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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 <stdint.h>
  23.  
  24. #include "avc.h"
  25. #include "hevc.h"
  26. #include "avformat.h"
  27. #include "avio_internal.h"
  28. #include "avlanguage.h"
  29. #include "flacenc.h"
  30. #include "internal.h"
  31. #include "isom.h"
  32. #include "matroska.h"
  33. #include "riff.h"
  34. #include "subtitles.h"
  35. #include "vorbiscomment.h"
  36. #include "wv.h"
  37.  
  38. #include "libavutil/avstring.h"
  39. #include "libavutil/channel_layout.h"
  40. #include "libavutil/dict.h"
  41. #include "libavutil/intfloat.h"
  42. #include "libavutil/intreadwrite.h"
  43. #include "libavutil/lfg.h"
  44. #include "libavutil/mathematics.h"
  45. #include "libavutil/opt.h"
  46. #include "libavutil/random_seed.h"
  47. #include "libavutil/rational.h"
  48. #include "libavutil/samplefmt.h"
  49. #include "libavutil/sha.h"
  50. #include "libavutil/stereo3d.h"
  51.  
  52. #include "libavcodec/xiph.h"
  53. #include "libavcodec/mpeg4audio.h"
  54. #include "libavcodec/internal.h"
  55.  
  56. typedef struct ebml_master {
  57.     int64_t         pos;                ///< absolute offset in the file where the master's elements start
  58.     int             sizebytes;          ///< how many bytes were reserved for the size
  59. } ebml_master;
  60.  
  61. typedef struct mkv_seekhead_entry {
  62.     unsigned int    elementid;
  63.     uint64_t        segmentpos;
  64. } mkv_seekhead_entry;
  65.  
  66. typedef struct mkv_seekhead {
  67.     int64_t                 filepos;
  68.     int64_t                 segment_offset;     ///< the file offset to the beginning of the segment
  69.     int                     reserved_size;      ///< -1 if appending to file
  70.     int                     max_entries;
  71.     mkv_seekhead_entry      *entries;
  72.     int                     num_entries;
  73. } mkv_seekhead;
  74.  
  75. typedef struct mkv_cuepoint {
  76.     uint64_t        pts;
  77.     int             stream_idx;
  78.     int             tracknum;
  79.     int64_t         cluster_pos;        ///< file offset of the cluster containing the block
  80.     int64_t         relative_pos;       ///< relative offset from the position of the cluster containing the block
  81.     int64_t         duration;           ///< duration of the block according to time base
  82. } mkv_cuepoint;
  83.  
  84. typedef struct mkv_cues {
  85.     int64_t         segment_offset;
  86.     mkv_cuepoint    *entries;
  87.     int             num_entries;
  88. } mkv_cues;
  89.  
  90. typedef struct mkv_track {
  91.     int             write_dts;
  92.     int             has_cue;
  93.     int64_t         ts_offset;
  94. } mkv_track;
  95.  
  96. #define MODE_MATROSKAv2 0x01
  97. #define MODE_WEBM       0x02
  98.  
  99. /** Maximum number of tracks allowed in a Matroska file (with track numbers in
  100.  * range 1 to 126 (inclusive) */
  101. #define MAX_TRACKS 126
  102.  
  103. typedef struct MatroskaMuxContext {
  104.     const AVClass  *class;
  105.     int             mode;
  106.     AVIOContext   *dyn_bc;
  107.     ebml_master     segment;
  108.     int64_t         segment_offset;
  109.     ebml_master     cluster;
  110.     int64_t         cluster_pos;        ///< file offset of the current cluster
  111.     int64_t         cluster_pts;
  112.     int64_t         duration_offset;
  113.     int64_t         duration;
  114.     mkv_seekhead    *main_seekhead;
  115.     mkv_cues        *cues;
  116.     mkv_track       *tracks;
  117.  
  118.     AVPacket        cur_audio_pkt;
  119.  
  120.     int have_attachments;
  121.  
  122.     int reserve_cues_space;
  123.     int cluster_size_limit;
  124.     int64_t cues_pos;
  125.     int64_t cluster_time_limit;
  126.     int is_dash;
  127.     int dash_track_number;
  128.     int is_live;
  129.  
  130.     uint32_t chapter_id_offset;
  131.     int wrote_chapters;
  132.  
  133.     int64_t last_track_timestamp[MAX_TRACKS];
  134.  
  135.     int64_t* stream_durations;
  136.     int64_t* stream_duration_offsets;
  137.  
  138.     int allow_raw_vfw;
  139. } MatroskaMuxContext;
  140.  
  141.  
  142. /** 2 bytes * 3 for EBML IDs, 3 1-byte EBML lengths, 8 bytes for 64 bit
  143.  * offset, 4 bytes for target EBML ID */
  144. #define MAX_SEEKENTRY_SIZE 21
  145.  
  146. /** per-cuepoint-track - 5 1-byte EBML IDs, 5 1-byte EBML sizes, 4
  147.  * 8-byte uint max */
  148. #define MAX_CUETRACKPOS_SIZE 42
  149.  
  150. /** per-cuepoint - 2 1-byte EBML IDs, 2 1-byte EBML sizes, 8-byte uint max */
  151. #define MAX_CUEPOINT_SIZE(num_tracks) 12 + MAX_CUETRACKPOS_SIZE * num_tracks
  152.  
  153. /** Seek preroll value for opus */
  154. #define OPUS_SEEK_PREROLL 80000000
  155.  
  156. static int ebml_id_size(unsigned int id)
  157. {
  158.     return (av_log2(id + 1) - 1) / 7 + 1;
  159. }
  160.  
  161. static void put_ebml_id(AVIOContext *pb, unsigned int id)
  162. {
  163.     int i = ebml_id_size(id);
  164.     while (i--)
  165.         avio_w8(pb, (uint8_t)(id >> (i * 8)));
  166. }
  167.  
  168. /**
  169.  * Write an EBML size meaning "unknown size".
  170.  *
  171.  * @param bytes The number of bytes the size should occupy (maximum: 8).
  172.  */
  173. static void put_ebml_size_unknown(AVIOContext *pb, int bytes)
  174. {
  175.     av_assert0(bytes <= 8);
  176.     avio_w8(pb, 0x1ff >> bytes);
  177.     ffio_fill(pb, 0xff, bytes - 1);
  178. }
  179.  
  180. /**
  181.  * Calculate how many bytes are needed to represent a given number in EBML.
  182.  */
  183. static int ebml_num_size(uint64_t num)
  184. {
  185.     int bytes = 1;
  186.     while ((num + 1) >> bytes * 7)
  187.         bytes++;
  188.     return bytes;
  189. }
  190.  
  191. /**
  192.  * Write a number in EBML variable length format.
  193.  *
  194.  * @param bytes The number of bytes that need to be used to write the number.
  195.  *              If zero, any number of bytes can be used.
  196.  */
  197. static void put_ebml_num(AVIOContext *pb, uint64_t num, int bytes)
  198. {
  199.     int i, needed_bytes = ebml_num_size(num);
  200.  
  201.     // sizes larger than this are currently undefined in EBML
  202.     av_assert0(num < (1ULL << 56) - 1);
  203.  
  204.     if (bytes == 0)
  205.         // don't care how many bytes are used, so use the min
  206.         bytes = needed_bytes;
  207.     // the bytes needed to write the given size would exceed the bytes
  208.     // that we need to use, so write unknown size. This shouldn't happen.
  209.     av_assert0(bytes >= needed_bytes);
  210.  
  211.     num |= 1ULL << bytes * 7;
  212.     for (i = bytes - 1; i >= 0; i--)
  213.         avio_w8(pb, (uint8_t)(num >> i * 8));
  214. }
  215.  
  216. static void put_ebml_uint(AVIOContext *pb, unsigned int elementid, uint64_t val)
  217. {
  218.     int i, bytes = 1;
  219.     uint64_t tmp = val;
  220.     while (tmp >>= 8)
  221.         bytes++;
  222.  
  223.     put_ebml_id(pb, elementid);
  224.     put_ebml_num(pb, bytes, 0);
  225.     for (i = bytes - 1; i >= 0; i--)
  226.         avio_w8(pb, (uint8_t)(val >> i * 8));
  227. }
  228.  
  229. static void put_ebml_sint(AVIOContext *pb, unsigned int elementid, int64_t val)
  230. {
  231.     int i, bytes = 1;
  232.     uint64_t tmp = 2*(val < 0 ? val^-1 : val);
  233.  
  234.     while (tmp>>=8) bytes++;
  235.  
  236.     put_ebml_id(pb, elementid);
  237.     put_ebml_num(pb, bytes, 0);
  238.     for (i = bytes - 1; i >= 0; i--)
  239.         avio_w8(pb, (uint8_t)(val >> i * 8));
  240. }
  241.  
  242. static void put_ebml_float(AVIOContext *pb, unsigned int elementid, double val)
  243. {
  244.     put_ebml_id(pb, elementid);
  245.     put_ebml_num(pb, 8, 0);
  246.     avio_wb64(pb, av_double2int(val));
  247. }
  248.  
  249. static void put_ebml_binary(AVIOContext *pb, unsigned int elementid,
  250.                             const void *buf, int size)
  251. {
  252.     put_ebml_id(pb, elementid);
  253.     put_ebml_num(pb, size, 0);
  254.     avio_write(pb, buf, size);
  255. }
  256.  
  257. static void put_ebml_string(AVIOContext *pb, unsigned int elementid,
  258.                             const char *str)
  259. {
  260.     put_ebml_binary(pb, elementid, str, strlen(str));
  261. }
  262.  
  263. /**
  264.  * Write a void element of a given size. Useful for reserving space in
  265.  * the file to be written to later.
  266.  *
  267.  * @param size The number of bytes to reserve, which must be at least 2.
  268.  */
  269. static void put_ebml_void(AVIOContext *pb, uint64_t size)
  270. {
  271.     int64_t currentpos = avio_tell(pb);
  272.  
  273.     av_assert0(size >= 2);
  274.  
  275.     put_ebml_id(pb, EBML_ID_VOID);
  276.     // we need to subtract the length needed to store the size from the
  277.     // size we need to reserve so 2 cases, we use 8 bytes to store the
  278.     // size if possible, 1 byte otherwise
  279.     if (size < 10)
  280.         put_ebml_num(pb, size - 1, 0);
  281.     else
  282.         put_ebml_num(pb, size - 9, 8);
  283.     ffio_fill(pb, 0, currentpos + size - avio_tell(pb));
  284. }
  285.  
  286. static ebml_master start_ebml_master(AVIOContext *pb, unsigned int elementid,
  287.                                      uint64_t expectedsize)
  288. {
  289.     int bytes = expectedsize ? ebml_num_size(expectedsize) : 8;
  290.     put_ebml_id(pb, elementid);
  291.     put_ebml_size_unknown(pb, bytes);
  292.     return (ebml_master) {avio_tell(pb), bytes };
  293. }
  294.  
  295. static void end_ebml_master(AVIOContext *pb, ebml_master master)
  296. {
  297.     int64_t pos = avio_tell(pb);
  298.  
  299.     if (avio_seek(pb, master.pos - master.sizebytes, SEEK_SET) < 0)
  300.         return;
  301.     put_ebml_num(pb, pos - master.pos, master.sizebytes);
  302.     avio_seek(pb, pos, SEEK_SET);
  303. }
  304.  
  305. static void put_xiph_size(AVIOContext *pb, int size)
  306. {
  307.     ffio_fill(pb, 255, size / 255);
  308.     avio_w8(pb, size % 255);
  309. }
  310.  
  311. /**
  312.  * Free the members allocated in the mux context.
  313.  */
  314. static void mkv_free(MatroskaMuxContext *mkv) {
  315.     if (mkv->main_seekhead) {
  316.         av_freep(&mkv->main_seekhead->entries);
  317.         av_freep(&mkv->main_seekhead);
  318.     }
  319.     if (mkv->cues) {
  320.         av_freep(&mkv->cues->entries);
  321.         av_freep(&mkv->cues);
  322.     }
  323.     av_freep(&mkv->tracks);
  324.     av_freep(&mkv->stream_durations);
  325.     av_freep(&mkv->stream_duration_offsets);
  326. }
  327.  
  328. /**
  329.  * Initialize a mkv_seekhead element to be ready to index level 1 Matroska
  330.  * elements. If a maximum number of elements is specified, enough space
  331.  * will be reserved at the current file location to write a seek head of
  332.  * that size.
  333.  *
  334.  * @param segment_offset The absolute offset to the position in the file
  335.  *                       where the segment begins.
  336.  * @param numelements The maximum number of elements that will be indexed
  337.  *                    by this seek head, 0 if unlimited.
  338.  */
  339. static mkv_seekhead *mkv_start_seekhead(AVIOContext *pb, int64_t segment_offset,
  340.                                         int numelements)
  341. {
  342.     mkv_seekhead *new_seekhead = av_mallocz(sizeof(mkv_seekhead));
  343.     if (!new_seekhead)
  344.         return NULL;
  345.  
  346.     new_seekhead->segment_offset = segment_offset;
  347.  
  348.     if (numelements > 0) {
  349.         new_seekhead->filepos = avio_tell(pb);
  350.         // 21 bytes max for a seek entry, 10 bytes max for the SeekHead ID
  351.         // and size, and 3 bytes to guarantee that an EBML void element
  352.         // will fit afterwards
  353.         new_seekhead->reserved_size = numelements * MAX_SEEKENTRY_SIZE + 13;
  354.         new_seekhead->max_entries   = numelements;
  355.         put_ebml_void(pb, new_seekhead->reserved_size);
  356.     }
  357.     return new_seekhead;
  358. }
  359.  
  360. static int mkv_add_seekhead_entry(mkv_seekhead *seekhead, unsigned int elementid, uint64_t filepos)
  361. {
  362.     mkv_seekhead_entry *entries = seekhead->entries;
  363.  
