3 * Copyright (c) 2007 David Conrad
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
27 typedef struct MatroskaMuxContext {
31 offset_t duration_offset;
35 static void put_ebml_id(ByteIOContext *pb, unsigned int id)
38 put_byte(pb, id >> 24);
40 put_byte(pb, id >> 16);
42 put_byte(pb, id >> 8);
46 // XXX: test this thoroughly and get rid of minbytes hack (currently needed to
47 // use up all of the space reserved in start_ebml_master)
48 static void put_ebml_size(ByteIOContext *pb, uint64_t size, int minbytes)
52 // sizes larger than this are currently undefined in EBML
53 // so write "unknown" size
54 size = FFMIN(size, (1ULL<<56)-1);
56 while (size >> (bytes*7 + 7)) bytes++;
58 put_byte(pb, (0x80 >> bytes) | (size >> bytes*8));
59 for (bytes -= 1; bytes >= 0; bytes--)
60 put_byte(pb, size >> bytes*8);
63 static void put_ebml_uint(ByteIOContext *pb, unsigned int elementid, uint64_t val)
66 while (val >> bytes*8) bytes++;
68 put_ebml_id(pb, elementid);
69 put_ebml_size(pb, bytes, 0);
70 for (bytes -= 1; bytes >= 0; bytes--)
71 put_byte(pb, val >> bytes*8);
74 static void put_ebml_float(ByteIOContext *pb, unsigned int elementid, double val)
76 // XXX: single-precision floats?
77 put_ebml_id(pb, elementid);
78 put_ebml_size(pb, 8, 0);
79 put_be64(pb, av_dbl2int(val));
82 static void put_ebml_binary(ByteIOContext *pb, unsigned int elementid,
83 const uint8_t *buf, int size)
85 put_ebml_id(pb, elementid);
86 put_ebml_size(pb, size, 0);
87 put_buffer(pb, buf, size);
90 static void put_ebml_string(ByteIOContext *pb, unsigned int elementid, const char *str)
92 put_ebml_binary(pb, elementid, str, strlen(str));
95 // this reserves exactly the amount of space specified by size, which must be at least 2
96 static void put_ebml_void(ByteIOContext *pb, uint64_t size)
98 offset_t currentpos = url_ftell(pb);
103 put_ebml_id(pb, EBML_ID_VOID);
104 // we need to subtract the length needed to store the size from the size we need to reserve
105 // so 2 cases, we use 8 bytes to store the size if possible, 1 byte otherwise
107 put_ebml_size(pb, size-1, 0);
109 put_ebml_size(pb, size-9, 7);
110 url_fseek(pb, currentpos + size, SEEK_SET);
113 static offset_t start_ebml_master(ByteIOContext *pb, unsigned int elementid)
115 put_ebml_id(pb, elementid);
116 // XXX: this always reserves the maximum needed space to store any size value
117 // we should be smarter (additional parameter for expected size?)
