/* * Matroska file muxer * Copyright (c) 2007 David Conrad * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include "avformat.h" #include "riff.h" #include "xiph.h" #include "matroska.h" typedef struct MatroskaMuxContext { offset_t segment; offset_t cluster; uint64_t cluster_pts; } MatroskaMuxContext; static void put_ebml_id(ByteIOContext *pb, unsigned int id) { if (id >= 0x3fffff) put_byte(pb, id >> 24); if (id >= 0x7fff) put_byte(pb, id >> 16); if (id >= 0xff) put_byte(pb, id >> 8); put_byte(pb, id); } // XXX: test this thoroughly and get rid of minbytes hack (currently needed to // use up all of the space reserved in start_ebml_master) static void put_ebml_size(ByteIOContext *pb, uint64_t size, int minbytes) { int bytes = minbytes; // sizes larger than this are currently undefined in EBML // so write "unknown" size size = FFMIN(size, (1ULL<<56)-1); while (size >> (bytes*7 + 7)) bytes++; put_byte(pb, (0x80 >> bytes) | (size >> bytes*8)); for (bytes -= 1; bytes >= 0; bytes--) put_byte(pb, size >> bytes*8); } static void put_ebml_uint(ByteIOContext *pb, unsigned int elementid, uint64_t val) { int bytes = 1; while (val >> bytes*8) bytes++; put_ebml_id(pb, elementid); put_ebml_size(pb, bytes, 0); for (bytes -= 1; bytes >= 0; bytes--) put_byte(pb, val >> bytes*8); } static void put_ebml_float(ByteIOContext *pb, unsigned int elementid, double val) { // XXX: single-precision floats? put_ebml_id(pb, elementid); put_ebml_size(pb, 8, 0); put_be64(pb, av_dbl2int(val)); } static void put_ebml_binary(ByteIOContext *pb, unsigned int elementid, const uint8_t *buf, int size) { put_ebml_id(pb, elementid); put_ebml_size(pb, size, 0); put_buffer(pb, buf, size); } static void put_ebml_string(ByteIOContext *pb, unsigned int elementid, const char *str) { put_ebml_binary(pb, elementid, str, strlen(str)); } // this reserves exactly the amount of space specified by size, which must be at least 2 static void put_ebml_void(ByteIOContext *pb, uint64_t size) { offset_t currentpos = url_ftell(pb); if (size < 2) return; put_ebml_id(pb, EBML_ID_VOID); // we need to subtract the length needed to store the size from the size we need to reserve // so 2 cases, we use 8 bytes to store the size if possible, 1 byte otherwise if (size < 10) put_ebml_size(pb, size-1, 0); else put_ebml_size(pb, size-9, 7); url_fseek(pb, currentpos + size, SEEK_SET); } static offset_t start_ebml_master(ByteIOContext *pb, unsigned int elementid) { put_ebml_id(pb, elementid); // XXX: this always reserves the maximum needed space to store any size value // we should be smarter (additional parameter for expected size?) put_ebml_size(pb, (1ULL<<56)-1, 0); // largest unknown size return url_ftell(pb); } static void end_ebml_master(ByteIOContext *pb, offset_t start) { offset_t pos = url_ftell(pb); url_fseek(pb, start - 8, SEEK_SET); put_ebml_size(pb, pos - start, 7); url_fseek(pb, pos, SEEK_SET); } static int mkv_write_header(AVFormatContext *s) { MatroskaMuxContext *mkv = s->priv_data; ByteIOContext *pb = &s->pb; offset_t ebml_header, segment_info, tracks; int i, j, k; ebml_header = start_ebml_master(pb, EBML_ID_HEADER); put_ebml_uint (pb, EBML_ID_EBMLVERSION , 1); put_ebml_uint (pb, EBML_ID_EBMLREADVERSION , 1); put_ebml_uint (pb, EBML_ID_EBMLMAXIDLENGTH , 4); put_ebml_uint (pb, EBML_ID_EBMLMAXSIZELENGTH , 8); put_ebml_string (pb, EBML_ID_DOCTYPE , "matroska"); put_ebml_uint (pb, EBML_ID_DOCTYPEVERSION , 2); put_ebml_uint (pb, EBML_ID_DOCTYPEREADVERSION , 2); end_ebml_master(pb, ebml_header); mkv->segment = start_ebml_master(pb, MATROSKA_ID_SEGMENT); segment_info = start_ebml_master(pb, MATROSKA_ID_INFO); put_ebml_uint(pb, MATROSKA_ID_TIMECODESCALE, 1000000); if (strlen(s->title)) put_ebml_string(pb, MATROSKA_ID_TITLE, s->title); if (!