diff options
Diffstat (limited to 'contrib/ffmpeg/libavformat/mpeg.c')
| -rw-r--r-- | contrib/ffmpeg/libavformat/mpeg.c | 580 |
1 files changed, 580 insertions, 0 deletions
diff --git a/contrib/ffmpeg/libavformat/mpeg.c b/contrib/ffmpeg/libavformat/mpeg.c new file mode 100644 index 000000000..97b2a637a --- /dev/null +++ b/contrib/ffmpeg/libavformat/mpeg.c @@ -0,0 +1,580 @@ +/* + * MPEG1/2 demuxer + * Copyright (c) 2000, 2001, 2002 Fabrice Bellard. + * + * 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 "mpeg.h" + +//#define DEBUG_SEEK + +#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; + p+=5; + }else if((*p&0xF0) == 0x30){ + pes1= p[0]&p[2]&p[4]&p[5]&p[7]&p[9]&1; + p+=10; + }else + pes1 = *p == 0x0F; + + return pes1||pes2; +} + +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 pes= check_pes(p->buf+i, p->buf+p->buf_size); + + if(code == SYSTEM_HEADER_START_CODE) sys++; + else if(code == PRIVATE_STREAM_1) priv1++; + else if(code == PACK_START_CODE) pspack++; + else if((code & 0xf0) == VIDEO_ID && pes) vid++; + else if((code & 0xe0) == AUDIO_ID && pes) audio++; + + else if((code & 0xf0) == VIDEO_ID && !pes) invalid++; + else if((code & 0xe0) == AUDIO_ID && !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 len:%d\n", sys, priv1, pspack,vid, audio, p->buf_size); + if(sys>invalid && sys*9 <= pspack*10) + return AVPROBE_SCORE_MAX/2+2; // +1 for .mpg + if(priv1 + vid + audio > invalid && (priv1+vid+audio)*9 <= pspack*10) + return AVPROBE_SCORE_MAX/2+2; // +1 for .mpg + if((!!vid ^ !!audio) && (audio+vid > 1) && !sys && !pspack && p->buf_size>2048) /* PES stream */ + return AVPROBE_SCORE_MAX/2+2; + + //02-Penguin.flac has sys:0 priv1:0 pspack:0 vid:0 audio:1 + 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, + AVFormatParameters *ap) +{ + 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 = get_byte(s->pb); + m->header_state = m->header_state << 8 | v; + m->sofdec++; + } while (v == sofdec[i] && i++ < 6); + + /* no need to do more */ + return 0; +} + +static int64_t get_pts(ByteIOContext *pb, int c) +{ + uint8_t buf[5]; + + buf[0] = c<0 ? get_byte(pb) : c; + get_buffer(pb, buf+1, 4); + + return ff_parse_pes_pts(buf); +} + +static int find_next_start_code(ByteIOContext *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 (url_feof(pb)) + break; + v = get_byte(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(ByteIOContext *pb, int *size_ptr) +{ + int64_t pos, pos_start; + int max_size, start_code; + + max_size = *size_ptr; + pos_start = url_ftell(pb); + + /* in order to go faster, we fill the buffer */ + pos = pos_start - 16386; + if (pos < 0) + pos = 0; + url_fseek(pb, pos, SEEK_SET); + get_byte(pb); + + pos = pos_start; + for(;;) { + pos--; + if (pos < 0 || (pos_start - pos) >= max_size) { + start_code = -1; + goto the_end; + } + url_fseek(pb, pos, SEEK_SET); + start_code = get_be32(pb); + if ((start_code & 0xffffff00) == 0x100) + break; + } + the_end: + *size_ptr = pos_start - pos; + return start_code; +} +#endif + +/** + * Extracts 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, ByteIOContext *pb) +{ + int psm_length, ps_info_length, es_map_length; + + psm_length = get_be16(pb); + get_byte(pb); + get_byte(pb); + ps_info_length = get_be16(pb); + + /* skip program_stream_info */ + url_fskip(pb, ps_info_length); + es_map_length = get_be16(pb); + + /* at least one es available? */ + while (es_map_length >= 4){ + unsigned char type = get_byte(pb); + unsigned char