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 {
33 static void put_ebml_id(ByteIOContext *pb, unsigned int id)
36 put_byte(pb, id >> 24);
38 put_byte(pb, id >> 16);
40 put_byte(pb, id >> 8);
44 // XXX: test this thoroughly and get rid of minbytes hack (currently needed to
45 // use up all of the space reserved in start_ebml_master)
46 static void put_ebml_size(ByteIOContext *pb, uint64_t size, int minbytes)
50 // sizes larger than this are currently undefined in EBML
51 // so write "unknown" size
52 size = FFMIN(size, (1ULL<<56)-1);
54 while (size >> (bytes*7 + 7)) bytes++;
56 put_byte(pb, (0x80 >> bytes) | (size >> bytes*8));
57 for (bytes -= 1; bytes >= 0; bytes--)
58 put_byte(pb, size >> bytes*8);
61 static void put_ebml_uint(ByteIOContext *pb, unsigned int elementid, uint64_t val)
64 while (val >> bytes*8) bytes++;
66 put_ebml_id(pb, elementid);
67 put_ebml_size(pb, bytes, 0);
68 for (bytes -= 1; bytes >= 0; bytes--)
69 put_byte(pb, val >> bytes*8);
72 static void put_ebml_float(ByteIOContext *pb, unsigned int elementid, double val)
74 // XXX: single-precision floats?
75 put_ebml_id(pb, elementid);
76 put_ebml_size(pb, 8, 0);
77 put_be64(pb, av_dbl2int(val));
80 static void put_ebml_binary(ByteIOContext *pb, unsigned int elementid,
81 const uint8_t *buf, int size)
83 put_ebml_id(pb, elementid);
84 put_ebml_size(pb, size, 0);
85 put_buffer(pb, buf, size);
88 static void put_ebml_string(ByteIOContext *pb, unsigned int elementid, const char *str)
90 put_ebml_binary(pb, elementid, str, strlen(str));
93 // this reserves exactly the amount of space specified by size, which must be at least 2
94 static void put_ebml_void(ByteIOContext *pb, uint64_t size)
96 offset_t currentpos = url_ftell(pb);
101 put_ebml_id(pb, EBML_ID_VOID);
102 // we need to subtract the length needed to store the size from the size we need to reserve
103 // so 2 cases, we use 8 bytes to store the size if possible, 1 byte otherwise
105 put_ebml_size(pb, size-1, 0);
107 put_ebml_size(pb, size-9, 7);
108 url_fseek(pb, currentpos + size, SEEK_SET);
111 static offset_t start_ebml_master(ByteIOContext *pb, unsigned int elementid)
113 put_ebml_id(pb, elementid);
114 // XXX: this always reserves the maximum needed space to store any size value
115 // we should be smarter (additional parameter for expected size?)
116 put_ebml_size(pb, (1ULL<<56)-1, 0); // largest unknown size
117 return url_ftell(pb);
120 static void end_ebml_master(ByteIOContext *pb, offset_t start)
122 offset_t pos = url_ftell(pb);
124 url_fseek(pb, start - 8, SEEK_SET);
125 put_ebml_size(pb, pos - start, 7);
126 url_fseek(pb, pos, SEEK_SET);
130 static int mkv_write_header(AVFormatContext *s)
132 MatroskaMuxContext *mkv = s->priv_data;
133 ByteIOContext *pb = &s->pb;
134 offset_t ebml_header, segment_info, tracks;
137 ebml_header = start_ebml_master(pb, EBML_ID_HEADER);
138 put_ebml_uint (pb, EBML_ID_EBMLVERSION , 1);
139 put_ebml_uint (pb, EBML_ID_EBMLREADVERSION , 1);
140 put_ebml_uint (pb, EBML_ID_EBMLMAXIDLENGTH , 4);
141 put_ebml_uint (pb, EBML_ID_EBMLMAXSIZELENGTH , 8);
142 put_ebml_string (pb, EBML_ID_DOCTYPE , "matroska");
143 put_ebml_uint (pb, EBML_ID_DOCTYPEVERSION , 2);
144 put_ebml_uint (pb, EBML_ID_DOCTYPEREADVERSION , 2);
145 end_ebml_master(pb, ebml_header);
147 mkv->segment = start_ebml_master(pb, MATROSKA_ID_SEGMENT);
149 segment_info = start_ebml_master(pb, MATROSKA_ID_INFO);
150 put_ebml_uint(pb, MATROSKA_ID_TIMECODESCALE, 1000000);
151 if (strlen(s->title))
152 put_ebml_string(pb, MATROSKA_ID_TITLE, s->title);
153 if (!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT)) {
154 put_ebml_string(pb, MATROSKA_ID_MUXINGAPP, LIBAVFORMAT_IDENT);
155 // XXX: both are required; something better for writing app?
156 put_ebml_string(pb, MATROSKA_ID_WRITINGAPP, LIBAVFORMAT_IDENT);
158 // XXX: segment UID and duration
159 end_ebml_master(pb, segment_info);
161 tracks = start_ebml_master(pb, MATROSKA_ID_TRACKS);
162 for (i = 0; i < s->nb_streams; i++) {
163 AVStream *st = s->streams[i];
164 AVCodecContext *codec = st->codec;
165 offset_t subinfo, track;
168 track = start_ebml_master(pb, MATROSKA_ID_TRACKENTRY);
169 put_ebml_uint (pb, MATROSKA_ID_TRACKNUMBER , i + 1);
170 put_ebml_uint (pb, MATROSKA_ID_TRACKUID , i + 1);
171 put_ebml_uint (pb, MATROSKA_ID_TRACKFLAGLACING , 0); // no lacing (yet)
174 put_ebml_string(pb, MATROSKA_ID_TRACKLANGUAGE, st->language);
176 // look for a codec id string specific to mkv to use, if none are found, use AVI codes
177 for (j = 0; ff_mkv_codec_tags[j].id != CODEC_ID_NONE; j++) {
178 if (ff_mkv_codec_tags[j].id == codec->codec_id) {
179 put_ebml_string(pb, MATROSKA_ID_CODECID, ff_mkv_codec_tags[j].str);
185 // XXX: CodecPrivate for vorbis, theora, aac, native mpeg4, ...