  364.     // don't store more elements than we reserved space for
  365.     if (seekhead->max_entries > 0 && seekhead->max_entries <= seekhead->num_entries)
  366.         return -1;
  367.  
  368.     entries = av_realloc_array(entries, seekhead->num_entries + 1, sizeof(mkv_seekhead_entry));
  369.     if (!entries)
  370.         return AVERROR(ENOMEM);
  371.     seekhead->entries = entries;
  372.  
  373.     seekhead->entries[seekhead->num_entries].elementid    = elementid;
  374.     seekhead->entries[seekhead->num_entries++].segmentpos = filepos - seekhead->segment_offset;
  375.  
  376.     return 0;
  377. }
  378.  
  379. /**
  380.  * Write the seek head to the file and free it. If a maximum number of
  381.  * elements was specified to mkv_start_seekhead(), the seek head will
  382.  * be written at the location reserved for it. Otherwise, it is written
  383.  * at the current location in the file.
  384.  *
  385.  * @return The file offset where the seekhead was written,
  386.  * -1 if an error occurred.
  387.  */
  388. static int64_t mkv_write_seekhead(AVIOContext *pb, MatroskaMuxContext *mkv)
  389. {
  390.     mkv_seekhead *seekhead = mkv->main_seekhead;
  391.     ebml_master metaseek, seekentry;
  392.     int64_t currentpos;
  393.     int i;
  394.  
  395.     currentpos = avio_tell(pb);
  396.  
  397.     if (seekhead->reserved_size > 0) {
  398.         if (avio_seek(pb, seekhead->filepos, SEEK_SET) < 0) {
  399.             currentpos = -1;
  400.             goto fail;
  401.         }
  402.     }
  403.  
  404.     metaseek = start_ebml_master(pb, MATROSKA_ID_SEEKHEAD, seekhead->reserved_size);
  405.     for (i = 0; i < seekhead->num_entries; i++) {
  406.         mkv_seekhead_entry *entry = &seekhead->entries[i];
  407.  
  408.         seekentry = start_ebml_master(pb, MATROSKA_ID_SEEKENTRY, MAX_SEEKENTRY_SIZE);
  409.  
  410.         put_ebml_id(pb, MATROSKA_ID_SEEKID);
  411.         put_ebml_num(pb, ebml_id_size(entry->elementid), 0);
  412.         put_ebml_id(pb, entry->elementid);
  413.  
  414.         put_ebml_uint(pb, MATROSKA_ID_SEEKPOSITION, entry->segmentpos);
  415.         end_ebml_master(pb, seekentry);
  416.     }
  417.     end_ebml_master(pb, metaseek);
  418.  
  419.     if (seekhead->reserved_size > 0) {
  420.         uint64_t remaining = seekhead->filepos + seekhead->reserved_size - avio_tell(pb);
  421.         put_ebml_void(pb, remaining);
  422.         avio_seek(pb, currentpos, SEEK_SET);
  423.  
  424.         currentpos = seekhead->filepos;
  425.     }
  426. fail:
  427.     av_freep(&mkv->main_seekhead->entries);
  428.     av_freep(&mkv->main_seekhead);
  429.  
  430.     return currentpos;
  431. }
  432.  
  433. static mkv_cues *mkv_start_cues(int64_t segment_offset)
  434. {
  435.     mkv_cues *cues = av_mallocz(sizeof(mkv_cues));
  436.     if (!cues)
  437.         return NULL;
  438.  
  439.     cues->segment_offset = segment_offset;
  440.     return cues;
  441. }
  442.  
  443. static int mkv_add_cuepoint(mkv_cues *cues, int stream, int tracknum, int64_t ts,
  444.                             int64_t cluster_pos, int64_t relative_pos, int64_t duration)
  445. {
  446.     mkv_cuepoint *entries = cues->entries;
  447.  
  448.     if (ts < 0)
  449.         return 0;
  450.  
  451.     entries = av_realloc_array(entries, cues->num_entries + 1, sizeof(mkv_cuepoint));
  452.     if (!entries)
  453.         return AVERROR(ENOMEM);
  454.     cues->entries = entries;
  455.  
  456.     cues->entries[cues->num_entries].pts           = ts;
  457.     cues->entries[cues->num_entries].stream_idx    = stream;
  458.     cues->entries[cues->num_entries].tracknum      = tracknum;
  459.     cues->entries[cues->num_entries].cluster_pos   = cluster_pos - cues->segment_offset;
  460.     cues->entries[cues->num_entries].relative_pos  = relative_pos;
  461.     cues->entries[cues->num_entries++].duration    = duration;
  462.  
  463.     return 0;
  464. }
  465.  
  466. static int64_t mkv_write_cues(AVFormatContext *s, mkv_cues *cues, mkv_track *tracks, int num_tracks)
  467. {
  468.     AVIOContext *pb = s->pb;
  469.     ebml_master cues_element;
  470.     int64_t currentpos;
  471.     int i, j;
  472.  
  473.     currentpos = avio_tell(pb);
  474.     cues_element = start_ebml_master(pb, MATROSKA_ID_CUES, 0);
  475.  
  476.     for (i = 0; i < cues->num_entries; i++) {
  477.         ebml_master cuepoint, track_positions;
  478.         mkv_cuepoint *entry = &cues->entries[i];
  479.         uint64_t pts = entry->pts;
  480.         int ctp_nb = 0;
  481.  
  482.         // Calculate the number of entries, so we know the element size
  483.         for (j = 0; j < num_tracks; j++)
  484.             tracks[j].has_cue = 0;
  485.         for (j = 0; j < cues->num_entries - i && entry[j].pts == pts; j++) {
  486.             int tracknum = entry[j].stream_idx;
  487.             av_assert0(tracknum>=0 && tracknum<num_tracks);
  488.             if (tracks[tracknum].has_cue && s->streams[tracknum]->codec->codec_type != AVMEDIA_TYPE_SUBTITLE)
  489.                 continue;
  490.             tracks[tracknum].has_cue = 1;
  491.             ctp_nb ++;
  492.         }
  493.  
  494.         cuepoint = start_ebml_master(pb, MATROSKA_ID_POINTENTRY, MAX_CUEPOINT_SIZE(ctp_nb));
  495.         put_ebml_uint(pb, MATROSKA_ID_CUETIME, pts);
  496.  
  497.         // put all the entries from different tracks that have the exact same
  498.         // timestamp into the same CuePoint
  499.         for (j = 0; j < num_tracks; j++)
  500.             tracks[j].has_cue = 0;
  501.         for (j = 0; j < cues->num_entries - i && entry[j].pts == pts; j++) {
  502.             int tracknum = entry[j].stream_idx;
  503.             av_assert0(tracknum>=0 && tracknum<num_tracks);
  504.             if (tracks[tracknum].has_cue && s->streams[tracknum]->codec->codec_type != AVMEDIA_TYPE_SUBTITLE)
  505.                 continue;
  506.             tracks[tracknum].has_cue = 1;
  507.             track_positions = start_ebml_master(pb, MATROSKA_ID_CUETRACKPOSITION, MAX_CUETRACKPOS_SIZE);
  508.             put_ebml_uint(pb, MATROSKA_ID_CUETRACK           , entry[j].tracknum   );
  509.             put_ebml_uint(pb, MATROSKA_ID_CUECLUSTERPOSITION , entry[j].cluster_pos);
  510.             put_ebml_uint(pb, MATROSKA_ID_CUERELATIVEPOSITION, entry[j].relative_pos);
  511.             if (entry[j].duration != -1)
  512.                 put_ebml_uint(pb, MATROSKA_ID_CUEDURATION    , entry[j].duration);
  513.             end_ebml_master(pb, track_positions);
  514.         }
  515.         i += j - 1;
  516.         end_ebml_master(pb, cuepoint);
  517.     }
  518.     end_ebml_master(pb, cues_element);
  519.  
  520.     return currentpos;
  521. }
  522.  
  523. static int put_xiph_codecpriv(AVFormatContext *s, AVIOContext *pb, AVCodecContext *codec)
  524. {
  525.     const uint8_t *header_start[3];
  526.     int header_len[3];
  527.     int first_header_size;
  528.     int j;
  529.  
  530.     if (codec->codec_id == AV_CODEC_ID_VORBIS)
  531.         first_header_size = 30;
  532.     else
  533.         first_header_size = 42;
  534.  
  535.     if (avpriv_split_xiph_headers(codec->extradata, codec->extradata_size,
  536.                               first_header_size, header_start, header_len) < 0) {
  537.         av_log(s, AV_LOG_ERROR, "Extradata corrupt.\n");
  538.         return -1;
  539.     }
  540.  
  541.     avio_w8(pb, 2);                    // number packets - 1
  542.     for (j = 0; j < 2; j++) {
  543.         put_xiph_size(pb, header_len[j]);
  544.     }
  545.     for (j = 0; j < 3; j++)
  546.         avio_write(pb, header_start[j], header_len[j]);
  547.  
  548.     return 0;
  549. }
  550.  
  551. static int put_wv_codecpriv(AVIOContext *pb, AVCodecContext *codec)
  552. {
  553.     if (codec->extradata && codec->extradata_size == 2)
  554.         avio_write(pb, codec->extradata, 2);
  555.     else
  556.         avio_wl16(pb, 0x403); // fallback to the version mentioned in matroska specs
  557.     return 0;
  558. }
  559.  
  560. static int put_flac_codecpriv(AVFormatContext *s,
  561.                               AVIOContext *pb, AVCodecContext *codec)
  562. {
  563.     int write_comment = (codec->channel_layout &&
  564.                          !(codec->channel_layout & ~0x3ffffULL) &&
  565.                          !ff_flac_is_native_layout(codec->channel_layout));
  566.     int ret = ff_flac_write_header(pb, codec->extradata, codec->extradata_size,
  567.                                    !write_comment);
  568.  
  569.     if (ret < 0)
  570.         return ret;
  571.  
  572.     if (write_comment) {
  573.         const char *vendor = (s->flags & AVFMT_FLAG_BITEXACT) ?
  574.                              "Lavf" : LIBAVFORMAT_IDENT;
  575.         AVDictionary *dict = NULL;
  576.         uint8_t buf[32], *data, *p;
  577.         int64_t len;
  578.  
  579.         snprintf(buf, sizeof(buf), "0x%"PRIx64, codec->channel_layout);
  580.         av_dict_set(&dict, "WAVEFORMATEXTENSIBLE_CHANNEL_MASK", buf, 0);
  581.  
  582.         len = ff_vorbiscomment_length(dict, vendor);
  583.         if (len >= ((1<<24) - 4))
  584.             return AVERROR(EINVAL);
  585.  
  586.         data = av_malloc(len + 4);
  587.         if (!data) {
  588.             av_dict_free(&dict);
  589.             return AVERROR(ENOMEM);
  590.         }
  591.  
  592.         data[0] = 0x84;
  593.         AV_WB24(data + 1, len);
  594.  
  595.         p = data + 4;
  596.         ff_vorbiscomment_write(&p, &dict, vendor);
  597.  
  598.         avio_write(pb, data, len + 4);
  599.  
  600.         av_freep(&data);
  601.         av_dict_free(&dict);
  602.     }
  603.  
  604.     return 0;
  605. }
  606.  
  607. static int get_aac_sample_rates(AVFormatContext *s, AVCodecContext *codec,
  608.                                 int *sample_rate, int *output_sample_rate)
  609. {
  610.     MPEG4AudioConfig mp4ac;
  611.  
  612.     if (avpriv_mpeg4audio_get_config(&mp4ac, codec->extradata,
  613.                                      codec->extradata_size * 8, 1) < 0) {
  614.         av_log(s, AV_LOG_ERROR,
  615.                "Error parsing AAC extradata, unable to determine samplerate.\n");
  616.         return AVERROR(EINVAL);
  617.     }
  618.  
  619.     *sample_rate        = mp4ac.sample_rate;
  620.     *output_sample_rate = mp4ac.ext_sample_rate;
  621.     return 0;
  622. }
  623.  
  624. static int mkv_write_native_codecprivate(AVFormatContext *s,
  625.                                          AVCodecContext *codec,
  626.                                          AVIOContext *dyn_cp)
  627. {
  628.     switch (codec->codec_id) {
  629.     case AV_CODEC_ID_VORBIS:
  630.     case AV_CODEC_ID_THEORA:
  631.         return put_xiph_codecpriv(s, dyn_cp, codec);
  632.     case AV_CODEC_ID_FLAC:
  633.         return put_flac_codecpriv(s, dyn_cp, codec);
  634.     case AV_CODEC_ID_WAVPACK:
  635.         return put_wv_codecpriv(dyn_cp, codec);
  636.     case AV_CODEC_ID_H264:
  637.         return ff_isom_write_avcc(dyn_cp, codec->extradata,
  638.                                   codec->extradata_size);
  639.     case AV_CODEC_ID_HEVC:
  640.         ff_isom_write_hvcc(dyn_cp, codec->extradata,
  641.                            codec->extradata_size, 0);
  642.         return 0;
  643.     case AV_CODEC_ID_ALAC:
  644.         if (codec->extradata_size < 36) {
  645.             av_log(s, AV_LOG_ERROR,
  646.                    "Invalid extradata found, ALAC expects a 36-byte "
  647.                    "QuickTime atom.");
  648.             return AVERROR_INVALIDDATA;
  649.         } else
  650.             avio_write(dyn_cp, codec->extradata + 12,
  651.                        codec->extradata_size - 12);
  652.         break;
  653.     default:
  654.         if (codec->codec_id == AV_CODEC_ID_PRORES &&
  655.             ff_codec_get_id(ff_codec_movvideo_tags, codec->codec_tag) == AV_CODEC_ID_PRORES) {
  656.             avio_wl32(dyn_cp, codec->codec_tag);
  657.         } else if (codec->extradata_size && codec->codec_id != AV_CODEC_ID_TTA)
  658.             avio_write(dyn_cp, codec->extradata, codec->extradata_size);
  659.     }
  660.  
  661.     return 0;
  662. }
  663.  