es_id = get_byte(pb); + uint16_t es_info_length = get_be16(pb); + /* remember mapping from stream id to stream type */ + m->psm_es_type[es_id] = type; + /* skip program_stream_info */ + url_fskip(pb, es_info_length); + es_map_length -= 4 + es_info_length; + } + get_be32(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= url_ftell(s->pb); + + error_redo: + url_fseek(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 = url_ftell(s->pb); + //printf("startcode=%x pos=0x%"PRIx64"\n", startcode, url_ftell(s->pb)); + if (startcode < 0) + return AVERROR(EIO); + if (startcode == PACK_START_CODE) + goto redo; + if (startcode == SYSTEM_HEADER_START_CODE) + goto redo; + if (startcode == PADDING_STREAM) { + url_fskip(s->pb, get_be16(s->pb)); + goto redo; + } + if (startcode == PRIVATE_STREAM_2) { + len = get_be16(s->pb); + if (!m->sofdec) { + while (len-- >= 6) { + if (get_byte(s->pb) == 'S') { + uint8_t buf[5]; + get_buffer(s->pb, buf, sizeof(buf)); + m->sofdec = !memcmp(buf, "ofdec", 5); + len -= sizeof(buf); + break; + } + } + m->sofdec -= !m->sofdec; + } + url_fskip(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 = url_ftell(s->pb) - 4; + } + len = get_be16(s->pb); + pts = + dts = AV_NOPTS_VALUE; + /* stuffing */ + for(;;) { + if (len < 1) + goto error_redo; + c = get_byte(s->pb); + len--; + /* XXX: for mpeg1, should test only bit 7 */ + if (c != 0xff) + break; + } + if ((c & 0xc0) == 0x40) { + /* buffer scale & size */ + get_byte(s->pb); + c = get_byte(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 = get_byte(s->pb); + header_len = get_byte(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 & 0x01) { /* PES extension */ + pes_ext = get_byte(s->pb); + header_len--; + if (pes_ext & 0x40) { /* pack header - should be zero in PS */ + goto error_redo; + } + /* Skip PES private data, program packet sequence counter and P-STD buffer */ + skip = (pes_ext >> 4) & 0xb; + skip += skip & 0x9; + url_fskip(s->pb, skip); + header_len -= skip; + + if (pes_ext & 0x01) { /* PES extension 2 */ + ext2_len = get_byte(s->pb); + header_len--; + if ((ext2_len & 0x7f) > 0) { + id_ext = get_byte(s->pb); + if ((id_ext & 0x80) == 0) + startcode = ((startcode & 0xff) << 8) | id_ext; + header_len--; + } + } + } + if(header_len < 0) + goto error_redo; + url_fskip(s->pb, header_len); + } + else if( c!= 0xf ) + goto redo; + + if (startcode == PRIVATE_STREAM_1 && !m->psm_es_type[startcode & 0xff]) { + startcode = get_byte(s->pb); + len--; + if (startcode >= 0x80 && startcode <= 0xcf) { + /* audio: skip header */ + get_byte(s->pb); + get_byte(s->pb); + get_byte(s->pb); + len -= 3; + if (startcode >= 0xb0 && startcode <= 0xbf) { + /* MLP/TrueHD audio has a 4-byte header */ + get_byte(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 && + !url_is_streamed(s->pb) /* 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, type, codec_id = 0, es_type; + int64_t pts, dts, dummy_pos; //dummy_pos is needed for the index building to work + + redo: + len = mpegps_read_pes_header(s, &dummy_pos, &startcode, &pts, &dts); + if (len < 0) + return len; + + /* 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){ + if(es_type == STREAM_TYPE_VIDEO_MPEG1){ + codec_id = CODEC_ID_MPEG2VIDEO; + type = CODEC_TYPE_VIDEO; + } else if(es_type == STREAM_TYPE_VIDEO_MPEG2){ + codec_id = CODEC_ID_MPEG2VIDEO; + type = CODEC_TYPE_VIDEO; + } else if(es_type == STREAM_TYPE_AUDIO_MPEG1 || + es_type == STREAM_TYPE_AUDIO_MPEG2){ + codec_id = CODEC_ID_MP3; + type = CODEC_TYPE_AUDIO; + } else if(es_type == STREAM_TYPE_AUDIO_AAC){ + codec_id = CODEC_ID_AAC; + type = CODEC_TYPE_AUDIO; + } else if(es_type == STREAM_TYPE_VIDEO_MPEG4){ + codec_id = CODEC_ID_MPEG4; + type = CODEC_TYPE_VIDEO; + } else if(es_type == STREAM_TYPE_VIDEO_H264){ + codec_id = CODEC_ID_H264; + type = CODEC_TYPE_VIDEO; + } else if(es_type == STREAM_TYPE_AUDIO_AC3){ + codec_id = CODEC_ID_AC3; + type = CODEC_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]; + get_buffer(s->pb, buf, 8); + url_fseek(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_MPEG2VIDEO; + type = CODEC_TYPE_VIDEO; + } else if (startcode >= 0x1c0 && startcode <= 0x1df) { + type = CODEC_TYPE_AUDIO; + codec_id = m->sofdec > 0 ? CODEC_ID_ADPCM_ADX : CODEC_ID_MP2; + } else if (startcode >= 0x80 && startcode <= 0x87) { + type = CODEC_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 = CODEC_TYPE_AUDIO; + codec_id = CODEC_ID_DTS; + } else if (startcode >= 0xa0 && startcode <= 0xaf) { + type = CODEC_TYPE_AUDIO; + codec_id = CODEC_ID_PCM_S16BE; + } else if (startcode >= 0xb0 && startcode <= 0xbf) { + type = CODEC_TYPE_AUDIO; + codec_id = CODEC_ID_MLP; + } else if (startcode >= 0xc0 && startcode <= 0xcf) { + /* Used for both AC-3 and E-AC-3 in EVOB files */ + type = CODEC_TYPE_AUDIO; + codec_id = CODEC_ID_AC3; + } else if (startcode >= 0x20 && startcode <= 0x3f) { + type = CODEC_TYPE_SUBTITLE; + codec_id = CODEC_ID_DVD_SUBTITLE; + } else if (startcode >= 0xfd55 && startcode <= 0xfd5f) { + type = CODEC_TYPE_VIDEO; + codec_id = CODEC_ID_VC1; + } else { + skip: + /* skip packet */ + url_fskip(s->pb, len); + goto redo; + } + /* no stream found: add a new stream */ + st = av_new_stream(s, startcode); + if (!st) + goto skip; + 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) { + int b1, freq; + + /* for LPCM, we just skip the header and consider it is raw + audio data */ + if (len <= 3) + goto skip; + get_byte(s->pb); /* emphasis (1), muse(1), reserved(1), frame number(5) */ + b1 = get_byte(s->pb); /* quant (2), freq(2), reserved(1), channels(3) */ + get_byte(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->bit_rate = st->codec->channels * st->codec->sample_rate * 2; + } + av_new_packet(pkt, len); + get_buffer(s->pb, pkt->data, pkt->size); + pkt->pts = pts; + pkt->dts = dts; + pkt->stream_index = st->index; +#if 0 + av_log(s, AV_LOG_DEBUG, "%d: pts=%0.3f dts=%0.3f size=%d\n", + pkt->stream_index, pkt->pts / 90000.0, pkt->dts / 90000.0, pkt->size); +#endif + + return 0; +} + +static int mpegps_read_close(AVFormatContext *s) +{ + return 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; +#ifdef DEBUG_SEEK + printf("read_dts: pos=0x%"PRIx64" next=%d -> ", pos, find_next); +#endif + url_fseek(s->pb, pos, SEEK_SET); + for(;;) { + len = mpegps_read_pes_header(s, &pos, &startcode, &pts, &dts); + if (len < 0) { +#ifdef DEBUG_SEEK + printf("none (ret=%d)\n", len); +#endif + return AV_NOPTS_VALUE; + } + if (startcode == s->streams[stream_index]->id && + dts != AV_NOPTS_VALUE) { + break; + } + url_fskip(s->pb, len); + } +#ifdef DEBUG_SEEK + printf("pos=0x%"PRIx64" dts=0x%"PRIx64" %0.3f\n", pos, dts, dts / 90000.0); +#endif + *ppos = pos; + return dts; +} + +AVInputFormat mpegps_demuxer = { + "mpeg", + "MPEG PS format", + sizeof(MpegDemuxContext), + mpegps_probe, + mpegps_read_header, + mpegps_read_packet, + mpegps_read_close, + NULL, //mpegps_read_seek, + mpegps_read_dts, + .flags = AVFMT_SHOW_IDS, +}; |