Libav 0.7.1
libavformat/matroskaenc.c
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00001 /*
00002  * Matroska muxer
00003  * Copyright (c) 2007 David Conrad
00004  *
00005  * This file is part of Libav.
00006  *
00007  * Libav is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * Libav is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with Libav; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00022 #include "avformat.h"
00023 #include "riff.h"
00024 #include "isom.h"
00025 #include "matroska.h"
00026 #include "avc.h"
00027 #include "flacenc.h"
00028 #include "avlanguage.h"
00029 #include "libavutil/samplefmt.h"
00030 #include "libavutil/intreadwrite.h"
00031 #include "libavutil/random_seed.h"
00032 #include "libavutil/lfg.h"
00033 #include "libavutil/dict.h"
00034 #include "libavcodec/xiph.h"
00035 #include "libavcodec/mpeg4audio.h"
00036 #include <strings.h>
00037 
00038 typedef struct ebml_master {
00039     int64_t         pos;                
00040     int             sizebytes;          
00041 } ebml_master;
00042 
00043 typedef struct mkv_seekhead_entry {
00044     unsigned int    elementid;
00045     uint64_t        segmentpos;
00046 } mkv_seekhead_entry;
00047 
00048 typedef struct mkv_seekhead {
00049     int64_t                 filepos;
00050     int64_t                 segment_offset;     
00051     int                     reserved_size;      
00052     int                     max_entries;
00053     mkv_seekhead_entry      *entries;
00054     int                     num_entries;
00055 } mkv_seekhead;
00056 
00057 typedef struct {
00058     uint64_t        pts;
00059     int             tracknum;
00060     int64_t         cluster_pos;        
00061 } mkv_cuepoint;
00062 
00063 typedef struct {
00064     int64_t         segment_offset;
00065     mkv_cuepoint    *entries;
00066     int             num_entries;
00067 } mkv_cues;
00068 
00069 typedef struct {
00070     int             write_dts;
00071 } mkv_track;
00072 
00073 #define MODE_MATROSKAv2 0x01
00074 #define MODE_WEBM       0x02
00075 
00076 typedef struct MatroskaMuxContext {
00077     int             mode;
00078     AVIOContext   *dyn_bc;
00079     ebml_master     segment;
00080     int64_t         segment_offset;
00081     ebml_master     cluster;
00082     int64_t         cluster_pos;        
00083     int64_t         cluster_pts;
00084     int64_t         duration_offset;
00085     int64_t         duration;
00086     mkv_seekhead    *main_seekhead;
00087     mkv_cues        *cues;
00088     mkv_track       *tracks;
00089 
00090     unsigned int    audio_buffer_size;
00091     AVPacket        cur_audio_pkt;
00092 } MatroskaMuxContext;
00093 
00094 
00097 #define MAX_SEEKENTRY_SIZE 21
00098 
00101 #define MAX_CUETRACKPOS_SIZE 22
00102 
00104 #define MAX_CUEPOINT_SIZE(num_tracks) 12 + MAX_CUETRACKPOS_SIZE*num_tracks
00105 
00106 
00107 static int ebml_id_size(unsigned int id)
00108 {
00109     return (av_log2(id+1)-1)/7+1;
00110 }
00111 
00112 static void put_ebml_id(AVIOContext *pb, unsigned int id)
00113 {
00114     int i = ebml_id_size(id);
00115     while (i--)
00116         avio_w8(pb, id >> (i*8));
00117 }
00118 
00124 static void put_ebml_size_unknown(AVIOContext *pb, int bytes)
00125 {
00126     assert(bytes <= 8);
00127     avio_w8(pb, 0x1ff >> bytes);
00128     while (--bytes)
00129         avio_w8(pb, 0xff);
00130 }
00131 
00135 static int ebml_num_size(uint64_t num)
00136 {
00137     int bytes = 1;
00138     while ((num+1) >> bytes*7) bytes++;
00139     return bytes;
00140 }
00141 
00148 static void put_ebml_num(AVIOContext *pb, uint64_t num, int bytes)
00149 {
00150     int i, needed_bytes = ebml_num_size(num);
00151 
00152     // sizes larger than this are currently undefined in EBML
00153     assert(num < (1ULL<<56)-1);
00154 
00155     if (bytes == 0)
00156         // don't care how many bytes are used, so use the min
00157         bytes = needed_bytes;
00158     // the bytes needed to write the given size would exceed the bytes
00159     // that we need to use, so write unknown size. This shouldn't happen.
00160     assert(bytes >= needed_bytes);
00161 
00162     num |= 1ULL << bytes*7;
00163     for (i = bytes - 1; i >= 0; i--)
00164         avio_w8(pb, num >> i*8);
00165 }
00166 
00167 static void put_ebml_uint(AVIOContext *pb, unsigned int elementid, uint64_t val)
00168 {
00169     int i, bytes = 1;
00170     uint64_t tmp = val;
00171     while (tmp>>=8) bytes++;
00172 
00173     put_ebml_id(pb, elementid);
00174     put_ebml_num(pb, bytes, 0);
00175     for (i = bytes - 1; i >= 0; i--)
00176         avio_w8(pb, val >> i*8);
00177 }
00178 
00179 static void put_ebml_float(AVIOContext *pb, unsigned int elementid, double val)
00180 {
00181     put_ebml_id(pb, elementid);
00182     put_ebml_num(pb, 8, 0);
00183     avio_wb64(pb, av_dbl2int(val));
00184 }
00185 
00186 static void put_ebml_binary(AVIOContext *pb, unsigned int elementid,
00187                             const void *buf, int size)
00188 {
00189     put_ebml_id(pb, elementid);
00190     put_ebml_num(pb, size, 0);
00191     avio_write(pb, buf, size);
00192 }
00193 
00194 static void put_ebml_string(AVIOContext *pb, unsigned int elementid, const char *str)
00195 {
00196     put_ebml_binary(pb, elementid, str, strlen(str));
00197 }
00198 
00205 static void put_ebml_void(AVIOContext *pb, uint64_t size)
00206 {
00207     int64_t currentpos = avio_tell(pb);
00208 
00209     assert(size >= 2);
00210 
00211     put_ebml_id(pb, EBML_ID_VOID);
00212     // we need to subtract the length needed to store the size from the
00213     // size we need to reserve so 2 cases, we use 8 bytes to store the
00214     // size if possible, 1 byte otherwise
00215     if (size < 10)
00216         put_ebml_num(pb, size-1, 0);
00217     else
00218         put_ebml_num(pb, size-9, 8);
00219     while(avio_tell(pb) < currentpos + size)
00220         avio_w8(pb, 0);