  664. static int mkv_write_codecprivate(AVFormatContext *s, AVIOContext *pb,
  665.                                   AVCodecContext *codec, int native_id,
  666.                                   int qt_id)
  667. {
  668.     AVIOContext *dyn_cp;
  669.     uint8_t *codecpriv;
  670.     int ret, codecpriv_size;
  671.  
  672.     ret = avio_open_dyn_buf(&dyn_cp);
  673.     if (ret < 0)
  674.         return ret;
  675.  
  676.     if (native_id) {
  677.         ret = mkv_write_native_codecprivate(s, codec, dyn_cp);
  678.     } else if (codec->codec_type == AVMEDIA_TYPE_VIDEO) {
  679.         if (qt_id) {
  680.             if (!codec->codec_tag)
  681.                 codec->codec_tag = ff_codec_get_tag(ff_codec_movvideo_tags,
  682.                                                     codec->codec_id);
  683.             if (codec->extradata_size) {
  684.                 if (   ff_codec_get_id(ff_codec_movvideo_tags, codec->codec_tag) == codec->codec_id
  685.                     && ff_codec_get_id(ff_codec_movvideo_tags, AV_RL32(codec->extradata + 4)) != codec->codec_id
  686.                 ) {
  687.                     int i;
  688.                     avio_wb32(dyn_cp, 0x5a + codec->extradata_size);
  689.                     avio_wl32(dyn_cp, codec->codec_tag);
  690.                     for(i = 0; i < 0x5a - 8; i++)
  691.                         avio_w8(dyn_cp, 0);
  692.                 }
  693.                 avio_write(dyn_cp, codec->extradata, codec->extradata_size);
  694.             }
  695.         } else {
  696.             if (!ff_codec_get_tag(ff_codec_bmp_tags, codec->codec_id))
  697.                 av_log(s, AV_LOG_WARNING, "codec %s is not supported by this format\n",
  698.                        avcodec_get_name(codec->codec_id));
  699.  
  700.             if (!codec->codec_tag)
  701.                 codec->codec_tag = ff_codec_get_tag(ff_codec_bmp_tags,
  702.                                                     codec->codec_id);
  703.             if (!codec->codec_tag && codec->codec_id != AV_CODEC_ID_RAWVIDEO) {
  704.                 av_log(s, AV_LOG_ERROR, "No bmp codec tag found for codec %s\n",
  705.                        avcodec_get_name(codec->codec_id));
  706.                 ret = AVERROR(EINVAL);
  707.             }
  708.  
  709.             ff_put_bmp_header(dyn_cp, codec, ff_codec_bmp_tags, 0, 0);
  710.         }
  711.     } else if (codec->codec_type == AVMEDIA_TYPE_AUDIO) {
  712.         unsigned int tag;
  713.         tag = ff_codec_get_tag(ff_codec_wav_tags, codec->codec_id);
  714.         if (!tag) {
  715.             av_log(s, AV_LOG_ERROR, "No wav codec tag found for codec %s\n",
  716.                    avcodec_get_name(codec->codec_id));
  717.             ret = AVERROR(EINVAL);
  718.         }
  719.         if (!codec->codec_tag)
  720.             codec->codec_tag = tag;
  721.  
  722.         ff_put_wav_header(dyn_cp, codec, FF_PUT_WAV_HEADER_FORCE_WAVEFORMATEX);
  723.     }
  724.  
  725.     codecpriv_size = avio_close_dyn_buf(dyn_cp, &codecpriv);
  726.     if (codecpriv_size)
  727.         put_ebml_binary(pb, MATROSKA_ID_CODECPRIVATE, codecpriv,
  728.                         codecpriv_size);
  729.     av_free(codecpriv);
  730.     return ret;
  731. }
  732.  
  733.  
  734. static int mkv_write_stereo_mode(AVFormatContext *s, AVIOContext *pb,
  735.                                  AVStream *st, int mode, int *h_width, int *h_height)
  736. {
  737.     int i;
  738.     int ret = 0;
  739.     AVDictionaryEntry *tag;
  740.     MatroskaVideoStereoModeType format = MATROSKA_VIDEO_STEREOMODE_TYPE_NB;
  741.  
  742.     *h_width = 1;
  743.     *h_height = 1;
  744.     // convert metadata into proper side data and add it to the stream
  745.     if ((tag = av_dict_get(st->metadata, "stereo_mode", NULL, 0)) ||
  746.         (tag = av_dict_get( s->metadata, "stereo_mode", NULL, 0))) {
  747.         int stereo_mode = atoi(tag->value);
  748.  
  749.         for (i=0; i<MATROSKA_VIDEO_STEREOMODE_TYPE_NB; i++)
  750.             if (!strcmp(tag->value, ff_matroska_video_stereo_mode[i])){
  751.                 stereo_mode = i;
  752.                 break;
  753.             }
  754.  
  755.         if (stereo_mode < MATROSKA_VIDEO_STEREOMODE_TYPE_NB &&
  756.             stereo_mode != 10 && stereo_mode != 12) {
  757.             int ret = ff_mkv_stereo3d_conv(st, stereo_mode);
  758.             if (ret < 0)
  759.                 return ret;
  760.         }
  761.     }
  762.  
  763.     // iterate to find the stereo3d side data
  764.     for (i = 0; i < st->nb_side_data; i++) {
  765.         AVPacketSideData sd = st->side_data[i];
  766.         if (sd.type == AV_PKT_DATA_STEREO3D) {
  767.             AVStereo3D *stereo = (AVStereo3D *)sd.data;
  768.  
  769.             switch (stereo->type) {
  770.             case AV_STEREO3D_2D:
  771.                 format = MATROSKA_VIDEO_STEREOMODE_TYPE_MONO;
  772.                 break;
  773.             case AV_STEREO3D_SIDEBYSIDE:
  774.                 format = (stereo->flags & AV_STEREO3D_FLAG_INVERT)
  775.                     ? MATROSKA_VIDEO_STEREOMODE_TYPE_RIGHT_LEFT
  776.                     : MATROSKA_VIDEO_STEREOMODE_TYPE_LEFT_RIGHT;
  777.                 *h_width = 2;
  778.                 break;
  779.             case AV_STEREO3D_TOPBOTTOM:
  780.                 format = MATROSKA_VIDEO_STEREOMODE_TYPE_TOP_BOTTOM;
  781.                 if (stereo->flags & AV_STEREO3D_FLAG_INVERT)
  782.                     format--;
  783.                 *h_height = 2;
  784.                 break;
  785.             case AV_STEREO3D_CHECKERBOARD:
  786.                 format = MATROSKA_VIDEO_STEREOMODE_TYPE_CHECKERBOARD_LR;
  787.                 if (stereo->flags & AV_STEREO3D_FLAG_INVERT)
  788.                     format--;
  789.                 break;
  790.             case AV_STEREO3D_LINES:
  791.                 format = MATROSKA_VIDEO_STEREOMODE_TYPE_ROW_INTERLEAVED_LR;
  792.                 if (stereo->flags & AV_STEREO3D_FLAG_INVERT)
  793.                     format--;
  794.                 *h_height = 2;
  795.                 break;
  796.             case AV_STEREO3D_COLUMNS:
  797.                 format = MATROSKA_VIDEO_STEREOMODE_TYPE_COL_INTERLEAVED_LR;
  798.                 if (stereo->flags & AV_STEREO3D_FLAG_INVERT)
  799.                     format--;
  800.                 *h_width = 2;
  801.                 break;
  802.             case AV_STEREO3D_FRAMESEQUENCE:
  803.                 format = MATROSKA_VIDEO_STEREOMODE_TYPE_BOTH_EYES_BLOCK_LR;
  804.                 if (stereo->flags & AV_STEREO3D_FLAG_INVERT)
  805.                     format++;
  806.                 break;
  807.             }
  808.             break;
  809.         }
  810.     }
  811.  
  812.     if (format == MATROSKA_VIDEO_STEREOMODE_TYPE_NB)
  813.         return ret;
  814.  
  815.     // if webm, do not write unsupported modes
  816.     if ((mode == MODE_WEBM &&
  817.         format > MATROSKA_VIDEO_STEREOMODE_TYPE_TOP_BOTTOM &&
  818.         format != MATROSKA_VIDEO_STEREOMODE_TYPE_RIGHT_LEFT)
  819.         || format >= MATROSKA_VIDEO_STEREOMODE_TYPE_NB) {
  820.         av_log(s, AV_LOG_ERROR,
  821.                "The specified stereo mode is not valid.\n");
  822.         format = MATROSKA_VIDEO_STEREOMODE_TYPE_NB;
  823.         return AVERROR(EINVAL);
  824.     }
  825.  
  826.     // write StereoMode if format is valid
  827.     put_ebml_uint(pb, MATROSKA_ID_VIDEOSTEREOMODE, format);
  828.  
  829.     return ret;
  830. }
  831.  
  832. static int mkv_write_track(AVFormatContext *s, MatroskaMuxContext *mkv,
  833.                            int i, AVIOContext *pb, int default_stream_exists)
  834. {
  835.     AVStream *st = s->streams[i];
  836.     AVCodecContext *codec = st->codec;
  837.     ebml_master subinfo, track;
  838.     int native_id = 0;
  839.     int qt_id = 0;
  840.     int bit_depth = av_get_bits_per_sample(codec->codec_id);
  841.     int sample_rate = codec->sample_rate;
  842.     int output_sample_rate = 0;
  843.     int display_width_div = 1;
  844.     int display_height_div = 1;
  845.     int j, ret;
  846.     AVDictionaryEntry *tag;
  847.  
  848.     // ms precision is the de-facto standard timescale for mkv files
  849.     avpriv_set_pts_info(st, 64, 1, 1000);
  850.  
  851.     if (codec->codec_type == AVMEDIA_TYPE_ATTACHMENT) {
  852.         mkv->have_attachments = 1;
  853.         return 0;
  854.     }
  855.  
  856.     if (!bit_depth && codec->codec_id != AV_CODEC_ID_ADPCM_G726)
  857.         bit_depth = av_get_bytes_per_sample(codec->sample_fmt) << 3;
  858.     if (!bit_depth)
  859.         bit_depth = codec->bits_per_coded_sample;
  860.  
  861.     if (codec->codec_id == AV_CODEC_ID_AAC) {
  862.         ret = get_aac_sample_rates(s, codec, &sample_rate, &output_sample_rate);
  863.         if (ret < 0)
  864.             return ret;
  865.     }
  866.  
  867.     track = start_ebml_master(pb, MATROSKA_ID_TRACKENTRY, 0);
  868.     put_ebml_uint (pb, MATROSKA_ID_TRACKNUMBER,
  869.                    mkv->is_dash ? mkv->dash_track_number : i + 1);
  870.     put_ebml_uint (pb, MATROSKA_ID_TRACKUID,
  871.                    mkv->is_dash ? mkv->dash_track_number : i + 1);
  872.     put_ebml_uint (pb, MATROSKA_ID_TRACKFLAGLACING , 0);    // no lacing (yet)
  873.  
  874.     if ((tag = av_dict_get(st->metadata, "title", NULL, 0)))
  875.         put_ebml_string(pb, MATROSKA_ID_TRACKNAME, tag->value);
  876.     tag = av_dict_get(st->metadata, "language", NULL, 0);
  877.     if (mkv->mode != MODE_WEBM || codec->codec_id != AV_CODEC_ID_WEBVTT) {
  878.         put_ebml_string(pb, MATROSKA_ID_TRACKLANGUAGE, tag && tag->value ? tag->value:"und");
  879.     } else if (tag && tag->value) {
  880.         put_ebml_string(pb, MATROSKA_ID_TRACKLANGUAGE, tag->value);
  881.     }
  882.  
  883.     // The default value for TRACKFLAGDEFAULT is 1, so add element
  884.     // if we need to clear it.
  885.     if (default_stream_exists && !(st->disposition & AV_DISPOSITION_DEFAULT))
  886.         put_ebml_uint(pb, MATROSKA_ID_TRACKFLAGDEFAULT, !!(st->disposition & AV_DISPOSITION_DEFAULT));
  887.  
  888.     if (st->disposition & AV_DISPOSITION_FORCED)
  889.         put_ebml_uint(pb, MATROSKA_ID_TRACKFLAGFORCED, 1);
  890.  
  891.     if (mkv->mode == MODE_WEBM && codec->codec_id == AV_CODEC_ID_WEBVTT) {
  892.         const char *codec_id;
  893.         if (st->disposition & AV_DISPOSITION_CAPTIONS) {
  894.             codec_id = "D_WEBVTT/CAPTIONS";
  895.             native_id = MATROSKA_TRACK_TYPE_SUBTITLE;
  896.         } else if (st->disposition & AV_DISPOSITION_DESCRIPTIONS) {
  897.             codec_id = "D_WEBVTT/DESCRIPTIONS";
  898.             native_id = MATROSKA_TRACK_TYPE_METADATA;
  899.         } else if (st->disposition & AV_DISPOSITION_METADATA) {
  900.             codec_id = "D_WEBVTT/METADATA";
  901.             native_id = MATROSKA_TRACK_TYPE_METADATA;
  902.         } else {
  903.             codec_id = "D_WEBVTT/SUBTITLES";
  904.             native_id = MATROSKA_TRACK_TYPE_SUBTITLE;
  905.         }
  906.         put_ebml_string(pb, MATROSKA_ID_CODECID, codec_id);
  907.     } else {
  908.         // look for a codec ID string specific to mkv to use,
  909.         // if none are found, use AVI codes
  910.         for (j = 0; ff_mkv_codec_tags[j].id != AV_CODEC_ID_NONE; j++) {
  911.             if (ff_mkv_codec_tags[j].id == codec->codec_id) {
  912.                 put_ebml_string(pb, MATROSKA_ID_CODECID, ff_mkv_codec_tags[j].str);
  913.                 native_id = 1;
  914.                 break;
  915.             }
  916.         }
  917.         if (codec->codec_id == AV_CODEC_ID_RAWVIDEO && !codec->codec_tag) {
  918.             if (mkv->allow_raw_vfw) {
  919.                 native_id = 0;
  920.             } else {
  921.                 av_log(s, AV_LOG_ERROR, "Raw RGB is not supported Natively in Matroska, you can use AVI or NUT or\n"
  922.                                         "If you would like to store it anyway using VFW mode, enable allow_raw_vfw (-allow_raw_vfw 1)\n");
  923.                 return AVERROR(EINVAL);
  924.             }
  925.         }
  926.     }
  927.  
