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libavformat/matroskaenc.c

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00001 /*
00002  * Matroska muxer
00003  * Copyright (c) 2007 David Conrad
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg 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  * FFmpeg 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 FFmpeg; 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 "libavutil/intreadwrite.h"
00029 #include "libavutil/md5.h"
00030 #include "libavcodec/xiph.h"
00031 #include "libavcodec/mpeg4audio.h"
00032 
00033 typedef struct ebml_master {
00034     int64_t         pos;                
00035     int             sizebytes;          
00036 } ebml_master;
00037 
00038 typedef struct mkv_seekhead_entry {
00039     unsigned int    elementid;
00040     uint64_t        segmentpos;
00041 } mkv_seekhead_entry;
00042 
00043 typedef struct mkv_seekhead {
00044     int64_t                 filepos;
00045     int64_t                 segment_offset;     
00046     int                     reserved_size;      
00047     int                     max_entries;
00048     mkv_seekhead_entry      *entries;
00049     int                     num_entries;
00050 } mkv_seekhead;
00051 
00052 typedef struct {
00053     uint64_t        pts;
00054     int             tracknum;
00055     int64_t         cluster_pos;        
00056 } mkv_cuepoint;
00057 
00058 typedef struct {
00059     int64_t         segment_offset;
00060     mkv_cuepoint    *entries;
00061     int             num_entries;
00062 } mkv_cues;
00063 
00064 typedef struct MatroskaMuxContext {
00065     ebml_master     segment;
00066     int64_t         segment_offset;
00067     int64_t         segment_uid;
00068     ebml_master     cluster;
00069     int64_t         cluster_pos;        
00070     uint64_t        cluster_pts;
00071     int64_t         duration_offset;
00072     uint64_t        duration;
00073     mkv_seekhead    *main_seekhead;
00074     mkv_seekhead    *cluster_seekhead;
00075     mkv_cues        *cues;
00076 
00077     struct AVMD5    *md5_ctx;
00078 } MatroskaMuxContext;
00079 
00080 
00083 #define MAX_SEEKENTRY_SIZE 21
00084 
00087 #define MAX_CUETRACKPOS_SIZE 22
00088 
00090 #define MAX_CUEPOINT_SIZE(num_tracks) 12 + MAX_CUETRACKPOS_SIZE*num_tracks
00091 
00092 
00093 static int ebml_id_size(unsigned int id)
00094 {
00095     return (av_log2(id+1)-1)/7+1;
00096 }
00097 
00098 static void put_ebml_id(ByteIOContext *pb, unsigned int id)
00099 {
00100     int i = ebml_id_size(id);
00101     while (i--)
00102         put_byte(pb, id >> (i*8));
00103 }
00104 
00110 static void put_ebml_size_unknown(ByteIOContext *pb, int bytes)
00111 {
00112     assert(bytes <= 8);
00113     put_byte(pb, 0x1ff >> bytes);
00114     while (--bytes)
00115         put_byte(pb, 0xff);
00116 }
00117 
00121 static int ebml_num_size(uint64_t num)
00122 {
00123     int bytes = 1;
00124     while ((num+1) >> bytes*7) bytes++;
00125     return bytes;
00126 }
00127 
00134 static void put_ebml_num(ByteIOContext *pb, uint64_t num, int bytes)
00135 {
00136     int i, needed_bytes = ebml_num_size(num);
00137 
00138     // sizes larger than this are currently undefined in EBML
00139     assert(num < (1ULL<<56)-1);
00140 
00141     if (bytes == 0)
00142         // don't care how many bytes are used, so use the min
00143         bytes = needed_bytes;
00144     // the bytes needed to write the given size would exceed the bytes
00145     // that we need to use, so write unknown size. This shouldn't happen.
