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);
164 static int mkv_write_tracks(AVFormatContext *s)
166 MatroskaMuxContext *mkv = s->priv_data;
167 ByteIOContext *pb = &s->pb;
171 tracks = start_ebml_master(pb, MATROSKA_ID_TRACKS);
172 for (i = 0; i < s->nb_streams; i++) {
173 AVStream *st = s->streams[i];
174 AVCodecContext *codec = st->codec;
175 offset_t subinfo, track;
178 track = start_ebml_master(pb, MATROSKA_ID_TRACKENTRY);
179 put_ebml_uint (pb, MATROSKA_ID_TRACKNUMBER , i + 1);
180 put_ebml_uint (pb, MATROSKA_ID_TRACKUID , i + 1);
181 put_ebml_uint (pb, MATROSKA_ID_TRACKFLAGLACING , 0); // no lacing (yet)
184 put_ebml_string(pb, MATROSKA_ID_TRACKLANGUAGE, st->language);
186 // look for a codec id string specific to mkv to use, if none are found, use AVI codes
187 for (j = 0; ff_mkv_codec_tags[j].id != CODEC_ID_NONE; j++) {
188 if (ff_mkv_codec_tags[j].id == codec->codec_id) {
189 put_ebml_string(pb, MATROSKA_ID_CODECID, ff_mkv_codec_tags[j].str);
195 // XXX: CodecPrivate for vorbis, theora, aac, native mpeg4, ...
197 if (codec->codec_id == CODEC_ID_VORBIS || codec->codec_id == CODEC_ID_THEORA) {
198 if (put_xiph_codecpriv(pb, codec) < 0)
201 put_ebml_binary(pb, MATROSKA_ID_CODECPRIVATE, codec->extradata, codec->extradata_size);
205 switch (codec->codec_type) {
206 case CODEC_TYPE_VIDEO:
207 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_VIDEO);
211 // if there is no mkv-specific codec id, use VFW mode
212 if (!codec->codec_tag)
213 codec->codec_tag = codec_get_tag(codec_bmp_tags, codec->codec_id);
215 put_ebml_string(pb, MATROSKA_ID_CODECID, MATROSKA_CODEC_ID_VIDEO_VFW_FOURCC);
216 // XXX: codec private isn't a master; is there a better way to re-use put_bmp_header?
217 bmp_header = start_ebml_master(pb, MATROSKA_ID_CODECPRIVATE);
218 put_bmp_header(pb, codec, codec_bmp_tags, 0);
219 end_ebml_master(pb, bmp_header);
221 subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKVIDEO);
222 // XXX: interlace flag?
223 put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELWIDTH , codec->width);
224 put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELHEIGHT, codec->height);
225 // XXX: display width/height
226 end_ebml_master(pb, subinfo);
229 case CODEC_TYPE_AUDIO:
230 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_AUDIO);
233 subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKAUDIO);
234 put_ebml_uint (pb, MATROSKA_ID_AUDIOCHANNELS , codec->channels);
235 put_ebml_float (pb, MATROSKA_ID_AUDIOSAMPLINGFREQ, codec->sample_rate);
236 // XXX: output sample freq (for sbr) and bitdepth (for pcm)
237 end_ebml_master(pb, subinfo);
241 av_log(s, AV_LOG_ERROR, "Only audio and video are supported for Matroska.");
244 end_ebml_master(pb, track);
246 // ms precision is the de-facto standard timescale for mkv files
247 av_set_pts_info(st, 64, 1, 1000);
249 end_ebml_master(pb, tracks);
253 static int mkv_write_header(AVFormatContext *s)