00221 }
00222 
00223 static ebml_master start_ebml_master(AVIOContext *pb, unsigned int elementid, uint64_t expectedsize)
00224 {
00225     int bytes = expectedsize ? ebml_num_size(expectedsize) : 8;
00226     put_ebml_id(pb, elementid);
00227     put_ebml_size_unknown(pb, bytes);
00228     return (ebml_master){ avio_tell(pb), bytes };
00229 }
00230 
00231 static void end_ebml_master(AVIOContext *pb, ebml_master master)
00232 {
00233     int64_t pos = avio_tell(pb);
00234 
00235     if (avio_seek(pb, master.pos - master.sizebytes, SEEK_SET) < 0)
00236         return;
00237     put_ebml_num(pb, pos - master.pos, master.sizebytes);
00238     avio_seek(pb, pos, SEEK_SET);
00239 }
00240 
00241 static void put_xiph_size(AVIOContext *pb, int size)
00242 {
00243     int i;
00244     for (i = 0; i < size / 255; i++)
00245         avio_w8(pb, 255);
00246     avio_w8(pb, size % 255);
00247 }
00248 
00260 static mkv_seekhead * mkv_start_seekhead(AVIOContext *pb, int64_t segment_offset, int numelements)
00261 {
00262     mkv_seekhead *new_seekhead = av_mallocz(sizeof(mkv_seekhead));
00263     if (new_seekhead == NULL)
00264         return NULL;
00265 
00266     new_seekhead->segment_offset = segment_offset;
00267 
00268     if (numelements > 0) {
00269         new_seekhead->filepos = avio_tell(pb);
00270         // 21 bytes max for a seek entry, 10 bytes max for the SeekHead ID
00271         // and size, and 3 bytes to guarantee that an EBML void element
00272         // will fit afterwards
00273         new_seekhead->reserved_size = numelements * MAX_SEEKENTRY_SIZE + 13;
00274         new_seekhead->max_entries = numelements;
00275         put_ebml_void(pb, new_seekhead->reserved_size);
00276     }
00277     return new_seekhead;
00278 }
00279 
00280 static int mkv_add_seekhead_entry(mkv_seekhead *seekhead, unsigned int elementid, uint64_t filepos)
00281 {
00282     mkv_seekhead_entry *entries = seekhead->entries;
00283 
00284     // don't store more elements than we reserved space for
00285     if (seekhead->max_entries > 0 && seekhead->max_entries <= seekhead->num_entries)
00286         return -1;
00287 
00288     entries = av_realloc(entries, (seekhead->num_entries + 1) * sizeof(mkv_seekhead_entry));
00289     if (entries == NULL)
00290         return AVERROR(ENOMEM);
00291 
00292     entries[seekhead->num_entries  ].elementid = elementid;
00293     entries[seekhead->num_entries++].segmentpos = filepos - seekhead->segment_offset;
00294 
00295     seekhead->entries = entries;
00296     return 0;
00297 }
00298 
00308 static int64_t mkv_write_seekhead(AVIOContext *pb, mkv_seekhead *seekhead)
00309 {
00310     ebml_master metaseek, seekentry;
00311     int64_t currentpos;
00312     int i;
00313 
00314     currentpos = avio_tell(pb);
00315 
00316     if (seekhead->reserved_size > 0)
00317         if (avio_seek(pb, seekhead->filepos, SEEK_SET) < 0)
00318             return -1;
00319 
00320     metaseek = start_ebml_master(pb, MATROSKA_ID_SEEKHEAD, seekhead->reserved_size);
00321     for (i = 0; i < seekhead->num_entries; i++) {
00322         mkv_seekhead_entry *entry = &seekhead->entries[i];
00323 
00324         seekentry = start_ebml_master(pb, MATROSKA_ID_SEEKENTRY, MAX_SEEKENTRY_SIZE);
00325 
00326         put_ebml_id(pb, MATROSKA_ID_SEEKID);
00327         put_ebml_num(pb, ebml_id_size(entry->elementid), 0);
00328         put_ebml_id(pb, entry->elementid);
00329 
00330         put_ebml_uint(pb, MATROSKA_ID_SEEKPOSITION, entry->segmentpos);
00331         end_ebml_master(pb, seekentry);
00332     }
00333     end_ebml_master(pb, metaseek);
00334 
00335     if (seekhead->reserved_size > 0) {
00336         uint64_t remaining = seekhead->filepos + seekhead->reserved_size - avio_tell(pb);
00337         put_ebml_void(pb, remaining);
00338         avio_seek(pb, currentpos, SEEK_SET);
00339 
00340         currentpos = seekhead->filepos;
00341     }
00342     av_free(seekhead->entries);
00343     av_free(seekhead);
00344 
00345     return currentpos;
00346 }
00347 
00348 static mkv_cues * mkv_start_cues(int64_t segment_offset)
00349 {
00350     mkv_cues *cues = av_mallocz(sizeof(mkv_cues));
00351     if (cues == NULL)
00352         return NULL;
00353 
00354     cues->segment_offset = segment_offset;
00355     return cues;
00356 }
00357 
00358 static int mkv_add_cuepoint(mkv_cues *cues, int stream, int64_t ts, int64_t cluster_pos)
00359 {
00360     mkv_cuepoint *entries = cues->entries;
00361 
00362     entries = av_realloc(entries, (cues->num_entries + 1) * sizeof(mkv_cuepoint));
00363     if (entries == NULL)
00364         return AVERROR(ENOMEM);
00365 
00366     if (ts < 0)
00367         return 0;
00368 
00369     entries[cues->num_entries  ].pts = ts;
00370     entries[cues->num_entries  ].tracknum = stream + 1;
00371     entries[cues->num_entries++].cluster_pos = cluster_pos - cues->segment_offset;
00372 
00373     cues->entries = entries;
00374     return 0;
00375 }
00376 
00377 static int64_t mkv_write_cues(AVIOContext *pb, mkv_cues *cues, int num_tracks)
00378 {
00379     ebml_master cues_element;
00380     int64_t currentpos;
00381     int i, j;
00382 
00383     currentpos = avio_tell(pb);
00384     cues_element = start_ebml_master(pb, MATROSKA_ID_CUES, 0);
00385 
00386     for (i = 0; i < cues->num_entries; i++) {
00387         ebml_master cuepoint, track_positions;
00388         mkv_cuepoint *entry = &cues->entries[i];
00389         uint64_t pts = entry->pts;
00390 
00391         cuepoint = start_ebml_master(pb, MATROSKA_ID_POINTENTRY, MAX_CUEPOINT_SIZE(num_tracks));
00392         put_ebml_uint(pb, MATROSKA_ID_CUETIME, pts);
00393 
00394         // put all the entries from different tracks that have the exact same
00395         // timestamp into the same CuePoint
00396         for (j = 0; j < cues->num_entries - i && entry[j].pts == pts; j++) {
00397             track_positions = start_ebml_master(pb, MATROSKA_ID_CUETRACKPOSITION, MAX_CUETRACKPOS_SIZE);