  928.     if (codec->codec_type == AVMEDIA_TYPE_AUDIO && codec->initial_padding && codec->codec_id == AV_CODEC_ID_OPUS) {
  929.         int64_t codecdelay = av_rescale_q(codec->initial_padding,
  930.                                           (AVRational){ 1, codec->sample_rate },
  931.                                           (AVRational){ 1, 1000000000 });
  932.         if (codecdelay < 0) {
  933.             av_log(s, AV_LOG_ERROR, "Initial padding is invalid\n");
  934.             return AVERROR(EINVAL);
  935.         }
  936. //         mkv->tracks[i].ts_offset = av_rescale_q(codec->initial_padding,
  937. //                                                 (AVRational){ 1, codec->sample_rate },
  938. //                                                 st->time_base);
  939.  
  940.         put_ebml_uint(pb, MATROSKA_ID_CODECDELAY, codecdelay);
  941.     }
  942.     if (codec->codec_id == AV_CODEC_ID_OPUS) {
  943.         put_ebml_uint(pb, MATROSKA_ID_SEEKPREROLL, OPUS_SEEK_PREROLL);
  944.     }
  945.  
  946.     if (mkv->mode == MODE_WEBM && !(codec->codec_id == AV_CODEC_ID_VP8 ||
  947.                                     codec->codec_id == AV_CODEC_ID_VP9 ||
  948.                                     codec->codec_id == AV_CODEC_ID_OPUS ||
  949.                                     codec->codec_id == AV_CODEC_ID_VORBIS ||
  950.                                     codec->codec_id == AV_CODEC_ID_WEBVTT)) {
  951.         av_log(s, AV_LOG_ERROR,
  952.                "Only VP8 or VP9 video and Vorbis or Opus audio and WebVTT subtitles are supported for WebM.\n");
  953.         return AVERROR(EINVAL);
  954.     }
  955.  
  956.     switch (codec->codec_type) {
  957.     case AVMEDIA_TYPE_VIDEO:
  958.         put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_VIDEO);
  959.  
  960.         if(   st->avg_frame_rate.num > 0 && st->avg_frame_rate.den > 0
  961.            && av_cmp_q(av_inv_q(st->avg_frame_rate), codec->time_base) > 0)
  962.             put_ebml_uint(pb, MATROSKA_ID_TRACKDEFAULTDURATION, 1000000000LL * st->avg_frame_rate.den / st->avg_frame_rate.num);
  963.         else
  964.             put_ebml_uint(pb, MATROSKA_ID_TRACKDEFAULTDURATION, 1000000000LL * codec->time_base.num / codec->time_base.den);
  965.  
  966.         if (!native_id &&
  967.             ff_codec_get_tag(ff_codec_movvideo_tags, codec->codec_id) &&
  968.             ((!ff_codec_get_tag(ff_codec_bmp_tags,   codec->codec_id) && codec->codec_id != AV_CODEC_ID_RAWVIDEO) ||
  969.              codec->codec_id == AV_CODEC_ID_SVQ1 ||
  970.              codec->codec_id == AV_CODEC_ID_SVQ3 ||
  971.              codec->codec_id == AV_CODEC_ID_CINEPAK))
  972.             qt_id = 1;
  973.  
  974.         if (qt_id)
  975.             put_ebml_string(pb, MATROSKA_ID_CODECID, "V_QUICKTIME");
  976.         else if (!native_id) {
  977.             // if there is no mkv-specific codec ID, use VFW mode
  978.             put_ebml_string(pb, MATROSKA_ID_CODECID, "V_MS/VFW/FOURCC");
  979.             mkv->tracks[i].write_dts = 1;
  980.             s->internal->avoid_negative_ts_use_pts = 0;
  981.         }
  982.  
  983.         subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKVIDEO, 0);
  984.         // XXX: interlace flag?
  985.         put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELWIDTH , codec->width);
  986.         put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELHEIGHT, codec->height);
  987.  
  988.         // check both side data and metadata for stereo information,
  989.         // write the result to the bitstream if any is found
  990.         ret = mkv_write_stereo_mode(s, pb, st, mkv->mode,
  991.                                     &display_width_div,
  992.                                     &display_height_div);
  993.         if (ret < 0)
  994.             return ret;
  995.  
  996.         if (((tag = av_dict_get(st->metadata, "alpha_mode", NULL, 0)) && atoi(tag->value)) ||
  997.             ((tag = av_dict_get( s->metadata, "alpha_mode", NULL, 0)) && atoi(tag->value)) ||
  998.             (codec->pix_fmt == AV_PIX_FMT_YUVA420P)) {
  999.             put_ebml_uint(pb, MATROSKA_ID_VIDEOALPHAMODE, 1);
  1000.         }
  1001.  
  1002.         // write DisplayWidth and DisplayHeight, they contain the size of
  1003.         // a single source view and/or the display aspect ratio
  1004.         if (st->sample_aspect_ratio.num) {
  1005.             int64_t d_width = av_rescale(codec->width, st->sample_aspect_ratio.num, st->sample_aspect_ratio.den);
  1006.             if (d_width > INT_MAX) {
  1007.                 av_log(s, AV_LOG_ERROR, "Overflow in display width\n");
  1008.                 return AVERROR(EINVAL);
  1009.             }
  1010.             put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYWIDTH , d_width / display_width_div);
  1011.             put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYHEIGHT, codec->height / display_height_div);
  1012.         } else if (display_width_div != 1 || display_height_div != 1) {
  1013.             put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYWIDTH , codec->width / display_width_div);
  1014.             put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYHEIGHT, codec->height / display_height_div);
  1015.         }
  1016.  
  1017.         if (codec->codec_id == AV_CODEC_ID_RAWVIDEO) {
  1018.             uint32_t color_space = av_le2ne32(codec->codec_tag);
  1019.             put_ebml_binary(pb, MATROSKA_ID_VIDEOCOLORSPACE, &color_space, sizeof(color_space));
  1020.         }
  1021.  
  1022.         end_ebml_master(pb, subinfo);
  1023.         break;
  1024.  
  1025.     case AVMEDIA_TYPE_AUDIO:
  1026.         put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_AUDIO);
  1027.  
  1028.         if (!native_id)
  1029.             // no mkv-specific ID, use ACM mode
  1030.             put_ebml_string(pb, MATROSKA_ID_CODECID, "A_MS/ACM");
  1031.  
  1032.         subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKAUDIO, 0);
  1033.         put_ebml_uint  (pb, MATROSKA_ID_AUDIOCHANNELS    , codec->channels);
  1034.         put_ebml_float (pb, MATROSKA_ID_AUDIOSAMPLINGFREQ, sample_rate);
  1035.         if (output_sample_rate)
  1036.             put_ebml_float(pb, MATROSKA_ID_AUDIOOUTSAMPLINGFREQ, output_sample_rate);
  1037.         if (bit_depth)
  1038.             put_ebml_uint(pb, MATROSKA_ID_AUDIOBITDEPTH, bit_depth);
  1039.         end_ebml_master(pb, subinfo);
  1040.         break;
  1041.  
  1042.     case AVMEDIA_TYPE_SUBTITLE:
  1043.         if (!native_id) {
  1044.             av_log(s, AV_LOG_ERROR, "Subtitle codec %d is not supported.\n", codec->codec_id);
  1045.             return AVERROR(ENOSYS);
  1046.         }
  1047.  
  1048.         if (mkv->mode != MODE_WEBM || codec->codec_id != AV_CODEC_ID_WEBVTT)
  1049.             native_id = MATROSKA_TRACK_TYPE_SUBTITLE;
  1050.  
  1051.         put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, native_id);
  1052.         break;
  1053.     default:
  1054.         av_log(s, AV_LOG_ERROR, "Only audio, video, and subtitles are supported for Matroska.\n");
  1055.         return AVERROR(EINVAL);
  1056.     }
  1057.  
  1058.     if (mkv->mode != MODE_WEBM || codec->codec_id != AV_CODEC_ID_WEBVTT) {
  1059.         ret = mkv_write_codecprivate(s, pb, codec, native_id, qt_id);
  1060.         if (ret < 0)
  1061.             return ret;
  1062.     }
  1063.  
  1064.     end_ebml_master(pb, track);
  1065.  
  1066.     return 0;
  1067. }
  1068.  
  1069. static int mkv_write_tracks(AVFormatContext *s)
  1070. {
  1071.     MatroskaMuxContext *mkv = s->priv_data;
  1072.     AVIOContext *pb = s->pb;
  1073.     ebml_master tracks;
  1074.     int i, ret, default_stream_exists = 0;
  1075.  
  1076.     ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_TRACKS, avio_tell(pb));
  1077.     if (ret < 0)
  1078.         return ret;
  1079.  
  1080.     tracks = start_ebml_master(pb, MATROSKA_ID_TRACKS, 0);
  1081.     for (i = 0; i < s->nb_streams; i++) {
  1082.         AVStream *st = s->streams[i];
  1083.         default_stream_exists |= st->disposition & AV_DISPOSITION_DEFAULT;
  1084.     }
  1085.     for (i = 0; i < s->nb_streams; i++) {
  1086.         ret = mkv_write_track(s, mkv, i, pb, default_stream_exists);
  1087.         if (ret < 0)
  1088.             return ret;
  1089.     }
  1090.     end_ebml_master(pb, tracks);
  1091.     return 0;
  1092. }
  1093.  
  1094. static int mkv_write_chapters(AVFormatContext *s)
  1095. {
  1096.     MatroskaMuxContext *mkv = s->priv_data;
  1097.     AVIOContext *pb = s->pb;
  1098.     ebml_master chapters, editionentry;
  1099.     AVRational scale = {1, 1E9};
  1100.     int i, ret;
  1101.  
  1102.     if (!s->nb_chapters || mkv->wrote_chapters)
  1103.         return 0;
  1104.  
  1105.     ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_CHAPTERS, avio_tell(pb));
  1106.     if (ret < 0) return ret;
  1107.  
  1108.     chapters     = start_ebml_master(pb, MATROSKA_ID_CHAPTERS    , 0);
  1109.     editionentry = start_ebml_master(pb, MATROSKA_ID_EDITIONENTRY, 0);
  1110.     put_ebml_uint(pb, MATROSKA_ID_EDITIONFLAGDEFAULT, 1);
  1111.     put_ebml_uint(pb, MATROSKA_ID_EDITIONFLAGHIDDEN , 0);
  1112.     for (i = 0; i < s->nb_chapters; i++) {
  1113.         ebml_master chapteratom, chapterdisplay;
  1114.         AVChapter *c     = s->chapters[i];
  1115.         int64_t chapterstart = av_rescale_q(c->start, c->time_base, scale);
  1116.         int64_t chapterend   = av_rescale_q(c->end,   c->time_base, scale);
  1117.         AVDictionaryEntry *t = NULL;
  1118.         if (chapterstart < 0 || chapterstart > chapterend || chapterend < 0) {
  1119.             av_log(s, AV_LOG_ERROR,
  1120.                    "Invalid chapter start (%"PRId64") or end (%"PRId64").\n",
  1121.                    chapterstart, chapterend);
  1122.             return AVERROR_INVALIDDATA;
  1123.         }
  1124.  
  1125.         chapteratom = start_ebml_master(pb, MATROSKA_ID_CHAPTERATOM, 0);
  1126.         put_ebml_uint(pb, MATROSKA_ID_CHAPTERUID, c->id + mkv->chapter_id_offset);
  1127.         put_ebml_uint(pb, MATROSKA_ID_CHAPTERTIMESTART, chapterstart);
  1128.         put_ebml_uint(pb, MATROSKA_ID_CHAPTERTIMEEND, chapterend);
  1129.         put_ebml_uint(pb, MATROSKA_ID_CHAPTERFLAGHIDDEN , 0);
  1130.         put_ebml_uint(pb, MATROSKA_ID_CHAPTERFLAGENABLED, 1);
  1131.         if ((t = av_dict_get(c->metadata, "title", NULL, 0))) {
  1132.             chapterdisplay = start_ebml_master(pb, MATROSKA_ID_CHAPTERDISPLAY, 0);
  1133.             put_ebml_string(pb, MATROSKA_ID_CHAPSTRING, t->value);
  1134.             put_ebml_string(pb, MATROSKA_ID_CHAPLANG  , "und");
  1135.             end_ebml_master(pb, chapterdisplay);
  1136.         }
  1137.         end_ebml_master(pb, chapteratom);
  1138.     }
  1139.     end_ebml_master(pb, editionentry);
  1140.     end_ebml_master(pb, chapters);
  1141.  
  1142.     mkv->wrote_chapters = 1;
  1143.     return 0;
  1144. }
  1145.  
  1146. static int mkv_write_simpletag(AVIOContext *pb, AVDictionaryEntry *t)
  1147. {
  1148.     uint8_t *key = av_strdup(t->key);
  1149.     uint8_t *p   = key;
  1150.     const uint8_t *lang = NULL;
  1151.     ebml_master tag;
  1152.  
  1153.     if (!key)
  1154.         return AVERROR(ENOMEM);
  1155.  
  1156.     if ((p = strrchr(p, '-')) &&
  1157.         (lang = av_convert_lang_to(p + 1, AV_LANG_ISO639_2_BIBL)))
  1158.         *p = 0;
  1159.  