118 put_ebml_size(pb, (1ULL<<56)-1, 0); // largest unknown size
119 return url_ftell(pb);
122 static void end_ebml_master(ByteIOContext *pb, offset_t start)
124 offset_t pos = url_ftell(pb);
126 url_fseek(pb, start - 8, SEEK_SET);
127 put_ebml_size(pb, pos - start, 7);
128 url_fseek(pb, pos, SEEK_SET);
131 static int put_xiph_codecpriv(ByteIOContext *pb, AVCodecContext *codec)
133 offset_t codecprivate;
134 uint8_t *header_start[3];
136 int first_header_size;
139 if (codec->codec_id == CODEC_ID_VORBIS)
140 first_header_size = 30;
142 first_header_size = 42;
144 if (ff_split_xiph_headers(codec->extradata, codec->extradata_size,
145 first_header_size, header_start, header_len) < 0) {
146 av_log(codec, AV_LOG_ERROR, "Extradata corrupt.\n");
150 codecprivate = start_ebml_master(pb, MATROSKA_ID_CODECPRIVATE);
151 put_byte(pb, 2); // number packets - 1
152 for (j = 0; j < 2; j++) {
153 for (k = 0; k < header_len[j] / 255; k++)
155 put_byte(pb, header_len[j] % 255);
157 for (j = 0; j < 3; j++)
158 put_buffer(pb, header_start[j], header_len[j]);
159 end_ebml_master(pb, codecprivate);
162 static int mkv_write_tracks(AVFormatContext *s)
164 MatroskaMuxContext *mkv = s->priv_data;
165 ByteIOContext *pb = &s->pb;
169 tracks = start_ebml_master(pb, MATROSKA_ID_TRACKS);
170 for (i = 0; i < s->nb_streams; i++) {
171 AVStream *st = s->streams[i];
172 AVCodecContext *codec = st->codec;
173 offset_t subinfo, track;
176 track = start_ebml_master(pb, MATROSKA_ID_TRACKENTRY);
177 put_ebml_uint (pb, MATROSKA_ID_TRACKNUMBER , i + 1);
178 put_ebml_uint (pb, MATROSKA_ID_TRACKUID , i + 1);
179 put_ebml_uint (pb, MATROSKA_ID_TRACKFLAGLACING , 0); // no lacing (yet)
182 put_ebml_string(pb, MATROSKA_ID_TRACKLANGUAGE, st->language);
184 // look for a codec id string specific to mkv to use, if none are found, use AVI codes
185 for (j = 0; ff_mkv_codec_tags[j].id != CODEC_ID_NONE; j++) {
186 if (ff_mkv_codec_tags[j].id == codec->codec_id) {
187 put_ebml_string(pb, MATROSKA_ID_CODECID, ff_mkv_codec_tags[j].str);
193 // XXX: CodecPrivate for vorbis, theora, aac, native mpeg4, ...
195 if (codec->codec_id == CODEC_ID_VORBIS || codec->codec_id == CODEC_ID_THEORA) {
196 if (put_xiph_codecpriv(pb, codec) < 0)
199 put_ebml_binary(pb, MATROSKA_ID_CODECPRIVATE, codec->extradata, codec->extradata_size);
203 switch (codec->codec_type) {
204 case CODEC_TYPE_VIDEO:
205 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_VIDEO);
209 // if there is no mkv-specific codec id, use VFW mode
210 if (!codec->codec_tag)
211 codec->codec_tag = codec_get_tag(codec_bmp_tags, codec->codec_id);
213 put_ebml_string(pb, MATROSKA_ID_CODECID, MATROSKA_CODEC_ID_VIDEO_VFW_FOURCC);
214 // XXX: codec private isn't a master; is there a better way to re-use put_bmp_header?
215 bmp_header = start_ebml_master(pb, MATROSKA_ID_CODECPRIVATE);
216 put_bmp_header(pb, codec, codec_bmp_tags, 0);
217 end_ebml_master(pb, bmp_header);
219 subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKVIDEO);
220 // XXX: interlace flag?