00398             put_ebml_uint(pb, MATROSKA_ID_CUETRACK          , entry[j].tracknum   );
00399             put_ebml_uint(pb, MATROSKA_ID_CUECLUSTERPOSITION, entry[j].cluster_pos);
00400             end_ebml_master(pb, track_positions);
00401         }
00402         i += j - 1;
00403         end_ebml_master(pb, cuepoint);
00404     }
00405     end_ebml_master(pb, cues_element);
00406 
00407     return currentpos;
00408 }
00409 
00410 static int put_xiph_codecpriv(AVFormatContext *s, AVIOContext *pb, AVCodecContext *codec)
00411 {
00412     uint8_t *header_start[3];
00413     int header_len[3];
00414     int first_header_size;
00415     int j;
00416 
00417     if (codec->codec_id == CODEC_ID_VORBIS)
00418         first_header_size = 30;
00419     else
00420         first_header_size = 42;
00421 
00422     if (ff_split_xiph_headers(codec->extradata, codec->extradata_size,
00423                               first_header_size, header_start, header_len) < 0) {
00424         av_log(s, AV_LOG_ERROR, "Extradata corrupt.\n");
00425         return -1;
00426     }
00427 
00428     avio_w8(pb, 2);                    // number packets - 1
00429     for (j = 0; j < 2; j++) {
00430         put_xiph_size(pb, header_len[j]);
00431     }
00432     for (j = 0; j < 3; j++)
00433         avio_write(pb, header_start[j], header_len[j]);
00434 
00435     return 0;
00436 }
00437 
00438 static void get_aac_sample_rates(AVFormatContext *s, AVCodecContext *codec, int *sample_rate, int *output_sample_rate)
00439 {
00440     MPEG4AudioConfig mp4ac;
00441 
00442     if (ff_mpeg4audio_get_config(&mp4ac, codec->extradata, codec->extradata_size) < 0) {
00443         av_log(s, AV_LOG_WARNING, "Error parsing AAC extradata, unable to determine samplerate.\n");
00444         return;
00445     }
00446 
00447     *sample_rate        = mp4ac.sample_rate;
00448     *output_sample_rate = mp4ac.ext_sample_rate;
00449 }
00450 
00451 static int mkv_write_codecprivate(AVFormatContext *s, AVIOContext *pb, AVCodecContext *codec, int native_id, int qt_id)
00452 {
00453     AVIOContext *dyn_cp;
00454     uint8_t *codecpriv;
00455     int ret, codecpriv_size;
00456 
00457     ret = avio_open_dyn_buf(&dyn_cp);
00458     if(ret < 0)
00459         return ret;
00460 
00461     if (native_id) {
00462         if (codec->codec_id == CODEC_ID_VORBIS || codec->codec_id == CODEC_ID_THEORA)
00463             ret = put_xiph_codecpriv(s, dyn_cp, codec);
00464         else if (codec->codec_id == CODEC_ID_FLAC)
00465             ret = ff_flac_write_header(dyn_cp, codec, 1);
00466         else if (codec->codec_id == CODEC_ID_H264)
00467             ret = ff_isom_write_avcc(dyn_cp, codec->extradata, codec->extradata_size);
00468         else if (codec->extradata_size)
00469             avio_write(dyn_cp, codec->extradata, codec->extradata_size);
00470     } else if (codec->codec_type == AVMEDIA_TYPE_VIDEO) {
00471         if (qt_id) {
00472             if (!codec->codec_tag)
00473                 codec->codec_tag = ff_codec_get_tag(codec_movvideo_tags, codec->codec_id);
00474             if (codec->extradata_size)
00475                 avio_write(dyn_cp, codec->extradata, codec->extradata_size);
00476         } else {
00477             if (!codec->codec_tag)
00478                 codec->codec_tag = ff_codec_get_tag(ff_codec_bmp_tags, codec->codec_id);
00479             if (!codec->codec_tag) {
00480                 av_log(s, AV_LOG_ERROR, "No bmp codec ID found.\n");
00481                 ret = -1;
00482             }
00483 
00484             ff_put_bmp_header(dyn_cp, codec, ff_codec_bmp_tags, 0);
00485         }
00486 
00487     } else if (codec->codec_type == AVMEDIA_TYPE_AUDIO) {
00488         unsigned int tag;
00489         tag = ff_codec_get_tag(ff_codec_wav_tags, codec->codec_id);
00490         if (!tag) {
00491             av_log(s, AV_LOG_ERROR, "No wav codec ID found.\n");
00492             ret = -1;
00493         }
00494         if (!codec->codec_tag)
00495             codec->codec_tag = tag;
00496 
00497         ff_put_wav_header(dyn_cp, codec);
00498     }
00499 
00500     codecpriv_size = avio_close_dyn_buf(dyn_cp, &codecpriv);
00501     if (codecpriv_size)
00502         put_ebml_binary(pb, MATROSKA_ID_CODECPRIVATE, codecpriv, codecpriv_size);
00503     av_free(codecpriv);
00504     return ret;
00505 }
00506 
00507 static int mkv_write_tracks(AVFormatContext *s)
00508 {
00509     MatroskaMuxContext *mkv = s->priv_data;
00510     AVIOContext *pb = s->pb;
00511     ebml_master tracks;
00512     int i, j, ret;
00513 
00514     ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_TRACKS, avio_tell(pb));
00515     if (ret < 0) return ret;
00516 
00517     tracks = start_ebml_master(pb, MATROSKA_ID_TRACKS, 0);
00518     for (i = 0; i < s->nb_streams; i++) {
00519         AVStream *st = s->streams[i];
00520         AVCodecContext *codec = st->codec;
00521         ebml_master subinfo, track;
00522         int native_id = 0;
00523         int qt_id = 0;
00524         int bit_depth = av_get_bits_per_sample(codec->codec_id);
00525         int sample_rate = codec->sample_rate;
00526         int output_sample_rate = 0;
00527         AVDictionaryEntry *tag;
00528 
00529         if (!bit_depth)
00530             bit_depth = av_get_bits_per_sample_fmt(codec->sample_fmt);
00531 
00532         if (codec->codec_id == CODEC_ID_AAC)
00533             get_aac_sample_rates(s, codec, &sample_rate, &output_sample_rate);
00534 
00535         track = start_ebml_master(pb, MATROSKA_ID_TRACKENTRY, 0);
00536         put_ebml_uint (pb, MATROSKA_ID_TRACKNUMBER     , i + 1);
00537         put_ebml_uint (pb, MATROSKA_ID_TRACKUID        , i + 1);
00538         put_ebml_uint (pb, MATROSKA_ID_TRACKFLAGLACING , 0);    // no lacing (yet)
00539 
00540         if ((tag = av_dict_get(st->metadata, "title", NULL, 0)))
