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FFmpeg4/libavformat/mpeg.c

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2023-07-02 12:20:28 +00:00
/*
* MPEG-1/2 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 "avio_internal.h"
#include "internal.h"
#include "mpeg.h"
/*********************************************/
/* demux code */
#define MAX_SYNC_SIZE 100000
static int check_pes(const uint8_t *p, const 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(const AVProbeData *p)
{
uint32_t code = -1;
int i;
int sys = 0, pspack = 0, priv1 = 0, vid = 0;
int audio = 0, invalid = 0, score = 0;
int endpes = 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 = endpes <= i && 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) {
endpes = i + len;
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 == 0x1fd && pes) vid++; //VC1
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 + 1) /* invalid VDR files nd short PES streams */
score = AVPROBE_SCORE_EXTENSION / 2;
// av_log(NULL, AV_LOG_ERROR, "vid:%d aud:%d sys:%d pspack:%d invalid:%d size:%d \n",
// vid, audio, sys, pspack, invalid, p->buf_size);
if (sys > invalid && sys * 9 <= pspack * 10)
return (audio > 12 || vid > 3 || pspack > 2) ? AVPROBE_SCORE_EXTENSION + 2
: AVPROBE_SCORE_EXTENSION / 2 + (audio + vid + pspack > 1); // 1 more than mp3
if (pspack > invalid && (priv1 + vid + audio) * 10 >= pspack * 9)
return pspack > 2 ? AVPROBE_SCORE_EXTENSION + 2
: AVPROBE_SCORE_EXTENSION / 2; // 1 more than .mpg
if ((!!vid ^ !!audio) && (audio > 4 || vid > 1) && !sys &&
!pspack && p->buf_size > 2048 && vid + audio > invalid) /* PES stream */
return (audio > 12 || vid > 6 + 2 * invalid) ? AVPROBE_SCORE_EXTENSION + 2
: AVPROBE_SCORE_EXTENSION / 2;
// 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
// Have\ Yourself\ a\ Merry\ Little\ Christmas.mp3 0 0 0 5 0 1 len:21618
return score;
}
typedef struct MpegDemuxContext {
int32_t header_state;
unsigned char psm_es_type[256];
int sofdec;
int dvd;
int imkh_cctv;
int raw_ac3;
} MpegDemuxContext;
static int mpegps_read_header(AVFormatContext *s)
{
MpegDemuxContext *m = s->priv_data;
char buffer[7] = { 0 };
int64_t last_pos = avio_tell(s->pb);
m->header_state = 0xff;
s->ctx_flags |= AVFMTCTX_NOHEADER;
avio_get_str(s->pb, 6, buffer, sizeof(buffer));
if (!memcmp("IMKH", buffer, 4)) {
m->imkh_cctv = 1;
} else if (!memcmp("Sofdec", buffer, 6)) {
m->sofdec = 1;
} else
avio_seek(s->pb, last_pos, SEEK_SET);
/* no need to do more */
return 0;
}
static int64_t get_pts(AVIOContext *pb, int c)
{
uint8_t buf[5];
int ret;
buf[0] = c < 0 ? avio_r8(pb) : c;
ret = avio_read(pb, buf + 1, 4);
if (ret < 4)
return AV_NOPTS_VALUE;
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 (avio_feof(pb))
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;
}
/**
* 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);
/* Ignore es_map_length, trust psm_length */
es_map_length = psm_length - ps_info_length - 10;
/* 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);
if (startcode < 0) {
if (avio_feof(s->pb))
return AVERROR_EOF;
// FIXME we should remember header_state
return FFERROR_REDO;
}
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) {
if (!m->sofdec) {