00146     assert(bytes >= needed_bytes);
00147 
00148     num |= 1ULL << bytes*7;
00149     for (i = bytes - 1; i >= 0; i--)
00150         put_byte(pb, num >> i*8);
00151 }
00152 
00153 static void put_ebml_uint(ByteIOContext *pb, unsigned int elementid, uint64_t val)
00154 {
00155     int i, bytes = 1;
00156     uint64_t tmp = val;
00157     while (tmp>>=8) bytes++;
00158 
00159     put_ebml_id(pb, elementid);
00160     put_ebml_num(pb, bytes, 0);
00161     for (i = bytes - 1; i >= 0; i--)
00162         put_byte(pb, val >> i*8);
00163 }
00164 
00165 static void put_ebml_float(ByteIOContext *pb, unsigned int elementid, double val)
00166 {
00167     put_ebml_id(pb, elementid);
00168     put_ebml_num(pb, 8, 0);
00169     put_be64(pb, av_dbl2int(val));
00170 }
00171 
00172 static void put_ebml_binary(ByteIOContext *pb, unsigned int elementid,
00173                             const uint8_t *buf, int size)
00174 {
00175     put_ebml_id(pb, elementid);
00176     put_ebml_num(pb, size, 0);
00177     put_buffer(pb, buf, size);
00178 }
00179 
00180 static void put_ebml_string(ByteIOContext *pb, unsigned int elementid, const char *str)
00181 {
00182     put_ebml_binary(pb, elementid, str, strlen(str));
00183 }
00184 
00191 static void put_ebml_void(ByteIOContext *pb, uint64_t size)
00192 {
00193     int64_t currentpos = url_ftell(pb);
00194 
00195     assert(size >= 2);
00196 
00197     put_ebml_id(pb, EBML_ID_VOID);
00198     // we need to subtract the length needed to store the size from the
00199     // size we need to reserve so 2 cases, we use 8 bytes to store the
00200     // size if possible, 1 byte otherwise
00201     if (size < 10)
00202         put_ebml_num(pb, size-1, 0);
00203     else
00204         put_ebml_num(pb, size-9, 8);
00205     while(url_ftell(pb) < currentpos + size)
00206         put_byte(pb, 0);
00207 }
00208 
00209 static ebml_master start_ebml_master(ByteIOContext *pb, unsigned int elementid, uint64_t expectedsize)
00210 {
00211     int bytes = expectedsize ? ebml_num_size(expectedsize) : 8;
00212     put_ebml_id(pb, elementid);
00213     put_ebml_size_unknown(pb, bytes);
00214     return (ebml_master){ url_ftell(pb), bytes };
00215 }
00216 
00217 static void end_ebml_master(ByteIOContext *pb, ebml_master master)
00218 {
00219     int64_t pos = url_ftell(pb);
00220 
00221     // leave the unknown size for masters when streaming
00222     if (url_is_streamed(pb))
00223         return;
00224 
00225     url_fseek(pb, master.pos - master.sizebytes, SEEK_SET);
00226     put_ebml_num(pb, pos - master.pos, master.sizebytes);
00227     url_fseek(pb, pos, SEEK_SET);
00228 }
00229 
00230 static void put_xiph_size(ByteIOContext *pb, int size)
00231 {
00232     int i;
00233     for (i = 0; i < size / 255; i++)
00234         put_byte(pb, 255);
00235     put_byte(pb, size % 255);
00236 }
00237 
00249 static mkv_seekhead * mkv_start_seekhead(ByteIOContext *pb, int64_t segment_offset, int numelements)
00250 {
00251     mkv_seekhead *new_seekhead = av_mallocz(sizeof(mkv_seekhead));
00252     if (new_seekhead == NULL)
00253         return NULL;
00254 
00255     new_seekhead->segment_offset = segment_offset;
00256 
00257     if (numelements > 0) {
00258         new_seekhead->filepos = url_ftell(pb);
00259         // 21 bytes max for a seek entry, 10 bytes max for the SeekHead ID
00260         // and size, and 3 bytes to guarantee that an EBML void element
00261         // will fit afterwards
00262         new_seekhead->reserved_size = numelements * MAX_SEEKENTRY_SIZE + 13;
00263         new_seekhead->max_entries = numelements;
00264         put_ebml_void(pb, new_seekhead->reserved_size);
00265     }
00266     return new_seekhead;
00267 }
00268 
00269 static int mkv_add_seekhead_entry(mkv_seekhead *seekhead, unsigned int elementid, uint64_t filepos)
00270 {
00271     mkv_seekhead_entry *entries = seekhead->entries;
00272 
00273     // don't store more elements than we reserved space for
00274     if (seekhead->max_entries > 0 && seekhead->max_entries <= seekhead->num_entries)
00275         return -1;
00276 
00277     entries = av_realloc(entries, (seekhead->num_entries + 1) * sizeof(mkv_seekhead_entry));
00278     if (entries == NULL)
00279         return AVERROR(ENOMEM);
00280 
00281     entries[seekhead->num_entries  ].elementid = elementid;
