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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 {
00065     int             write_dts;
00066 } mkv_track;
00067 
00068 #define MODE_MATROSKAv2 0x01
00069 #define MODE_WEBM       0x02
00070 
00071 typedef struct MatroskaMuxContext {
00072     int             mode;
00073     ByteIOContext   *dyn_bc;
00074     ebml_master     segment;
00075     int64_t         segment_offset;
00076     int64_t         segment_uid;
00077     ebml_master     cluster;
00078     int64_t         cluster_pos;        
00079     int64_t         cluster_pts;
00080     int64_t         duration_offset;
00081     int64_t         duration;
00082     mkv_seekhead    *main_seekhead;
00083     mkv_seekhead    *cluster_seekhead;
00084     mkv_cues        *cues;
00085     mkv_track       *tracks;
00086 
00087     struct AVMD5    *md5_ctx;
00088 } MatroskaMuxContext;
00089 
00090 
00093 #define MAX_SEEKENTRY_SIZE 21
00094 
00097 #define MAX_CUETRACKPOS_SIZE 22
00098 
00100 #define MAX_CUEPOINT_SIZE(num_tracks) 12 + MAX_CUETRACKPOS_SIZE*num_tracks
00101 
00102 
00103 static int ebml_id_size(unsigned int id)
00104 {
00105     return (av_log2(id+1)-1)/7+1;
00106 }
00107 
00108 static void put_ebml_id(ByteIOContext *pb, unsigned int id)
00109 {
00110     int i = ebml_id_size(id);
00111     while (i--)
00112         put_byte(pb, id >> (i*8));
00113 }
00114 
00120 static void put_ebml_size_unknown(ByteIOContext *pb, int bytes)
00121 {
00122     assert(bytes <= 8);
00123     put_byte(pb, 0x1ff >> bytes);
00124     while (--bytes)
00125         put_byte(pb, 0xff);
00126 }
00127 
00131 static int ebml_num_size(uint64_t num)
00132 {
00133     int bytes = 1;
00134     while ((num+1) >> bytes*7) bytes++;
00135     return bytes;
00136 }
00137 
00144 static void put_ebml_num(ByteIOContext *pb, uint64_t num, int bytes)
00145 {
00146     int i, needed_bytes = ebml_num_size(num);
00147 
00148     // sizes larger than this are currently undefined in EBML
00149     assert(num < (1ULL<<56)-1);
00150 
00151     if (bytes == 0)
00152         // don't care how many bytes are used, so use the min
00153         bytes = needed_bytes;
00154     // the bytes needed to write the given size would exceed the bytes
00155     // that we need to use, so write unknown size. This shouldn't happen.
00156     assert(bytes >= needed_bytes);
00157 
00158     num |= 1ULL << bytes*7;
00159     for (i = bytes - 1; i >= 0; i--)
00160         put_byte(pb, num >> i*8);
00161 }
00162 
00163 static void put_ebml_uint(ByteIOContext *pb, unsigned int elementid, uint64_t val)
00164 {
00165     int i, bytes = 1;
00166     uint64_t tmp = val;
00167     while (tmp>>=8) bytes++;
00168 
00169     put_ebml_id(pb, elementid);
00170     put_ebml_num(pb, bytes, 0);
00171     for (i = bytes - 1; i >= 0; i--)
00172         put_byte(pb, val >> i*8);
00173 }
00174 
00175 static void put_ebml_float(ByteIOContext *pb, unsigned int elementid, double val)
00176 {
00177     put_ebml_id(pb, elementid);
00178     put_ebml_num(pb, 8, 0);
00179     put_be64(pb, av_dbl2int(val));
00180 }
00181 
00182 static void put_ebml_binary(ByteIOContext *pb, unsigned int elementid,
00183                             const uint8_t *buf, int size)
00184 {
00185     put_ebml_id(pb, elementid);
00186     put_ebml_num(pb, size, 0);
00187     put_buffer(pb, buf, size);
00188 }
00189 
00190 static void put_ebml_string(ByteIOContext *pb, unsigned int elementid, const char *str)
00191 {
00192     put_ebml_binary(pb, elementid, str, strlen(str));
00193 }
00194 
00201 static void put_ebml_void(ByteIOContext *pb, uint64_t size)
00202 {
00203     int64_t currentpos = url_ftell(pb);
00204 
00205     assert(size >= 2);
00206 
00207     put_ebml_id(pb, EBML_ID_VOID);
00208     // we need to subtract the length needed to store the size from the
00209     // size we need to reserve so 2 cases, we use 8 bytes to store the
00210     // size if possible, 1 byte otherwise
00211     if (size < 10)
00212         put_ebml_num(pb, size-1, 0);
00213     else
00214         put_ebml_num(pb, size-9, 8);
00215     while(url_ftell(pb) < currentpos + size)
00216         put_byte(pb, 0);
00217 }
00218 
00219 static ebml_master start_ebml_master(ByteIOContext *pb, unsigned int elementid, uint64_t expectedsize)
00220 {
00221     int bytes = expectedsize ? ebml_num_size(expectedsize) : 8;
00222     put_ebml_id(pb, elementid);
00223     put_ebml_size_unknown(pb, bytes);
00224     return (ebml_master){ url_ftell(pb), bytes };
00225 }
00226 
00227 static void end_ebml_master(ByteIOContext *pb, ebml_master master)
00228 {
00229     int64_t pos = url_ftell(pb);
00230 
00231     if (url_fseek(pb, master.pos - master.sizebytes, SEEK_SET) < 0)
00232         return;
