/* * MPEG1/2 demuxer * Copyright (c) 2000, 2001, 2002 Fabrice Bellard * * This file is part of Libav. * * Libav 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. * * Libav 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 Libav; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include "avformat.h" #include "internal.h" #include "mpeg.h" #undef NDEBUG #include <assert.h> /*********************************************/ /* demux code */ #define MAX_SYNC_SIZE 100000 static int check_pes(uint8_t *p, uint8_t *end){ int pes1; int pes2= (p[3] & 0xC0) == 0x80 && (p[4] & 0xC0) != 0x40 &&((p[4] & 0xC0) == 0x00 || (p[4]&0xC0)>>2 == (p[6]&0xF0)); for(p+=3; p<end && *p == 0xFF; p++); if((*p&0xC0) == 0x40) p+=2; if((*p&0xF0) == 0x20){ pes1= p[0]&p[2]&p[4]&1; }else if((*p&0xF0) == 0x30){ pes1= p[0]&p[2]&p[4]&p[5]&p[7]&p[9]&1; }else pes1 = *p == 0x0F; return pes1||pes2; } static int check_pack_header(const uint8_t *buf) { return (buf[1] & 0xC0) == 0x40 || (buf[1] & 0xF0) == 0x20; } static int mpegps_probe(AVProbeData *p) { uint32_t code= -1; int sys=0, pspack=0, priv1=0, vid=0, audio=0, invalid=0; int i; int score=0; for(i=0; i<p->buf_size; i++){ code = (code<<8) + p->buf[i]; if ((code & 0xffffff00) == 0x100) { int len= p->buf[i+1] << 8 | p->buf[i+2]; int pes= check_pes(p->buf+i, p->buf+p->buf_size); int pack = check_pack_header(p->buf+i); if(code == SYSTEM_HEADER_START_CODE) sys++; else if(code == PACK_START_CODE && pack) pspack++; else if((code & 0xf0) == VIDEO_ID && pes) vid++; // skip pes payload to avoid start code emulation for private // and audio streams else if((code & 0xe0) == AUDIO_ID && pes) {audio++; i+=len;} else if(code == PRIVATE_STREAM_1 && pes) {priv1++; i+=len;} else if((code & 0xf0) == VIDEO_ID && !pes) invalid++; else if((code & 0xe0) == AUDIO_ID && !pes) invalid++; else if(code == PRIVATE_STREAM_1 && !pes) invalid++; } } if(vid+audio > invalid) /* invalid VDR files nd short PES streams */ score= AVPROBE_SCORE_MAX/4; //av_log(NULL, AV_LOG_ERROR, "%d %d %d %d %d %d len:%d\n", sys, priv1, pspack,vid, audio, invalid, p->buf_size); if(sys>invalid && sys*9 <= pspack*10) return pspack > 2 ? AVPROBE_SCORE_MAX/2+2 : AVPROBE_SCORE_MAX/4; // +1 for .mpg if(pspack > invalid && (priv1+vid+audio)*10 >= pspack*9) return pspack > 2 ? AVPROBE_SCORE_MAX/2+2 : AVPROBE_SCORE_MAX/4; // +1 for .mpg if((!!vid ^ !!audio) && (audio > 4 || vid > 1) && !sys && !pspack && p->buf_size>2048 && vid + audio > invalid) /* PES stream */ return (audio > 12 || vid > 3) ? AVPROBE_SCORE_MAX/2+2 : AVPROBE_SCORE_MAX/4; //02-Penguin.flac has sys:0 priv1:0 pspack:0 vid:0 audio:1 //mp3_misidentified_2.mp3 has sys:0 priv1:0 pspack:0 vid:0 audio:6 return score; } typedef struct MpegDemuxContext { int32_t header_state; unsigned char psm_es_type[256]; int sofdec; } MpegDemuxContext; static int mpegps_read_header(AVFormatContext *s) { MpegDemuxContext *m = s->priv_data; const char *sofdec = "Sofdec"; int v, i = 0; m->header_state = 0xff; s->ctx_flags |= AVFMTCTX_NOHEADER; m->sofdec = -1; do { v = avio_r8(s->pb); m->header_state = m->header_state << 8 | v; m->sofdec++; } while (v == sofdec[i] && i++ < 6); m->sofdec = (m->sofdec == 6) ? 