00282     entries[seekhead->num_entries++].segmentpos = filepos - seekhead->segment_offset;
00283 
00284     seekhead->entries = entries;
00285     return 0;
00286 }
00287 
00296 static int64_t mkv_write_seekhead(ByteIOContext *pb, mkv_seekhead *seekhead)
00297 {
00298     ebml_master metaseek, seekentry;
00299     int64_t currentpos;
00300     int i;
00301 
00302     currentpos = url_ftell(pb);
00303 
00304     if (seekhead->reserved_size > 0)
00305         url_fseek(pb, seekhead->filepos, SEEK_SET);
00306 
00307     metaseek = start_ebml_master(pb, MATROSKA_ID_SEEKHEAD, seekhead->reserved_size);
00308     for (i = 0; i < seekhead->num_entries; i++) {
00309         mkv_seekhead_entry *entry = &seekhead->entries[i];
00310 
00311         seekentry = start_ebml_master(pb, MATROSKA_ID_SEEKENTRY, MAX_SEEKENTRY_SIZE);
00312 
00313         put_ebml_id(pb, MATROSKA_ID_SEEKID);
00314         put_ebml_num(pb, ebml_id_size(entry->elementid), 0);
00315         put_ebml_id(pb, entry->elementid);
00316 
00317         put_ebml_uint(pb, MATROSKA_ID_SEEKPOSITION, entry->segmentpos);
00318         end_ebml_master(pb, seekentry);
00319     }
00320     end_ebml_master(pb, metaseek);
00321 
00322     if (seekhead->reserved_size > 0) {
00323         uint64_t remaining = seekhead->filepos + seekhead->reserved_size - url_ftell(pb);
00324         put_ebml_void(pb, remaining);
00325         url_fseek(pb, currentpos, SEEK_SET);
00326 
00327         currentpos = seekhead->filepos;
00328     }
00329     av_free(seekhead->entries);
00330     av_free(seekhead);
00331 
00332     return currentpos;
00333 }
00334 
00335 static mkv_cues * mkv_start_cues(int64_t segment_offset)
00336 {
00337     mkv_cues *cues = av_mallocz(sizeof(mkv_cues));
00338     if (cues == NULL)
00339         return NULL;
00340 
00341     cues->segment_offset = segment_offset;
00342     return cues;
00343 }
00344 
00345 static int mkv_add_cuepoint(mkv_cues *cues, AVPacket *pkt, int64_t cluster_pos)
00346 {
00347     mkv_cuepoint *entries = cues->entries;
00348 
00349     entries = av_realloc(entries, (cues->num_entries + 1) * sizeof(mkv_cuepoint));
00350     if (entries == NULL)
00351         return AVERROR(ENOMEM);
00352 
00353     entries[cues->num_entries  ].pts = pkt->pts;
00354     entries[cues->num_entries  ].tracknum = pkt->stream_index + 1;
00355     entries[cues->num_entries++].cluster_pos = cluster_pos - cues->segment_offset;
00356 
00357     cues->entries = entries;
00358     return 0;
00359 }
00360 
00361 static int64_t mkv_write_cues(ByteIOContext *pb, mkv_cues *cues, int num_tracks)
00362 {
00363     ebml_master cues_element;
00364     int64_t currentpos;
00365     int i, j;
00366 
00367     currentpos = url_ftell(pb);
00368     cues_element = start_ebml_master(pb, MATROSKA_ID_CUES, 0);
00369 
00370     for (i = 0; i < cues->num_entries; i++) {
00371         ebml_master cuepoint, track_positions;
00372         mkv_cuepoint *entry = &cues->entries[i];
00373         uint64_t pts = entry->pts;
00374 
00375         cuepoint = start_ebml_master(pb, MATROSKA_ID_POINTENTRY, MAX_CUEPOINT_SIZE(num_tracks));
00376         put_ebml_uint(pb, MATROSKA_ID_CUETIME, pts);
00377 
00378         // put all the entries from different tracks that have the exact same
00379         // timestamp into the same CuePoint
00380         for (j = 0; j < cues->num_entries - i && entry[j].pts == pts; j++) {
00381             track_positions = start_ebml_master(pb, MATROSKA_ID_CUETRACKPOSITION, MAX_CUETRACKPOS_SIZE);
00382             put_ebml_uint(pb, MATROSKA_ID_CUETRACK          , entry[j].tracknum   );
00383             put_ebml_uint(pb, MATROSKA_ID_CUECLUSTERPOSITION, entry[j].cluster_pos);
00384             end_ebml_master(pb, track_positions);
00385         }
00386         i += j - 1;
00387         end_ebml_master(pb, cuepoint);
00388     }
00389     end_ebml_master(pb, cues_element);
00390 
00391     av_free(cues->entries);
00392     av_free(cues);
00393     return currentpos;
00394 }
00395 
00396 static int put_xiph_codecpriv(AVFormatContext *s, ByteIOContext *pb, AVCodecContext *codec)
00397 {
00398     uint8_t *header_start[3];
00399     int header_len[3];
00400     int first_header_size;
00401     int j;
00402 
00403     if (codec->codec_id == CODEC_ID_VORBIS)
00404         first_header_size = 30;
00405     else
00406         first_header_size = 42;
00407 
00408     if (ff_split_xiph_headers(codec->extradata, codec->extradata_size,