00541             put_ebml_string(pb, MATROSKA_ID_TRACKNAME, tag->value);
00542         tag = av_dict_get(st->metadata, "language", NULL, 0);
00543         put_ebml_string(pb, MATROSKA_ID_TRACKLANGUAGE, tag ? tag->value:"und");
00544 
00545         if (st->disposition)
00546             put_ebml_uint(pb, MATROSKA_ID_TRACKFLAGDEFAULT, !!(st->disposition & AV_DISPOSITION_DEFAULT));
00547 
00548         // look for a codec ID string specific to mkv to use,
00549         // if none are found, use AVI codes
00550         for (j = 0; ff_mkv_codec_tags[j].id != CODEC_ID_NONE; j++) {
00551             if (ff_mkv_codec_tags[j].id == codec->codec_id) {
00552                 put_ebml_string(pb, MATROSKA_ID_CODECID, ff_mkv_codec_tags[j].str);
00553                 native_id = 1;
00554                 break;
00555             }
00556         }
00557 
00558         if (mkv->mode == MODE_WEBM && !(codec->codec_id == CODEC_ID_VP8 ||
00559                                         codec->codec_id == CODEC_ID_VORBIS)) {
00560             av_log(s, AV_LOG_ERROR,
00561                    "Only VP8 video and Vorbis audio are supported for WebM.\n");
00562             return AVERROR(EINVAL);
00563         }
00564 
00565         switch (codec->codec_type) {
00566             case AVMEDIA_TYPE_VIDEO:
00567                 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_VIDEO);
00568                 put_ebml_uint(pb, MATROSKA_ID_TRACKDEFAULTDURATION, av_q2d(codec->time_base)*1E9);
00569 
00570                 if (!native_id &&
00571                       ff_codec_get_tag(codec_movvideo_tags, codec->codec_id) &&
00572                     (!ff_codec_get_tag(ff_codec_bmp_tags,   codec->codec_id)
00573                      || codec->codec_id == CODEC_ID_SVQ1
00574                      || codec->codec_id == CODEC_ID_SVQ3
00575                      || codec->codec_id == CODEC_ID_CINEPAK))
00576                     qt_id = 1;
00577 
00578                 if (qt_id)
00579                     put_ebml_string(pb, MATROSKA_ID_CODECID, "V_QUICKTIME");
00580                 else if (!native_id) {
00581                     // if there is no mkv-specific codec ID, use VFW mode
00582                     put_ebml_string(pb, MATROSKA_ID_CODECID, "V_MS/VFW/FOURCC");
00583                     mkv->tracks[i].write_dts = 1;
00584                 }
00585 
00586                 subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKVIDEO, 0);
00587                 // XXX: interlace flag?
00588                 put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELWIDTH , codec->width);
00589                 put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELHEIGHT, codec->height);
00590                 if ((tag = av_dict_get(s->metadata, "stereo_mode", NULL, 0))) {
00591                     uint8_t stereo_fmt = atoi(tag->value);
00592                     int valid_fmt = 0;
00593 
00594                     switch (mkv->mode) {
00595                     case MODE_WEBM:
00596                         if (stereo_fmt <= MATROSKA_VIDEO_STEREOMODE_TYPE_TOP_BOTTOM
00597                             || stereo_fmt == MATROSKA_VIDEO_STEREOMODE_TYPE_RIGHT_LEFT)
00598                             valid_fmt = 1;
00599                         break;
00600                     case MODE_MATROSKAv2:
00601                         if (stereo_fmt <= MATROSKA_VIDEO_STEREOMODE_TYPE_BOTH_EYES_BLOCK_RL)
00602                             valid_fmt = 1;
00603                         break;
00604                     }
00605 
00606                     if (valid_fmt)
00607                         put_ebml_uint (pb, MATROSKA_ID_VIDEOSTEREOMODE, stereo_fmt);
00608                 }
00609                 if (st->sample_aspect_ratio.num) {
00610                     int d_width = codec->width*av_q2d(st->sample_aspect_ratio);
00611                     put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYWIDTH , d_width);
00612                     put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYHEIGHT, codec->height);
00613                     put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYUNIT, 3);
00614                 }
00615                 end_ebml_master(pb, subinfo);
00616                 break;
00617 
00618             case AVMEDIA_TYPE_AUDIO:
00619                 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_AUDIO);
00620 
00621                 if (!native_id)
00622                     // no mkv-specific ID, use ACM mode
00623                     put_ebml_string(pb, MATROSKA_ID_CODECID, "A_MS/ACM");
00624 
00625                 subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKAUDIO, 0);
00626                 put_ebml_uint  (pb, MATROSKA_ID_AUDIOCHANNELS    , codec->channels);
00627                 put_ebml_float (pb, MATROSKA_ID_AUDIOSAMPLINGFREQ, sample_rate);
00628                 if (output_sample_rate)
00629                     put_ebml_float(pb, MATROSKA_ID_AUDIOOUTSAMPLINGFREQ, output_sample_rate);
00630                 if (bit_depth)
00631                     put_ebml_uint(pb, MATROSKA_ID_AUDIOBITDEPTH, bit_depth);
00632                 end_ebml_master(pb, subinfo);
00633                 break;
00634 
00635             case AVMEDIA_TYPE_SUBTITLE:
00636                 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_SUBTITLE);
00637                 if (!native_id) {
00638                     av_log(s, AV_LOG_ERROR, "Subtitle codec %d is not supported.\n", codec->codec_id);
00639                     return AVERROR(ENOSYS);
00640                 }
00641                 break;
00642             default:
00643                 av_log(s, AV_LOG_ERROR, "Only audio, video, and subtitles are supported for Matroska.\n");
00644                 break;
00645         }
00646         ret = mkv_write_codecprivate(s, pb, codec, native_id, qt_id);
00647         if (ret < 0) return ret;
00648 
00649         end_ebml_master(pb, track);
00650 