1 : 0; /* no need to do more */ return 0; } static int64_t get_pts(AVIOContext *pb, int c) { uint8_t buf[5]; buf[0] = c<0 ? avio_r8(pb) : c; avio_read(pb, buf+1, 4); return ff_parse_pes_pts(buf); } static int find_next_start_code(AVIOContext *pb, int *size_ptr, int32_t *header_state) { unsigned int state, v; int val, n; state = *header_state; n = *size_ptr; while (n > 0) { if (pb->eof_reached) break; v = avio_r8(pb); n--; if (state == 0x000001) { state = ((state << 8) | v) & 0xffffff; val = state; goto found; } state = ((state << 8) | v) & 0xffffff; } val = -1; found: *header_state = state; *size_ptr = n; return val; } #if 0 /* unused, remove? */ /* XXX: optimize */ static int find_prev_start_code(AVIOContext *pb, int *size_ptr) { int64_t pos, pos_start; int max_size, start_code; max_size = *size_ptr; pos_start = avio_tell(pb); /* in order to go faster, we fill the buffer */ pos = pos_start - 16386; if (pos < 0) pos = 0; avio_seek(pb, pos, SEEK_SET); avio_r8(pb); pos = pos_start; for(;;) { pos--; if (pos < 0 || (pos_start - pos) >= max_size) { start_code = -1; goto the_end; } avio_seek(pb, pos, SEEK_SET); start_code = avio_rb32(pb); if ((start_code & 0xffffff00) == 0x100) break; } the_end: *size_ptr = pos_start - pos; return start_code; } #endif /** * Extract stream types from a program stream map * According to ISO/IEC 13818-1 ('MPEG-2 Systems') table 2-35 * * @return number of bytes occupied by PSM in the bitstream */ static long mpegps_psm_parse(MpegDemuxContext *m, AVIOContext *pb) { int psm_length, ps_info_length, es_map_length; psm_length = avio_rb16(pb); avio_r8(pb); avio_r8(pb); ps_info_length = avio_rb16(pb); /* skip program_stream_info */ avio_skip(pb, ps_info_length); es_map_length = avio_rb16(pb); /* at least one es available? */ while (es_map_length >= 4){ unsigned char type = avio_r8(pb); unsigned char es_id = avio_r8(pb); uint16_t es_info_length = avio_rb16(pb); /* remember mapping from stream id to stream type */ m->psm_es_type[es_id] = type; /* skip program_stream_info */ avio_skip(pb, es_info_length); es_map_length -= 4 + es_info_length; } avio_rb32(pb); /* crc32 */ return 2 + psm_length; } /* read the next PES header. Return its position in ppos (if not NULL), and its start code, pts and dts. */ static int mpegps_read_pes_header(AVFormatContext *s, int64_t *ppos, int *pstart_code, int64_t *ppts, int64_t *pdts) { MpegDemuxContext *m = s->priv_data; int len, size, startcode, c, flags, header_len; int pes_ext, ext2_len, id_ext, skip; int64_t pts, dts; int64_t last_sync= avio_tell(s->pb); error_redo: avio_seek(s->pb, last_sync, SEEK_SET); redo: /* next start code (should be immediately after) */ m->header_state = 0xff; size = MAX_SYNC_SIZE; startcode = find_next_start_code(s->pb, &size, &m->header_state); last_sync = avio_tell(s->pb); //printf("startcode=%x pos=0x%"PRIx64"\n", startcode, avio_tell(s->pb)); if (startcode < 0){ if(s->pb->eof_reached) return