00409                               first_header_size, header_start, header_len) < 0) {
00410         av_log(s, AV_LOG_ERROR, "Extradata corrupt.\n");
00411         return -1;
00412     }
00413 
00414     put_byte(pb, 2);                    // number packets - 1
00415     for (j = 0; j < 2; j++) {
00416         put_xiph_size(pb, header_len[j]);
00417     }
00418     for (j = 0; j < 3; j++)
00419         put_buffer(pb, header_start[j], header_len[j]);
00420 
00421     return 0;
00422 }
00423 
00424 static void get_aac_sample_rates(AVFormatContext *s, AVCodecContext *codec, int *sample_rate, int *output_sample_rate)
00425 {
00426     int sri;
00427 
00428     if (codec->extradata_size < 2) {
00429         av_log(s, AV_LOG_WARNING, "No AAC extradata, unable to determine samplerate.\n");
00430         return;
00431     }
00432 
00433     sri = ((codec->extradata[0] << 1) & 0xE) | (codec->extradata[1] >> 7);
00434     if (sri > 12) {
00435         av_log(s, AV_LOG_WARNING, "AAC samplerate index out of bounds\n");
00436         return;
00437     }
00438     *sample_rate = ff_mpeg4audio_sample_rates[sri];
00439 
00440     // if sbr, get output sample rate as well
00441     if (codec->extradata_size == 5) {
00442         sri = (codec->extradata[4] >> 3) & 0xF;
00443         if (sri > 12) {
00444             av_log(s, AV_LOG_WARNING, "AAC output samplerate index out of bounds\n");
00445             return;
00446         }
00447         *output_sample_rate = ff_mpeg4audio_sample_rates[sri];
00448     }
00449 }
00450 
00451 static int mkv_write_codecprivate(AVFormatContext *s, ByteIOContext *pb, AVCodecContext *codec, int native_id, int qt_id)
00452 {
00453     ByteIOContext *dyn_cp;
00454     uint8_t *codecpriv;
00455     int ret, codecpriv_size;
00456 
00457     ret = url_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);
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             put_buffer(dyn_cp, codec->extradata, codec->extradata_size);
00470     } else if (codec->codec_type == CODEC_TYPE_VIDEO) {
00471         if (qt_id) {
00472             if (!codec->codec_tag)
00473                 codec->codec_tag = codec_get_tag(codec_movvideo_tags, codec->codec_id);
00474             if (codec->extradata_size)
00475                 put_buffer(dyn_cp, codec->extradata, codec->extradata_size);
00476         } else {
00477         if (!codec->codec_tag)
00478             codec->codec_tag = codec_get_tag(codec_bmp_tags, codec->codec_id);
00479         if (!codec->codec_tag) {
00480             av_log(s, AV_LOG_ERROR, "No bmp codec ID found.");
00481             ret = -1;
00482         }
00483 
00484         put_bmp_header(dyn_cp, codec, codec_bmp_tags, 0);
00485         }
00486 
00487     } else if (codec->codec_type == CODEC_TYPE_AUDIO) {
00488         if (!codec->codec_tag)
00489             codec->codec_tag = codec_get_tag(codec_wav_tags, codec->codec_id);
00490         if (!codec->codec_tag) {
00491             av_log(s, AV_LOG_ERROR, "No wav codec ID found.");
00492             ret = -1;
00493         }
00494 
00495         put_wav_header(dyn_cp, codec);
00496     }
00497 
00498     codecpriv_size = url_close_dyn_buf(dyn_cp, &codecpriv);
00499     if (codecpriv_size)
00500         put_ebml_binary(pb, MATROSKA_ID_CODECPRIVATE, codecpriv, codecpriv_size);
00501     av_free(codecpriv);
00502     return ret;
00503 }
00504 
00505 static int mkv_write_tracks(AVFormatContext *s)
00506 {
00507     MatroskaMuxContext *mkv = s->priv_data;
00508     ByteIOContext *pb = s->pb;
00509     ebml_master tracks;
00510     int i, j, ret;
00511 
00512     ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_TRACKS, url_ftell(pb));
00513     if (ret < 0) return ret;
00514 
00515     tracks = start_ebml_master(pb, MATROSKA_ID_TRACKS, 0);
00516     for (i = 0; i < s->nb_streams; i++) {
00517         AVStream *st = s->streams[i];
00518         AVCodecContext *codec = st->codec;
00519         ebml_master subinfo, track;
00520         int native_id = 0;
00521         int qt_id = 0;
00522         int bit_depth = av_get_bits_per_sample(codec->codec_id);
00523         int sample_rate = codec->sample_rate;
00524         int output_sample_rate = 0;
00525         AVMetadataTag *tag;
00526 
00527         if (!bit_depth)
00528             bit_depth = av_get_bits_per_sample_format(codec->sample_fmt);