(s->streams[0]->codec->flags & CODEC_FLAG_BITEXACT)) { put_ebml_string(pb, MATROSKA_ID_MUXINGAPP, LIBAVFORMAT_IDENT); // XXX: both are required; something better for writing app? put_ebml_string(pb, MATROSKA_ID_WRITINGAPP, LIBAVFORMAT_IDENT); } // XXX: segment UID and duration end_ebml_master(pb, segment_info); tracks = start_ebml_master(pb, MATROSKA_ID_TRACKS); for (i = 0; i < s->nb_streams; i++) { AVStream *st = s->streams[i]; AVCodecContext *codec = st->codec; offset_t subinfo, track; int native_id = 0; track = start_ebml_master(pb, MATROSKA_ID_TRACKENTRY); put_ebml_uint (pb, MATROSKA_ID_TRACKNUMBER , i + 1); put_ebml_uint (pb, MATROSKA_ID_TRACKUID , i + 1); put_ebml_uint (pb, MATROSKA_ID_TRACKFLAGLACING , 0); // no lacing (yet) if (st->language[0]) put_ebml_string(pb, MATROSKA_ID_TRACKLANGUAGE, st->language); // look for a codec id string specific to mkv to use, if none are found, use AVI codes for (j = 0; ff_mkv_codec_tags[j].id != CODEC_ID_NONE; j++) { if (ff_mkv_codec_tags[j].id == codec->codec_id) { put_ebml_string(pb, MATROSKA_ID_CODECID, ff_mkv_codec_tags[j].str); native_id = 1; break; } } // XXX: CodecPrivate for vorbis, theora, aac, native mpeg4, ... if (native_id) { offset_t codecprivate; if (codec->codec_id == CODEC_ID_VORBIS || codec->codec_id == CODEC_ID_THEORA) { uint8_t *header_start[3]; int header_len[3]; int first_header_size; if (codec->codec_id == CODEC_ID_VORBIS) first_header_size = 30; else first_header_size = 42; if (ff_split_xiph_headers(codec->extradata, codec->extradata_size, first_header_size, header_start, header_len) < 0) { av_log(s, AV_LOG_ERROR, "Extradata corrupt.\n"); return -1; } codecprivate = start_ebml_master(pb, MATROSKA_ID_CODECPRIVATE); put_byte(pb, 2); // number packets - 1 for (j = 0; j < 2; j++) { for (k = 0; k < header_len[j] / 255; k++) put_byte(pb, 255); put_byte(pb, header_len[j] % 255); } for (j = 0; j < 3; j++) put_buffer(pb, header_start[j], header_len[j]); end_ebml_master(pb, codecprivate); } else { put_ebml_binary(pb, MATROSKA_ID_CODECPRIVATE, codec->extradata, codec->extradata_size); } } switch (codec->codec_type) { case CODEC_TYPE_VIDEO: put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_VIDEO); if (!native_id) { offset_t bmp_header; // if there is no mkv-specific codec id, use VFW mode if (!codec->codec_tag) codec->codec_tag = codec_get_tag(codec_bmp_tags, codec->codec_id); put_ebml_string(pb, MATROSKA_ID_CODECID, MATROSKA_CODEC_ID_VIDEO_VFW_FOURCC); // XXX: codec private isn't a master; is there a better way to re-use put_bmp_header? bmp_header = start_ebml_master(pb, MATROSKA_ID_CODECPRIVATE); put_bmp_header(pb, codec, codec_bmp_tags, 0); end_ebml_master(pb, bmp_header); } subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKVIDEO); // XXX: interlace flag? put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELWIDTH , codec->width); put_ebml_uint (pb, MATROSKA_ID_VIDEOPIXELHEIGHT, codec->height); // XXX: display width/height end_ebml_master(pb, subinfo); break; case CODEC_TYPE_AUDIO: put_ebml_uint(pb, MATROSKA_ID_TRACKTYPE, MATROSKA_TRACK_TYPE_AUDIO); // XXX: A_MS/ACM subinfo = start_ebml_master(pb, MATROSKA_ID_TRACKAUDIO); put_ebml_uint (pb, MATROSKA_ID_AUDIOCHANNELS , codec->channels); put_ebml_float (pb, MATROSKA_ID_AUDIOSAMPLINGFREQ, codec->sample_rate); // XXX: output sample freq (for sbr) and bitdepth (for pcm) end_ebml_master(pb, subinfo); break; default: av_log(s, AV_LOG_ERROR, "Only audio and video are supported for Matroska."); break; } end_ebml_master(pb, track); // ms precision is the de-facto standard timescale for mkv files av_set_pts_info(st, 64, 1, 1000); } end_ebml_master(pb, tracks); mkv->cluster = start_ebml_master(pb, MATROSKA_ID_CLUSTER); put_ebml_uint(pb, MATROSKA_ID_CLUSTERTIMECODE, 0); mkv->cluster_pts = 0; return 0; } static int mkv_write_packet(AVFormatContext *s, AVPacket *pkt) { MatroskaMuxContext *mkv = s->priv_data; ByteIOContext *pb = &s->pb; offset_t block; // start a new cluster every 5 MB or 5 sec if (url_ftell(pb) > mkv->cluster + 5*1024*1024 || pkt->pts > mkv->cluster_pts + 5000) { end_ebml_master(pb, mkv->cluster); mkv->cluster = start_ebml_master(pb, MATROSKA_ID_CLUSTER); put_ebml_uint(pb, MATROSKA_ID_CLUSTERTIMECODE, pkt->pts); mkv->cluster_pts = pkt->pts; } block = start_ebml_master(pb, MATROSKA_ID_SIMPLEBLOCK); put_byte(pb, 0x80 | (pkt->stream_index + 1)); // this assumes stream_index is less than 126 put_be16(pb, pkt->pts - mkv->cluster_pts); put_byte(pb, !!(pkt->flags & PKT_FLAG_KEY)); put_buffer(pb, pkt->data, pkt->size); end_ebml_master(pb, block); return 0; } static int mkv_write_trailer(AVFormatContext *s) { MatroskaMuxContext *mkv = s->priv_data; ByteIOContext *pb = &s->pb; end_ebml_master(pb, mkv->cluster); end_ebml_master(pb, mkv->segment); return 0; } AVOutputFormat matroska_muxer = { "matroska", "Matroska File Format", "video/x-matroska", "mkv", sizeof(MatroskaMuxContext), CODEC_ID_MP2, CODEC_ID_MPEG4, mkv_write_header, mkv_write_packet, mkv_write_trailer, .codec_tag = (const AVCodecTag*[]){codec_bmp_tags, codec_wav_tags, 0}, };