255 MatroskaMuxContext *mkv = s->priv_data;
256 ByteIOContext *pb = &s->pb;
257 offset_t ebml_header, segment_info;
259 ebml_header = start_ebml_master(pb, EBML_ID_HEADER);
260 put_ebml_uint (pb, EBML_ID_EBMLVERSION , 1);
261 put_ebml_uint (pb, EBML_ID_EBMLREADVERSION , 1);
262 put_ebml_uint (pb, EBML_ID_EBMLMAXIDLENGTH , 4);
263 put_ebml_uint (pb, EBML_ID_EBMLMAXSIZELENGTH , 8);
264 put_ebml_string (pb, EBML_ID_DOCTYPE , "matroska");
265 put_ebml_uint (pb, EBML_ID_DOCTYPEVERSION , 2);
266 put_ebml_uint (pb, EBML_ID_DOCTYPEREADVERSION , 2);
267 end_ebml_master(pb, ebml_header);
269 mkv->segment = start_ebml_master(pb, MATROSKA_ID_SEGMENT);
271 segment_info = start_ebml_master(pb, MATROSKA_ID_INFO);
272 put_ebml_uint(pb, MATROSKA_ID_TIMECODESCALE, 1000000);
273 if (strlen(s->title))
274 put_ebml_string(pb, MATROSKA_ID_TITLE, s->title);
275 if (!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT)) {
276 put_ebml_string(pb, MATROSKA_ID_MUXINGAPP, LIBAVFORMAT_IDENT);
277 // XXX: both are required; something better for writing app?
278 put_ebml_string(pb, MATROSKA_ID_WRITINGAPP, LIBAVFORMAT_IDENT);
281 // reserve space for the duration
283 mkv->duration_offset = url_ftell(pb);
284 put_ebml_void(pb, 11); // assumes double-precision float to be written
285 end_ebml_master(pb, segment_info);
287 if (mkv_write_tracks(s) < 0)
290 mkv->cluster = start_ebml_master(pb, MATROSKA_ID_CLUSTER);
291 put_ebml_uint(pb, MATROSKA_ID_CLUSTERTIMECODE, 0);
292 mkv->cluster_pts = 0;
297 static int mkv_write_packet(AVFormatContext *s, AVPacket *pkt)
299 MatroskaMuxContext *mkv = s->priv_data;
300 ByteIOContext *pb = &s->pb;
303 // start a new cluster every 5 MB or 5 sec
304 if (url_ftell(pb) > mkv->cluster + 5*1024*1024 || pkt->pts > mkv->cluster_pts + 5000) {
305 end_ebml_master(pb, mkv->cluster);
306 mkv->cluster = start_ebml_master(pb, MATROSKA_ID_CLUSTER);
307 put_ebml_uint(pb, MATROSKA_ID_CLUSTERTIMECODE, pkt->pts);
308 mkv->cluster_pts = pkt->pts;
311 block = start_ebml_master(pb, MATROSKA_ID_SIMPLEBLOCK);
312 put_byte(pb, 0x80 | (pkt->stream_index + 1)); // this assumes stream_index is less than 126
313 put_be16(pb, pkt->pts - mkv->cluster_pts);
314 put_byte(pb, !!(pkt->flags & PKT_FLAG_KEY));
315 put_buffer(pb, pkt->data, pkt->size);
316 end_ebml_master(pb, block);
318 mkv->duration = pkt->pts + pkt->duration;
322 static int mkv_write_trailer(AVFormatContext *s)
324 MatroskaMuxContext *mkv = s->priv_data;
325 ByteIOContext *pb = &s->pb;
328 end_ebml_master(pb, mkv->cluster);
330 // update the duration
331 currentpos = url_ftell(pb);
332 url_fseek(pb, mkv->duration_offset, SEEK_SET);
333 put_ebml_float(pb, MATROSKA_ID_DURATION, mkv->duration);
334 url_fseek(pb, currentpos, SEEK_SET);
336 end_ebml_master(pb, mkv->segment);
340 AVOutputFormat matroska_muxer = {
342 "Matroska File Format",
345 sizeof(MatroskaMuxContext),
351 .codec_tag = (const AVCodecTag*[]){codec_bmp_tags, codec_wav_tags, 0},