00529 
00530         if (codec->codec_id == CODEC_ID_AAC)
00531             get_aac_sample_rates(s, codec, &sample_rate, &output_sample_rate);
00532 
00533         track = start_ebml_master(pb, MATROSKA_ID_TRACKENTRY, 0);
00534         put_ebml_uint (pb, MATROSKA_ID_TRACKNUMBER     , i + 1);
00535         put_ebml_uint (pb, MATROSKA_ID_TRACKUID        , i + 1);
00536         put_ebml_uint (pb, MATROSKA_ID_TRACKFLAGLACING , 0);    // no lacing (yet)
00537 
00538         if ((tag = av_metadata_get(st->metadata, "description", NULL, 0)))
00539             put_ebml_string(pb, MATROSKA_ID_TRACKNAME, tag->value);
00540         tag = av_metadata_get(st->metadata, "language", NULL, 0);
00541         put_ebml_string(pb, MATROSKA_ID_TRACKLANGUAGE, tag ? tag->value:"und");
00542 
00543         if (st->disposition)
00544             put_ebml_uint(pb, MATROSKA_ID_TRACKFLAGDEFAULT, !!(st->disposition & AV_DISPOSITION_DEFAULT));
00545 
00546         // look for a codec ID string specific to mkv to use,
00547         // if none are found, use AVI codes
00548         for (j = 0; ff_mkv_codec_tags[j].id != CODEC_ID_NONE; j++) {
00549             if (ff_mkv_codec_tags[j].id == codec->codec_id) {
00550                 put_ebml_string(pb, MATROSKA_ID_CODECID, ff_mkv_codec_tags[j].str);
00551                 native_id = 1;
00552                 break;
00553             }
00554         }
00555 
00556         switch (codec->codec_type) {
00557             case CODEC_TYPE_VIDEO:
00558                 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_VIDEO);
00559 
00560                 if (!native_id &&
00561                       codec_get_tag(codec_movvideo_tags, codec->codec_id) &&
00562                     (!codec_get_tag(codec_bmp_tags,      codec->codec_id)
00563                      || codec->codec_id == CODEC_ID_SVQ1
00564                      || codec->codec_id == CODEC_ID_SVQ3
00565                      || codec->codec_id == CODEC_ID_CINEPAK))
00566                     qt_id = 1;
00567 
00568                 if (qt_id)
00569                     put_ebml_string(pb, MATROSKA_ID_CODECID, "V_QUICKTIME");
00570                 else if (!native_id)
00571                     // if there is no mkv-specific codec ID, use VFW mode
00572                     put_ebml_string(pb, MATROSKA_ID_CODECID, "V_MS/VFW/FOURCC");
00573 
00574                 subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKVIDEO, 0);
00575                 // XXX: interlace flag?
00576                 put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELWIDTH , codec->width);
00577                 put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELHEIGHT, codec->height);
00578                 if (st->sample_aspect_ratio.num) {
00579                     int d_width = codec->width*av_q2d(st->sample_aspect_ratio);
00580                     put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYWIDTH , d_width);
00581                     put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYHEIGHT, codec->height);
00582                 }
00583                 end_ebml_master(pb, subinfo);
00584                 break;
00585 
00586             case CODEC_TYPE_AUDIO:
00587                 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_AUDIO);
00588 
00589                 if (!native_id)
00590                     // no mkv-specific ID, use ACM mode
00591                     put_ebml_string(pb, MATROSKA_ID_CODECID, "A_MS/ACM");
00592 
00593                 subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKAUDIO, 0);
00594                 put_ebml_uint  (pb, MATROSKA_ID_AUDIOCHANNELS    , codec->channels);
00595                 put_ebml_float (pb, MATROSKA_ID_AUDIOSAMPLINGFREQ, sample_rate);
00596                 if (output_sample_rate)
00597                     put_ebml_float(pb, MATROSKA_ID_AUDIOOUTSAMPLINGFREQ, output_sample_rate);
00598                 if (bit_depth)
00599                     put_ebml_uint(pb, MATROSKA_ID_AUDIOBITDEPTH, bit_depth);
00600                 end_ebml_master(pb, subinfo);
00601                 break;
00602 
00603             case CODEC_TYPE_SUBTITLE:
00604                 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_SUBTITLE);
00605                 break;
00606             default:
00607                 av_log(s, AV_LOG_ERROR, "Only audio, video, and subtitles are supported for Matroska.");
