(pb, mkv->cues, mkv->tracks, s->nb_streams);
  1680.             }
  1681.  
  1682.             ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_CUES, cuespos);
  1683.             if (ret < 0) return ret;
  1684.         }
  1685.  
  1686.         mkv_write_seekhead(pb, mkv->main_seekhead);
  1687.  
  1688.         // update the duration
  1689.         av_log(s, AV_LOG_DEBUG, "end duration = %" PRIu64 "\n", mkv->duration);
  1690.         currentpos = avio_tell(pb);
  1691.         avio_seek(pb, mkv->duration_offset, SEEK_SET);
  1692.         put_ebml_float(pb, MATROSKA_ID_DURATION, mkv->duration);
  1693.  
  1694.         avio_seek(pb, currentpos, SEEK_SET);
  1695.     }
  1696.  
  1697.     end_ebml_master(pb, mkv->segment);
  1698.     av_freep(&mkv->tracks);
  1699.     av_freep(&mkv->cues->entries);
  1700.     av_freep(&mkv->cues);
  1701.  
  1702.     return 0;
  1703. }
  1704.  
  1705. static int mkv_query_codec(enum AVCodecID codec_id, int std_compliance)
  1706. {
  1707.     int i;
  1708.     for (i = 0; ff_mkv_codec_tags[i].id != AV_CODEC_ID_NONE; i++)
  1709.         if (ff_mkv_codec_tags[i].id == codec_id)
  1710.             return 1;
  1711.  
  1712.     if (std_compliance < FF_COMPLIANCE_NORMAL) {                // mkv theoretically supports any
  1713.         enum AVMediaType type = avcodec_get_type(codec_id);     // video/audio through VFW/ACM
  1714.         if (type == AVMEDIA_TYPE_VIDEO || type == AVMEDIA_TYPE_AUDIO)
  1715.             return 1;
  1716.     }
  1717.  
  1718.     return 0;
  1719. }
  1720.  
  1721. static const AVCodecTag additional_audio_tags[] = {
  1722.     { AV_CODEC_ID_ALAC,      0XFFFFFFFF },
  1723.     { AV_CODEC_ID_EAC3,      0XFFFFFFFF },
  1724.     { AV_CODEC_ID_MLP,       0xFFFFFFFF },
  1725.     { AV_CODEC_ID_OPUS,      0xFFFFFFFF },
  1726.     { AV_CODEC_ID_PCM_S16BE, 0xFFFFFFFF },
  1727.     { AV_CODEC_ID_PCM_S24BE, 0xFFFFFFFF },
  1728.     { AV_CODEC_ID_PCM_S32BE, 0xFFFFFFFF },
  1729.     { AV_CODEC_ID_QDM2,      0xFFFFFFFF },
  1730.     { AV_CODEC_ID_RA_144,    0xFFFFFFFF },
  1731.     { AV_CODEC_ID_RA_288,    0xFFFFFFFF },
  1732.     { AV_CODEC_ID_COOK,      0xFFFFFFFF },
  1733.     { AV_CODEC_ID_TRUEHD,    0xFFFFFFFF },
  1734.     { AV_CODEC_ID_NONE,      0xFFFFFFFF }
  1735. };
  1736.  
  1737. static const AVCodecTag additional_video_tags[] = {
  1738.     { AV_CODEC_ID_RV10,      0xFFFFFFFF },
  1739.     { AV_CODEC_ID_RV20,      0xFFFFFFFF },
  1740.     { AV_CODEC_ID_RV30,      0xFFFFFFFF },
  1741.     { AV_CODEC_ID_RV40,      0xFFFFFFFF },
  1742.     { AV_CODEC_ID_VP9,       0xFFFFFFFF },
  1743.     { AV_CODEC_ID_NONE,      0xFFFFFFFF }
  1744. };
  1745.  
  1746. #define OFFSET(x) offsetof(MatroskaMuxContext, x)
  1747. #define FLAGS AV_OPT_FLAG_ENCODING_PARAM
  1748. static const AVOption options[] = {
  1749.     { "reserve_index_space", "Reserve a given amount of space (in bytes) at the beginning of the file for the index (cues).", OFFSET(reserve_cues_space), AV_OPT_TYPE_INT,   { .i64 = 0 },   0, INT_MAX,   FLAGS },
  1750.     { "cluster_size_limit",  "Store at most the provided amount of bytes in a cluster. ",                                     OFFSET(cluster_size_limit), AV_OPT_TYPE_INT  , { .i64 = -1 }, -1, INT_MAX,   FLAGS },
  1751.     { "cluster_time_limit",  "Store at most the provided number of milliseconds in a cluster.",                               OFFSET(cluster_time_limit), AV_OPT_TYPE_INT64, { .i64 = -1 }, -1, INT64_MAX, FLAGS },
  1752.     { NULL },
  1753. };
  1754.  
