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5fd63f3c3b
FFmpeg/libavformat/mpegts.c
Michael Niedermayer 5fd63f3c3b Ensure that the timestamp reading code used for seeking chooses a position 
which is a multiple of the packet size from the last packet start instead
of the file start. This fixes some seek issues with randomly cut ts files
and the mysterious "4 byte PCR somehing MTS something bug".

Originally committed as revision 12932 to svn://svn.ffmpeg.org/ffmpeg/trunk
2008-04-23 21:16:25 +00:00

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/*
* MPEG2 transport stream (aka DVB) demuxer
* Copyright (c) 2002-2003 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 "crc.h"
#include "mpegts.h"
//#define DEBUG_SI
//#define DEBUG_SEEK
/* 1.0 second at 24Mbit/s */
#define MAX_SCAN_PACKETS 32000
/* maximum size in which we look for synchronisation if
synchronisation is lost */
#define MAX_RESYNC_SIZE 4096
#define REGISTRATION_DESCRIPTOR 5
typedef struct PESContext PESContext;
static PESContext* add_pes_stream(MpegTSContext *ts, int pid, int pcr_pid, int stream_type);
static AVStream* new_pes_av_stream(PESContext *pes, uint32_t code);
extern void av_set_program_name(AVProgram *program, char *provider_name, char *name);
extern void av_program_add_stream_index(AVFormatContext *ac, int progid, unsigned int idx);
enum MpegTSFilterType {
MPEGTS_PES,
MPEGTS_SECTION,
};
typedef struct MpegTSFilter MpegTSFilter;
typedef void PESCallback(MpegTSFilter *f, const uint8_t *buf, int len, int is_start);
typedef struct MpegTSPESFilter {
PESCallback *pes_cb;
void *opaque;
} MpegTSPESFilter;
typedef void SectionCallback(MpegTSFilter *f, const uint8_t *buf, int len);
typedef void SetServiceCallback(void *opaque, int ret);
typedef struct MpegTSSectionFilter {
int section_index;
int section_h_size;
uint8_t *section_buf;
int check_crc:1;
int end_of_section_reached:1;
SectionCallback *section_cb;
void *opaque;
} MpegTSSectionFilter;
struct MpegTSFilter {
int pid;
int last_cc; /* last cc code (-1 if first packet) */
enum MpegTSFilterType type;
union {
MpegTSPESFilter pes_filter;
MpegTSSectionFilter section_filter;
} u;
};
#define MAX_PIDS_PER_PROGRAM 64
typedef struct {
unsigned int id; //program id/service id
unsigned int nb_pids;
unsigned int pids[MAX_PIDS_PER_PROGRAM];
} Program_t;
struct MpegTSContext {
/* user data */
AVFormatContext *stream;
/** raw packet size, including FEC if present */
int raw_packet_size;
int pos47;
/** if true, all pids are analyzed to find streams */
int auto_guess;
/** compute exact PCR for each transport stream packet */
int mpeg2ts_compute_pcr;
int64_t cur_pcr; /**< used to estimate the exact PCR */
int pcr_incr; /**< used to estimate the exact PCR */
/* data needed to handle file based ts */
/** stop parsing loop */
int stop_parse;
/** packet containing Audio/Video data */
AVPacket *pkt;
/******************************************/
/* private mpegts data */
/* scan context */
/** structure to keep track of Program->pids mapping */
unsigned int nb_prg;
Program_t *prg;