/* Need to detect whether this from a DVD or a 'Sofdec' stream */
int len = avio_rb16(s->pb);
int bytesread = 0;
uint8_t *ps2buf = av_malloc(len);
if (ps2buf) {
bytesread = avio_read(s->pb, ps2buf, len);
if (bytesread != len) {
avio_skip(s->pb, len - bytesread);
} else {
uint8_t *p = 0;
if (len >= 6)
p = memchr(ps2buf, 'S', len - 5);
if (p)
m->sofdec = !memcmp(p+1, "ofdec", 5);
m->sofdec -= !m->sofdec;
if (m->sofdec < 0) {
if (len == 980 && ps2buf[0] == 0) {
/* PCI structure? */
uint32_t startpts = AV_RB32(ps2buf + 0x0d);
uint32_t endpts = AV_RB32(ps2buf + 0x11);
uint8_t hours = ((ps2buf[0x19] >> 4) * 10) + (ps2buf[0x19] & 0x0f);
uint8_t mins = ((ps2buf[0x1a] >> 4) * 10) + (ps2buf[0x1a] & 0x0f);
uint8_t secs = ((ps2buf[0x1b] >> 4) * 10) + (ps2buf[0x1b] & 0x0f);
m->dvd = (hours <= 23 &&
mins <= 59 &&
secs <= 59 &&
(ps2buf[0x19] & 0x0f) < 10 &&
(ps2buf[0x1a] & 0x0f) < 10 &&
(ps2buf[0x1b] & 0x0f) < 10 &&
endpts >= startpts);
} else if (len == 1018 && ps2buf[0] == 1) {
/* DSI structure? */
uint8_t hours = ((ps2buf[0x1d] >> 4) * 10) + (ps2buf[0x1d] & 0x0f);
uint8_t mins = ((ps2buf[0x1e] >> 4) * 10) + (ps2buf[0x1e] & 0x0f);
uint8_t secs = ((ps2buf[0x1f] >> 4) * 10) + (ps2buf[0x1f] & 0x0f);
m->dvd = (hours <= 23 &&
mins <= 59 &&
secs <= 59 &&
(ps2buf[0x1d] & 0x0f) < 10 &&
(ps2buf[0x1e] & 0x0f) < 10 &&
(ps2buf[0x1f] & 0x0f) < 10);
}
}
}
av_free(ps2buf);
/* If this isn't a DVD packet or no memory
* could be allocated, just ignore it.
* If we did, move back to the start of the
* packet (plus 'length' field) */
if (!m->dvd || avio_skip(s->pb, -(len + 2)) < 0) {
/* Skip back failed.
* This packet will be lost but that can't be helped
* if we can't skip back
*/
goto redo;
}
} else {
/* No memory */
avio_skip(s->pb, len);
goto redo;
}
} else if (!m->dvd) {
int len = avio_rb16(s->pb);
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 == PRIVATE_STREAM_2) ||
(startcode == 0x1fd)))
goto redo;
if (ppos) {
*ppos = avio_tell(s->pb) - 4;
}
len = avio_rb16(s->pb);
pts =
dts = AV_NOPTS_VALUE;
if (startcode != PRIVATE_STREAM_2)
{
/* stuffing */
for (;;) {
if (len < 1)
goto error_redo;
c = avio_r8(s->pb);
len--;
/* XXX: for MPEG-1, 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 */
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) {
int ret = ffio_ensure_seekback(s->pb, 2);
if (ret < 0)
return ret;
startcode = avio_r8(s->pb);
m->raw_ac3 = 0;
if (startcode == 0x0b) {
if (avio_r8(s->pb) == 0x77) {
startcode = 0x80;
m->raw_ac3 = 1;
avio_skip(s->pb, -2);
} else {
avio_skip(s->pb, -1);
}
} else {
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 & AVIO_SEEKABLE_NORMAL) /* 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;
int pcm_dvd = 0;
int request_probe= 0;
enum AVCodecID codec_id = AV_CODEC_ID_NONE;
enum AVMediaType 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;
if (startcode >= 0x80 && startcode <= 0xcf) {
if (len < 4)
goto skip;
if (!m->raw_ac3) {
/* audio: skip header */
avio_skip(s->pb, 3);
len -= 3;
if (startcode >= 0xb0 && startcode <= 0xbf) {
/* MLP/TrueHD audio has a 4-byte header */
avio_r8(s->pb);
len--;
} else if (startcode >= 0xa0 && startcode <= 0xaf) {
ret = ffio_ensure_seekback(s->pb, 3);
if (ret < 0)
return ret;