00651         // ms precision is the de-facto standard timescale for mkv files
00652         av_set_pts_info(st, 64, 1, 1000);
00653     }
00654     end_ebml_master(pb, tracks);
00655     return 0;
00656 }
00657 
00658 static int mkv_write_chapters(AVFormatContext *s)
00659 {
00660     MatroskaMuxContext *mkv = s->priv_data;
00661     AVIOContext *pb = s->pb;
00662     ebml_master chapters, editionentry;
00663     AVRational scale = {1, 1E9};
00664     int i, ret;
00665 
00666     if (!s->nb_chapters)
00667         return 0;
00668 
00669     ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_CHAPTERS, avio_tell(pb));
00670     if (ret < 0) return ret;
00671 
00672     chapters     = start_ebml_master(pb, MATROSKA_ID_CHAPTERS    , 0);
00673     editionentry = start_ebml_master(pb, MATROSKA_ID_EDITIONENTRY, 0);
00674     put_ebml_uint(pb, MATROSKA_ID_EDITIONFLAGDEFAULT, 1);
00675     put_ebml_uint(pb, MATROSKA_ID_EDITIONFLAGHIDDEN , 0);
00676     for (i = 0; i < s->nb_chapters; i++) {
00677         ebml_master chapteratom, chapterdisplay;
00678         AVChapter *c     = s->chapters[i];
00679         AVDictionaryEntry *t = NULL;
00680 
00681         chapteratom = start_ebml_master(pb, MATROSKA_ID_CHAPTERATOM, 0);
00682         put_ebml_uint(pb, MATROSKA_ID_CHAPTERUID, c->id);
00683         put_ebml_uint(pb, MATROSKA_ID_CHAPTERTIMESTART,
00684                       av_rescale_q(c->start, c->time_base, scale));
00685         put_ebml_uint(pb, MATROSKA_ID_CHAPTERTIMEEND,
00686                       av_rescale_q(c->end,   c->time_base, scale));
00687         put_ebml_uint(pb, MATROSKA_ID_CHAPTERFLAGHIDDEN , 0);
00688         put_ebml_uint(pb, MATROSKA_ID_CHAPTERFLAGENABLED, 1);
00689         if ((t = av_dict_get(c->metadata, "title", NULL, 0))) {
00690             chapterdisplay = start_ebml_master(pb, MATROSKA_ID_CHAPTERDISPLAY, 0);
00691             put_ebml_string(pb, MATROSKA_ID_CHAPSTRING, t->value);
00692             put_ebml_string(pb, MATROSKA_ID_CHAPLANG  , "und");
00693             end_ebml_master(pb, chapterdisplay);
00694         }
00695         end_ebml_master(pb, chapteratom);
00696     }
00697     end_ebml_master(pb, editionentry);
00698     end_ebml_master(pb, chapters);
00699     return 0;
00700 }
00701 
00702 static void mkv_write_simpletag(AVIOContext *pb, AVDictionaryEntry *t)
00703 {
00704     uint8_t *key = av_strdup(t->key);
00705     uint8_t *p   = key;
00706     const uint8_t *lang = NULL;
00707     ebml_master tag;
00708 
00709     if ((p = strrchr(p, '-')) &&
00710         (lang = av_convert_lang_to(p + 1, AV_LANG_ISO639_2_BIBL)))
00711         *p = 0;
00712 
00713     p = key;
00714     while (*p) {
00715         if (*p == ' ')
00716             *p = '_';
00717         else if (*p >= 'a' && *p <= 'z')
00718             *p -= 'a' - 'A';
00719         p++;
00720     }
00721 
00722     tag = start_ebml_master(pb, MATROSKA_ID_SIMPLETAG, 0);
00723     put_ebml_string(pb, MATROSKA_ID_TAGNAME, key);
00724     if (lang)
00725         put_ebml_string(pb, MATROSKA_ID_TAGLANG, lang);
00726     put_ebml_string(pb, MATROSKA_ID_TAGSTRING, t->value);
00727     end_ebml_master(pb, tag);
00728 
00729     av_freep(&key);
00730 }
00731 
00732 static int mkv_write_tag(AVFormatContext *s, AVDictionary *m, unsigned int elementid,
00733                          unsigned int uid, ebml_master *tags)
00734 {
00735     MatroskaMuxContext *mkv = s->priv_data;
00736     ebml_master tag, targets;
00737     AVDictionaryEntry *t = NULL;
00738     int ret;
00739 
00740     if (!tags->pos) {
00741         ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_TAGS, avio_tell(s->pb));
00742         if (ret < 0) return ret;
00743 
00744         *tags = start_ebml_master(s->pb, MATROSKA_ID_TAGS, 0);
00745     }
00746 
00747     tag     = start_ebml_master(s->pb, MATROSKA_ID_TAG,        0);
00748     targets = start_ebml_master(s->pb, MATROSKA_ID_TAGTARGETS, 0);
00749     if (elementid)
00750         put_ebml_uint(s->pb, elementid, uid);
00751     end_ebml_master(s->pb, targets);
00752 
00753     while ((t = av_dict_get(m, "", t, AV_DICT_IGNORE_SUFFIX)))
00754         if (strcasecmp(t->key, "title"))
00755             mkv_write_simpletag(s->pb, t);
00756 
00757     end_ebml_master(s->pb, tag);
00758     return 0;
00759 }
00760 
00761 static int mkv_write_tags(AVFormatContext *s)
00762 {
00763     ebml_master tags = {0};
00764     int i, ret;
00765 
00766     ff_metadata_conv_ctx(s, ff_mkv_metadata_conv, NULL);
00767 
00768     if (av_dict_get(s->metadata, "", NULL, AV_DICT_IGNORE_SUFFIX)) {
00769         ret = mkv_write_tag(s, s->metadata, 0, 0, &tags);
00770         if (ret < 0) return ret;
00771     }
00772 
00773     for (i = 0; i < s->nb_streams; i++) {
00774         AVStream *st = s->streams[i];
00775 
00776         if (!av_dict_get(st->metadata, "", 0, AV_DICT_IGNORE_SUFFIX))
00777             continue;
00778 
00779         ret = mkv_write_tag(s, st->metadata, MATROSKA_ID_TAGTARGETS_TRACKUID, i + 1, &tags);
00780         if (ret < 0) return ret;
00781     }
00782 
00783     for (i = 0; i < s->nb_chapters; i++) {
00784         AVChapter *ch = s->chapters[i];
00785 
00786         if (!av_dict_get(ch->metadata, "", NULL, AV_DICT_IGNORE_SUFFIX))
00787             continue;
00788 
00789         ret = mkv_write_tag(s, ch->metadata, MATROSKA_ID_TAGTARGETS_CHAPTERUID, ch->id, &tags);
00790         if (ret < 0) return ret;
00791     }
00792 
00793     if (tags.pos)
00794         end_ebml_master(s->pb, tags);
00795     return 0;
00796 }
00797 
00798 static int mkv_write_header(AVFormatContext *s)
00799 {
00800     MatroskaMuxContext *mkv = s->priv_data;
00801     AVIOContext *pb = s->pb;
00802     ebml_master ebml_header, segment_info;
00803     AVDictionaryEntry *tag;
00804     int ret, i;
00805 
00806     if (!strcmp(s->oformat->name, "webm")) mkv->mode = MODE_WEBM;
00807     else                                   mkv->mode = MODE_MATROSKAv2;