00608                 break;
00609         }
00610         ret = mkv_write_codecprivate(s, pb, codec, native_id, qt_id);
00611         if (ret < 0) return ret;
00612 
00613         end_ebml_master(pb, track);
00614 
00615         // ms precision is the de-facto standard timescale for mkv files
00616         av_set_pts_info(st, 64, 1, 1000);
00617     }
00618     end_ebml_master(pb, tracks);
00619     return 0;
00620 }
00621 
00622 static int mkv_write_header(AVFormatContext *s)
00623 {
00624     MatroskaMuxContext *mkv = s->priv_data;
00625     ByteIOContext *pb = s->pb;
00626     ebml_master ebml_header, segment_info;
00627     AVMetadataTag *tag;
00628     int ret;
00629 
00630     mkv->md5_ctx = av_mallocz(av_md5_size);
00631     av_md5_init(mkv->md5_ctx);
00632 
00633     ebml_header = start_ebml_master(pb, EBML_ID_HEADER, 0);
00634     put_ebml_uint   (pb, EBML_ID_EBMLVERSION        ,           1);
00635     put_ebml_uint   (pb, EBML_ID_EBMLREADVERSION    ,           1);
00636     put_ebml_uint   (pb, EBML_ID_EBMLMAXIDLENGTH    ,           4);
00637     put_ebml_uint   (pb, EBML_ID_EBMLMAXSIZELENGTH  ,           8);
00638     put_ebml_string (pb, EBML_ID_DOCTYPE            ,  "matroska");
00639     put_ebml_uint   (pb, EBML_ID_DOCTYPEVERSION     ,           2);
00640     put_ebml_uint   (pb, EBML_ID_DOCTYPEREADVERSION ,           2);
00641     end_ebml_master(pb, ebml_header);
00642 
00643     mkv->segment = start_ebml_master(pb, MATROSKA_ID_SEGMENT, 0);
00644     mkv->segment_offset = url_ftell(pb);
00645 
00646     // we write 2 seek heads - one at the end of the file to point to each
00647     // cluster, and one at the beginning to point to all other level one
00648     // elements (including the seek head at the end of the file), which
00649     // isn't more than 10 elements if we only write one of each other
00650     // currently defined level 1 element
00651     mkv->main_seekhead    = mkv_start_seekhead(pb, mkv->segment_offset, 10);
00652     mkv->cluster_seekhead = mkv_start_seekhead(pb, mkv->segment_offset, 0);
00653     if (mkv->main_seekhead == NULL || mkv->cluster_seekhead == NULL)
00654         return AVERROR(ENOMEM);
00655 
00656     ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_INFO, url_ftell(pb));
00657     if (ret < 0) return ret;
00658 
00659     segment_info = start_ebml_master(pb, MATROSKA_ID_INFO, 0);
00660     put_ebml_uint(pb, MATROSKA_ID_TIMECODESCALE, 1000000);
00661     if ((tag = av_metadata_get(s->metadata, "title", NULL, 0)))
00662         put_ebml_string(pb, MATROSKA_ID_TITLE, tag->value);
00663     if (!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT)) {
00664         put_ebml_string(pb, MATROSKA_ID_MUXINGAPP , LIBAVFORMAT_IDENT);
00665         put_ebml_string(pb, MATROSKA_ID_WRITINGAPP, LIBAVFORMAT_IDENT);
00666 
00667         // reserve space to write the segment UID later
00668         mkv->segment_uid = url_ftell(pb);
00669         put_ebml_void(pb, 19);
00670     }
00671 
00672     // reserve space for the duration
00673     mkv->duration = 0;
00674     mkv->duration_offset = url_ftell(pb);
00675     put_ebml_void(pb, 11);                  // assumes double-precision float to be written
00676     end_ebml_master(pb, segment_info);
00677 
00678     ret = mkv_write_tracks(s);
00679     if (ret < 0) return ret;
00680 
00681     ret = mkv_add_seekhead_entry(mkv->cluster_seekhead, MATROSKA_ID_CLUSTER, url_ftell(pb));
00682     if (ret < 0) return ret;
00683 
00684     mkv->cluster_pos = url_ftell(pb);
00685     mkv->cluster = start_ebml_master(pb, MATROSKA_ID_CLUSTER, 0);
00686     put_ebml_uint(pb, MATROSKA_ID_CLUSTERTIMECODE, 0);
00687     mkv->cluster_pts = 0;
00688 
00689     mkv->cues = mkv_start_cues(mkv->segment_offset);
00690     if (mkv->cues == NULL)
00691         return AVERROR(ENOMEM);
00692 
00693     put_flush_packet(pb);
00694     return 0;
00695 }
00696 
00697 static int mkv_blockgroup_size(int pkt_size)
00698 {
00699     int size = pkt_size + 4;
00700     size += ebml_num_size(size);
00701     size += 2;              // EBML ID for block and block duration
00702     size += 8;              // max size of block duration
00703     size += ebml_num_size(size);
00704     size += 1;              // blockgroup EBML ID
00705     return size;
00706 }
00707 
00708 static int ass_get_duration(const uint8_t *p)