  1755. #if CONFIG_MATROSKA_MUXER
  1756. static const AVClass matroska_class = {
  1757.     .class_name = "matroska muxer",
  1758.     .item_name  = av_default_item_name,
  1759.     .option     = options,
  1760.     .version    = LIBAVUTIL_VERSION_INT,
  1761. };
  1762.  
  1763. AVOutputFormat ff_matroska_muxer = {
  1764.     .name              = "matroska",
  1765.     .long_name         = NULL_IF_CONFIG_SMALL("Matroska"),
  1766.     .mime_type         = "video/x-matroska",
  1767.     .extensions        = "mkv",
  1768.     .priv_data_size    = sizeof(MatroskaMuxContext),
  1769.     .audio_codec       = CONFIG_LIBVORBIS_ENCODER ?
  1770.                          AV_CODEC_ID_VORBIS : AV_CODEC_ID_AC3,
  1771.     .video_codec       = CONFIG_LIBX264_ENCODER ?
  1772.                          AV_CODEC_ID_H264 : AV_CODEC_ID_MPEG4,
  1773.     .write_header      = mkv_write_header,
  1774.     .write_packet      = mkv_write_flush_packet,
  1775.     .write_trailer     = mkv_write_trailer,
  1776.     .flags             = AVFMT_GLOBALHEADER | AVFMT_VARIABLE_FPS |
  1777.                          AVFMT_TS_NONSTRICT | AVFMT_ALLOW_FLUSH,
  1778.     .codec_tag         = (const AVCodecTag* const []){
  1779.          ff_codec_bmp_tags, ff_codec_wav_tags,
  1780.          additional_audio_tags, additional_video_tags, 0
  1781.     },
  1782. #if FF_API_ASS_SSA
  1783.     .subtitle_codec    = AV_CODEC_ID_SSA,
  1784. #else
  1785.     .subtitle_codec    = AV_CODEC_ID_ASS,
  1786. #endif
  1787.     .query_codec       = mkv_query_codec,
  1788.     .priv_class        = &matroska_class,
  1789. };
  1790. #endif
  1791.  
  1792. #if CONFIG_WEBM_MUXER
  1793. static const AVClass webm_class = {
  1794.     .class_name = "webm muxer",
  1795.     .item_name  = av_default_item_name,
  1796.     .option     = options,
  1797.     .version    = LIBAVUTIL_VERSION_INT,
  1798. };
  1799.  
  1800. AVOutputFormat ff_webm_muxer = {
  1801.     .name              = "webm",
  1802.     .long_name         = NULL_IF_CONFIG_SMALL("WebM"),
  1803.     .mime_type         = "video/webm",
  1804.     .extensions        = "webm",
  1805.     .priv_data_size    = sizeof(MatroskaMuxContext),
  1806.     .audio_codec       = AV_CODEC_ID_VORBIS,
  1807.     .video_codec       = AV_CODEC_ID_VP8,
  1808.     .subtitle_codec    = AV_CODEC_ID_WEBVTT,
  1809.     .write_header      = mkv_write_header,
  1810.     .write_packet      = mkv_write_flush_packet,
  1811.     .write_trailer     = mkv_write_trailer,
  1812.     .flags             = AVFMT_GLOBALHEADER | AVFMT_VARIABLE_FPS |
  1813.                          AVFMT_TS_NONSTRICT | AVFMT_ALLOW_FLUSH,
  1814.     .priv_class        = &webm_class,
  1815. };
  1816. #endif
  1817.  
  1818. #if CONFIG_MATROSKA_AUDIO_MUXER
  1819. static const AVClass mka_class = {
  1820.     .class_name = "matroska audio muxer",
  1821.     .item_name  = av_default_item_name,
  1822.     .option     = options,
  1823.     .version    = LIBAVUTIL_VERSION_INT,
  1824. };
  1825. AVOutputFormat ff_matroska_audio_muxer = {
  1826.     .name              = "matroska",
  1827.     .long_name         = NULL_IF_CONFIG_SMALL("Matroska Audio"),
  1828.     .mime_type         = "audio/x-matroska",
  1829.     .extensions        = "mka",
  1830.     .priv_data_size    = sizeof(MatroskaMuxContext),
  1831.     .audio_codec       = CONFIG_LIBVORBIS_ENCODER ?
  1832.                          AV_CODEC_ID_VORBIS : AV_CODEC_ID_AC3,
  1833.     .video_codec       = AV_CODEC_ID_NONE,
  1834.     .write_header      = mkv_write_header,
  1835.     .write_packet      = mkv_write_flush_packet,
  1836.     .write_trailer     = mkv_write_trailer,
  1837.     .flags             = AVFMT_GLOBALHEADER | AVFMT_TS_NONSTRICT |
  1838.                          AVFMT_ALLOW_FLUSH,
  1839.     .codec_tag         = (const AVCodecTag* const []){
  1840.         ff_codec_wav_tags, additional_audio_tags, 0
  1841.     },
  1842.     .priv_class        = &mka_class,
  1843. };
  1844. #endif
  1845.