00233     put_ebml_num(pb, pos - master.pos, master.sizebytes);
00234     url_fseek(pb, pos, SEEK_SET);
00235 }
00236 
00237 static void put_xiph_size(ByteIOContext *pb, int size)
00238 {
00239     int i;
00240     for (i = 0; i < size / 255; i++)
00241         put_byte(pb, 255);
00242     put_byte(pb, size % 255);
00243 }
00244 
00256 static mkv_seekhead * mkv_start_seekhead(ByteIOContext *pb, int64_t segment_offset, int numelements)
00257 {
00258     mkv_seekhead *new_seekhead = av_mallocz(sizeof(mkv_seekhead));
00259     if (new_seekhead == NULL)
00260         return NULL;
00261 
00262     new_seekhead->segment_offset = segment_offset;
00263 
00264     if (numelements > 0) {
00265         new_seekhead->filepos = url_ftell(pb);
00266         // 21 bytes max for a seek entry, 10 bytes max for the SeekHead ID
00267         // and size, and 3 bytes to guarantee that an EBML void element
00268         // will fit afterwards
00269         new_seekhead->reserved_size = numelements * MAX_SEEKENTRY_SIZE + 13;
00270         new_seekhead->max_entries = numelements;
00271         put_ebml_void(pb, new_seekhead->reserved_size);
00272     }
00273     return new_seekhead;
00274 }
00275 
00276 static int mkv_add_seekhead_entry(mkv_seekhead *seekhead, unsigned int elementid, uint64_t filepos)
00277 {
00278     mkv_seekhead_entry *entries = seekhead->entries;
00279 
00280     // don't store more elements than we reserved space for
00281     if (seekhead->max_entries > 0 && seekhead->max_entries <= seekhead->num_entries)
00282         return -1;
00283 
00284     entries = av_realloc(entries, (seekhead->num_entries + 1) * sizeof(mkv_seekhead_entry));
00285     if (entries == NULL)
00286         return AVERROR(ENOMEM);
00287 
00288     entries[seekhead->num_entries  ].elementid = elementid;
00289     entries[seekhead->num_entries++].segmentpos = filepos - seekhead->segment_offset;
00290 
00291     seekhead->entries = entries;
00292     return 0;
00293 }
00294 
00304 static int64_t mkv_write_seekhead(ByteIOContext *pb, mkv_seekhead *seekhead)
00305 {
00306     ebml_master metaseek, seekentry;
00307     int64_t currentpos;
00308     int i;
00309 
00310     currentpos = url_ftell(pb);
00311 
00312     if (seekhead->reserved_size > 0)
00313         if (url_fseek(pb, seekhead->filepos, SEEK_SET) < 0)
00314             return -1;
00315 
00316     metaseek = start_ebml_master(pb, MATROSKA_ID_SEEKHEAD, seekhead->reserved_size);
00317     for (i = 0; i < seekhead->num_entries; i++) {
00318         mkv_seekhead_entry *entry = &seekhead->entries[i];
00319 
00320         seekentry = start_ebml_master(pb, MATROSKA_ID_SEEKENTRY, MAX_SEEKENTRY_SIZE);
00321 
00322         put_ebml_id(pb, MATROSKA_ID_SEEKID);
00323         put_ebml_num(pb, ebml_id_size(entry->elementid), 0);
00324         put_ebml_id(pb, entry->elementid);
00325 
00326         put_ebml_uint(pb, MATROSKA_ID_SEEKPOSITION, entry->segmentpos);
00327         end_ebml_master(pb, seekentry);
00328     }
00329     end_ebml_master(pb, metaseek);
00330 
00331     if (seekhead->reserved_size > 0) {
00332         uint64_t remaining = seekhead->filepos + seekhead->reserved_size - url_ftell(pb);
00333         put_ebml_void(pb, remaining);
00334         url_fseek(pb, currentpos, SEEK_SET);
00335 
00336         currentpos = seekhead->filepos;
00337     }
00338     av_free(seekhead->entries);
00339     av_free(seekhead);
00340 
00341     return currentpos;
00342 }
00343 
00344 static mkv_cues * mkv_start_cues(int64_t segment_offset)
00345 {
00346     mkv_cues *cues = av_mallocz(sizeof(mkv_cues));
00347     if (cues == NULL)
00348         return NULL;
00349 
00350     cues->segment_offset = segment_offset;
00351     return cues;
00352 }
00353 
00354 static int mkv_add_cuepoint(mkv_cues *cues, int stream, int64_t ts, int64_t cluster_pos)
00355 {
00356     mkv_cuepoint *entries = cues->entries;
00357 
00358     entries = av_realloc(entries, (cues->num_entries + 1) * sizeof(mkv_cuepoint));
00359     if (entries == NULL)
00360         return AVERROR(ENOMEM);
00361 
00362     if (ts < 0)
00363         return 0;
00364 
00365     entries[cues->num_entries  ].pts = ts;
00366     entries[cues->num_entries  ].tracknum = stream + 1;
00367     entries[cues->num_entries++].cluster_pos = cluster_pos - cues->segment_offset;
00368 
00369     cues->entries = entries;
00370     return 0;
00371 }
00372 
00373 static int64_t mkv_write_cues(ByteIOContext *pb, mkv_cues *cues, int num_tracks)
00374 {
00375     ebml_master cues_element;
00376     int64_t currentpos;
00377     int i, j;
00378 
00379     currentpos = url_ftell(pb);
00380     cues_element = start_ebml_master(pb, MATROSKA_ID_CUES, 0);
00381 
00382     for (i = 0; i < cues->num_entries; i++) {
00383         ebml_master cuepoint, track_positions;