AVERROR_EOF; //FIXME we should remember header_state return AVERROR(EAGAIN); } if (startcode == PACK_START_CODE) goto redo; if (startcode == SYSTEM_HEADER_START_CODE) goto redo; if (startcode == PADDING_STREAM) { avio_skip(s->pb, avio_rb16(s->pb)); goto redo; } if (startcode == PRIVATE_STREAM_2) { len = avio_rb16(s->pb); if (!m->sofdec) { while (len-- >= 6) { if (avio_r8(s->pb) == 'S') { uint8_t buf[5]; avio_read(s->pb, buf, sizeof(buf)); m->sofdec = !memcmp(buf, "ofdec", 5); len -= sizeof(buf); break; } } m->sofdec -= !m->sofdec; } avio_skip(s->pb, len); goto redo; } if (startcode == PROGRAM_STREAM_MAP) { mpegps_psm_parse(m, s->pb); goto redo; } /* find matching stream */ if (!((startcode >= 0x1c0 && startcode <= 0x1df) || (startcode >= 0x1e0 && startcode <= 0x1ef) || (startcode == 0x1bd) || (startcode == 0x1fd))) goto redo; if (ppos) { *ppos = avio_tell(s->pb) - 4; } len = avio_rb16(s->pb); pts = dts = AV_NOPTS_VALUE; /* stuffing */ for(;;) { if (len < 1) goto error_redo; c = avio_r8(s->pb); len--; /* XXX: for mpeg1, should test only bit 7 */ if (c != 0xff) break; } if ((c & 0xc0) == 0x40) { /* buffer scale & size */ avio_r8(s->pb); c = avio_r8(s->pb); len -= 2; } if ((c & 0xe0) == 0x20) { dts = pts = get_pts(s->pb, c); len -= 4; if (c & 0x10){ dts = get_pts(s->pb, -1); len -= 5; } } else if ((c & 0xc0) == 0x80) { /* mpeg 2 PES */ #if 0 /* some streams have this field set for no apparent reason */ if ((c & 0x30) != 0) { /* Encrypted multiplex not handled */ goto redo; } #endif flags = avio_r8(s->pb); header_len = avio_r8(s->pb); len -= 2; if (header_len > len) goto error_redo; len -= header_len; if (flags & 0x80) { dts = pts = get_pts(s->pb, -1); header_len -= 5; if (flags & 0x40) { dts = get_pts(s->pb, -1); header_len -= 5; } } if (flags & 0x3f && header_len == 0){ flags &= 0xC0; av_log(s, AV_LOG_WARNING, "Further flags set but no bytes left\n"); } if (flags & 0x01) { /* PES extension */ pes_ext = avio_r8(s->pb); header_len--; /* Skip PES private data, program packet sequence counter and P-STD buffer */ skip = (pes_ext >> 4) & 0xb; skip += skip & 0x9; if (pes_ext & 0x40 || skip > header_len){ av_log(s, AV_LOG_WARNING, "pes_ext %X is invalid\n", pes_ext); pes_ext=skip=0; } avio_skip(s->pb, skip); header_len -= skip; if (pes_ext & 0x01) { /* PES extension 2 */ ext2_len = avio_r8(s->pb); header_len--; if ((ext2_len & 0x7f) > 0) { id_ext = avio_r8(s->pb); if ((id_ext & 0x80) == 0) startcode = ((startcode & 0xff) << 8) | id_ext; header_len--; } } } if(header_len < 0) goto error_redo; avio_skip(s->pb, header_len); } else if( c!= 0xf ) goto redo; if (startcode == PRIVATE_STREAM_1 && !m->psm_es_type[startcode & 0xff]) { startcode = avio_r8(s->pb); len--; if (startcode >= 0x80 && startcode <= 0xcf) { /* audio: skip header */ avio_r8(s->pb); avio_r8(s->pb); avio_r8(s->pb); len -= 3; if (startcode >= 0xb0 && startcode <= 0xbf) { /* MLP/TrueHD audio has a 4-byte header */ avio_r8(s->pb); len--; } } } if(len<0) goto error_redo; if(dts != AV_NOPTS_VALUE && ppos){ int