/** filters for various streams specified by PMT + for the PAT and PMT */
MpegTSFilter *pids[NB_PID_MAX];
};
/* TS stream handling */
enum MpegTSState {
MPEGTS_HEADER = 0,
MPEGTS_PESHEADER_FILL,
MPEGTS_PAYLOAD,
MPEGTS_SKIP,
};
/* enough for PES header + length */
#define PES_START_SIZE 9
#define MAX_PES_HEADER_SIZE (9 + 255)
struct PESContext {
int pid;
int pcr_pid; /**< if -1 then all packets containing PCR are considered */
int stream_type;
MpegTSContext *ts;
AVFormatContext *stream;
AVStream *st;
enum MpegTSState state;
/* used to get the format */
int data_index;
int total_size;
int pes_header_size;
int64_t pts, dts;
uint8_t header[MAX_PES_HEADER_SIZE];
};
extern AVInputFormat mpegts_demuxer;
static void clear_program(MpegTSContext *ts, unsigned int programid)
{
int i;
for(i=0; i<ts->nb_prg; i++)
if(ts->prg[i].id == programid)
ts->prg[i].nb_pids = 0;
}
static void clear_programs(MpegTSContext *ts)
{
av_freep(&ts->prg);
ts->nb_prg=0;
}
static void add_pat_entry(MpegTSContext *ts, unsigned int programid)
{
Program_t *p;
void *tmp = av_realloc(ts->prg, (ts->nb_prg+1)*sizeof(Program_t));
if(!tmp)
return;
ts->prg = tmp;
p = &ts->prg[ts->nb_prg];
p->id = programid;
p->nb_pids = 0;
ts->nb_prg++;
}
static void add_pid_to_pmt(MpegTSContext *ts, unsigned int programid, unsigned int pid)
{
int i;
Program_t *p = NULL;
for(i=0; i<ts->nb_prg; i++) {
if(ts->prg[i].id == programid) {
p = &ts->prg[i];
break;
}
}
if(!p)
return;
if(p->nb_pids >= MAX_PIDS_PER_PROGRAM)
return;
p->pids[p->nb_pids++] = pid;
}
/**
* \brief discard_pid() decides if the pid is to be discarded according
* to caller's programs selection
* \param ts : - TS context
* \param pid : - pid
* \return 1 if the pid is only comprised in programs that have .discard=AVDISCARD_ALL
* 0 otherwise
*/
static int discard_pid(MpegTSContext *ts, unsigned int pid)
{
int i, j, k;
int used = 0, discarded = 0;
Program_t *p;
for(i=0; i<ts->nb_prg; i++) {
p = &ts->prg[i];
for(j=0; j<p->nb_pids; j++) {
if(p->pids[j] != pid)
continue;
//is program with id p->id set to be discarded?
for(k=0; k<ts->stream->nb_programs; k++) {
if(ts->stream->programs[k]->id == p->id) {
if(ts->stream->programs[k]->discard == AVDISCARD_ALL)
discarded++;
else
used++;
}
}
}
}
return (!used && discarded);
}
/**
* Assembles PES packets out of TS packets, and then calls the "section_cb"
* function when they are complete.
*/
static void write_section_data(AVFormatContext *s, MpegTSFilter *tss1,
const uint8_t *buf, int buf_size, int is_start)
{
MpegTSSectionFilter *tss = &tss1->u.section_filter;
int len;
if (is_start) {
memcpy(tss->section_buf, buf, buf_size);
tss->section_index = buf_size;
tss->section_h_size = -1;
tss->end_of_section_reached = 0;
} else {
if (tss->end_of_section_reached)
return;
len = 4096 - tss->section_index;
if (buf_size < len)
len = buf_size;
memcpy(tss->section_buf + tss->section_index, buf, len);
tss->section_index += len;
}
/* compute section length if possible */
if (tss->section_h_size == -1 && tss->section_index >= 3) {
len = (AV_RB16(tss->section_buf + 1) & 0xfff) + 3;
if (len > 4096)
return;