00384         mkv_cuepoint *entry = &cues->entries[i];
00385         uint64_t pts = entry->pts;
00386 
00387         cuepoint = start_ebml_master(pb, MATROSKA_ID_POINTENTRY, MAX_CUEPOINT_SIZE(num_tracks));
00388         put_ebml_uint(pb, MATROSKA_ID_CUETIME, pts);
00389 
00390         // put all the entries from different tracks that have the exact same
00391         // timestamp into the same CuePoint
00392         for (j = 0; j < cues->num_entries - i && entry[j].pts == pts; j++) {
00393             track_positions = start_ebml_master(pb, MATROSKA_ID_CUETRACKPOSITION, MAX_CUETRACKPOS_SIZE);
00394             put_ebml_uint(pb, MATROSKA_ID_CUETRACK          , entry[j].tracknum   );
00395             put_ebml_uint(pb, MATROSKA_ID_CUECLUSTERPOSITION, entry[j].cluster_pos);
00396             end_ebml_master(pb, track_positions);
00397         }
00398         i += j - 1;
00399         end_ebml_master(pb, cuepoint);
00400     }
00401     end_ebml_master(pb, cues_element);
00402 
00403     av_free(cues->entries);
00404     av_free(cues);
00405     return currentpos;
00406 }
00407 
00408 static int put_xiph_codecpriv(AVFormatContext *s, ByteIOContext *pb, AVCodecContext *codec)
00409 {
00410     uint8_t *header_start[3];
00411     int header_len[3];
00412     int first_header_size;
00413     int j;
00414 
00415     if (codec->codec_id == CODEC_ID_VORBIS)
00416         first_header_size = 30;
00417     else
00418         first_header_size = 42;
00419 
00420     if (ff_split_xiph_headers(codec->extradata, codec->extradata_size,
00421                               first_header_size, header_start, header_len) < 0) {
00422         av_log(s, AV_LOG_ERROR, "Extradata corrupt.\n");
00423         return -1;
00424     }
00425 
00426     put_byte(pb, 2);                    // number packets - 1
00427     for (j = 0; j < 2; j++) {
00428         put_xiph_size(pb, header_len[j]);
00429     }
00430     for (j = 0; j < 3; j++)
00431         put_buffer(pb, header_start[j], header_len[j]);
00432 
00433     return 0;
00434 }
00435 
00436 static void get_aac_sample_rates(AVFormatContext *s, AVCodecContext *codec, int *sample_rate, int *output_sample_rate)
00437 {
00438     int sri;
00439 
00440     if (codec->extradata_size < 2) {
00441         av_log(s, AV_LOG_WARNING, "No AAC extradata, unable to determine samplerate.\n");
00442         return;
00443     }
00444 
00445     sri = ((codec->extradata[0] << 1) & 0xE) | (codec->extradata[1] >> 7);
00446     if (sri > 12) {
00447         av_log(s, AV_LOG_WARNING, "AAC samplerate index out of bounds\n");
00448         return;
00449     }
00450     *sample_rate = ff_mpeg4audio_sample_rates[sri];
00451 
00452     // if sbr, get output sample rate as well
00453     if (codec->extradata_size == 5) {
00454         sri = (codec->extradata[4] >> 3) & 0xF;
00455         if (sri > 12) {
00456             av_log(s, AV_LOG_WARNING, "AAC output samplerate index out of bounds\n");
00457             return;
00458         }
00459         *output_sample_rate = ff_mpeg4audio_sample_rates[sri];
00460     }
00461 }
00462 
00463 static int mkv_write_codecprivate(AVFormatContext *s, ByteIOContext *pb, AVCodecContext *codec, int native_id, int qt_id)
00464 {
00465     ByteIOContext *dyn_cp;
00466     uint8_t *codecpriv;
00467     int ret, codecpriv_size;
00468 
00469     ret = url_open_dyn_buf(&dyn_cp);
00470     if(ret < 0)
00471         return ret;
00472 
00473     if (native_id) {
00474         if (codec->codec_id == CODEC_ID_VORBIS || codec->codec_id == CODEC_ID_THEORA)
00475             ret = put_xiph_codecpriv(s, dyn_cp, codec);
00476         else if (codec->codec_id == CODEC_ID_FLAC)
00477             ret = ff_flac_write_header(dyn_cp, codec, 1);
00478         else if (codec->codec_id == CODEC_ID_H264)
00479             ret = ff_isom_write_avcc(dyn_cp, codec->extradata, codec->extradata_size);
00480         else if (codec->extradata_size)
00481             put_buffer(dyn_cp, codec->extradata, codec->extradata_size);
00482     } else if (codec->codec_type == AVMEDIA_TYPE_VIDEO) {
00483         if (qt_id) {
00484             if (!codec->codec_tag)
00485                 codec->codec_tag = ff_codec_get_tag(codec_movvideo_tags, codec->codec_id);
00486             if (codec->extradata_size)
00487                 put_buffer(dyn_cp, codec->extradata, codec->extradata_size);
00488         } else {
00489             if (!codec->codec_tag)
00490                 codec->codec_tag = ff_codec_get_tag(ff_codec_bmp_tags, codec->codec_id);
00491             if (!codec->codec_tag) {
00492                 av_log(s, AV_LOG_ERROR, "No bmp codec ID found.\n");
00493                 ret = -1;
00494             }
00495 
00496             ff_put_bmp_header(dyn_cp, codec, ff_codec_bmp_tags, 0);