pcm_dvd = (avio_rb24(s->pb) & 0xFF) == 0x80;
avio_skip(s->pb, -3);
}
}
}
/* 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 == STREAM_TYPE_VIDEO_MPEG1) {
codec_id = AV_CODEC_ID_MPEG2VIDEO;
type = AVMEDIA_TYPE_VIDEO;
} else if (es_type == STREAM_TYPE_VIDEO_MPEG2) {
codec_id = AV_CODEC_ID_MPEG2VIDEO;
type = AVMEDIA_TYPE_VIDEO;
} else if (es_type == STREAM_TYPE_AUDIO_MPEG1 ||
es_type == STREAM_TYPE_AUDIO_MPEG2) {
codec_id = AV_CODEC_ID_MP3;
type = AVMEDIA_TYPE_AUDIO;
} else if (es_type == STREAM_TYPE_AUDIO_AAC) {
codec_id = AV_CODEC_ID_AAC;
type = AVMEDIA_TYPE_AUDIO;
} else if (es_type == STREAM_TYPE_VIDEO_MPEG4) {
codec_id = AV_CODEC_ID_MPEG4;
type = AVMEDIA_TYPE_VIDEO;
} else if (es_type == STREAM_TYPE_VIDEO_H264) {
codec_id = AV_CODEC_ID_H264;
type = AVMEDIA_TYPE_VIDEO;
} else if (es_type == STREAM_TYPE_VIDEO_HEVC) {
codec_id = AV_CODEC_ID_HEVC;
type = AVMEDIA_TYPE_VIDEO;
} else if (es_type == STREAM_TYPE_AUDIO_AC3) {
codec_id = AV_CODEC_ID_AC3;
type = AVMEDIA_TYPE_AUDIO;
} else if (m->imkh_cctv && es_type == 0x91) {
codec_id = AV_CODEC_ID_PCM_MULAW;
type = AVMEDIA_TYPE_AUDIO;
} 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 = AV_CODEC_ID_CAVS;
else
request_probe= 1;
type = AVMEDIA_TYPE_VIDEO;
} else if (startcode == PRIVATE_STREAM_2) {
type = AVMEDIA_TYPE_DATA;
codec_id = AV_CODEC_ID_DVD_NAV;
} else if (startcode >= 0x1c0 && startcode <= 0x1df) {
type = AVMEDIA_TYPE_AUDIO;
if (m->sofdec > 0) {
codec_id = AV_CODEC_ID_ADPCM_ADX;
// Auto-detect AC-3
request_probe = 50;
} else if (m->imkh_cctv && startcode == 0x1c0 && len > 80) {
codec_id = AV_CODEC_ID_PCM_ALAW;
request_probe = 50;
} else {
codec_id = AV_CODEC_ID_MP2;
if (m->imkh_cctv)
request_probe = 25;
}
} else if (startcode >= 0x80 && startcode <= 0x87) {
type = AVMEDIA_TYPE_AUDIO;
codec_id = AV_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 = AV_CODEC_ID_DTS;
} else if (startcode >= 0xa0 && startcode <= 0xaf) {
type = AVMEDIA_TYPE_AUDIO;
if (!pcm_dvd) {
codec_id = AV_CODEC_ID_MLP;
} else {
codec_id = AV_CODEC_ID_PCM_DVD;
}
} else if (startcode >= 0xb0 && startcode <= 0xbf) {
type = AVMEDIA_TYPE_AUDIO;
codec_id = AV_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 = AV_CODEC_ID_AC3;
} else if (startcode >= 0x20 && startcode <= 0x3f) {
type = AVMEDIA_TYPE_SUBTITLE;
codec_id = AV_CODEC_ID_DVD_SUBTITLE;
} else if (startcode >= 0xfd55 && startcode <= 0xfd5f) {
type = AVMEDIA_TYPE_VIDEO;
codec_id = AV_CODEC_ID_VC1;
} 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->codecpar->codec_type = type;
st->codecpar->codec_id = codec_id;
if ( st->codecpar->codec_id == AV_CODEC_ID_PCM_MULAW
|| st->codecpar->codec_id == AV_CODEC_ID_PCM_ALAW) {
st->codecpar->channels = 1;
st->codecpar->channel_layout = AV_CH_LAYOUT_MONO;
st->codecpar->sample_rate = 8000;
}
st->request_probe = request_probe;
st->need_parsing = AVSTREAM_PARSE_FULL;
found:
if (st->discard >= AVDISCARD_ALL)
goto skip;
if (startcode >= 0xa0 && startcode <= 0xaf) {
if (st->codecpar->codec_id == AV_CODEC_ID_MLP) {
if (len < 6)
goto skip;
avio_skip(s->pb, 6);
len -=6;
}
}
ret = av_get_packet(s->pb, pkt, len);
pkt->pts = pts;
pkt->dts = dts;
pkt->pos = dummy_pos;
pkt->stream_index = st->index;
if (s->debug & FF_FDEBUG_TS)