tss->section_h_size = len;
}
if (tss->section_h_size != -1 && tss->section_index >= tss->section_h_size) {
tss->end_of_section_reached = 1;
if (!tss->check_crc ||
av_crc(av_crc_get_table(AV_CRC_32_IEEE), -1,
tss->section_buf, tss->section_h_size) == 0)
tss->section_cb(tss1, tss->section_buf, tss->section_h_size);
}
}
static MpegTSFilter *mpegts_open_section_filter(MpegTSContext *ts, unsigned int pid,
SectionCallback *section_cb, void *opaque,
int check_crc)
{
MpegTSFilter *filter;
MpegTSSectionFilter *sec;
#ifdef DEBUG_SI
av_log(ts->stream, AV_LOG_DEBUG, "Filter: pid=0x%x\n", pid);
#endif
if (pid >= NB_PID_MAX || ts->pids[pid])
return NULL;
filter = av_mallocz(sizeof(MpegTSFilter));
if (!filter)
return NULL;
ts->pids[pid] = filter;
filter->type = MPEGTS_SECTION;
filter->pid = pid;
filter->last_cc = -1;
sec = &filter->u.section_filter;
sec->section_cb = section_cb;
sec->opaque = opaque;
sec->section_buf = av_malloc(MAX_SECTION_SIZE);
sec->check_crc = check_crc;
if (!sec->section_buf) {
av_free(filter);
return NULL;
}
return filter;
}
static MpegTSFilter *mpegts_open_pes_filter(MpegTSContext *ts, unsigned int pid,
PESCallback *pes_cb,
void *opaque)
{
MpegTSFilter *filter;
MpegTSPESFilter *pes;
if (pid >= NB_PID_MAX || ts->pids[pid])
return NULL;
filter = av_mallocz(sizeof(MpegTSFilter));
if (!filter)
return NULL;
ts->pids[pid] = filter;
filter->type = MPEGTS_PES;
filter->pid = pid;
filter->last_cc = -1;
pes = &filter->u.pes_filter;
pes->pes_cb = pes_cb;
pes->opaque = opaque;
return filter;
}
static void mpegts_close_filter(MpegTSContext *ts, MpegTSFilter *filter)
{
int pid;
pid = filter->pid;
if (filter->type == MPEGTS_SECTION)
av_freep(&filter->u.section_filter.section_buf);
else if (filter->type == MPEGTS_PES)
av_freep(&filter->u.pes_filter.opaque);
av_free(filter);
ts->pids[pid] = NULL;
}
static int analyze(const uint8_t *buf, int size, int packet_size, int *index){
int stat[packet_size];
int i;
int x=0;
int best_score=0;
memset(stat, 0, packet_size*sizeof(int));
for(x=i=0; i<size; i++){
if(buf[i] == 0x47){
stat[x]++;
if(stat[x] > best_score){
best_score= stat[x];
if(index) *index= x;
}
}
x++;
if(x == packet_size) x= 0;
}
return best_score;
}
/* autodetect fec presence. Must have at least 1024 bytes */
static int get_packet_size(const uint8_t *buf, int size)
{
int score, fec_score, dvhs_score;
if (size < (TS_FEC_PACKET_SIZE * 5 + 1))
return -1;
score = analyze(buf, size, TS_PACKET_SIZE, NULL);
dvhs_score = analyze(buf, size, TS_DVHS_PACKET_SIZE, NULL);
fec_score= analyze(buf, size, TS_FEC_PACKET_SIZE, NULL);
// av_log(NULL, AV_LOG_DEBUG, "score: %d, dvhs_score: %d, fec_score: %d \n", score, dvhs_score, fec_score);
if (score > fec_score && score > dvhs_score) return TS_PACKET_SIZE;
else if(dvhs_score > score && dvhs_score > fec_score) return TS_DVHS_PACKET_SIZE;
else if(score < fec_score && dvhs_score < fec_score) return TS_FEC_PACKET_SIZE;
else return -1;
}
typedef struct SectionHeader {
uint8_t tid;
uint16_t id;
uint8_t version;
uint8_t sec_num;
uint8_t last_sec_num;
} SectionHeader;