00497         }
00498 
00499     } else if (codec->codec_type == AVMEDIA_TYPE_AUDIO) {
00500         unsigned int tag;
00501         tag = ff_codec_get_tag(ff_codec_wav_tags, codec->codec_id);
00502         if (!tag) {
00503             av_log(s, AV_LOG_ERROR, "No wav codec ID found.\n");
00504             ret = -1;
00505         }
00506         if (!codec->codec_tag)
00507             codec->codec_tag = tag;
00508 
00509         ff_put_wav_header(dyn_cp, codec);
00510     }
00511 
00512     codecpriv_size = url_close_dyn_buf(dyn_cp, &codecpriv);
00513     if (codecpriv_size)
00514         put_ebml_binary(pb, MATROSKA_ID_CODECPRIVATE, codecpriv, codecpriv_size);
00515     av_free(codecpriv);
00516     return ret;
00517 }
00518 
00519 static int mkv_write_tracks(AVFormatContext *s)
00520 {
00521     MatroskaMuxContext *mkv = s->priv_data;
00522     ByteIOContext *pb = s->pb;
00523     ebml_master tracks;
00524     int i, j, ret;
00525 
00526     ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_TRACKS, url_ftell(pb));
00527     if (ret < 0) return ret;
00528 
00529     tracks = start_ebml_master(pb, MATROSKA_ID_TRACKS, 0);
00530     for (i = 0; i < s->nb_streams; i++) {
00531         AVStream *st = s->streams[i];
00532         AVCodecContext *codec = st->codec;
00533         ebml_master subinfo, track;
00534         int native_id = 0;
00535         int qt_id = 0;
00536         int bit_depth = av_get_bits_per_sample(codec->codec_id);
00537         int sample_rate = codec->sample_rate;
00538         int output_sample_rate = 0;
00539         AVMetadataTag *tag;
00540 
00541         if (!bit_depth)
00542             bit_depth = av_get_bits_per_sample_format(codec->sample_fmt);
00543 
00544         if (codec->codec_id == CODEC_ID_AAC)
00545             get_aac_sample_rates(s, codec, &sample_rate, &output_sample_rate);
00546 
00547         track = start_ebml_master(pb, MATROSKA_ID_TRACKENTRY, 0);
00548         put_ebml_uint (pb, MATROSKA_ID_TRACKNUMBER     , i + 1);
00549         put_ebml_uint (pb, MATROSKA_ID_TRACKUID        , i + 1);
00550         put_ebml_uint (pb, MATROSKA_ID_TRACKFLAGLACING , 0);    // no lacing (yet)
00551 
00552         if ((tag = av_metadata_get(st->metadata, "title", NULL, 0)))
00553             put_ebml_string(pb, MATROSKA_ID_TRACKNAME, tag->value);
00554         tag = av_metadata_get(st->metadata, "language", NULL, 0);
00555         put_ebml_string(pb, MATROSKA_ID_TRACKLANGUAGE, tag ? tag->value:"und");
00556 
00557         if (st->disposition)
00558             put_ebml_uint(pb, MATROSKA_ID_TRACKFLAGDEFAULT, !!(st->disposition & AV_DISPOSITION_DEFAULT));
00559 
00560         // look for a codec ID string specific to mkv to use,
00561         // if none are found, use AVI codes
00562         for (j = 0; ff_mkv_codec_tags[j].id != CODEC_ID_NONE; j++) {
00563             if (ff_mkv_codec_tags[j].id == codec->codec_id) {
00564                 put_ebml_string(pb, MATROSKA_ID_CODECID, ff_mkv_codec_tags[j].str);
00565                 native_id = 1;
00566                 break;
00567             }
00568         }
00569 
00570         if (mkv->mode == MODE_WEBM && !(codec->codec_id == CODEC_ID_VP8 ||
00571                                         codec->codec_id == CODEC_ID_VORBIS)) {
00572             av_log(s, AV_LOG_ERROR,
00573                    "Only VP8 video and Vorbis audio are supported for WebM.\n");
00574             return AVERROR(EINVAL);
00575         }
00576 
00577         switch (codec->codec_type) {
00578             case AVMEDIA_TYPE_VIDEO:
00579                 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_VIDEO);
00580                 put_ebml_uint(pb, MATROSKA_ID_TRACKDEFAULTDURATION, av_q2d(codec->time_base)*1E9);
00581 
00582                 if (!native_id &&
00583                       ff_codec_get_tag(codec_movvideo_tags, codec->codec_id) &&
00584                     (!ff_codec_get_tag(ff_codec_bmp_tags,   codec->codec_id)
00585                      || codec->codec_id == CODEC_ID_SVQ1
00586                      || codec->codec_id == CODEC_ID_SVQ3
00587                      || codec->codec_id == CODEC_ID_CINEPAK))
00588                     qt_id = 1;
00589 
00590                 if (qt_id)
00591                     put_ebml_string(pb, MATROSKA_ID_CODECID, "V_QUICKTIME");
00592                 else if (!native_id) {
00593                     // if there is no mkv-specific codec ID, use VFW mode
00594                     put_ebml_string(pb, MATROSKA_ID_CODECID, "V_MS/VFW/FOURCC");
00595                     mkv->tracks[i].write_dts = 1;
00596                 }
00597 
00598                 subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKVIDEO, 0);
00599                 // XXX: interlace flag?