00808 
00809     mkv->tracks = av_mallocz(s->nb_streams * sizeof(*mkv->tracks));
00810     if (!mkv->tracks)
00811         return AVERROR(ENOMEM);
00812 
00813     ebml_header = start_ebml_master(pb, EBML_ID_HEADER, 0);
00814     put_ebml_uint   (pb, EBML_ID_EBMLVERSION        ,           1);
00815     put_ebml_uint   (pb, EBML_ID_EBMLREADVERSION    ,           1);
00816     put_ebml_uint   (pb, EBML_ID_EBMLMAXIDLENGTH    ,           4);
00817     put_ebml_uint   (pb, EBML_ID_EBMLMAXSIZELENGTH  ,           8);
00818     put_ebml_string (pb, EBML_ID_DOCTYPE            , s->oformat->name);
00819     put_ebml_uint   (pb, EBML_ID_DOCTYPEVERSION     ,           2);
00820     put_ebml_uint   (pb, EBML_ID_DOCTYPEREADVERSION ,           2);
00821     end_ebml_master(pb, ebml_header);
00822 
00823     mkv->segment = start_ebml_master(pb, MATROSKA_ID_SEGMENT, 0);
00824     mkv->segment_offset = avio_tell(pb);
00825 
00826     // we write 2 seek heads - one at the end of the file to point to each
00827     // cluster, and one at the beginning to point to all other level one
00828     // elements (including the seek head at the end of the file), which
00829     // isn't more than 10 elements if we only write one of each other
00830     // currently defined level 1 element
00831     mkv->main_seekhead    = mkv_start_seekhead(pb, mkv->segment_offset, 10);
00832     if (!mkv->main_seekhead)
00833         return AVERROR(ENOMEM);
00834 
00835     ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_INFO, avio_tell(pb));
00836     if (ret < 0) return ret;
00837 
00838     segment_info = start_ebml_master(pb, MATROSKA_ID_INFO, 0);
00839     put_ebml_uint(pb, MATROSKA_ID_TIMECODESCALE, 1000000);
00840     if ((tag = av_dict_get(s->metadata, "title", NULL, 0)))
00841         put_ebml_string(pb, MATROSKA_ID_TITLE, tag->value);
00842     if (!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT)) {
00843         uint32_t segment_uid[4];
00844         AVLFG lfg;
00845 
00846         av_lfg_init(&lfg, av_get_random_seed());
00847 
00848         for (i = 0; i < 4; i++)
00849             segment_uid[i] = av_lfg_get(&lfg);
00850 
00851         put_ebml_string(pb, MATROSKA_ID_MUXINGAPP , LIBAVFORMAT_IDENT);
00852         put_ebml_string(pb, MATROSKA_ID_WRITINGAPP, LIBAVFORMAT_IDENT);
00853         put_ebml_binary(pb, MATROSKA_ID_SEGMENTUID, segment_uid, 16);
00854     }
00855 
00856     // reserve space for the duration
00857     mkv->duration = 0;
00858     mkv->duration_offset = avio_tell(pb);
00859     put_ebml_void(pb, 11);                  // assumes double-precision float to be written
00860     end_ebml_master(pb, segment_info);
00861 
00862     ret = mkv_write_tracks(s);
00863     if (ret < 0) return ret;
00864 
00865     if (mkv->mode != MODE_WEBM) {
00866         ret = mkv_write_chapters(s);
00867         if (ret < 0) return ret;
00868 
00869         ret = mkv_write_tags(s);
00870         if (ret < 0) return ret;
00871     }
00872 
00873     if (!s->pb->seekable)
00874         mkv_write_seekhead(pb, mkv->main_seekhead);
00875 
00876     mkv->cues = mkv_start_cues(mkv->segment_offset);
00877     if (mkv->cues == NULL)
00878         return AVERROR(ENOMEM);
00879 
00880     av_init_packet(&mkv->cur_audio_pkt);
00881     mkv->cur_audio_pkt.size = 0;
00882     mkv->audio_buffer_size  = 0;
00883 
00884     avio_flush(pb);
00885     return 0;
00886 }
00887 
00888 static int mkv_blockgroup_size(int pkt_size)
00889 {
00890     int size = pkt_size + 4;
00891     size += ebml_num_size(size);
00892     size += 2;              // EBML ID for block and block duration
00893     size += 8;              // max size of block duration
00894     size += ebml_num_size(size);
00895     size += 1;              // blockgroup EBML ID
00896     return size;
00897 }
00898 
00899 static int ass_get_duration(const uint8_t *p)
00900 {
00901     int sh, sm, ss, sc, eh, em, es, ec;
00902     uint64_t start, end;
00903 
00904     if (sscanf(p, "%*[^,],%d:%d:%d%*c%d,%d:%d:%d%*c%d",
00905                &sh, &sm, &ss, &sc, &eh, &em, &es, &ec) != 8)
00906         return 0;
00907     start = 3600000*sh + 60000*sm + 1000*ss + 10*sc;
00908     end   = 3600000*eh + 60000*em + 1000*es + 10*ec;
00909     return end - start;
00910 }
00911 
00912 static int mkv_write_ass_blocks(AVFormatContext *s, AVIOContext *pb, AVPacket *pkt)
00913 {
00914     MatroskaMuxContext *mkv = s->priv_data;
00915     int i, layer = 0, max_duration = 0, size, line_size, data_size = pkt->size;
00916     uint8_t *start, *end, *data = pkt->data;
00917     ebml_master blockgroup;
00918     char buffer[2048];
00919 
00920     while (data_size) {
00921         int duration = ass_get_duration(data);
00922         max_duration = FFMAX(duration, max_duration);
00923         end = memchr(data, '\n', data_size);
00924         size = line_size = end ? end-data+1 : data_size;
00925         size -= end ? (end[-1]=='\r')+1 : 0;
00926         start = data;
00927         for (i=0; i<3; i++, start++)
00928             if (!(start = memchr(start, ',', size-(start-data))))
00929                 return max_duration;
00930         size -= start - data;
00931         sscanf(data, "Dialogue: %d,", &layer);
00932         i = snprintf(buffer, sizeof(buffer), "%"PRId64",%d,",
00933                      s->streams[pkt->stream_index]->nb_frames++, layer);
00934         size = FFMIN(i+size, sizeof(buffer));
00935         memcpy(buffer+i, start, size-i);
00936 
00937         av_log(s, AV_LOG_DEBUG, "Writing block at offset %" PRIu64 ", size %d, "
00938                "pts %" PRId64 ", duration %d\n",
00939                avio_tell(pb), size, pkt->pts, duration);
00940         blockgroup = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP, mkv_blockgroup_size(size));
00941         put_ebml_id(pb, MATROSKA_ID_BLOCK);
00942         put_ebml_num(pb, size+4, 0);
