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FFmpeg/libavformat/mpeg.c
Andreas Rheinhardt 6d354aeb29 avformat/mpeg: Remove secondary packet for reading VobSub 
When vobsub_read_packet() reads a packet, it uses a dedicated AVPacket
to get the subtitle timing and position from an FFDemuxSubtitlesQueue
(which has been filled with this data during reading the idx file in
vobsub_read_header); afterwards the actual subtitle data is read into
the packet destined for output and the timing and position are copied
to this packet. Afterwards, the local packet is unreferenced.

This can be simplified: Simply use the output packet to get the timing
and position from the FFDemuxSubtitlesQueue. The packet's size will be
zero afterwards, so that it can be directly used to read the actual
subtitle data. This makes copying the packet fields as well as
unreferencing the local packet unecessary and also removes an instance
of usage of sizeof(AVPacket) in libavformat.

The only difference is that the returned packet will already be flagged
as a keyframe. This currently only happens in compute_pkt_fields().

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
2020-01-01 16:38:28 +01:00

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/*
* 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 + 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];
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 (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);
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;
goto fail;
}
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)
goto fail;
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;
fail:
av_packet_unref(pkt);
return ret;
}
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
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