00600                 put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELWIDTH , codec->width);
00601                 put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELHEIGHT, codec->height);
00602                 if (st->sample_aspect_ratio.num) {
00603                     int d_width = codec->width*av_q2d(st->sample_aspect_ratio);
00604                     put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYWIDTH , d_width);
00605                     put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYHEIGHT, codec->height);
00606                 }
00607                 end_ebml_master(pb, subinfo);
00608                 break;
00609 
00610             case AVMEDIA_TYPE_AUDIO:
00611                 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_AUDIO);
00612 
00613                 if (!native_id)
00614                     // no mkv-specific ID, use ACM mode
00615                     put_ebml_string(pb, MATROSKA_ID_CODECID, "A_MS/ACM");
00616 
00617                 subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKAUDIO, 0);
00618                 put_ebml_uint  (pb, MATROSKA_ID_AUDIOCHANNELS    , codec->channels);
00619                 put_ebml_float (pb, MATROSKA_ID_AUDIOSAMPLINGFREQ, sample_rate);
00620                 if (output_sample_rate)
00621                     put_ebml_float(pb, MATROSKA_ID_AUDIOOUTSAMPLINGFREQ, output_sample_rate);
00622                 if (bit_depth)
00623                     put_ebml_uint(pb, MATROSKA_ID_AUDIOBITDEPTH, bit_depth);
00624                 end_ebml_master(pb, subinfo);
00625                 break;
00626 
00627             case AVMEDIA_TYPE_SUBTITLE:
00628                 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_SUBTITLE);
00629                 break;
00630             default:
00631                 av_log(s, AV_LOG_ERROR, "Only audio, video, and subtitles are supported for Matroska.");
00632                 break;
00633         }
00634         ret = mkv_write_codecprivate(s, pb, codec, native_id, qt_id);
00635         if (ret < 0) return ret;
00636 
00637         end_ebml_master(pb, track);
00638 
00639         // ms precision is the de-facto standard timescale for mkv files
00640         av_set_pts_info(st, 64, 1, 1000);
00641     }
00642     end_ebml_master(pb, tracks);
00643     return 0;
00644 }
00645 
00646 static int mkv_write_chapters(AVFormatContext *s)
00647 {
00648     MatroskaMuxContext *mkv = s->priv_data;
00649     ByteIOContext *pb = s->pb;
00650     ebml_master chapters, editionentry;
00651     AVRational scale = {1, 1E9};
00652     int i, ret;
00653 
00654     if (!s->nb_chapters)
00655         return 0;
00656 
00657     ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_CHAPTERS, url_ftell(pb));
00658     if (ret < 0) return ret;
00659 
00660     chapters     = start_ebml_master(pb, MATROSKA_ID_CHAPTERS    , 0);
00661     editionentry = start_ebml_master(pb, MATROSKA_ID_EDITIONENTRY, 0);
00662     put_ebml_uint(pb, MATROSKA_ID_EDITIONFLAGDEFAULT, 1);
00663     put_ebml_uint(pb, MATROSKA_ID_EDITIONFLAGHIDDEN , 0);
00664     for (i = 0; i < s->nb_chapters; i++) {
00665         ebml_master chapteratom, chapterdisplay;
00666         AVChapter *c     = s->chapters[i];
00667         AVMetadataTag *t = NULL;
00668 
00669         chapteratom = start_ebml_master(pb, MATROSKA_ID_CHAPTERATOM, 0);
00670         put_ebml_uint(pb, MATROSKA_ID_CHAPTERUID, c->id);
00671         put_ebml_uint(pb, MATROSKA_ID_CHAPTERTIMESTART,
00672                       av_rescale_q(c->start, c->time_base, scale));
00673         put_ebml_uint(pb, MATROSKA_ID_CHAPTERTIMEEND,
00674                       av_rescale_q(c->end,   c->time_base, scale));
00675         put_ebml_uint(pb, MATROSKA_ID_CHAPTERFLAGHIDDEN , 0);
00676         put_ebml_uint(pb, MATROSKA_ID_CHAPTERFLAGENABLED, 1);
00677         if ((t = av_metadata_get(c->metadata, "title", NULL, 0))) {
00678             chapterdisplay = start_ebml_master(pb, MATROSKA_ID_CHAPTERDISPLAY, 0);
00679             put_ebml_string(pb, MATROSKA_ID_CHAPSTRING, t->value);
00680             put_ebml_string(pb, MATROSKA_ID_CHAPLANG  , "und");
00681             end_ebml_master(pb, chapterdisplay);
00682         }
00683         end_ebml_master(pb, chapteratom);
00684     }
00685     end_ebml_master(pb, editionentry);
00686     end_ebml_master(pb, chapters);
00687     return 0;
00688 }
00689 
00690 static int mkv_write_header(AVFormatContext *s)
00691 {
00692     MatroskaMuxContext *mkv = s->priv_data;
00693     ByteIOContext *pb = s->pb;
00694     ebml_master ebml_header, segment_info;
00695     AVMetadataTag *tag;
00696     int ret;
00697 
00698     if (!strcmp(s->oformat->name, "webm")) mkv->mode = MODE_WEBM;
00699     else                                   mkv->mode = MODE_MATROSKAv2;
00700 