00943         avio_w8(pb, 0x80 | (pkt->stream_index + 1));     // this assumes stream_index is less than 126
00944         avio_wb16(pb, pkt->pts - mkv->cluster_pts);
00945         avio_w8(pb, 0);
00946         avio_write(pb, buffer, size);
00947         put_ebml_uint(pb, MATROSKA_ID_BLOCKDURATION, duration);
00948         end_ebml_master(pb, blockgroup);
00949 
00950         data += line_size;
00951         data_size -= line_size;
00952     }
00953 
00954     return max_duration;
00955 }
00956 
00957 static void mkv_write_block(AVFormatContext *s, AVIOContext *pb,
00958                             unsigned int blockid, AVPacket *pkt, int flags)
00959 {
00960     MatroskaMuxContext *mkv = s->priv_data;
00961     AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
00962     uint8_t *data = NULL;
00963     int size = pkt->size;
00964     int64_t ts = mkv->tracks[pkt->stream_index].write_dts ? pkt->dts : pkt->pts;
00965 
00966     av_log(s, AV_LOG_DEBUG, "Writing block at offset %" PRIu64 ", size %d, "
00967            "pts %" PRId64 ", dts %" PRId64 ", duration %d, flags %d\n",
00968            avio_tell(pb), pkt->size, pkt->pts, pkt->dts, pkt->duration, flags);
00969     if (codec->codec_id == CODEC_ID_H264 && codec->extradata_size > 0 &&
00970         (AV_RB24(codec->extradata) == 1 || AV_RB32(codec->extradata) == 1))
00971         ff_avc_parse_nal_units_buf(pkt->data, &data, &size);
00972     else
00973         data = pkt->data;
00974     put_ebml_id(pb, blockid);
00975     put_ebml_num(pb, size+4, 0);
00976     avio_w8(pb, 0x80 | (pkt->stream_index + 1));     // this assumes stream_index is less than 126
00977     avio_wb16(pb, ts - mkv->cluster_pts);
00978     avio_w8(pb, flags);
00979     avio_write(pb, data, size);
00980     if (data != pkt->data)
00981         av_free(data);
00982 }
00983 
00984 static int srt_get_duration(uint8_t **buf)
00985 {
00986     int i, duration = 0;
00987 
00988     for (i=0; i<2 && !duration; i++) {
00989         int s_hour, s_min, s_sec, s_hsec, e_hour, e_min, e_sec, e_hsec;
00990         if (sscanf(*buf, "%d:%2d:%2d%*1[,.]%3d --> %d:%2d:%2d%*1[,.]%3d",
00991                    &s_hour, &s_min, &s_sec, &s_hsec,
00992                    &e_hour, &e_min, &e_sec, &e_hsec) == 8) {
00993             s_min  +=   60*s_hour;      e_min  +=   60*e_hour;
00994             s_sec  +=   60*s_min;       e_sec  +=   60*e_min;
00995             s_hsec += 1000*s_sec;       e_hsec += 1000*e_sec;
00996             duration = e_hsec - s_hsec;
00997         }
00998         *buf += strcspn(*buf, "\n") + 1;
00999     }
01000     return duration;
01001 }
01002 
01003 static int mkv_write_srt_blocks(AVFormatContext *s, AVIOContext *pb, AVPacket *pkt)
01004 {
01005     ebml_master blockgroup;
01006     AVPacket pkt2 = *pkt;
01007     int64_t duration = srt_get_duration(&pkt2.data);
01008     pkt2.size -= pkt2.data - pkt->data;
01009 
01010     blockgroup = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP,
01011                                    mkv_blockgroup_size(pkt2.size));
01012     mkv_write_block(s, pb, MATROSKA_ID_BLOCK, &pkt2, 0);
01013     put_ebml_uint(pb, MATROSKA_ID_BLOCKDURATION, duration);
01014     end_ebml_master(pb, blockgroup);
01015 
01016     return duration;
01017 }
01018 
01019 static void mkv_flush_dynbuf(AVFormatContext *s)
01020 {
01021     MatroskaMuxContext *mkv = s->priv_data;
01022     int bufsize;
01023     uint8_t *dyn_buf;
01024 
01025     if (!mkv->dyn_bc)
01026         return;
01027 
01028     bufsize = avio_close_dyn_buf(mkv->dyn_bc, &dyn_buf);
01029     avio_write(s->pb, dyn_buf, bufsize);
01030     av_free(dyn_buf);
01031     mkv->dyn_bc = NULL;
01032 }
01033 
01034 static int mkv_write_packet_internal(AVFormatContext *s, AVPacket *pkt)
01035 {
01036     MatroskaMuxContext *mkv = s->priv_data;
01037     AVIOContext *pb = s->pb;
01038     AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
01039     int keyframe = !!(pkt->flags & AV_PKT_FLAG_KEY);
01040     int duration = pkt->duration;
01041     int ret;
01042     int64_t ts = mkv->tracks[pkt->stream_index].write_dts ? pkt->dts : pkt->pts;
01043 
01044     if (ts == AV_NOPTS_VALUE) {
01045         av_log(s, AV_LOG_ERROR, "Can't write packet with unknown timestamp\n");
01046         return AVERROR(EINVAL);
01047     }
01048 
01049     if (!s->pb->seekable) {
01050         if (!mkv->dyn_bc)
01051             avio_open_dyn_buf(&mkv->dyn_bc);
01052         pb = mkv->dyn_bc;
01053     }
01054 
01055     if (!mkv->cluster_pos) {
01056         mkv->cluster_pos = avio_tell(s->pb);
01057         mkv->cluster = start_ebml_master(pb, MATROSKA_ID_CLUSTER, 0);
01058         put_ebml_uint(pb, MATROSKA_ID_CLUSTERTIMECODE, FFMAX(0, ts));
01059         mkv->cluster_pts = FFMAX(0, ts);
01060     }
01061 
01062     if (codec->codec_type != AVMEDIA_TYPE_SUBTITLE) {
01063         mkv_write_block(s, pb, MATROSKA_ID_SIMPLEBLOCK, pkt, keyframe << 7);
01064     } else if (codec->codec_id == CODEC_ID_SSA) {
01065         duration = mkv_write_ass_blocks(s, pb, pkt);
01066     } else if (codec->codec_id == CODEC_ID_SRT) {
01067         duration = mkv_write_srt_blocks(s, pb, pkt);
01068     } else {
01069         ebml_master blockgroup = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP, mkv_blockgroup_size(pkt->size));
01070         duration = pkt->convergence_duration;
01071         mkv_write_block(s, pb, MATROSKA_ID_BLOCK, pkt, 0);
01072         put_ebml_uint(pb, MATROSKA_ID_BLOCKDURATION, duration);
01073         end_ebml_master(pb, blockgroup);
01074     }
01075 
01076     if (codec->codec_type == AVMEDIA_TYPE_VIDEO && keyframe) {
01077         ret = mkv_add_cuepoint(mkv->cues, pkt->stream_index, ts, mkv->cluster_pos);
01078         if (ret < 0) return ret;
01079     }
01080 
01081     mkv->duration = FFMAX(mkv->duration, ts + duration);
01082     return 0;
01083 }
01084 
01085 static int mkv_copy_packet(MatroskaMuxContext *mkv, const AVPacket *pkt)