  1160.     p = key;
  1161.     while (*p) {
  1162.         if (*p == ' ')
  1163.             *p = '_';
  1164.         else if (*p >= 'a' && *p <= 'z')
  1165.             *p -= 'a' - 'A';
  1166.         p++;
  1167.     }
  1168.  
  1169.     tag = start_ebml_master(pb, MATROSKA_ID_SIMPLETAG, 0);
  1170.     put_ebml_string(pb, MATROSKA_ID_TAGNAME, key);
  1171.     if (lang)
  1172.         put_ebml_string(pb, MATROSKA_ID_TAGLANG, lang);
  1173.     put_ebml_string(pb, MATROSKA_ID_TAGSTRING, t->value);
  1174.     end_ebml_master(pb, tag);
  1175.  
  1176.     av_freep(&key);
  1177.     return 0;
  1178. }
  1179.  
  1180. static int mkv_write_tag_targets(AVFormatContext *s,
  1181.                                  unsigned int elementid, unsigned int uid,
  1182.                                  ebml_master *tags, ebml_master* tag)
  1183. {
  1184.     MatroskaMuxContext *mkv = s->priv_data;
  1185.     ebml_master targets;
  1186.     int ret;
  1187.  
  1188.     if (!tags->pos) {
  1189.         ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_TAGS, avio_tell(s->pb));
  1190.         if (ret < 0) return ret;
  1191.  
  1192.         *tags = start_ebml_master(s->pb, MATROSKA_ID_TAGS, 0);
  1193.     }
  1194.  
  1195.     *tag     = start_ebml_master(s->pb, MATROSKA_ID_TAG,        0);
  1196.     targets = start_ebml_master(s->pb, MATROSKA_ID_TAGTARGETS, 0);
  1197.     if (elementid)
  1198.         put_ebml_uint(s->pb, elementid, uid);
  1199.     end_ebml_master(s->pb, targets);
  1200.     return 0;
  1201. }
  1202.  
  1203. static int mkv_write_tag(AVFormatContext *s, AVDictionary *m, unsigned int elementid,
  1204.                          unsigned int uid, ebml_master *tags)
  1205. {
  1206.     ebml_master tag;
  1207.     int ret;
  1208.     AVDictionaryEntry *t = NULL;
  1209.  
  1210.     ret = mkv_write_tag_targets(s, elementid, uid, tags, &tag);
  1211.     if (ret < 0)
  1212.         return ret;
  1213.  
  1214.     while ((t = av_dict_get(m, "", t, AV_DICT_IGNORE_SUFFIX))) {
  1215.         if (av_strcasecmp(t->key, "title") &&
  1216.             av_strcasecmp(t->key, "stereo_mode") &&
  1217.             av_strcasecmp(t->key, "encoding_tool")) {
  1218.             ret = mkv_write_simpletag(s->pb, t);
  1219.             if (ret < 0)
  1220.                 return ret;
  1221.         }
  1222.     }
  1223.  
  1224.     end_ebml_master(s->pb, tag);
  1225.     return 0;
  1226. }
  1227.  
  1228. static int mkv_check_tag(AVDictionary *m)
  1229. {
  1230.     AVDictionaryEntry *t = NULL;
  1231.  
  1232.     while ((t = av_dict_get(m, "", t, AV_DICT_IGNORE_SUFFIX)))
  1233.         if (av_strcasecmp(t->key, "title") && av_strcasecmp(t->key, "stereo_mode"))
  1234.             return 1;
  1235.  
  1236.     return 0;
  1237. }
  1238.  
  1239. static int mkv_write_tags(AVFormatContext *s)
  1240. {
  1241.     MatroskaMuxContext *mkv = s->priv_data;
  1242.     ebml_master tags = {0};
  1243.     int i, ret;
  1244.  
  1245.     ff_metadata_conv_ctx(s, ff_mkv_metadata_conv, NULL);
  1246.  
  1247.     if (mkv_check_tag(s->metadata)) {
  1248.         ret = mkv_write_tag(s, s->metadata, 0, 0, &tags);
  1249.         if (ret < 0) return ret;
  1250.     }
  1251.  
  1252.     for (i = 0; i < s->nb_streams; i++) {
  1253.         AVStream *st = s->streams[i];
  1254.  
  1255.         if (!mkv_check_tag(st->metadata))
  1256.             continue;
  1257.  
  1258.         ret = mkv_write_tag(s, st->metadata, MATROSKA_ID_TAGTARGETS_TRACKUID, i + 1, &tags);
  1259.         if (ret < 0) return ret;
  1260.     }
  1261.  
  1262.     if (!mkv->is_live) {
  1263.         for (i = 0; i < s->nb_streams; i++) {
  1264.             ebml_master tag_target;
  1265.             ebml_master tag;
  1266.  
  1267.             mkv_write_tag_targets(s, MATROSKA_ID_TAGTARGETS_TRACKUID, i + 1, &tags, &tag_target);
  1268.  
  1269.             tag = start_ebml_master(s->pb, MATROSKA_ID_SIMPLETAG, 0);
  1270.             put_ebml_string(s->pb, MATROSKA_ID_TAGNAME, "DURATION");
  1271.             mkv->stream_duration_offsets[i] = avio_tell(s->pb);
  1272.  
  1273.             // Reserve space to write duration as a 20-byte string.
  1274.             // 2 (ebml id) + 1 (data size) + 20 (data)
  1275.             put_ebml_void(s->pb, 23);
  1276.             end_ebml_master(s->pb, tag);
  1277.             end_ebml_master(s->pb, tag_target);
  1278.         }
  1279.     }
  1280.  
  1281.     for (i = 0; i < s->nb_chapters; i++) {
  1282.         AVChapter *ch = s->chapters[i];
  1283.  
  1284.         if (!mkv_check_tag(ch->metadata))
  1285.             continue;
  1286.  
  1287.         ret = mkv_write_tag(s, ch->metadata, MATROSKA_ID_TAGTARGETS_CHAPTERUID, ch->id + mkv->chapter_id_offset, &tags);
  1288.         if (ret < 0) return ret;
  1289.     }
  1290.  
  1291.     if (tags.pos)
  1292.         end_ebml_master(s->pb, tags);
  1293.     return 0;
  1294. }
  1295.  
  1296. static int mkv_write_attachments(AVFormatContext *s)
  1297. {
  1298.     MatroskaMuxContext *mkv = s->priv_data;
  1299.     AVIOContext *pb = s->pb;
  1300.     ebml_master attachments;
  1301.     AVLFG c;
  1302.     int i, ret;
  1303.  
  1304.     if (!mkv->have_attachments)
  1305.         return 0;
  1306.  
  1307.     av_lfg_init(&c, av_get_random_seed());
  1308.  
  1309.     ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_ATTACHMENTS, avio_tell(pb));
  1310.     if (ret < 0) return ret;
  1311.  
  1312.     attachments = start_ebml_master(pb, MATROSKA_ID_ATTACHMENTS, 0);
  1313.  
  1314.     for (i = 0; i < s->nb_streams; i++) {
  1315.         AVStream *st = s->streams[i];
  1316.         ebml_master attached_file;
  1317.         AVDictionaryEntry *t;
  1318.         const char *mimetype = NULL;
  1319.         uint64_t fileuid;
  1320.  
  1321.         if (st->codec->codec_type != AVMEDIA_TYPE_ATTACHMENT)
  1322.             continue;
  1323.  
  1324.         attached_file = start_ebml_master(pb, MATROSKA_ID_ATTACHEDFILE, 0);
  1325.  
  1326.         if (t = av_dict_get(st->metadata, "title", NULL, 0))
  1327.             put_ebml_string(pb, MATROSKA_ID_FILEDESC, t->value);
  1328.         if (!(t = av_dict_get(st->metadata, "filename", NULL, 0))) {
  1329.             av_log(s, AV_LOG_ERROR, "Attachment stream %d has no filename tag.\n", i);
  1330.             return AVERROR(EINVAL);
  1331.         }
  1332.         put_ebml_string(pb, MATROSKA_ID_FILENAME, t->value);
  1333.         if (t = av_dict_get(st->metadata, "mimetype", NULL, 0))
  1334.             mimetype = t->value;
  1335.         else if (st->codec->codec_id != AV_CODEC_ID_NONE ) {
  1336.             int i;
  1337.             for (i = 0; ff_mkv_mime_tags[i].id != AV_CODEC_ID_NONE; i++)
  1338.                 if (ff_mkv_mime_tags[i].id == st->codec->codec_id) {
  1339.                     mimetype = ff_mkv_mime_tags[i].str;
  1340.                     break;
  1341.                 }
  1342.             for (i = 0; ff_mkv_image_mime_tags[i].id != AV_CODEC_ID_NONE; i++)
  1343.                 if (ff_mkv_image_mime_tags[i].id == st->codec->codec_id) {
  1344.                     mimetype = ff_mkv_image_mime_tags[i].str;
  1345.                     break;
  1346.                 }
  1347.         }
  1348.         if (!mimetype) {
  1349.             av_log(s, AV_LOG_ERROR, "Attachment stream %d has no mimetype tag and "
  1350.                                     "it cannot be deduced from the codec id.\n", i);
  1351.             return AVERROR(EINVAL);
  1352.         }
  1353.  
  1354.         if (s->flags & AVFMT_FLAG_BITEXACT) {
  1355.             struct AVSHA *sha = av_sha_alloc();
  1356.             uint8_t digest[20];
  1357.             if (!sha)
  1358.                 return AVERROR(ENOMEM);
  1359.             av_sha_init(sha, 160);
  1360.             av_sha_update(sha, st->codec->extradata, st->codec->extradata_size);
  1361.             av_sha_final(sha, digest);
  1362.             av_free(sha);
  1363.             fileuid = AV_RL64(digest);
  1364.         } else {
  1365.             fileuid = av_lfg_get(&c);
  1366.         }
  1367.         av_log(s, AV_LOG_VERBOSE, "Using %.16"PRIx64" for attachment %d\n",
  1368.                fileuid, i);
  1369.  
  1370.         put_ebml_string(pb, MATROSKA_ID_FILEMIMETYPE, mimetype);
  1371.         put_ebml_binary(pb, MATROSKA_ID_FILEDATA, st->codec->extradata, st->codec->extradata_size);
  1372.         put_ebml_uint(pb, MATROSKA_ID_FILEUID, fileuid);
  1373.         end_ebml_master(pb, attached_file);
  1374.     }
  1375.     end_ebml_master(pb, attachments);
  1376.  
  1377.     return 0;
  1378. }
  1379.  
  1380. static int mkv_write_header(AVFormatContext *s)
  1381. {
  1382.     MatroskaMuxContext *mkv = s->priv_data;
  1383.     AVIOContext *pb = s->pb;
  1384.     ebml_master ebml_header, segment_info;
  1385.     AVDictionaryEntry *tag;
  1386.     int ret, i, version = 2;
  1387.  
  1388.     if (!strcmp(s->oformat->name, "webm"))
  1389.         mkv->mode = MODE_WEBM;
  1390.     else
  1391.         mkv->mode = MODE_MATROSKAv2;
  1392.  
  1393.     if (s->avoid_negative_ts < 0) {
  1394.         s->avoid_negative_ts = 1;
  1395.         s->internal->avoid_negative_ts_use_pts = 1;
  1396.     }
  1397.  
  1398.     if (mkv->mode != MODE_WEBM ||
  1399.         av_dict_get(s->metadata, "stereo_mode", NULL, 0) ||
  1400.         av_dict_get(s->metadata, "alpha_mode", NULL, 0))
  1401.         version = 4;
  1402.  
  1403.     for (i = 0; i < s->nb_streams; i++) {
  1404.         if (s->streams[i]->codec->codec_id == AV_CODEC_ID_ATRAC3 ||
  1405.             s->streams[i]->codec->codec_id == AV_CODEC_ID_COOK ||
  1406.             s->streams[i]->codec->codec_id == AV_CODEC_ID_RA_288 ||
  1407.             s->streams[i]->codec->codec_id == AV_CODEC_ID_SIPR ||
  1408.             s->streams[i]->codec->codec_id == AV_CODEC_ID_RV10 ||
  1409.             s->streams[i]->codec->codec_id == AV_CODEC_ID_RV20) {
  1410.             av_log(s, AV_LOG_ERROR,
  1411.                    "The Matroska muxer does not yet support muxing %s\n",
  1412.                    avcodec_get_name(s->streams[i]->codec->codec_id));
  1413.             return AVERROR_PATCHWELCOME;
  1414.         }
  1415.         if (s->streams[i]->codec->codec_id == AV_CODEC_ID_OPUS ||
  1416.             av_dict_get(s->streams[i]->metadata, "stereo_mode", NULL, 0) ||
  1417.             av_dict_get(s->streams[i]->metadata, "alpha_mode", NULL, 0))
  1418.             version = 4;
  1419.     }
  1420.  
  1421.     mkv->tracks = av_mallocz_array(s->nb_streams, sizeof(*mkv->tracks));
  1422.     if (!mkv->tracks) {
  1423.         ret = AVERROR(ENOMEM);
  1424.         goto fail;
  1425.     }
  1426.     ebml_header = start_ebml_master(pb, EBML_ID_HEADER, 0);
  1427.     put_ebml_uint   (pb, EBML_ID_EBMLVERSION        ,           1);
  1428.     put_ebml_uint   (pb, EBML_ID_EBMLREADVERSION    ,           1);
  1429.     put_ebml_uint   (pb, EBML_ID_EBMLMAXIDLENGTH    ,           4);
  1430.     put_ebml_uint   (pb, EBML_ID_EBMLMAXSIZELENGTH  ,           8);
  1431.     put_ebml_string (pb, EBML_ID_DOCTYPE            , s->oformat->name);
  1432.     put_ebml_uint   (pb, EBML_ID_DOCTYPEVERSION     ,     version);
  1433.     put_ebml_uint   (pb, EBML_ID_DOCTYPEREADVERSION ,           2);
  1434.     end_ebml_master(pb, ebml_header);
  1435.  