00701     mkv->md5_ctx = av_mallocz(av_md5_size);
00702     av_md5_init(mkv->md5_ctx);
00703     mkv->tracks = av_mallocz(s->nb_streams * sizeof(*mkv->tracks));
00704 
00705     ebml_header = start_ebml_master(pb, EBML_ID_HEADER, 0);
00706     put_ebml_uint   (pb, EBML_ID_EBMLVERSION        ,           1);
00707     put_ebml_uint   (pb, EBML_ID_EBMLREADVERSION    ,           1);
00708     put_ebml_uint   (pb, EBML_ID_EBMLMAXIDLENGTH    ,           4);
00709     put_ebml_uint   (pb, EBML_ID_EBMLMAXSIZELENGTH  ,           8);
00710     put_ebml_string (pb, EBML_ID_DOCTYPE            , s->oformat->name);
00711     put_ebml_uint   (pb, EBML_ID_DOCTYPEVERSION     ,           2);
00712     put_ebml_uint   (pb, EBML_ID_DOCTYPEREADVERSION ,           2);
00713     end_ebml_master(pb, ebml_header);
00714 
00715     mkv->segment = start_ebml_master(pb, MATROSKA_ID_SEGMENT, 0);
00716     mkv->segment_offset = url_ftell(pb);
00717 
00718     // we write 2 seek heads - one at the end of the file to point to each
00719     // cluster, and one at the beginning to point to all other level one
00720     // elements (including the seek head at the end of the file), which
00721     // isn't more than 10 elements if we only write one of each other
00722     // currently defined level 1 element
00723     mkv->main_seekhead    = mkv_start_seekhead(pb, mkv->segment_offset, 10);
00724     mkv->cluster_seekhead = mkv_start_seekhead(pb, mkv->segment_offset, 0);
00725     if (mkv->main_seekhead == NULL || mkv->cluster_seekhead == NULL)
00726         return AVERROR(ENOMEM);
00727 
00728     ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_INFO, url_ftell(pb));
00729     if (ret < 0) return ret;
00730 
00731     segment_info = start_ebml_master(pb, MATROSKA_ID_INFO, 0);
00732     put_ebml_uint(pb, MATROSKA_ID_TIMECODESCALE, 1000000);
00733     if ((tag = av_metadata_get(s->metadata, "title", NULL, 0)))
00734         put_ebml_string(pb, MATROSKA_ID_TITLE, tag->value);
00735     if (!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT)) {
00736         put_ebml_string(pb, MATROSKA_ID_MUXINGAPP , LIBAVFORMAT_IDENT);
00737         put_ebml_string(pb, MATROSKA_ID_WRITINGAPP, LIBAVFORMAT_IDENT);
00738 
00739         // reserve space to write the segment UID later
00740         mkv->segment_uid = url_ftell(pb);
00741         put_ebml_void(pb, 19);
00742     }
00743 
00744     // reserve space for the duration
00745     mkv->duration = 0;
00746     mkv->duration_offset = url_ftell(pb);
00747     put_ebml_void(pb, 11);                  // assumes double-precision float to be written
00748     end_ebml_master(pb, segment_info);
00749 
00750     ret = mkv_write_tracks(s);
00751     if (ret < 0) return ret;
00752 
00753     if (mkv->mode != MODE_WEBM) {
00754         ret = mkv_write_chapters(s);
00755         if (ret < 0) return ret;
00756     }
00757 
00758     if (url_is_streamed(s->pb))
00759         mkv_write_seekhead(pb, mkv->main_seekhead);
00760 
00761     mkv->cues = mkv_start_cues(mkv->segment_offset);
00762     if (mkv->cues == NULL)
00763         return AVERROR(ENOMEM);
00764 
00765     put_flush_packet(pb);
00766     return 0;
00767 }
00768 
00769 static int mkv_blockgroup_size(int pkt_size)
00770 {
00771     int size = pkt_size + 4;
00772     size += ebml_num_size(size);
00773     size += 2;              // EBML ID for block and block duration
00774     size += 8;              // max size of block duration
00775     size += ebml_num_size(size);
00776     size += 1;              // blockgroup EBML ID
00777     return size;
00778 }
00779 
00780 static int ass_get_duration(const uint8_t *p)
00781 {
00782     int sh, sm, ss, sc, eh, em, es, ec;
00783     uint64_t start, end;
00784 
00785     if (sscanf(p, "%*[^,],%d:%d:%d%*c%d,%d:%d:%d%*c%d",
00786                &sh, &sm, &ss, &sc, &eh, &em, &es, &ec) != 8)
00787         return 0;
00788     start = 3600000*sh + 60000*sm + 1000*ss + 10*sc;
00789     end   = 3600000*eh + 60000*em + 1000*es + 10*ec;
00790     return end - start;
00791 }
00792 
00793 static int mkv_write_ass_blocks(AVFormatContext *s, ByteIOContext *pb, AVPacket *pkt)
00794 {
00795     MatroskaMuxContext *mkv = s->priv_data;
00796     int i, layer = 0, max_duration = 0, size, line_size, data_size = pkt->size;
00797     uint8_t *start, *end, *data = pkt->data;
00798     ebml_master blockgroup;
00799     char buffer[2048];
00800 
00801     while (data_size) {
00802         int duration = ass_get_duration(data);
00803         max_duration = FFMAX(duration, max_duration);
00804         end = memchr(data, '\n', data_size);
00805         size = line_size = end ? end-data+1 : data_size;
00806         size -= end ? (end[-1]=='\r')+1 : 0;
00807         start = data;
00808         for (i=0; i<3; i++, start++)