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);
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) {
if (s->debug & FF_FDEBUG_TS)
av_log(s, AV_LOG_DEBUG, "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);
}
if (s->debug & FF_FDEBUG_TS)
av_log(s, AV_LOG_DEBUG, "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 (MPEG-2 Program Stream)"),
.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,
};
#if CONFIG_VOBSUB_DEMUXER
#include "subtitles.h"
#include "libavutil/avassert.h"
#include "libavutil/bprint.h"
#include "libavutil/opt.h"
#define REF_STRING "# VobSub index file,"
#define MAX_LINE_SIZE 2048
typedef struct VobSubDemuxContext {
const AVClass *class;
AVFormatContext *sub_ctx;
FFDemuxSubtitlesQueue q[32];
char *sub_name;
} VobSubDemuxContext;
static int vobsub_probe(const AVProbeData *p)
{
if (!strncmp(p->buf, REF_STRING, sizeof(REF_STRING) - 1))
return AVPROBE_SCORE_MAX;
return 0;
}
static int vobsub_read_close(AVFormatContext *s)
{
VobSubDemuxContext *vobsub = s->priv_data;
int i;
for (i = 0; i < s->nb_streams; i++)
ff_subtitles_queue_clean(&vobsub->q[i]);
if (vobsub->sub_ctx)
avformat_close_input(&vobsub->sub_ctx);
return 0;
}
static int vobsub_read_header(AVFormatContext *s)
{
int i, ret = 0, header_parsed = 0, langidx = 0;
VobSubDemuxContext *vobsub = s->priv_data;
size_t fname_len;
AVBPrint header;
int64_t delay = 0;
AVStream *st = NULL;
int stream_id = -1;
char id[64] = {0};
char alt[MAX_LINE_SIZE] = {0};
ff_const59 AVInputFormat *iformat;
if (!vobsub->sub_name) {
char *ext;
vobsub->sub_name = av_strdup(s->url);
if (!vobsub->sub_name) {
return AVERROR(ENOMEM);
}
fname_len = strlen(vobsub->sub_name);
ext = vobsub->sub_name - 3 + fname_len;
if (fname_len < 4 || *(ext - 1) != '.') {
av_log(s, AV_LOG_ERROR, "The input index filename is too short "
"to guess the associated .SUB file\n");
return AVERROR_INVALIDDATA;
}
memcpy(ext, !strncmp(ext, "IDX", 3) ? "SUB" : "sub", 3);
av_log(s, AV_LOG_VERBOSE, "IDX/SUB: %s -> %s\n", s->url, vobsub->sub_name);
}
if (!(iformat = av_find_input_format("mpeg"))) {
return AVERROR_DEMUXER_NOT_FOUND;
}
vobsub->sub_ctx = avformat_alloc_context();
if (!vobsub->sub_ctx) {
return AVERROR(ENOMEM);
}
av_bprint_init(&header, 0, INT_MAX - AV_INPUT_BUFFER_PADDING_SIZE);
if ((ret = ff_copy_whiteblacklists(vobsub->sub_ctx, s)) < 0)
goto end;
ret = avformat_open_input(&vobsub->sub_ctx, vobsub->sub_name, iformat, NULL);
if (ret < 0) {
av_log(s, AV_LOG_ERROR, "Unable to open %s as MPEG subtitles\n", vobsub->sub_name);
goto end;
}
while (!avio_feof(s->pb)) {
char line[MAX_LINE_SIZE];
int len = ff_get_line(s->pb, line, sizeof(line));
if (!len)
break;
line[strcspn(line, "\r\n")] = 0;
if (!strncmp(line, "id:", 3)) {
if (sscanf(line, "id: %63[^,], index: %u", id, &stream_id) != 2) {
av_log(s, AV_LOG_WARNING, "Unable to parse index line '%s', "
"assuming 'id: und, index: 0'\n", line);
strcpy(id, "und");
stream_id = 0;
}
if (stream_id >= FF_ARRAY_ELEMS(vobsub->q)) {
av_log(s, AV_LOG_ERROR, "Maximum number of subtitles streams reached\n");
ret = AVERROR(EINVAL);
goto end;
}
header_parsed = 1;
alt[0] = '\0';
/* We do not create the stream immediately to avoid adding empty
* streams. See the following timestamp entry. */
