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
26 typedef struct MatroskaMuxContext {
31 static void put_ebml_id(ByteIOContext *pb, unsigned int id)
34 put_byte(pb, id >> 24);
36 put_byte(pb, id >> 16);
38 put_byte(pb, id >> 8);
42 // XXX: test this thoroughly and get rid of minbytes hack (currently needed to
43 // use up all of the space reserved in start_ebml_master)
44 static void put_ebml_size(ByteIOContext *pb, uint64_t size, int minbytes)
47 while (size >> (bytes*7 + 7)) bytes++;
49 // sizes larger than this are currently undefined in EBML
50 // XXX: error condition?
51 if (size > (1ULL<<56)-1) return;
53 put_byte(pb, (0x80 >> bytes) | (size >> bytes*8));
54 for (bytes -= 1; bytes >= 0; bytes--)
55 put_byte(pb, size >> bytes*8);
58 static void put_ebml_uint(ByteIOContext *pb, unsigned int elementid, uint64_t val)
61 while (val >> bytes*8) bytes++;
63 put_ebml_id(pb, elementid);
64 put_ebml_size(pb, bytes, 0);
65 for (bytes -= 1; bytes >= 0; bytes--)
66 put_byte(pb, val >> bytes*8);
69 //static void put_ebml_sint(ByteIOContext *pb, unsigned int elementid, int64_t val)
71 static void put_ebml_float(ByteIOContext *pb, unsigned int elementid, double val)
73 // XXX: single-precision floats?
74 put_ebml_id(pb, elementid);
75 put_ebml_size(pb, 8, 0);
76 put_be64(pb, av_dbl2int(val));
79 static void put_ebml_binary(ByteIOContext *pb, unsigned int elementid,
80 const uint8_t *buf, int size)
82 put_ebml_id(pb, elementid);
83 put_ebml_size(pb, size, 0);
84 put_buffer(pb, buf, size);
87 static void put_ebml_string(ByteIOContext *pb, unsigned int elementid, const char *str)
89 put_ebml_binary(pb, elementid, str, strlen(str));
92 static offset_t start_ebml_master(ByteIOContext *pb, unsigned int elementid)
94 put_ebml_id(pb, elementid);
95 // XXX: this always reserves the maximum needed space to store any size value
96 // we should be smarter (additional parameter for expected size?)
97 put_ebml_size(pb, (1ULL<<56)-1, 0); // largest unknown size
101 static void end_ebml_master(ByteIOContext *pb, offset_t start)
103 offset_t pos = url_ftell(pb);
105 url_fseek(pb, start - 8, SEEK_SET);
106 put_ebml_size(pb, pos - start, 7);
107 url_fseek(pb, pos, SEEK_SET);
111 static int mkv_write_header(AVFormatContext *s)
113 MatroskaMuxContext *mkv = s->priv_data;
114 ByteIOContext *pb = &s->pb;
115 offset_t ebml_header, segment_info, tracks;
118 ebml_header = start_ebml_master(pb, EBML_ID_HEADER);
119 put_ebml_uint (pb, EBML_ID_EBMLVERSION , 1);
120 put_ebml_uint (pb, EBML_ID_EBMLREADVERSION , 1);
121 put_ebml_uint (pb, EBML_ID_EBMLMAXIDLENGTH , 4);
122 put_ebml_uint (pb, EBML_ID_EBMLMAXSIZELENGTH , 8);
123 put_ebml_string (pb, EBML_ID_DOCTYPE , "matroska");
124 put_ebml_uint (pb, EBML_ID_DOCTYPEVERSION , 1);
125 put_ebml_uint (pb, EBML_ID_DOCTYPEREADVERSION , 1);
126 end_ebml_master(pb, ebml_header);
128 mkv->segment = start_ebml_master(pb, MATROSKA_ID_SEGMENT);
130 segment_info = start_ebml_master(pb, MATROSKA_ID_INFO);
131 put_ebml_uint(pb, MATROSKA_ID_TIMECODESCALE, 1000000);
132 if (strlen(s->title))
133 put_ebml_string(pb, MATROSKA_ID_TITLE, s->title);
134 if (!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT)) {
135 put_ebml_string(pb, MATROSKA_ID_MUXINGAPP, LIBAVFORMAT_IDENT);
136 // XXX: both are required; something better for writing app?