00809             if (!(start = memchr(start, ',', size-(start-data))))
00810                 return max_duration;
00811         size -= start - data;
00812         sscanf(data, "Dialogue: %d,", &layer);
00813         i = snprintf(buffer, sizeof(buffer), "%"PRId64",%d,",
00814                      s->streams[pkt->stream_index]->nb_frames++, layer);
00815         size = FFMIN(i+size, sizeof(buffer));
00816         memcpy(buffer+i, start, size-i);
00817 
00818         av_log(s, AV_LOG_DEBUG, "Writing block at offset %" PRIu64 ", size %d, "
00819                "pts %" PRId64 ", duration %d\n",
00820                url_ftell(pb), size, pkt->pts, duration);
00821         blockgroup = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP, mkv_blockgroup_size(size));
00822         put_ebml_id(pb, MATROSKA_ID_BLOCK);
00823         put_ebml_num(pb, size+4, 0);
00824         put_byte(pb, 0x80 | (pkt->stream_index + 1));     // this assumes stream_index is less than 126
00825         put_be16(pb, pkt->pts - mkv->cluster_pts);
00826         put_byte(pb, 0);
00827         put_buffer(pb, buffer, size);
00828         put_ebml_uint(pb, MATROSKA_ID_BLOCKDURATION, duration);
00829         end_ebml_master(pb, blockgroup);
00830 
00831         data += line_size;
00832         data_size -= line_size;
00833     }
00834 
00835     return max_duration;
00836 }
00837 
00838 static void mkv_write_block(AVFormatContext *s, ByteIOContext *pb,
00839                             unsigned int blockid, AVPacket *pkt, int flags)
00840 {
00841     MatroskaMuxContext *mkv = s->priv_data;
00842     AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
00843     uint8_t *data = NULL;
00844     int size = pkt->size;
00845     int64_t ts = mkv->tracks[pkt->stream_index].write_dts ? pkt->dts : pkt->pts;
00846 
00847     av_log(s, AV_LOG_DEBUG, "Writing block at offset %" PRIu64 ", size %d, "
00848            "pts %" PRId64 ", dts %" PRId64 ", duration %d, flags %d\n",
00849            url_ftell(pb), pkt->size, pkt->pts, pkt->dts, pkt->duration, flags);
00850     if (codec->codec_id == CODEC_ID_H264 && codec->extradata_size > 0 &&
00851         (AV_RB24(codec->extradata) == 1 || AV_RB32(codec->extradata) == 1))
00852         ff_avc_parse_nal_units_buf(pkt->data, &data, &size);
00853     else
00854         data = pkt->data;
00855     put_ebml_id(pb, blockid);
00856     put_ebml_num(pb, size+4, 0);
00857     put_byte(pb, 0x80 | (pkt->stream_index + 1));     // this assumes stream_index is less than 126
00858     put_be16(pb, ts - mkv->cluster_pts);
00859     put_byte(pb, flags);
00860     put_buffer(pb, data, size);
00861     if (data != pkt->data)
00862         av_free(data);
00863 }
00864 
00865 static void mkv_flush_dynbuf(AVFormatContext *s)
00866 {
00867     MatroskaMuxContext *mkv = s->priv_data;
00868     int bufsize;
00869     uint8_t *dyn_buf;
00870 
00871     if (!mkv->dyn_bc)
00872         return;
00873 
00874     bufsize = url_close_dyn_buf(mkv->dyn_bc, &dyn_buf);
00875     put_buffer(s->pb, dyn_buf, bufsize);
00876     av_free(dyn_buf);
00877     mkv->dyn_bc = NULL;
00878 }
00879 
00880 static int mkv_write_packet(AVFormatContext *s, AVPacket *pkt)
00881 {
00882     MatroskaMuxContext *mkv = s->priv_data;
00883     ByteIOContext *pb = s->pb;
00884     AVCodecContext *codec = s->streams[pkt->stream_index]->codec;
00885     int keyframe = !!(pkt->flags & AV_PKT_FLAG_KEY);
00886     int duration = pkt->duration;
00887     int ret;
00888     int64_t ts = mkv->tracks[pkt->stream_index].write_dts ? pkt->dts : pkt->pts;
00889 
00890     if (ts == AV_NOPTS_VALUE) {
00891         av_log(s, AV_LOG_ERROR, "Can't write packet with unknown timestamp\n");
00892         return AVERROR(EINVAL);
00893     }
00894 
00895     if (url_is_streamed(s->pb)) {
00896         if (!mkv->dyn_bc)
00897             url_open_dyn_buf(&mkv->dyn_bc);
00898         pb = mkv->dyn_bc;
00899     }
00900 
00901     if (!mkv->cluster_pos) {
00902         ret = mkv_add_seekhead_entry(mkv->cluster_seekhead, MATROSKA_ID_CLUSTER, url_ftell(pb));
00903         if (ret < 0) return ret;
00904 
00905         mkv->cluster_pos = url_ftell(s->pb);
00906         mkv->cluster = start_ebml_master(pb, MATROSKA_ID_CLUSTER, 0);
00907         put_ebml_uint(pb, MATROSKA_ID_CLUSTERTIMECODE, FFMAX(0, ts));
00908         mkv->cluster_pts = FFMAX(0, ts);
00909         av_md5_update(mkv->md5_ctx, pkt->data, FFMIN(200, pkt->size));
00910     }
00911 
00912     if (codec->codec_type != AVMEDIA_TYPE_SUBTITLE) {
00913         mkv_write_block(s, pb, MATROSKA_ID_SIMPLEBLOCK, pkt, keyframe << 7);
00914     } else if (codec->codec_id == CODEC_ID_SSA) {
00915         duration = mkv_write_ass_blocks(s, pb, pkt);
00916     } else {
00917         ebml_master blockgroup = start_ebml_master(pb, MATROSKA_ID_BLOCKGROUP, mkv_blockgroup_size(pkt->size));