i; for(i=0; i<s->nb_streams; i++){ if(startcode == s->streams[i]->id && s->pb->seekable /* index useless on streams anyway */) { ff_reduce_index(s, i); av_add_index_entry(s->streams[i], *ppos, dts, 0, 0, AVINDEX_KEYFRAME /* FIXME keyframe? */); } } } *pstart_code = startcode; *ppts = pts; *pdts = dts; return len; } static int mpegps_read_packet(AVFormatContext *s, AVPacket *pkt) { MpegDemuxContext *m = s->priv_data; AVStream *st; int len, startcode, i, es_type, ret; enum CodecID codec_id = CODEC_ID_NONE; enum AVMediaType type; int64_t pts, dts, dummy_pos; //dummy_pos is needed for the index building to work uint8_t av_uninit(dvdaudio_substream_type); redo: len = mpegps_read_pes_header(s, &dummy_pos, &startcode, &pts, &dts); if (len < 0) return len; if(startcode == 0x1bd) { dvdaudio_substream_type = avio_r8(s->pb); avio_skip(s->pb, 3); len -= 4; } /* now find stream */ for(i=0;i<s->nb_streams;i++) { st = s->streams[i]; if (st->id == startcode) goto found; } es_type = m->psm_es_type[startcode & 0xff]; if(es_type > 0 && es_type != STREAM_TYPE_PRIVATE_DATA){ if(es_type == STREAM_TYPE_VIDEO_MPEG1){ codec_id = CODEC_ID_MPEG2VIDEO; type = AVMEDIA_TYPE_VIDEO; } else if(es_type == STREAM_TYPE_VIDEO_MPEG2){ codec_id = CODEC_ID_MPEG2VIDEO; type = AVMEDIA_TYPE_VIDEO; } else if(es_type == STREAM_TYPE_AUDIO_MPEG1 || es_type == STREAM_TYPE_AUDIO_MPEG2){ codec_id = CODEC_ID_MP3; type = AVMEDIA_TYPE_AUDIO; } else if(es_type == STREAM_TYPE_AUDIO_AAC){ codec_id = CODEC_ID_AAC; type = AVMEDIA_TYPE_AUDIO; } else if(es_type == STREAM_TYPE_VIDEO_MPEG4){ codec_id = CODEC_ID_MPEG4; type = AVMEDIA_TYPE_VIDEO; } else if(es_type == STREAM_TYPE_VIDEO_H264){ codec_id = CODEC_ID_H264; type = AVMEDIA_TYPE_VIDEO; } else if(es_type == STREAM_TYPE_AUDIO_AC3){ codec_id = CODEC_ID_AC3; type = AVMEDIA_TYPE_AUDIO; } else { goto skip; } } else if (startcode >= 0x1e0 && startcode <= 0x1ef) { static const unsigned char avs_seqh[4] = { 0, 0, 1, 0xb0 }; unsigned char buf[8]; avio_read(s->pb, buf, 8); avio_seek(s->pb, -8, SEEK_CUR); if(!memcmp(buf, avs_seqh, 4) && (buf[6] != 0 || buf[7] != 1)) codec_id = CODEC_ID_CAVS; else codec_id = CODEC_ID_PROBE; type = AVMEDIA_TYPE_VIDEO; } else if (startcode >= 0x1c0 && startcode <= 0x1df) { type = AVMEDIA_TYPE_AUDIO; codec_id = m->sofdec > 0 ? CODEC_ID_ADPCM_ADX : CODEC_ID_MP2; } else if (startcode >= 0x80 && startcode <= 0x87) { type = AVMEDIA_TYPE_AUDIO; codec_id = CODEC_ID_AC3; } else if ( ( startcode >= 0x88 && startcode <= 0x8f) ||( startcode >= 0x98 && startcode <= 0x9f)) { /* 0x90 - 0x97 is reserved for SDDS in DVD specs */ type = AVMEDIA_TYPE_AUDIO; codec_id = CODEC_ID_DTS; } else if (startcode >= 0xa0 && startcode <= 0xaf) { type = AVMEDIA_TYPE_AUDIO; /* 16 bit form will be handled as CODEC_ID_PCM_S16BE */ codec_id = CODEC_ID_PCM_DVD; } else if (startcode >= 0xb0 && startcode <= 0xbf) { type = AVMEDIA_TYPE_AUDIO; codec_id = CODEC_ID_TRUEHD; } else if (startcode >= 0xc0 && startcode <= 0xcf) { /* Used for both AC-3 and E-AC-3 in EVOB files */ type = AVMEDIA_TYPE_AUDIO; codec_id = CODEC_ID_AC3; } else