01086 {
01087     uint8_t *data           = mkv->cur_audio_pkt.data;
01088     mkv->cur_audio_pkt      = *pkt;
01089     mkv->cur_audio_pkt.data = av_fast_realloc(data, &mkv->audio_buffer_size, pkt->size);
01090     if (!mkv->cur_audio_pkt.data)
01091         return AVERROR(ENOMEM);
01092 
01093     memcpy(mkv->cur_audio_pkt.data, pkt->data, pkt->size);
01094     mkv->cur_audio_pkt.size = pkt->size;
01095     return 0;
01096 }
01097 
01098 static int mkv_write_packet(AVFormatContext *s, AVPacket *pkt)
01099 {
01100     MatroskaMuxContext *mkv = s->priv_data;
01101     AVIOContext *pb = s->pb->seekable ? s->pb : mkv->dyn_bc;
01102     AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
01103     int ret, keyframe = !!(pkt->flags & AV_PKT_FLAG_KEY);
01104     int64_t ts = mkv->tracks[pkt->stream_index].write_dts ? pkt->dts : pkt->pts;
01105     int cluster_size = avio_tell(pb) - (s->pb->seekable ? mkv->cluster_pos : 0);
01106 
01107     // start a new cluster every 5 MB or 5 sec, or 32k / 1 sec for streaming or
01108     // after 4k and on a keyframe
01109     if (mkv->cluster_pos &&
01110         ((!s->pb->seekable && (cluster_size > 32*1024 || ts > mkv->cluster_pts + 1000))
01111          ||                      cluster_size > 5*1024*1024 || ts > mkv->cluster_pts + 5000
01112          || (codec->codec_type == AVMEDIA_TYPE_VIDEO && keyframe && cluster_size > 4*1024))) {
01113         av_log(s, AV_LOG_DEBUG, "Starting new cluster at offset %" PRIu64
01114                " bytes, pts %" PRIu64 "\n", avio_tell(pb), ts);
01115         end_ebml_master(pb, mkv->cluster);
01116         mkv->cluster_pos = 0;
01117         if (mkv->dyn_bc)
01118             mkv_flush_dynbuf(s);
01119     }
01120 
01121     // check if we have an audio packet cached
01122     if (mkv->cur_audio_pkt.size > 0) {
01123         ret = mkv_write_packet_internal(s, &mkv->cur_audio_pkt);
01124         mkv->cur_audio_pkt.size = 0;
01125         if (ret < 0) {
01126             av_log(s, AV_LOG_ERROR, "Could not write cached audio packet ret:%d\n", ret);
01127             return ret;
01128         }
01129     }
01130 
01131     // buffer an audio packet to ensure the packet containing the video
01132     // keyframe's timecode is contained in the same cluster for WebM
01133     if (codec->codec_type == AVMEDIA_TYPE_AUDIO)
01134         ret = mkv_copy_packet(mkv, pkt);
01135     else
01136         ret = mkv_write_packet_internal(s, pkt);
01137     return ret;
01138 }
01139 
01140 static int mkv_write_trailer(AVFormatContext *s)
01141 {
01142     MatroskaMuxContext *mkv = s->priv_data;
01143     AVIOContext *pb = s->pb;
01144     int64_t currentpos, cuespos;
01145     int ret;
01146 
01147     // check if we have an audio packet cached
01148     if (mkv->cur_audio_pkt.size > 0) {
01149         ret = mkv_write_packet_internal(s, &mkv->cur_audio_pkt);
01150         mkv->cur_audio_pkt.size = 0;
01151         if (ret < 0) {
01152             av_log(s, AV_LOG_ERROR, "Could not write cached audio packet ret:%d\n", ret);
01153             return ret;
01154         }
01155     }
01156 
01157     if (mkv->dyn_bc) {
01158         end_ebml_master(mkv->dyn_bc, mkv->cluster);
01159         mkv_flush_dynbuf(s);
01160     } else if (mkv->cluster_pos) {
01161         end_ebml_master(pb, mkv->cluster);
01162     }
01163 
01164     if (pb->seekable) {
01165         if (mkv->cues->num_entries) {
01166             cuespos = mkv_write_cues(pb, mkv->cues, s->nb_streams);
01167 
01168             ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_CUES, cuespos);
01169             if (ret < 0) return ret;
01170         }
01171 
01172         mkv_write_seekhead(pb, mkv->main_seekhead);
01173 
01174         // update the duration
01175         av_log(s, AV_LOG_DEBUG, "end duration = %" PRIu64 "\n", mkv->duration);
01176         currentpos = avio_tell(pb);
01177         avio_seek(pb, mkv->duration_offset, SEEK_SET);
01178         put_ebml_float(pb, MATROSKA_ID_DURATION, mkv->duration);
01179 
01180         avio_seek(pb, currentpos, SEEK_SET);
01181     }
01182 
01183     end_ebml_master(pb, mkv->segment);
01184     av_free(mkv->tracks);
01185     av_freep(&mkv->cues->entries);
01186     av_freep(&mkv->cues);
01187     av_destruct_packet(&mkv->cur_audio_pkt);
01188     avio_flush(pb);
01189     return 0;
01190 }
01191 
01192 #if CONFIG_MATROSKA_MUXER
01193 AVOutputFormat ff_matroska_muxer = {
01194     "matroska",
01195     NULL_IF_CONFIG_SMALL("Matroska file format"),
01196     "video/x-matroska",
01197     "mkv",
01198     sizeof(MatroskaMuxContext),
01199     CODEC_ID_MP2,
01200     CODEC_ID_MPEG4,
01201     mkv_write_header,
01202     mkv_write_packet,
01203     mkv_write_trailer,
01204     .flags = AVFMT_GLOBALHEADER | AVFMT_VARIABLE_FPS,
01205     .codec_tag = (const AVCodecTag* const []){ff_codec_bmp_tags, ff_codec_wav_tags, 0},
01206     .subtitle_codec = CODEC_ID_TEXT,
01207 };
01208 #endif
01209 
01210 #if CONFIG_WEBM_MUXER
01211 AVOutputFormat ff_webm_muxer = {
01212     "webm",
01213     NULL_IF_CONFIG_SMALL("WebM file format"),
01214     "video/webm",
01215     "webm",
01216     sizeof(MatroskaMuxContext),
01217     CODEC_ID_VORBIS,
01218     CODEC_ID_VP8,
01219     mkv_write_header,
01220     mkv_write_packet,
01221     mkv_write_trailer,
01222     .flags = AVFMT_GLOBALHEADER | AVFMT_VARIABLE_FPS,
01223 };
01224 #endif
01225 
01226 #if CONFIG_MATROSKA_AUDIO_MUXER
01227 AVOutputFormat ff_matroska_audio_muxer = {
01228     "matroska",
01229     NULL_IF_CONFIG_SMALL("Matroska file format"),
01230     "audio/x-matroska",
01231     "mka",
01232     sizeof(MatroskaMuxContext),
01233     CODEC_ID_MP2,
01234     CODEC_ID_NONE,
01235     mkv_write_header,
01236     mkv_write_packet,
01237     mkv_write_trailer,
01238     .flags = AVFMT_GLOBALHEADER,
01239     .codec_tag = (const AVCodecTag* const []){ff_codec_wav_tags, 0},
01240 };
01241 #endif