00918         duration = pkt->convergence_duration;
00919         mkv_write_block(s, pb, MATROSKA_ID_BLOCK, pkt, 0);
00920         put_ebml_uint(pb, MATROSKA_ID_BLOCKDURATION, duration);
00921         end_ebml_master(pb, blockgroup);
00922     }
00923 
00924     if (codec->codec_type == AVMEDIA_TYPE_VIDEO && keyframe) {
00925         ret = mkv_add_cuepoint(mkv->cues, pkt->stream_index, ts, mkv->cluster_pos);
00926         if (ret < 0) return ret;
00927     }
00928 
00929     // start a new cluster every 5 MB or 5 sec, or 32k / 1 sec for streaming
00930     if ((url_is_streamed(s->pb) && (url_ftell(pb) > 32*1024 || ts > mkv->cluster_pts + 1000))
00931         ||  url_ftell(pb) > mkv->cluster_pos + 5*1024*1024 || ts > mkv->cluster_pts + 5000) {
00932         av_log(s, AV_LOG_DEBUG, "Starting new cluster at offset %" PRIu64
00933                " bytes, pts %" PRIu64 "\n", url_ftell(pb), ts);
00934         end_ebml_master(pb, mkv->cluster);
00935         mkv->cluster_pos = 0;
00936         if (mkv->dyn_bc)
00937             mkv_flush_dynbuf(s);
00938     }
00939 
00940     mkv->duration = FFMAX(mkv->duration, ts + duration);
00941     return 0;
00942 }
00943 
00944 static int mkv_write_trailer(AVFormatContext *s)
00945 {
00946     MatroskaMuxContext *mkv = s->priv_data;
00947     ByteIOContext *pb = s->pb;
00948     int64_t currentpos, second_seekhead, cuespos;
00949     int ret;
00950 
00951     if (mkv->dyn_bc) {
00952         end_ebml_master(mkv->dyn_bc, mkv->cluster);
00953         mkv_flush_dynbuf(s);
00954     } else if (mkv->cluster_pos) {
00955         end_ebml_master(pb, mkv->cluster);
00956     }
00957 
00958     if (!url_is_streamed(pb)) {
00959         cuespos = mkv_write_cues(pb, mkv->cues, s->nb_streams);
00960         second_seekhead = mkv_write_seekhead(pb, mkv->cluster_seekhead);
00961 
00962         ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_CUES    , cuespos);
00963         if (ret < 0) return ret;
00964         if (second_seekhead >= 0) {
00965             ret = mkv_add_seekhead_entry(mkv->main_seekhead, MATROSKA_ID_SEEKHEAD, second_seekhead);
00966             if (ret < 0) return ret;
00967         }
00968         mkv_write_seekhead(pb, mkv->main_seekhead);
00969 
00970         // update the duration
00971         av_log(s, AV_LOG_DEBUG, "end duration = %" PRIu64 "\n", mkv->duration);
00972         currentpos = url_ftell(pb);
00973         url_fseek(pb, mkv->duration_offset, SEEK_SET);
00974         put_ebml_float(pb, MATROSKA_ID_DURATION, mkv->duration);
00975 
00976         // write the md5sum of some frames as the segment UID
00977         if (!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT)) {
00978             uint8_t segment_uid[16];
00979             av_md5_final(mkv->md5_ctx, segment_uid);
00980             url_fseek(pb, mkv->segment_uid, SEEK_SET);
00981             put_ebml_binary(pb, MATROSKA_ID_SEGMENTUID, segment_uid, 16);
00982         }
00983         url_fseek(pb, currentpos, SEEK_SET);
00984     }
00985 
00986     end_ebml_master(pb, mkv->segment);
00987     av_free(mkv->md5_ctx);
00988     av_free(mkv->tracks);
00989     put_flush_packet(pb);
00990     return 0;
00991 }
00992 
00993 #if CONFIG_MATROSKA_MUXER
00994 AVOutputFormat matroska_muxer = {
00995     "matroska",
00996     NULL_IF_CONFIG_SMALL("Matroska file format"),
00997     "video/x-matroska",
00998     "mkv",
00999     sizeof(MatroskaMuxContext),
01000     CODEC_ID_MP2,
01001     CODEC_ID_MPEG4,
01002     mkv_write_header,
01003     mkv_write_packet,
01004     mkv_write_trailer,
01005     .flags = AVFMT_GLOBALHEADER | AVFMT_VARIABLE_FPS,
01006     .codec_tag = (const AVCodecTag* const []){ff_codec_bmp_tags, ff_codec_wav_tags, 0},
01007     .subtitle_codec = CODEC_ID_TEXT,
01008 };
01009 #endif
01010 
01011 #if CONFIG_WEBM_MUXER
01012 AVOutputFormat webm_muxer = {
01013     "webm",
01014     NULL_IF_CONFIG_SMALL("WebM file format"),
01015     "video/webm",
01016     "webm",
01017     sizeof(MatroskaMuxContext),
01018     CODEC_ID_VORBIS,
01019     CODEC_ID_VP8,
01020     mkv_write_header,
01021     mkv_write_packet,
01022     mkv_write_trailer,
01023     .flags = AVFMT_GLOBALHEADER | AVFMT_VARIABLE_FPS,
01024 };
01025 #endif
01026 
01027 #if CONFIG_MATROSKA_AUDIO_MUXER
01028 AVOutputFormat matroska_audio_muxer = {
01029     "matroska",
01030     NULL_IF_CONFIG_SMALL("Matroska file format"),
01031     "audio/x-matroska",
01032     "mka",
01033     sizeof(MatroskaMuxContext),
01034     CODEC_ID_MP2,
01035     CODEC_ID_NONE,
01036     mkv_write_header,
01037     mkv_write_packet,
01038     mkv_write_trailer,
01039     .flags = AVFMT_GLOBALHEADER,
01040     .codec_tag = (const AVCodecTag* const []){ff_codec_wav_tags, 0},
01041 };
01042 #endif

Generated on Fri Sep 16 2011 17:17:48 for FFmpeg by  doxygen 1.7.1