137 put_ebml_string(pb, MATROSKA_ID_WRITINGAPP, LIBAVFORMAT_IDENT);
139 // XXX: segment UID and duration
140 end_ebml_master(pb, segment_info);
142 tracks = start_ebml_master(pb, MATROSKA_ID_TRACKS);
143 for (i = 0; i < s->nb_streams; i++) {
144 AVStream *st = s->streams[i];
145 AVCodecContext *codec = st->codec;
146 offset_t subinfo, track;
149 track = start_ebml_master(pb, MATROSKA_ID_TRACKENTRY);
150 put_ebml_uint (pb, MATROSKA_ID_TRACKNUMBER , i);
151 // XXX: random number for UID? and can we use the same UID when copying
152 // from another MKV as the specs recommend?
153 put_ebml_uint (pb, MATROSKA_ID_TRACKUID , i);
154 put_ebml_uint (pb, MATROSKA_ID_TRACKFLAGLACING , 0); // no lacing (yet)
157 put_ebml_string(pb, MATROSKA_ID_TRACKLANGUAGE, st->language);
159 // look for a codec id string specific to mkv to use, if none are found, use AVI codes
160 for (j = 0; ff_mkv_codec_tags[j].id != CODEC_ID_NONE; j++) {
161 if (ff_mkv_codec_tags[j].id == codec->codec_id) {
162 put_ebml_string(pb, MATROSKA_ID_CODECID, ff_mkv_codec_tags[j].str);
168 // XXX: CodecPrivate for vorbis, theora, aac, native mpeg4, ...
170 put_ebml_binary(pb, MATROSKA_ID_CODECPRIVATE, codec->extradata, codec->extradata_size);
173 switch (codec->codec_type) {
174 case CODEC_TYPE_VIDEO:
175 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_VIDEO);
179 // if there is no mkv-specific codec id, use VFW mode
180 if (!codec->codec_tag)
181 codec->codec_tag = codec_get_tag(codec_bmp_tags, codec->codec_id);
183 put_ebml_string(pb, MATROSKA_ID_CODECID, MATROSKA_CODEC_ID_VIDEO_VFW_FOURCC);
184 // XXX: codec private isn't a master; is there a better way to re-use put_bmp_header?
185 bmp_header = start_ebml_master(pb, MATROSKA_ID_CODECPRIVATE);
186 put_bmp_header(pb, codec, codec_bmp_tags, 0);
187 end_ebml_master(pb, bmp_header);
189 subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKVIDEO);
190 // XXX: interlace flag?
191 put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELWIDTH , codec->width);
192 put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELHEIGHT, codec->height);
193 // XXX: display width/height
194 end_ebml_master(pb, subinfo);
197 case CODEC_TYPE_AUDIO:
198 put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_AUDIO);
201 subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKAUDIO);
202 put_ebml_uint (pb, MATROSKA_ID_AUDIOCHANNELS , codec->channels);
203 put_ebml_float (pb, MATROSKA_ID_AUDIOSAMPLINGFREQ, codec->sample_rate);
204 // XXX: output sample freq (for sbr) and bitdepth (for pcm)
205 end_ebml_master(pb, subinfo);
209 av_log(s, AV_LOG_ERROR, "Only audio and video are supported for Matroska.");
212 end_ebml_master(pb, track);
214 // ms precision is the de-facto standard timescale for mkv files
215 av_set_pts_info(st, 64, 1, 1000);
217 end_ebml_master(pb, tracks);
219 mkv->cluster = start_ebml_master(pb, MATROSKA_ID_CLUSTER);
220 put_ebml_uint(pb, MATROSKA_ID_CLUSTERTIMECODE, 0);
225 static int mkv_write_packet(AVFormatContext *s, AVPacket *pkt)
227 ByteIOContext *pb = &s->pb;
229 block = start_ebml_master(pb, MATROSKA_ID_SIMPLEBLOCK);
230 put_byte(pb, 0x80 | pkt->stream_index); // this assumes stream_index is less than 127
231 put_be16(pb, pkt->pts);
232 put_byte(pb, !!(pkt->flags & PKT_FLAG_KEY));
233 put_buffer(pb, pkt->data, pkt->size);
234 end_ebml_master(pb, block);
238 static int mkv_write_trailer(AVFormatContext *s)
240 MatroskaMuxContext *mkv = s->priv_data;
241 ByteIOContext *pb = &s->pb;
242 end_ebml_master(pb, mkv->cluster);
243 end_ebml_master(pb, mkv->segment);
247 AVOutputFormat matroska_muxer = {
249 "Matroska File Format",
252 sizeof(MatroskaMuxContext),
258 .codec_tag = (const AVCodecTag*[]){codec_bmp_tags, codec_wav_tags, 0},