187 offset_t codecprivate;
189 if (codec->codec_id == CODEC_ID_VORBIS || codec->codec_id == CODEC_ID_THEORA) {
190 uint8_t *header_start[3];
192 int first_header_size;
194 if (codec->codec_id == CODEC_ID_VORBIS)
195 first_header_size = 30;
197 first_header_size = 42;
199 if (ff_split_xiph_headers(codec->extradata, codec->extradata_size,
200 first_header_size, header_start, header_len) < 0) {
201 av_log(s, AV_LOG_ERROR, "Extradata corrupt.\n");
205 codecprivate = start_ebml_master(pb, MATROSKA_ID_CODECPRIVATE);
206 put_byte(pb, 2); // number packets - 1
207 for (j = 0; j < 2; j++) {
208 for (k = 0; k < header_len[j] / 255; k++)
210 put_byte(pb, header_len[j] % 255);
212 for (j = 0; j < 3; j++)
213 put_buffer(pb, header_start[j], header_len[j]);
214 end_ebml_master(pb, codecprivate);
216 put_ebml_binary(pb, MATROSKA_ID_CODECPRIVATE, codec->extradata, codec->extradata_size);
220 switch (codec->codec_type) {
221 case CODEC_TYPE_VIDEO:
222 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_VIDEO);
226 // if there is no mkv-specific codec id, use VFW mode
227 if (!codec->codec_tag)
228 codec->codec_tag = codec_get_tag(codec_bmp_tags, codec->codec_id);
230 put_ebml_string(pb, MATROSKA_ID_CODECID, MATROSKA_CODEC_ID_VIDEO_VFW_FOURCC);
231 // XXX: codec private isn't a master; is there a better way to re-use put_bmp_header?
232 bmp_header = start_ebml_master(pb, MATROSKA_ID_CODECPRIVATE);
233 put_bmp_header(pb, codec, codec_bmp_tags, 0);
234 end_ebml_master(pb, bmp_header);
236 subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKVIDEO);
237 // XXX: interlace flag?
238 put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELWIDTH , codec->width);
239 put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELHEIGHT, codec->height);
240 // XXX: display width/height
241 end_ebml_master(pb, subinfo);
244 case CODEC_TYPE_AUDIO:
245 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_AUDIO);
248 subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKAUDIO);
249 put_ebml_uint (pb, MATROSKA_ID_AUDIOCHANNELS , codec->channels);
250 put_ebml_float (pb, MATROSKA_ID_AUDIOSAMPLINGFREQ, codec->sample_rate);
251 // XXX: output sample freq (for sbr) and bitdepth (for pcm)
252 end_ebml_master(pb, subinfo);
256 av_log(s, AV_LOG_ERROR, "Only audio and video are supported for Matroska.");
259 end_ebml_master(pb, track);
261 // ms precision is the de-facto standard timescale for mkv files
262 av_set_pts_info(st, 64, 1, 1000);
264 end_ebml_master(pb, tracks);
266 mkv->cluster = start_ebml_master(pb, MATROSKA_ID_CLUSTER);
267 put_ebml_uint(pb, MATROSKA_ID_CLUSTERTIMECODE, 0);
268 mkv->cluster_pts = 0;
273 static int mkv_write_packet(AVFormatContext *s, AVPacket *pkt)
275 MatroskaMuxContext *mkv = s->priv_data;
276 ByteIOContext *pb = &s->pb;
279 // start a new cluster every 5 MB or 5 sec
280 if (url_ftell(pb) > mkv->cluster + 5*1024*1024 || pkt->pts > mkv->cluster_pts + 5000) {
281 end_ebml_master(pb, mkv->cluster);
282 mkv->cluster = start_ebml_master(pb, MATROSKA_ID_CLUSTER);
283 put_ebml_uint(pb, MATROSKA_ID_CLUSTERTIMECODE, pkt->pts);
284 mkv->cluster_pts = pkt->pts;
287 block = start_ebml_master(pb, MATROSKA_ID_SIMPLEBLOCK);
288 put_byte(pb, 0x80 | (pkt->stream_index + 1)); // this assumes stream_index is less than 126
289 put_be16(pb, pkt->pts - mkv->cluster_pts);
290 put_byte(pb, !!(pkt->flags & PKT_FLAG_KEY));
291 put_buffer(pb, pkt->data, pkt->size);
292 end_ebml_master(pb, block);
296 static int mkv_write_trailer(AVFormatContext *s)
298 MatroskaMuxContext *mkv = s->priv_data;
299 ByteIOContext *pb = &s->pb;
300 end_ebml_master(pb, mkv->cluster);
301 end_ebml_master(pb, mkv->segment);
305 AVOutputFormat matroska_muxer = {
307 "Matroska File Format",
310 sizeof(MatroskaMuxContext),
316 .codec_tag = (const AVCodecTag*[]){codec_bmp_tags, codec_wav_tags, 0},