av_log(s, AV_LOG_DEBUG, "IDX stream[%d] id=%s\n", stream_id, id);
} else if (!strncmp(line, "timestamp:", 10)) {
AVPacket *sub;
int hh, mm, ss, ms;
int64_t pos, timestamp;
const char *p = line + 10;
if (stream_id == -1) {
av_log(s, AV_LOG_ERROR, "Timestamp declared before any stream\n");
ret = AVERROR_INVALIDDATA;
goto end;
}
if (!st || st->id != stream_id) {
st = avformat_new_stream(s, NULL);
if (!st) {
ret = AVERROR(ENOMEM);
goto end;
}
st->id = stream_id;
st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE;
st->codecpar->codec_id = AV_CODEC_ID_DVD_SUBTITLE;
avpriv_set_pts_info(st, 64, 1, 1000);
av_dict_set(&st->metadata, "language", id, 0);
if (alt[0])
av_dict_set(&st->metadata, "title", alt, 0);
}
if (sscanf(p, "%02d:%02d:%02d:%03d, filepos: %"SCNx64,
&hh, &mm, &ss, &ms, &pos) != 5) {
av_log(s, AV_LOG_ERROR, "Unable to parse timestamp line '%s', "
"abort parsing\n", line);
ret = AVERROR_INVALIDDATA;
goto end;
}
timestamp = (hh*3600LL + mm*60LL + ss) * 1000LL + ms + delay;
timestamp = av_rescale_q(timestamp, av_make_q(1, 1000), st->time_base);
sub = ff_subtitles_queue_insert(&vobsub->q[s->nb_streams - 1], "", 0, 0);
if (!sub) {
ret = AVERROR(ENOMEM);
goto end;
}
sub->pos = pos;
sub->pts = timestamp;
sub->stream_index = s->nb_streams - 1;
} else if (!strncmp(line, "alt:", 4)) {
const char *p = line + 4;
while (*p == ' ')
p++;
av_log(s, AV_LOG_DEBUG, "IDX stream[%d] name=%s\n", stream_id, p);
av_strlcpy(alt, p, sizeof(alt));
header_parsed = 1;
} else if (!strncmp(line, "delay:", 6)) {
int sign = 1, hh = 0, mm = 0, ss = 0, ms = 0;
const char *p = line + 6;
while (*p == ' ')
p++;
if (*p == '-' || *p == '+') {
sign = *p == '-' ? -1 : 1;
p++;
}
sscanf(p, "%d:%d:%d:%d", &hh, &mm, &ss, &ms);
delay = ((hh*3600LL + mm*60LL + ss) * 1000LL + ms) * sign;
} else if (!strncmp(line, "langidx:", 8)) {
const char *p = line + 8;
if (sscanf(p, "%d", &langidx) != 1)
av_log(s, AV_LOG_ERROR, "Invalid langidx specified\n");
} else if (!header_parsed) {
if (line[0] && line[0] != '#')
av_bprintf(&header, "%s\n", line);
}
}
if (langidx < s->nb_streams)
s->streams[langidx]->disposition |= AV_DISPOSITION_DEFAULT;
for (i = 0; i < s->nb_streams; i++) {
vobsub->q[i].sort = SUB_SORT_POS_TS;
vobsub->q[i].keep_duplicates = 1;
ff_subtitles_queue_finalize(s, &vobsub->q[i]);
}
if (!av_bprint_is_complete(&header)) {
ret = AVERROR(ENOMEM);
goto end;
}
for (i = 0; i < s->nb_streams; i++) {
AVCodecParameters *par = s->streams[i]->codecpar;
ret = ff_alloc_extradata(par, header.len);
if (ret < 0) {
goto end;
}
memcpy(par->extradata, header.str, header.len);
}
end:
if (ret < 0)
vobsub_read_close(s);
av_bprint_finalize(&header, NULL);
return ret;
}
static int vobsub_read_packet(AVFormatContext *s, AVPacket *pkt)
{
VobSubDemuxContext *vobsub = s->priv_data;
FFDemuxSubtitlesQueue *q;
AVIOContext *pb = vobsub->sub_ctx->pb;
int ret, psize, total_read = 0, i;
int64_t min_ts = INT64_MAX;
int sid = 0;
for (i = 0; i < s->nb_streams; i++) {
FFDemuxSubtitlesQueue *tmpq = &vobsub->q[i];
int64_t ts;
av_assert0(tmpq->nb_subs);
if (tmpq->current_sub_idx >= tmpq->nb_subs)
continue;
ts = tmpq->subs[tmpq->current_sub_idx].pts;
if (ts < min_ts) {
min_ts = ts;
sid = i;
}
}
q = &vobsub->q[sid];