  1436.     mkv->segment = start_ebml_master(pb, MATROSKA_ID_SEGMENT, 0);
  1437.     mkv->segment_offset = avio_tell(pb);
  1438.  
  1439.     // we write 2 seek heads - one at the end of the file to point to each
  1440.     // cluster, and one at the beginning to point to all other level one
  1441.     // elements (including the seek head at the end of the file), which
  1442.     // isn't more than 10 elements if we only write one of each other
  1443.     // currently defined level 1 element
  1444.     mkv->main_seekhead    = mkv_start_seekhead(pb, mkv->segment_offset, 10);
  1445.     if (!mkv->main_seekhead) {
  1446.         ret = AVERROR(ENOMEM);
  1447.         goto fail;
  1448.     }
  1449.  
  1450.     ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_INFO, avio_tell(pb));
  1451.     if (ret < 0) goto fail;
  1452.  
  1453.     segment_info = start_ebml_master(pb, MATROSKA_ID_INFO, 0);
  1454.     put_ebml_uint(pb, MATROSKA_ID_TIMECODESCALE, 1000000);
  1455.     if ((tag = av_dict_get(s->metadata, "title", NULL, 0)))
  1456.         put_ebml_string(pb, MATROSKA_ID_TITLE, tag->value);
  1457.     if (!(s->flags & AVFMT_FLAG_BITEXACT)) {
  1458.         uint32_t segment_uid[4];
  1459.         AVLFG lfg;
  1460.  
  1461.         av_lfg_init(&lfg, av_get_random_seed());
  1462.  
  1463.         for (i = 0; i < 4; i++)
  1464.             segment_uid[i] = av_lfg_get(&lfg);
  1465.  
  1466.         put_ebml_string(pb, MATROSKA_ID_MUXINGAPP, LIBAVFORMAT_IDENT);
  1467.         if ((tag = av_dict_get(s->metadata, "encoding_tool", NULL, 0)))
  1468.             put_ebml_string(pb, MATROSKA_ID_WRITINGAPP, tag->value);
  1469.         else
  1470.             put_ebml_string(pb, MATROSKA_ID_WRITINGAPP, LIBAVFORMAT_IDENT);
  1471.         put_ebml_binary(pb, MATROSKA_ID_SEGMENTUID, segment_uid, 16);
  1472.     } else {
  1473.         const char *ident = "Lavf";
  1474.         put_ebml_string(pb, MATROSKA_ID_MUXINGAPP , ident);
  1475.         put_ebml_string(pb, MATROSKA_ID_WRITINGAPP, ident);
  1476.     }
  1477.  
  1478.     if (tag = av_dict_get(s->metadata, "creation_time", NULL, 0)) {
  1479.         // Adjust time so it's relative to 2001-01-01 and convert to nanoseconds.
  1480.         int64_t date_utc = (ff_iso8601_to_unix_time(tag->value) - 978307200) * 1000000000;
  1481.         uint8_t date_utc_buf[8];
  1482.         AV_WB64(date_utc_buf, date_utc);
  1483.         put_ebml_binary(pb, MATROSKA_ID_DATEUTC, date_utc_buf, 8);
  1484.     }
  1485.  
  1486.     // reserve space for the duration
  1487.     mkv->duration = 0;
  1488.     mkv->duration_offset = avio_tell(pb);
  1489.     if (!mkv->is_live) {
  1490.         put_ebml_void(pb, 11);              // assumes double-precision float to be written
  1491.     }
  1492.     end_ebml_master(pb, segment_info);
  1493.  
  1494.     // initialize stream_duration fields
  1495.     mkv->stream_durations = av_mallocz(s->nb_streams * sizeof(int64_t));
  1496.     mkv->stream_duration_offsets = av_mallocz(s->nb_streams * sizeof(int64_t));
  1497.  
  1498.     ret = mkv_write_tracks(s);
  1499.     if (ret < 0)
  1500.         goto fail;
  1501.  
  1502.     for (i = 0; i < s->nb_chapters; i++)
  1503.         mkv->chapter_id_offset = FFMAX(mkv->chapter_id_offset, 1LL - s->chapters[i]->id);
  1504.  
  1505.     if (mkv->mode != MODE_WEBM) {
  1506.         ret = mkv_write_chapters(s);
  1507.         if (ret < 0)
  1508.             goto fail;
  1509.  
  1510.         ret = mkv_write_tags(s);
  1511.         if (ret < 0)
  1512.             goto fail;
  1513.  
  1514.         ret = mkv_write_attachments(s);
  1515.         if (ret < 0)
  1516.             goto fail;
  1517.     }
  1518.  
  1519.     if (!s->pb->seekable && !mkv->is_live)
  1520.         mkv_write_seekhead(pb, mkv);
  1521.  
  1522.     mkv->cues = mkv_start_cues(mkv->segment_offset);
  1523.     if (!mkv->cues) {
  1524.         ret = AVERROR(ENOMEM);
  1525.         goto fail;
  1526.     }
  1527.     if (pb->seekable && mkv->reserve_cues_space) {
  1528.         mkv->cues_pos = avio_tell(pb);
  1529.         put_ebml_void(pb, mkv->reserve_cues_space);
  1530.     }
  1531.  
  1532.     av_init_packet(&mkv->cur_audio_pkt);
  1533.     mkv->cur_audio_pkt.size = 0;
  1534.     mkv->cluster_pos = -1;
  1535.  
  1536.     avio_flush(pb);
  1537.  
  1538.     // start a new cluster every 5 MB or 5 sec, or 32k / 1 sec for streaming or
  1539.     // after 4k and on a keyframe
  1540.     if (pb->seekable) {
  1541.         if (mkv->cluster_time_limit < 0)
  1542.             mkv->cluster_time_limit = 5000;
  1543.         if (mkv->cluster_size_limit < 0)
  1544.             mkv->cluster_size_limit = 5 * 1024 * 1024;
  1545.     } else {
  1546.         if (mkv->cluster_time_limit < 0)
  1547.             mkv->cluster_time_limit = 1000;
  1548.         if (mkv->cluster_size_limit < 0)
  1549.             mkv->cluster_size_limit = 32 * 1024;
  1550.     }
  1551.  
  1552.     return 0;
  1553. fail:
  1554.     mkv_free(mkv);
  1555.     return ret;
  1556. }
  1557.  
  1558. static int mkv_blockgroup_size(int pkt_size)
  1559. {
  1560.     int size = pkt_size + 4;
  1561.     size += ebml_num_size(size);
  1562.     size += 2;              // EBML ID for block and block duration
  1563.     size += 8;              // max size of block duration
  1564.     size += ebml_num_size(size);
  1565.     size += 1;              // blockgroup EBML ID
  1566.     return size;
  1567. }
  1568.  
  1569. static int mkv_strip_wavpack(const uint8_t *src, uint8_t **pdst, int *size)
  1570. {
  1571.     uint8_t *dst;
  1572.     int srclen = *size;
  1573.     int offset = 0;
  1574.     int ret;
  1575.  
  1576.     dst = av_malloc(srclen);
  1577.     if (!dst)
  1578.         return AVERROR(ENOMEM);
  1579.  
  1580.     while (srclen >= WV_HEADER_SIZE) {
  1581.         WvHeader header;
  1582.  
  1583.         ret = ff_wv_parse_header(&header, src);
  1584.         if (ret < 0)
  1585.             goto fail;
  1586.         src    += WV_HEADER_SIZE;
  1587.         srclen -= WV_HEADER_SIZE;
  1588.  
  1589.         if (srclen < header.blocksize) {
  1590.             ret = AVERROR_INVALIDDATA;
  1591.             goto fail;
  1592.         }
  1593.  
  1594.         if (header.initial) {
  1595.             AV_WL32(dst + offset, header.samples);
  1596.             offset += 4;
  1597.         }
  1598.         AV_WL32(dst + offset,     header.flags);
  1599.         AV_WL32(dst + offset + 4, header.crc);
  1600.         offset += 8;
  1601.  
  1602.         if (!(header.initial && header.final)) {
  1603.             AV_WL32(dst + offset, header.blocksize);
  1604.             offset += 4;
  1605.         }
  1606.  
  1607.         memcpy(dst + offset, src, header.blocksize);
  1608.         src    += header.blocksize;
  1609.         srclen -= header.blocksize;
  1610.         offset += header.blocksize;
  1611.     }
  1612.  
  1613.     *pdst = dst;
  1614.     *size = offset;
  1615.  
  1616.     return 0;
  1617. fail:
  1618.     av_freep(&dst);
  1619.     return ret;
  1620. }
  1621.  
  1622. static void mkv_write_block(AVFormatContext *s, AVIOContext *pb,
  1623.                             unsigned int blockid, AVPacket *pkt, int keyframe)
  1624. {
  1625.     MatroskaMuxContext *mkv = s->priv_data;
  1626.     AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
  1627.     uint8_t *data = NULL, *side_data = NULL;
  1628.     int offset = 0, size = pkt->size, side_data_size = 0;
  1629.     int64_t ts = mkv->tracks[pkt->stream_index].write_dts ? pkt->dts : pkt->pts;
  1630.     uint64_t additional_id = 0;
  1631.     int64_t discard_padding = 0;
  1632.     uint8_t track_number = (mkv->is_dash ? mkv->dash_track_number : (pkt->stream_index + 1));
  1633.     ebml_master block_group, block_additions, block_more;
  1634.  
  1635.     av_log(s, AV_LOG_DEBUG, "Writing block at offset %" PRIu64 ", size %d, "
  1636.            "pts %" PRId64 ", dts %" PRId64 ", duration %d, keyframe %d\n",
  1637.            avio_tell(pb), pkt->size, pkt->pts, pkt->dts, pkt->duration,
  1638.            keyframe != 0);
  1639.     if (codec->codec_id == AV_CODEC_ID_H264 && codec->extradata_size > 0 &&
  1640.         (AV_RB24(codec->extradata) == 1 || AV_RB32(codec->extradata) == 1))
  1641.         ff_avc_parse_nal_units_buf(pkt->data, &data, &size);
  1642.     else if (codec->codec_id == AV_CODEC_ID_HEVC && codec->extradata_size > 6 &&
  1643.              (AV_RB24(codec->extradata) == 1 || AV_RB32(codec->extradata) == 1))
  1644.         /* extradata is Annex B, assume the bitstream is too and convert it */
  1645.         ff_hevc_annexb2mp4_buf(pkt->data, &data, &size, 0, NULL);
  1646.     else if (codec->codec_id == AV_CODEC_ID_WAVPACK) {
  1647.         int ret = mkv_strip_wavpack(pkt->data, &data, &size);
  1648.         if (ret < 0) {
  1649.             av_log(s, AV_LOG_ERROR, "Error stripping a WavPack packet.\n");
  1650.             return;
  1651.         }
  1652.     } else
  1653.         data = pkt->data;
  1654.  
  1655.     if (codec->codec_id == AV_CODEC_ID_PRORES && size >= 8) {
  1656.         /* Matroska specification requires to remove the first QuickTime atom
  1657.          */
  1658.         size  -= 8;
  1659.         offset = 8;
  1660.     }
  1661.  
  1662.     side_data = av_packet_get_side_data(pkt,
  1663.                                         AV_PKT_DATA_SKIP_SAMPLES,
  1664.                                         &side_data_size);
  1665.  
  1666.     if (side_data && side_data_size >= 10) {
  1667.         discard_padding = av_rescale_q(AV_RL32(side_data + 4),
  1668.                                        (AVRational){1, codec->sample_rate},
  1669.                                        (AVRational){1, 1000000000});
  1670.     }
  1671.  
  1672.     side_data = av_packet_get_side_data(pkt,
  1673.                                         AV_PKT_DATA_MATROSKA_BLOCKADDITIONAL,
  1674.                                         &side_data_size);
  1675.     if (side_data) {
  1676.         additional_id = AV_RB64(side_data);
  1677.         side_data += 8;
  1678.         side_data_size -= 8;
  1679.     }
  1680.  
  1681.     if ((side_data_size && additional_id == 1) || discard_padding) {
  1682.         block_group = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP, 0);
  1683.         blockid = MATROSKA_ID_BLOCK;
  1684.     }
  1685.  
  1686.     put_ebml_id(pb, blockid);
  1687.     put_ebml_num(pb, size + 4, 0);
  1688.     // this assumes stream_index is less than 126
  1689.     avio_w8(pb, 0x80 | track_number);
  1690.     avio_wb16(pb, ts - mkv->cluster_pts);
  1691.     avio_w8(pb, (blockid == MATROSKA_ID_SIMPLEBLOCK && keyframe) ? (1 << 7) : 0);
  1692.     avio_write(pb, data + offset, size);
  1693.     if (data != pkt->data)
  1694.         av_free(data);
  1695.  
  1696.     if (blockid == MATROSKA_ID_BLOCK && !keyframe) {
  1697.         put_ebml_sint(pb, MATROSKA_ID_BLOCKREFERENCE,
  1698.                       mkv->last_track_timestamp[track_number - 1]);
  1699.     }
  1700.     mkv->last_track_timestamp[track_number - 1] = ts - mkv->cluster_pts;
  1701.  
  1702.     if (discard_padding) {
  1703.         put_ebml_sint(pb, MATROSKA_ID_DISCARDPADDING, discard_padding);
  1704.     }
  1705.  
  1706.     if (side_data_size && additional_id == 1) {
  1707.         block_additions = start_ebml_master(pb, MATROSKA_ID_BLOCKADDITIONS, 0);
  1708.         block_more = start_ebml_master(pb, MATROSKA_ID_BLOCKMORE, 0);
  1709.         put_ebml_uint(pb, MATROSKA_ID_BLOCKADDID, 1);
  1710.         put_ebml_id(pb, MATROSKA_ID_BLOCKADDITIONAL);
  1711.         put_ebml_num(pb, side_data_size, 0);
  1712.         avio_write(pb, side_data, side_data_size);
  1713.         end_ebml_master(pb, block_more);
  1714.         end_ebml_master(pb, block_additions);
  1715.     }
  1716.     if ((side_data_size && additional_id == 1) || discard_padding) {
  1717.         end_ebml_master(pb, block_group);
  1718.     }
  1719. }
  1720.  