00709 {
00710     int sh, sm, ss, sc, eh, em, es, ec;
00711     uint64_t start, end;
00712 
00713     if (sscanf(p, "%*[^,],%d:%d:%d%*c%d,%d:%d:%d%*c%d",
00714                &sh, &sm, &ss, &sc, &eh, &em, &es, &ec) != 8)
00715         return 0;
00716     start = 3600000*sh + 60000*sm + 1000*ss + 10*sc;
00717     end   = 3600000*eh + 60000*em + 1000*es + 10*ec;
00718     return end - start;
00719 }
00720 
00721 static int mkv_write_ass_blocks(AVFormatContext *s, AVPacket *pkt)
00722 {
00723     MatroskaMuxContext *mkv = s->priv_data;
00724     ByteIOContext *pb = s->pb;
00725     int i, layer = 0, max_duration = 0, size, line_size, data_size = pkt->size;
00726     uint8_t *start, *end, *data = pkt->data;
00727     ebml_master blockgroup;
00728     char buffer[2048];
00729 
00730     while (data_size) {
00731         int duration = ass_get_duration(data);
00732         max_duration = FFMAX(duration, max_duration);
00733         end = memchr(data, '\n', data_size);
00734         size = line_size = end ? end-data+1 : data_size;
00735         size -= end ? (end[-1]=='\r')+1 : 0;
00736         start = data;
00737         for (i=0; i<3; i++, start++)
00738             if (!(start = memchr(start, ',', size-(start-data))))
00739                 return max_duration;
00740         size -= start - data;
00741         sscanf(data, "Dialogue: %d,", &layer);
00742         i = snprintf(buffer, sizeof(buffer), "%"PRId64",%d,",
00743                      s->streams[pkt->stream_index]->nb_frames++, layer);
00744         size = FFMIN(i+size, sizeof(buffer));
00745         memcpy(buffer+i, start, size-i);
00746 
00747         av_log(s, AV_LOG_DEBUG, "Writing block at offset %" PRIu64 ", size %d, "
00748                "pts %" PRId64 ", duration %d\n",
00749                url_ftell(pb), size, pkt->pts, duration);
00750         blockgroup = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP, mkv_blockgroup_size(size));
00751         put_ebml_id(pb, MATROSKA_ID_BLOCK);
00752         put_ebml_num(pb, size+4, 0);
00753         put_byte(pb, 0x80 | (pkt->stream_index + 1));     // this assumes stream_index is less than 126
00754         put_be16(pb, pkt->pts - mkv->cluster_pts);
00755         put_byte(pb, 0);
00756         put_buffer(pb, buffer, size);
00757         put_ebml_uint(pb, MATROSKA_ID_BLOCKDURATION, duration);
00758         end_ebml_master(pb, blockgroup);
00759 
00760         data += line_size;
00761         data_size -= line_size;
00762     }
00763 
00764     return max_duration;
00765 }
00766 
00767 static void mkv_write_block(AVFormatContext *s, unsigned int blockid, AVPacket *pkt, int flags)
00768 {
00769     MatroskaMuxContext *mkv = s->priv_data;
00770     ByteIOContext *pb = s->pb;
00771     AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
00772     uint8_t *data = NULL;
00773     int size = pkt->size;
00774 
00775     av_log(s, AV_LOG_DEBUG, "Writing block at offset %" PRIu64 ", size %d, "
00776            "pts %" PRId64 ", dts %" PRId64 ", duration %d, flags %d\n",
00777            url_ftell(pb), pkt->size, pkt->pts, pkt->dts, pkt->duration, flags);
00778     if (codec->codec_id == CODEC_ID_H264 && codec->extradata_size > 0 &&
00779         (AV_RB24(codec->extradata) == 1 || AV_RB32(codec->extradata) == 1))
00780         ff_avc_parse_nal_units_buf(pkt->data, &data, &size);
00781     else
00782         data = pkt->data;
00783     put_ebml_id(pb, blockid);
00784     put_ebml_num(pb, size+4, 0);
00785     put_byte(pb, 0x80 | (pkt->stream_index + 1));     // this assumes stream_index is less than 126
00786     put_be16(pb, pkt->pts - mkv->cluster_pts);
00787     put_byte(pb, flags);
00788     put_buffer(pb, data, size);
00789     if (data != pkt->data)
00790         av_free(data);
00791 }
00792 
00793 static int mkv_write_packet(AVFormatContext *s, AVPacket *pkt)
00794 {
00795     MatroskaMuxContext *mkv = s->priv_data;
00796     ByteIOContext *pb = s->pb;
00797     AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
00798     int keyframe = !!(pkt->flags & PKT_FLAG_KEY);
00799     int duration = pkt->duration;
00800     int ret;
00801 
00802     // start a new cluster every 5 MB or 5 sec
00803     if (url_ftell(pb) > mkv->cluster_pos + 5*1024*1024 || pkt->pts > mkv->cluster_pts + 5000) {
00804         av_log(s, AV_LOG_DEBUG, "Starting new cluster at offset %" PRIu64