/* The returned packet will have size zero,
* so that it can be directly used with av_grow_packet. */
ret = ff_subtitles_queue_read_packet(q, pkt);
if (ret < 0)
return ret;
/* compute maximum packet size using the next packet position. This is
* useful when the len in the header is non-sense */
if (q->current_sub_idx < q->nb_subs) {
psize = q->subs[q->current_sub_idx].pos - pkt->pos;
} else {
int64_t fsize = avio_size(pb);
psize = fsize < 0 ? 0xffff : fsize - pkt->pos;
}
avio_seek(pb, pkt->pos, SEEK_SET);
do {
int n, to_read, startcode;
int64_t pts, dts;
int64_t old_pos = avio_tell(pb), new_pos;
int pkt_size;
ret = mpegps_read_pes_header(vobsub->sub_ctx, NULL, &startcode, &pts, &dts);
if (ret < 0) {
if (pkt->size) // raise packet even if incomplete
break;
return ret;
}
to_read = ret & 0xffff;
new_pos = avio_tell(pb);
pkt_size = ret + (new_pos - old_pos);
/* this prevents reads above the current packet */
if (total_read + pkt_size > psize)
break;
total_read += pkt_size;
/* the current chunk doesn't match the stream index (unlikely) */
if ((startcode & 0x1f) != s->streams[pkt->stream_index]->id)
break;
ret = av_grow_packet(pkt, to_read);
if (ret < 0)
return ret;
n = avio_read(pb, pkt->data + (pkt->size - to_read), to_read);
if (n < to_read)
pkt->size -= to_read - n;
} while (total_read < psize);
return 0;
}
static int vobsub_read_seek(AVFormatContext *s, int stream_index,
int64_t min_ts, int64_t ts, int64_t max_ts, int flags)
{
VobSubDemuxContext *vobsub = s->priv_data;
/* Rescale requested timestamps based on the first stream (timebase is the
* same for all subtitles stream within a .idx/.sub). Rescaling is done just
* like in avformat_seek_file(). */
if (stream_index == -1 && s->nb_streams != 1) {
int i, ret = 0;
AVRational time_base = s->streams[0]->time_base;
ts = av_rescale_q(ts, AV_TIME_BASE_Q, time_base);
min_ts = av_rescale_rnd(min_ts, time_base.den,
time_base.num * (int64_t)AV_TIME_BASE,
AV_ROUND_UP | AV_ROUND_PASS_MINMAX);
max_ts = av_rescale_rnd(max_ts, time_base.den,
time_base.num * (int64_t)AV_TIME_BASE,
AV_ROUND_DOWN | AV_ROUND_PASS_MINMAX);
for (i = 0; i < s->nb_streams; i++) {
int r = ff_subtitles_queue_seek(&vobsub->q[i], s, stream_index,
min_ts, ts, max_ts, flags);
if (r < 0)
ret = r;
}
return ret;
}
if (stream_index == -1) // only 1 stream
stream_index = 0;
return ff_subtitles_queue_seek(&vobsub->q[stream_index], s, stream_index,
min_ts, ts, max_ts, flags);
}
static const AVOption options[] = {
{ "sub_name", "URI for .sub file", offsetof(VobSubDemuxContext, sub_name), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, AV_OPT_FLAG_DECODING_PARAM },
{ NULL }
};
static const AVClass vobsub_demuxer_class = {
.class_name = "vobsub",
.item_name = av_default_item_name,
.option = options,
.version = LIBAVUTIL_VERSION_INT,
};
AVInputFormat ff_vobsub_demuxer = {
.name = "vobsub",
.long_name = NULL_IF_CONFIG_SMALL("VobSub subtitle format"),
.priv_data_size = sizeof(VobSubDemuxContext),
.read_probe = vobsub_probe,
.read_header = vobsub_read_header,
.read_packet = vobsub_read_packet,
.read_seek2 = vobsub_read_seek,
.read_close = vobsub_read_close,
.flags = AVFMT_SHOW_IDS,
.extensions = "idx",
.priv_class = &vobsub_demuxer_class,
};
#endif