  1721. static int mkv_write_vtt_blocks(AVFormatContext *s, AVIOContext *pb, AVPacket *pkt)
  1722. {
  1723.     MatroskaMuxContext *mkv = s->priv_data;
  1724.     ebml_master blockgroup;
  1725.     int id_size, settings_size, size;
  1726.     uint8_t *id, *settings;
  1727.     int64_t ts = mkv->tracks[pkt->stream_index].write_dts ? pkt->dts : pkt->pts;
  1728.     const int flags = 0;
  1729.  
  1730.     id_size = 0;
  1731.     id = av_packet_get_side_data(pkt, AV_PKT_DATA_WEBVTT_IDENTIFIER,
  1732.                                  &id_size);
  1733.  
  1734.     settings_size = 0;
  1735.     settings = av_packet_get_side_data(pkt, AV_PKT_DATA_WEBVTT_SETTINGS,
  1736.                                        &settings_size);
  1737.  
  1738.     size = id_size + 1 + settings_size + 1 + pkt->size;
  1739.  
  1740.     av_log(s, AV_LOG_DEBUG, "Writing block at offset %" PRIu64 ", size %d, "
  1741.            "pts %" PRId64 ", dts %" PRId64 ", duration %d, flags %d\n",
  1742.            avio_tell(pb), size, pkt->pts, pkt->dts, pkt->duration, flags);
  1743.  
  1744.     blockgroup = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP, mkv_blockgroup_size(size));
  1745.  
  1746.     put_ebml_id(pb, MATROSKA_ID_BLOCK);
  1747.     put_ebml_num(pb, size + 4, 0);
  1748.     avio_w8(pb, 0x80 | (pkt->stream_index + 1));     // this assumes stream_index is less than 126
  1749.     avio_wb16(pb, ts - mkv->cluster_pts);
  1750.     avio_w8(pb, flags);
  1751.     avio_printf(pb, "%.*s\n%.*s\n%.*s", id_size, id, settings_size, settings, pkt->size, pkt->data);
  1752.  
  1753.     put_ebml_uint(pb, MATROSKA_ID_BLOCKDURATION, pkt->duration);
  1754.     end_ebml_master(pb, blockgroup);
  1755.  
  1756.     return pkt->duration;
  1757. }
  1758.  
  1759. static void mkv_flush_dynbuf(AVFormatContext *s)
  1760. {
  1761.     MatroskaMuxContext *mkv = s->priv_data;
  1762.     int bufsize;
  1763.     uint8_t *dyn_buf;
  1764.  
  1765.     if (!mkv->dyn_bc)
  1766.         return;
  1767.  
  1768.     bufsize = avio_close_dyn_buf(mkv->dyn_bc, &dyn_buf);
  1769.     avio_write(s->pb, dyn_buf, bufsize);
  1770.     av_free(dyn_buf);
  1771.     mkv->dyn_bc = NULL;
  1772. }
  1773.  
  1774. static void mkv_start_new_cluster(AVFormatContext *s, AVPacket *pkt)
  1775. {
  1776.     MatroskaMuxContext *mkv = s->priv_data;
  1777.     AVIOContext *pb;
  1778.  
  1779.     if (s->pb->seekable) {
  1780.         pb = s->pb;
  1781.     } else {
  1782.         pb = mkv->dyn_bc;
  1783.     }
  1784.  
  1785.     av_log(s, AV_LOG_DEBUG,
  1786.             "Starting new cluster at offset %" PRIu64 " bytes, "
  1787.             "pts %" PRIu64 "dts %" PRIu64 "\n",
  1788.             avio_tell(pb), pkt->pts, pkt->dts);
  1789.     end_ebml_master(pb, mkv->cluster);
  1790.     mkv->cluster_pos = -1;
  1791.     if (mkv->dyn_bc)
  1792.         mkv_flush_dynbuf(s);
  1793.     avio_flush(s->pb);
  1794. }
  1795.  
  1796. static int mkv_write_packet_internal(AVFormatContext *s, AVPacket *pkt, int add_cue)
  1797. {
  1798.     MatroskaMuxContext *mkv = s->priv_data;
  1799.     AVIOContext *pb         = s->pb;
  1800.     AVCodecContext *codec   = s->streams[pkt->stream_index]->codec;
  1801.     int keyframe            = !!(pkt->flags & AV_PKT_FLAG_KEY);
  1802.     int duration            = pkt->duration;
  1803.     int ret;
  1804.     int64_t ts = mkv->tracks[pkt->stream_index].write_dts ? pkt->dts : pkt->pts;
  1805.     int64_t relative_packet_pos;
  1806.     int dash_tracknum = mkv->is_dash ? mkv->dash_track_number : pkt->stream_index + 1;
  1807.  
  1808.     if (ts == AV_NOPTS_VALUE) {
  1809.         av_log(s, AV_LOG_ERROR, "Can't write packet with unknown timestamp\n");
  1810.         return AVERROR(EINVAL);
  1811.     }
  1812.     ts += mkv->tracks[pkt->stream_index].ts_offset;
  1813.  
  1814.     if (mkv->cluster_pos != -1) {
  1815.         int64_t cluster_time = ts - mkv->cluster_pts + mkv->tracks[pkt->stream_index].ts_offset;
  1816.         if ((int16_t)cluster_time != cluster_time) {
  1817.             av_log(s, AV_LOG_WARNING, "Starting new cluster due to timestamp\n");
  1818.             mkv_start_new_cluster(s, pkt);
  1819.         }
  1820.     }
  1821.  
  1822.     if (!s->pb->seekable) {
  1823.         if (!mkv->dyn_bc) {
  1824.             ret = avio_open_dyn_buf(&mkv->dyn_bc);
  1825.             if (ret < 0) {
  1826.                 av_log(s, AV_LOG_ERROR, "Failed to open dynamic buffer\n");
  1827.                 return ret;
  1828.             }
  1829.         }
  1830.         pb = mkv->dyn_bc;
  1831.     }
  1832.  
  1833.     if (mkv->cluster_pos == -1) {
  1834.         mkv->cluster_pos = avio_tell(s->pb);
  1835.         mkv->cluster     = start_ebml_master(pb, MATROSKA_ID_CLUSTER, 0);
  1836.         put_ebml_uint(pb, MATROSKA_ID_CLUSTERTIMECODE, FFMAX(0, ts));
  1837.         mkv->cluster_pts = FFMAX(0, ts);
  1838.     }
  1839.  
  1840.     relative_packet_pos = avio_tell(s->pb) - mkv->cluster.pos;
  1841.  
  1842.     if (codec->codec_type != AVMEDIA_TYPE_SUBTITLE) {
  1843.         mkv_write_block(s, pb, MATROSKA_ID_SIMPLEBLOCK, pkt, keyframe);
  1844.         if (s->pb->seekable && (codec->codec_type == AVMEDIA_TYPE_VIDEO && keyframe || add_cue)) {
  1845.             ret = mkv_add_cuepoint(mkv->cues, pkt->stream_index, dash_tracknum, ts, mkv->cluster_pos, relative_packet_pos, -1);
  1846.             if (ret < 0) return ret;
  1847.         }
  1848.     } else {
  1849.         if (codec->codec_id == AV_CODEC_ID_WEBVTT) {
  1850.             duration = mkv_write_vtt_blocks(s, pb, pkt);
  1851.         } else {
  1852.             ebml_master blockgroup = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP,
  1853.                                                        mkv_blockgroup_size(pkt->size));
  1854.             /* For backward compatibility, prefer convergence_duration. */
  1855.             if (pkt->convergence_duration > 0) {
  1856.                 duration = pkt->convergence_duration;
  1857.             }
  1858.             /* All subtitle blocks are considered to be keyframes. */
  1859.             mkv_write_block(s, pb, MATROSKA_ID_BLOCK, pkt, 1);
  1860.             put_ebml_uint(pb, MATROSKA_ID_BLOCKDURATION, duration);
  1861.             end_ebml_master(pb, blockgroup);
  1862.         }
  1863.  
  1864.         if (s->pb->seekable) {
  1865.             ret = mkv_add_cuepoint(mkv->cues, pkt->stream_index, dash_tracknum, ts,
  1866.                                    mkv->cluster_pos, relative_packet_pos, duration);
  1867.             if (ret < 0)
  1868.                 return ret;
  1869.         }
  1870.     }
  1871.  
  1872.     mkv->duration = FFMAX(mkv->duration, ts + duration);
  1873.  
  1874.     if (mkv->stream_durations)
  1875.         mkv->stream_durations[pkt->stream_index] =
  1876.             FFMAX(mkv->stream_durations[pkt->stream_index], ts + duration);
  1877.  
  1878.     return 0;
  1879. }
  1880.  
  1881. static int mkv_write_packet(AVFormatContext *s, AVPacket *pkt)
  1882. {
  1883.     MatroskaMuxContext *mkv = s->priv_data;
  1884.     int codec_type          = s->streams[pkt->stream_index]->codec->codec_type;
  1885.     int keyframe            = !!(pkt->flags & AV_PKT_FLAG_KEY);
  1886.     int cluster_size;
  1887.     int64_t cluster_time;
  1888.     int ret;
  1889.     int start_new_cluster;
  1890.  
  1891.     if (mkv->tracks[pkt->stream_index].write_dts)
  1892.         cluster_time = pkt->dts - mkv->cluster_pts;
  1893.     else
  1894.         cluster_time = pkt->pts - mkv->cluster_pts;
  1895.     cluster_time += mkv->tracks[pkt->stream_index].ts_offset;
  1896.  
  1897.     // start a new cluster every 5 MB or 5 sec, or 32k / 1 sec for streaming or
  1898.     // after 4k and on a keyframe
  1899.     if (s->pb->seekable) {
  1900.         cluster_size = avio_tell(s->pb) - mkv->cluster_pos;
  1901.     } else {
  1902.         cluster_size = avio_tell(mkv->dyn_bc);
  1903.     }
  1904.  
  1905.     if (mkv->is_dash && codec_type == AVMEDIA_TYPE_VIDEO) {
  1906.         // WebM DASH specification states that the first block of every cluster
  1907.         // has to be a key frame. So for DASH video, we only create a cluster
  1908.         // on seeing key frames.
  1909.         start_new_cluster = keyframe;
  1910.     } else if (mkv->is_dash && codec_type == AVMEDIA_TYPE_AUDIO &&
  1911.                (mkv->cluster_pos == -1 ||
  1912.                 cluster_time > mkv->cluster_time_limit)) {
  1913.         // For DASH audio, we create a Cluster based on cluster_time_limit
  1914.         start_new_cluster = 1;
  1915.     } else if (!mkv->is_dash &&
  1916.                (cluster_size > mkv->cluster_size_limit ||
  1917.                 cluster_time > mkv->cluster_time_limit ||
  1918.                 (codec_type == AVMEDIA_TYPE_VIDEO && keyframe &&
  1919.                  cluster_size > 4 * 1024))) {
  1920.         start_new_cluster = 1;
  1921.     } else {
  1922.         start_new_cluster = 0;
  1923.     }
  1924.  
  1925.     if (mkv->cluster_pos != -1 && start_new_cluster) {
  1926.         mkv_start_new_cluster(s, pkt);
  1927.     }
  1928.  
  1929.     // check if we have an audio packet cached
  1930.     if (mkv->cur_audio_pkt.size > 0) {
  1931.         // for DASH audio, a CuePoint has to be added when there is a new cluster.
  1932.         ret = mkv_write_packet_internal(s, &mkv->cur_audio_pkt,
  1933.                                         mkv->is_dash ? start_new_cluster : 0);
  1934.         av_free_packet(&mkv->cur_audio_pkt);
  1935.         if (ret < 0) {
  1936.             av_log(s, AV_LOG_ERROR,
  1937.                    "Could not write cached audio packet ret:%d\n", ret);
  1938.             return ret;
  1939.         }
  1940.     }
  1941.  
  1942.     // buffer an audio packet to ensure the packet containing the video
  1943.     // keyframe's timecode is contained in the same cluster for WebM
  1944.     if (codec_type == AVMEDIA_TYPE_AUDIO) {
  1945.         mkv->cur_audio_pkt = *pkt;
  1946.         if (pkt->buf) {
  1947.             mkv->cur_audio_pkt.buf = av_buffer_ref(pkt->buf);
  1948.             ret = mkv->cur_audio_pkt.buf ? 0 : AVERROR(ENOMEM);
  1949.         } else
  1950.             ret = av_dup_packet(&mkv->cur_audio_pkt);
  1951.         if (mkv->cur_audio_pkt.side_data_elems > 0) {
  1952.             ret = av_copy_packet_side_data(&mkv->cur_audio_pkt, &mkv->cur_audio_pkt);
  1953.         }
  1954.     } else
  1955.         ret = mkv_write_packet_internal(s, pkt, 0);
  1956.     return ret;
  1957. }
  1958.  
  1959. static int mkv_write_flush_packet(AVFormatContext *s, AVPacket *pkt)
  1960. {
  1961.     MatroskaMuxContext *mkv = s->priv_data;
  1962.     AVIOContext *pb;
  1963.     if (s->pb->seekable)
  1964.         pb = s->pb;
  1965.     else
  1966.         pb = mkv->dyn_bc;
  1967.     if (!pkt) {
  1968.         if (mkv->cluster_pos != -1) {
  1969.             av_log(s, AV_LOG_DEBUG,
  1970.                    "Flushing cluster at offset %" PRIu64 " bytes\n",
  1971.                    avio_tell(pb));
  1972.             end_ebml_master(pb, mkv->cluster);
  1973.             mkv->cluster_pos = -1;
  1974.             if (mkv->dyn_bc)
  1975.                 mkv_flush_dynbuf(s);
  1976.             avio_flush(s->pb);
  1977.         }
  1978.         return 1;
  1979.     }
  1980.     return mkv_write_packet(s, pkt);
  1981. }
  1982.  