00805                " bytes, pts %" PRIu64 "\n", url_ftell(pb), pkt->pts);
00806         end_ebml_master(pb, mkv->cluster);
00807 
00808         ret = mkv_add_seekhead_entry(mkv->cluster_seekhead, MATROSKA_ID_CLUSTER, url_ftell(pb));
00809         if (ret < 0) return ret;
00810 
00811         mkv->cluster_pos = url_ftell(pb);
00812         mkv->cluster = start_ebml_master(pb, MATROSKA_ID_CLUSTER, 0);
00813         put_ebml_uint(pb, MATROSKA_ID_CLUSTERTIMECODE, pkt->pts);
00814         mkv->cluster_pts = pkt->pts;
00815         av_md5_update(mkv->md5_ctx, pkt->data, FFMIN(200, pkt->size));
00816     }
00817 
00818     if (codec->codec_type != CODEC_TYPE_SUBTITLE) {
00819         mkv_write_block(s, MATROSKA_ID_SIMPLEBLOCK, pkt, keyframe << 7);
00820     } else if (codec->codec_id == CODEC_ID_SSA) {
00821         duration = mkv_write_ass_blocks(s, pkt);
00822     } else {
00823         ebml_master blockgroup = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP, mkv_blockgroup_size(pkt->size));
00824         duration = pkt->convergence_duration;
00825         mkv_write_block(s, MATROSKA_ID_BLOCK, pkt, 0);
00826         put_ebml_uint(pb, MATROSKA_ID_BLOCKDURATION, duration);
00827         end_ebml_master(pb, blockgroup);
00828     }
00829 
00830     if (codec->codec_type == CODEC_TYPE_VIDEO && keyframe) {
00831         ret = mkv_add_cuepoint(mkv->cues, pkt, mkv->cluster_pos);
00832         if (ret < 0) return ret;
00833     }
00834 
00835     mkv->duration = FFMAX(mkv->duration, pkt->pts + duration);
00836     return 0;
00837 }
00838 
00839 static int mkv_write_trailer(AVFormatContext *s)
00840 {
00841     MatroskaMuxContext *mkv = s->priv_data;
00842     ByteIOContext *pb = s->pb;
00843     int64_t currentpos, second_seekhead, cuespos;
00844     int ret;
00845 
00846     end_ebml_master(pb, mkv->cluster);
00847 
00848     if (!url_is_streamed(pb)) {
00849         cuespos = mkv_write_cues(pb, mkv->cues, s->nb_streams);
00850         second_seekhead = mkv_write_seekhead(pb, mkv->cluster_seekhead);
00851 
00852         ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_CUES    , cuespos);
00853         if (ret < 0) return ret;
00854         ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_SEEKHEAD, second_seekhead);
00855         if (ret < 0) return ret;
00856         mkv_write_seekhead(pb, mkv->main_seekhead);
00857 
00858         // update the duration
00859         av_log(s, AV_LOG_DEBUG, "end duration = %" PRIu64 "\n", mkv->duration);
00860         currentpos = url_ftell(pb);
00861         url_fseek(pb, mkv->duration_offset, SEEK_SET);
00862         put_ebml_float(pb, MATROSKA_ID_DURATION, mkv->duration);
00863 
00864         // write the md5sum of some frames as the segment UID
00865         if (!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT)) {
00866             uint8_t segment_uid[16];
00867             av_md5_final(mkv->md5_ctx, segment_uid);
00868             url_fseek(pb, mkv->segment_uid, SEEK_SET);
00869             put_ebml_binary(pb, MATROSKA_ID_SEGMENTUID, segment_uid, 16);
00870         }
00871         url_fseek(pb, currentpos, SEEK_SET);
00872     }
00873 
00874     end_ebml_master(pb, mkv->segment);
00875     av_free(mkv->md5_ctx);
00876     put_flush_packet(pb);
00877     return 0;
00878 }
00879 
00880 AVOutputFormat matroska_muxer = {
00881     "matroska",
00882     NULL_IF_CONFIG_SMALL("Matroska file format"),
00883     "video/x-matroska",
00884     "mkv",
00885     sizeof(MatroskaMuxContext),
00886     CODEC_ID_MP2,
00887     CODEC_ID_MPEG4,
00888     mkv_write_header,
00889     mkv_write_packet,
00890     mkv_write_trailer,
00891     .flags = AVFMT_GLOBALHEADER | AVFMT_VARIABLE_FPS,
00892     .codec_tag = (const AVCodecTag* const []){codec_bmp_tags, codec_wav_tags, 0},
00893     .subtitle_codec = CODEC_ID_TEXT,
00894 };
00895 
00896 AVOutputFormat matroska_audio_muxer = {
00897     "matroska",
00898     NULL_IF_CONFIG_SMALL("Matroska file format"),
00899     "audio/x-matroska",
00900     "mka",
00901     sizeof(MatroskaMuxContext),
00902     CODEC_ID_MP2,
00903     CODEC_ID_NONE,
00904     mkv_write_header,
00905     mkv_write_packet,
00906     mkv_write_trailer,
00907     .flags = AVFMT_GLOBALHEADER,
00908     .codec_tag = (const AVCodecTag* const []){codec_wav_tags, 0},
00909 };

Generated on Sat Feb 16 2013 09:23:14 for ffmpeg by  doxygen 1.7.1