221 put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELWIDTH , codec->width);
222 put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELHEIGHT, codec->height);
223 // XXX: display width/height
224 end_ebml_master(pb, subinfo);
227 case CODEC_TYPE_AUDIO:
228 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_AUDIO);
231 subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKAUDIO);
232 put_ebml_uint (pb, MATROSKA_ID_AUDIOCHANNELS , codec->channels);
233 put_ebml_float (pb, MATROSKA_ID_AUDIOSAMPLINGFREQ, codec->sample_rate);
234 // XXX: output sample freq (for sbr) and bitdepth (for pcm)
235 end_ebml_master(pb, subinfo);
239 av_log(s, AV_LOG_ERROR, "Only audio and video are supported for Matroska.");
242 end_ebml_master(pb, track);
244 // ms precision is the de-facto standard timescale for mkv files
245 av_set_pts_info(st, 64, 1, 1000);
247 end_ebml_master(pb, tracks);
250 static int mkv_write_header(AVFormatContext *s)
252 MatroskaMuxContext *mkv = s->priv_data;
253 ByteIOContext *pb = &s->pb;
254 offset_t ebml_header, segment_info;
256 ebml_header = start_ebml_master(pb, EBML_ID_HEADER);
257 put_ebml_uint (pb, EBML_ID_EBMLVERSION , 1);
258 put_ebml_uint (pb, EBML_ID_EBMLREADVERSION , 1);
259 put_ebml_uint (pb, EBML_ID_EBMLMAXIDLENGTH , 4);
260 put_ebml_uint (pb, EBML_ID_EBMLMAXSIZELENGTH , 8);
261 put_ebml_string (pb, EBML_ID_DOCTYPE , "matroska");
262 put_ebml_uint (pb, EBML_ID_DOCTYPEVERSION , 2);
263 put_ebml_uint (pb, EBML_ID_DOCTYPEREADVERSION , 2);
264 end_ebml_master(pb, ebml_header);
266 mkv->segment = start_ebml_master(pb, MATROSKA_ID_SEGMENT);
268 segment_info = start_ebml_master(pb, MATROSKA_ID_INFO);
269 put_ebml_uint(pb, MATROSKA_ID_TIMECODESCALE, 1000000);
270 if (strlen(s->title))
271 put_ebml_string(pb, MATROSKA_ID_TITLE, s->title);
272 if (!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT)) {
273 put_ebml_string(pb, MATROSKA_ID_MUXINGAPP, LIBAVFORMAT_IDENT);
274 // XXX: both are required; something better for writing app?
275 put_ebml_string(pb, MATROSKA_ID_WRITINGAPP, LIBAVFORMAT_IDENT);
278 // reserve space for the duration
280 mkv->duration_offset = url_ftell(pb);
281 put_ebml_void(pb, 11); // assumes double-precision float to be written
282 end_ebml_master(pb, segment_info);
284 if (mkv_write_tracks(s) < 0)
287 mkv->cluster = start_ebml_master(pb, MATROSKA_ID_CLUSTER);
288 put_ebml_uint(pb, MATROSKA_ID_CLUSTERTIMECODE, 0);
289 mkv->cluster_pts = 0;
294 static int mkv_write_packet(AVFormatContext *s, AVPacket *pkt)
296 MatroskaMuxContext *mkv = s->priv_data;
297 ByteIOContext *pb = &s->pb;
300 // start a new cluster every 5 MB or 5 sec
301 if (url_ftell(pb) > mkv->cluster + 5*1024*1024 || pkt->pts > mkv->cluster_pts + 5000) {
302 end_ebml_master(pb, mkv->cluster);
303 mkv->cluster = start_ebml_master(pb, MATROSKA_ID_CLUSTER);
304 put_ebml_uint(pb, MATROSKA_ID_CLUSTERTIMECODE, pkt->pts);
305 mkv->cluster_pts = pkt->pts;
308 block = start_ebml_master(pb, MATROSKA_ID_SIMPLEBLOCK);
309 put_byte(pb, 0x80 | (pkt->stream_index + 1)); // this assumes stream_index is less than 126
310 put_be16(pb, pkt->pts - mkv->cluster_pts);
311 put_byte(pb, !!(pkt->flags & PKT_FLAG_KEY));
312 put_buffer(pb, pkt->data, pkt->size);
313 end_ebml_master(pb, block);
315 mkv->duration = pkt->pts + pkt->duration;
319 static int mkv_write_trailer(AVFormatContext *s)
321 MatroskaMuxContext *mkv = s->priv_data;
322 ByteIOContext *pb = &s->pb;
325 end_ebml_master(pb, mkv->cluster);
327 // update the duration
328 currentpos = url_ftell(pb);
329 url_fseek(pb, mkv->duration_offset, SEEK_SET);
330 put_ebml_float(pb, MATROSKA_ID_DURATION, mkv->duration);
331 url_fseek(pb, currentpos, SEEK_SET);
333 end_ebml_master(pb, mkv->segment);
337 AVOutputFormat matroska_muxer = {
339 "Matroska File Format",
342 sizeof(MatroskaMuxContext),
348 .codec_tag = (const AVCodecTag*[]){codec_bmp_tags, codec_wav_tags, 0},