  1983. static int mkv_write_trailer(AVFormatContext *s)
  1984. {
  1985.     MatroskaMuxContext *mkv = s->priv_data;
  1986.     AVIOContext *pb = s->pb;
  1987.     int64_t currentpos, cuespos;
  1988.     int ret;
  1989.  
  1990.     // check if we have an audio packet cached
  1991.     if (mkv->cur_audio_pkt.size > 0) {
  1992.         ret = mkv_write_packet_internal(s, &mkv->cur_audio_pkt, 0);
  1993.         av_free_packet(&mkv->cur_audio_pkt);
  1994.         if (ret < 0) {
  1995.             av_log(s, AV_LOG_ERROR,
  1996.                    "Could not write cached audio packet ret:%d\n", ret);
  1997.             return ret;
  1998.         }
  1999.     }
  2000.  
  2001.     if (mkv->dyn_bc) {
  2002.         end_ebml_master(mkv->dyn_bc, mkv->cluster);
  2003.         mkv_flush_dynbuf(s);
  2004.     } else if (mkv->cluster_pos != -1) {
  2005.         end_ebml_master(pb, mkv->cluster);
  2006.     }
  2007.  
  2008.     if (mkv->mode != MODE_WEBM) {
  2009.         ret = mkv_write_chapters(s);
  2010.         if (ret < 0)
  2011.             return ret;
  2012.     }
  2013.  
  2014.     if (pb->seekable) {
  2015.         if (mkv->cues->num_entries) {
  2016.             if (mkv->reserve_cues_space) {
  2017.                 int64_t cues_end;
  2018.  
  2019.                 currentpos = avio_tell(pb);
  2020.                 avio_seek(pb, mkv->cues_pos, SEEK_SET);
  2021.  
  2022.                 cuespos  = mkv_write_cues(s, mkv->cues, mkv->tracks, s->nb_streams);
  2023.                 cues_end = avio_tell(pb);
  2024.                 if (cues_end > cuespos + mkv->reserve_cues_space) {
  2025.                     av_log(s, AV_LOG_ERROR,
  2026.                            "Insufficient space reserved for cues: %d "
  2027.                            "(needed: %" PRId64 ").\n",
  2028.                            mkv->reserve_cues_space, cues_end - cuespos);
  2029.                     return AVERROR(EINVAL);
  2030.                 }
  2031.  
  2032.                 if (cues_end < cuespos + mkv->reserve_cues_space)
  2033.                     put_ebml_void(pb, mkv->reserve_cues_space -
  2034.                                   (cues_end - cuespos));
  2035.  
  2036.                 avio_seek(pb, currentpos, SEEK_SET);
  2037.             } else {
  2038.                 cuespos = mkv_write_cues(s, mkv->cues, mkv->tracks, s->nb_streams);
  2039.             }
  2040.  
  2041.             ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_CUES,
  2042.                                          cuespos);
  2043.             if (ret < 0)
  2044.                 return ret;
  2045.         }
  2046.  
  2047.         mkv_write_seekhead(pb, mkv);
  2048.  
  2049.         // update the duration
  2050.         av_log(s, AV_LOG_DEBUG, "end duration = %" PRIu64 "\n", mkv->duration);
  2051.         currentpos = avio_tell(pb);
  2052.         avio_seek(pb, mkv->duration_offset, SEEK_SET);
  2053.         put_ebml_float(pb, MATROSKA_ID_DURATION, mkv->duration);
  2054.  
  2055.         // update stream durations
  2056.         if (mkv->stream_durations) {
  2057.             int i;
  2058.             for (i = 0; i < s->nb_streams; ++i) {
  2059.                 AVStream *st = s->streams[i];
  2060.                 double duration_sec = mkv->stream_durations[i] * av_q2d(st->time_base);
  2061.                 char duration_string[20] = "";
  2062.  
  2063.                 av_log(s, AV_LOG_DEBUG, "stream %d end duration = %" PRIu64 "\n", i,
  2064.                        mkv->stream_durations[i]);
  2065.  
  2066.                 if (!mkv->is_live && mkv->stream_duration_offsets[i] > 0) {
  2067.                     avio_seek(pb, mkv->stream_duration_offsets[i], SEEK_SET);
  2068.  
  2069.                     snprintf(duration_string, 20, "%02d:%02d:%012.9f",
  2070.                              (int) duration_sec / 3600, ((int) duration_sec / 60) % 60,
  2071.                              fmod(duration_sec, 60));
  2072.  
  2073.                     put_ebml_binary(pb, MATROSKA_ID_TAGSTRING, duration_string, 20);
  2074.                 }
  2075.             }
  2076.         }
  2077.  
  2078.         avio_seek(pb, currentpos, SEEK_SET);
  2079.     }
  2080.  
  2081.     if (!mkv->is_live) {
  2082.         end_ebml_master(pb, mkv->segment);
  2083.     }
  2084.  
  2085.     mkv_free(mkv);
  2086.     return 0;
  2087. }
  2088.  
  2089. static int mkv_query_codec(enum AVCodecID codec_id, int std_compliance)
  2090. {
  2091.     int i;
  2092.     for (i = 0; ff_mkv_codec_tags[i].id != AV_CODEC_ID_NONE; i++)
  2093.         if (ff_mkv_codec_tags[i].id == codec_id)
  2094.             return 1;
  2095.  
  2096.     if (std_compliance < FF_COMPLIANCE_NORMAL) {
  2097.         enum AVMediaType type = avcodec_get_type(codec_id);
  2098.         // mkv theoretically supports any video/audio through VFW/ACM
  2099.         if (type == AVMEDIA_TYPE_VIDEO || type == AVMEDIA_TYPE_AUDIO)
  2100.             return 1;
  2101.     }
  2102.  
  2103.     return 0;
  2104. }
  2105.  
  2106. static const AVCodecTag additional_audio_tags[] = {
  2107.     { AV_CODEC_ID_ALAC,      0XFFFFFFFF },
  2108.     { AV_CODEC_ID_EAC3,      0XFFFFFFFF },
  2109.     { AV_CODEC_ID_MLP,       0xFFFFFFFF },
  2110.     { AV_CODEC_ID_OPUS,      0xFFFFFFFF },
  2111.     { AV_CODEC_ID_PCM_S16BE, 0xFFFFFFFF },
  2112.     { AV_CODEC_ID_PCM_S24BE, 0xFFFFFFFF },
  2113.     { AV_CODEC_ID_PCM_S32BE, 0xFFFFFFFF },
  2114.     { AV_CODEC_ID_QDM2,      0xFFFFFFFF },
  2115.     { AV_CODEC_ID_RA_144,    0xFFFFFFFF },
  2116.     { AV_CODEC_ID_RA_288,    0xFFFFFFFF },
  2117.     { AV_CODEC_ID_COOK,      0xFFFFFFFF },
  2118.     { AV_CODEC_ID_TRUEHD,    0xFFFFFFFF },
  2119.     { AV_CODEC_ID_NONE,      0xFFFFFFFF }
  2120. };
  2121.  
  2122. static const AVCodecTag additional_video_tags[] = {
  2123.     { AV_CODEC_ID_RV10,      0xFFFFFFFF },
  2124.     { AV_CODEC_ID_RV20,      0xFFFFFFFF },
  2125.     { AV_CODEC_ID_RV30,      0xFFFFFFFF },
  2126.     { AV_CODEC_ID_RV40,      0xFFFFFFFF },
  2127.     { AV_CODEC_ID_VP9,       0xFFFFFFFF },
  2128.     { AV_CODEC_ID_NONE,      0xFFFFFFFF }
  2129. };
  2130.  
  2131. static const AVCodecTag additional_subtitle_tags[] = {
  2132.     { AV_CODEC_ID_DVB_SUBTITLE,      0xFFFFFFFF },
  2133.     { AV_CODEC_ID_HDMV_PGS_SUBTITLE, 0xFFFFFFFF },
  2134.     { AV_CODEC_ID_NONE,              0xFFFFFFFF }
  2135. };
  2136.  
  2137. #define OFFSET(x) offsetof(MatroskaMuxContext, x)
  2138. #define FLAGS AV_OPT_FLAG_ENCODING_PARAM
  2139. static const AVOption options[] = {
  2140.     { "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 },
  2141.     { "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 },
  2142.     { "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 },
  2143.     { "dash", "Create a WebM file conforming to WebM DASH specification", OFFSET(is_dash), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, FLAGS },
  2144.     { "dash_track_number", "Track number for the DASH stream", OFFSET(dash_track_number), AV_OPT_TYPE_INT, { .i64 = 1 }, 0, 127, FLAGS },
  2145.     { "live", "Write files assuming it is a live stream.", OFFSET(is_live), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, FLAGS },
  2146.     { "allow_raw_vfw", "allow RAW VFW mode", OFFSET(allow_raw_vfw), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, FLAGS },
  2147.     { NULL },
  2148. };
  2149.  
  2150. #if CONFIG_MATROSKA_MUXER
  2151. static const AVClass matroska_class = {
  2152.     .class_name = "matroska muxer",
  2153.     .item_name  = av_default_item_name,
  2154.     .option     = options,
  2155.     .version    = LIBAVUTIL_VERSION_INT,
  2156. };
  2157.  
  2158. AVOutputFormat ff_matroska_muxer = {
  2159.     .name              = "matroska",
  2160.     .long_name         = NULL_IF_CONFIG_SMALL("Matroska"),
  2161.     .mime_type         = "video/x-matroska",
  2162.     .extensions        = "mkv",
  2163.     .priv_data_size    = sizeof(MatroskaMuxContext),
  2164.     .audio_codec       = CONFIG_LIBVORBIS_ENCODER ?
  2165.                          AV_CODEC_ID_VORBIS : AV_CODEC_ID_AC3,
  2166.     .video_codec       = CONFIG_LIBX264_ENCODER ?
  2167.                          AV_CODEC_ID_H264 : AV_CODEC_ID_MPEG4,
  2168.     .write_header      = mkv_write_header,
  2169.     .write_packet      = mkv_write_flush_packet,
  2170.     .write_trailer     = mkv_write_trailer,
  2171.     .flags             = AVFMT_GLOBALHEADER | AVFMT_VARIABLE_FPS |
  2172.                          AVFMT_TS_NONSTRICT | AVFMT_ALLOW_FLUSH,
  2173.     .codec_tag         = (const AVCodecTag* const []){
  2174.          ff_codec_bmp_tags, ff_codec_wav_tags,
  2175.          additional_audio_tags, additional_video_tags, additional_subtitle_tags, 0
  2176.     },
  2177.     .subtitle_codec    = AV_CODEC_ID_ASS,
  2178.     .query_codec       = mkv_query_codec,
  2179.     .priv_class        = &matroska_class,
  2180. };
  2181. #endif
  2182.  
  2183. #if CONFIG_WEBM_MUXER
  2184. static const AVClass webm_class = {
  2185.     .class_name = "webm muxer",
  2186.     .item_name  = av_default_item_name,
  2187.     .option     = options,
  2188.     .version    = LIBAVUTIL_VERSION_INT,
  2189. };
  2190.  
  2191. AVOutputFormat ff_webm_muxer = {
  2192.     .name              = "webm",
  2193.     .long_name         = NULL_IF_CONFIG_SMALL("WebM"),
  2194.     .mime_type         = "video/webm",
  2195.     .extensions        = "webm",
  2196.     .priv_data_size    = sizeof(MatroskaMuxContext),
  2197.     .audio_codec       = CONFIG_LIBOPUS_ENCODER ? AV_CODEC_ID_OPUS : AV_CODEC_ID_VORBIS,
  2198.     .video_codec       = CONFIG_LIBVPX_VP9_ENCODER? AV_CODEC_ID_VP9 : AV_CODEC_ID_VP8,
  2199.     .subtitle_codec    = AV_CODEC_ID_WEBVTT,
  2200.     .write_header      = mkv_write_header,
  2201.     .write_packet      = mkv_write_flush_packet,
  2202.     .write_trailer     = mkv_write_trailer,
  2203.     .flags             = AVFMT_GLOBALHEADER | AVFMT_VARIABLE_FPS |
  2204.                          AVFMT_TS_NONSTRICT | AVFMT_ALLOW_FLUSH,
  2205.     .priv_class        = &webm_class,
  2206. };
  2207. #endif
  2208.  
  2209. #if CONFIG_MATROSKA_AUDIO_MUXER
  2210. static const AVClass mka_class = {
  2211.     .class_name = "matroska audio muxer",
  2212.     .item_name  = av_default_item_name,
  2213.     .option     = options,
  2214.     .version    = LIBAVUTIL_VERSION_INT,
  2215. };
  2216. AVOutputFormat ff_matroska_audio_muxer = {
  2217.     .name              = "matroska",
  2218.     .long_name         = NULL_IF_CONFIG_SMALL("Matroska Audio"),
  2219.     .mime_type         = "audio/x-matroska",
  2220.     .extensions        = "mka",
  2221.     .priv_data_size    = sizeof(MatroskaMuxContext),
  2222.     .audio_codec       = CONFIG_LIBVORBIS_ENCODER ?
  2223.                          AV_CODEC_ID_VORBIS : AV_CODEC_ID_AC3,
  2224.     .video_codec       = AV_CODEC_ID_NONE,
  2225.     .write_header      = mkv_write_header,
  2226.     .write_packet      = mkv_write_flush_packet,
  2227.     .write_trailer     = mkv_write_trailer,
  2228.     .flags             = AVFMT_GLOBALHEADER | AVFMT_TS_NONSTRICT |
  2229.                          AVFMT_ALLOW_FLUSH,
  2230.     .codec_tag         = (const AVCodecTag* const []){
  2231.         ff_codec_wav_tags, additional_audio_tags, 0
  2232.     },
  2233.     .priv_class        = &mka_class,
  2234. };
  2235. #endif
  2236.