if (startcode >= 0x20 && startcode <= 0x3f) { type = AVMEDIA_TYPE_SUBTITLE; codec_id = CODEC_ID_DVD_SUBTITLE; } else if (startcode >= 0xfd55 && startcode <= 0xfd5f) { type = AVMEDIA_TYPE_VIDEO; codec_id = CODEC_ID_VC1; } else if (startcode == 0x1bd) { // check dvd audio substream type type = AVMEDIA_TYPE_AUDIO; switch(dvdaudio_substream_type & 0xe0) { case 0xa0: codec_id = CODEC_ID_PCM_DVD; break; case 0x80: if((dvdaudio_substream_type & 0xf8) == 0x88) codec_id = CODEC_ID_DTS; else codec_id = CODEC_ID_AC3; break; default: av_log(s, AV_LOG_ERROR, "Unknown 0x1bd sub-stream\n"); goto skip; } } else { skip: /* skip packet */ avio_skip(s->pb, len); goto redo; } /* no stream found: add a new stream */ st = avformat_new_stream(s, NULL); if (!st) goto skip; st->id = startcode; st->codec->codec_type = type; st->codec->codec_id = codec_id; if (codec_id != CODEC_ID_PCM_S16BE) st->need_parsing = AVSTREAM_PARSE_FULL; found: if(st->discard >= AVDISCARD_ALL) goto skip; if ((startcode >= 0xa0 && startcode <= 0xaf) || (startcode == 0x1bd && ((dvdaudio_substream_type & 0xe0) == 0xa0))) { int b1, freq; /* for LPCM, we just skip the header and consider it is raw audio data */ if (len <= 3) goto skip; avio_r8(s->pb); /* emphasis (1), muse(1), reserved(1), frame number(5) */ b1 = avio_r8(s->pb); /* quant (2), freq(2), reserved(1), channels(3) */ avio_r8(s->pb); /* dynamic range control (0x80 = off) */ len -= 3; freq = (b1 >> 4) & 3; st->codec->sample_rate = lpcm_freq_tab[freq]; st->codec->channels = 1 + (b1 & 7); st->codec->bits_per_coded_sample = 16 + ((b1 >> 6) & 3) * 4; st->codec->bit_rate = st->codec->channels * st->codec->sample_rate * st->codec->bits_per_coded_sample; if (st->codec->bits_per_coded_sample == 16) st->codec->codec_id = CODEC_ID_PCM_S16BE; else if (st->codec->bits_per_coded_sample == 28) return AVERROR(EINVAL); } ret = av_get_packet(s->pb, pkt, len); pkt->pts = pts; pkt->dts = dts; pkt->pos = dummy_pos; pkt->stream_index = st->index; av_dlog(s, "%d: pts=%0.3f dts=%0.3f size=%d\n", pkt->stream_index, pkt->pts / 90000.0, pkt->dts / 90000.0, pkt->size); return (ret < 0) ? ret : 0; } static int64_t mpegps_read_dts(AVFormatContext *s, int stream_index, int64_t *ppos, int64_t pos_limit) { int len, startcode; int64_t pos, pts, dts; pos = *ppos; if (avio_seek(s->pb, pos, SEEK_SET) < 0) return AV_NOPTS_VALUE; for(;;) { len = mpegps_read_pes_header(s, &pos, &startcode, &pts, &dts); if (len < 0) { av_dlog(s, "none (ret=%d)\n", len); return AV_NOPTS_VALUE; } if (startcode == s->streams[stream_index]->id && dts != AV_NOPTS_VALUE) { break; } avio_skip(s->pb, len); } av_dlog(s, "pos=0x%"PRIx64" dts=0x%"PRIx64" %0.3f\n", pos, dts, dts / 90000.0); *ppos = pos; return dts; } AVInputFormat ff_mpegps_demuxer = { .name = "mpeg", .long_name = NULL_IF_CONFIG_SMALL("MPEG-PS format"), .priv_data_size = sizeof(MpegDemuxContext), .read_probe = mpegps_probe, .read_header = mpegps_read_header, .read_packet = mpegps_read_packet, .read_timestamp = mpegps_read_dts, .flags = AVFMT_SHOW_IDS | AVFMT_TS_DISCONT, };