static inline int get8(const uint8_t **pp, const uint8_t *p_end)
{
const uint8_t *p;
int c;
p = *pp;
if (p >= p_end)
return -1;
c = *p++;
*pp = p;
return c;
}
static inline int get16(const uint8_t **pp, const uint8_t *p_end)
{
const uint8_t *p;
int c;
p = *pp;
if ((p + 1) >= p_end)
return -1;
c = AV_RB16(p);
p += 2;
*pp = p;
return c;
}
/* read and allocate a DVB string preceeded by its length */
static char *getstr8(const uint8_t **pp, const uint8_t *p_end)
{
int len;
const uint8_t *p;
char *str;
p = *pp;
len = get8(&p, p_end);
if (len < 0)
return NULL;
if ((p + len) > p_end)
return NULL;
str = av_malloc(len + 1);
if (!str)
return NULL;
memcpy(str, p, len);
str[len] = '\0';
p += len;
*pp = p;
return str;
}
static int parse_section_header(SectionHeader *h,
const uint8_t **pp, const uint8_t *p_end)
{
int val;
val = get8(pp, p_end);
if (val < 0)
return -1;
h->tid = val;
*pp += 2;
val = get16(pp, p_end);
if (val < 0)
return -1;
h->id = val;
val = get8(pp, p_end);
if (val < 0)
return -1;
h->version = (val >> 1) & 0x1f;
val = get8(pp, p_end);
if (val < 0)
return -1;
h->sec_num = val;
val = get8(pp, p_end);
if (val < 0)
return -1;
h->last_sec_num = val;
return 0;
}
static void pmt_cb(MpegTSFilter *filter, const uint8_t *section, int section_len)
{
MpegTSContext *ts = filter->u.section_filter.opaque;
SectionHeader h1, *h = &h1;
PESContext *pes;
AVStream *st;
const uint8_t *p, *p_end, *desc_list_end, *desc_end;
int program_info_length, pcr_pid, pid, stream_type;
int desc_list_len, desc_len, desc_tag;
int comp_page = 0, anc_page = 0; /* initialize to kill warnings */
char language[4] = {0}; /* initialize to kill warnings */
int has_hdmv_descr = 0;
#ifdef DEBUG_SI
av_log(ts->stream, AV_LOG_DEBUG, "PMT: len %i\n", section_len);
av_hex_dump_log(ts->stream, AV_LOG_DEBUG, (uint8_t *)section, section_len);
#endif
p_end = section + section_len - 4;
p = section;
if (parse_section_header(h, &p, p_end) < 0)
return;
#ifdef DEBUG_SI
av_log(ts->stream, AV_LOG_DEBUG, "sid=0x%x sec_num=%d/%d\n",
h->id, h->sec_num, h->last_sec_num);
#endif
if (h->tid != PMT_TID)
return;
clear_program(ts, h->id);
pcr_pid = get16(&p, p_end) & 0x1fff;
if (pcr_pid < 0)
return;
add_pid_to_pmt(ts, h->id, pcr_pid);
#ifdef DEBUG_SI
av_log(ts->stream, AV_LOG_DEBUG, "pcr_pid=0x%x\n", pcr_pid);
#endif
program_info_length = get16(&p, p_end) & 0xfff;
if (program_info_length < 0)
return;
while(program_info_length >= 2) {
uint8_t tag, len;
tag = get8(&p, p_end);
len = get8(&p, p_end);
if(len > program_info_length - 2)
//something else is broken, exit the program_descriptors_loop
break;
program_info_length -= len + 2;
if(tag == REGISTRATION_DESCRIPTOR && len >= 4) {
uint8_t bytes[4];
bytes[0] = get8(&p, p_end);
bytes[1] = get8(&p, p_end);
bytes[2] = get8(&p, p_end);
bytes[3] = get8(&p, p_end);
len -= 4;
if(bytes[0] == 'H' && bytes[1] == 'D' &&
bytes[2] == 'M' && bytes[3] == 'V')
has_hdmv_descr = 1;
}
p += len;
}
p += program_info_length;
if (p >= p_end)
return;
for(;;) {
language[0] = 0;
st = 0;
stream_type = get8(&p, p_end);
if (stream_type < 0)
break;
pid = get16(&p, p_end) & 0x1fff;
if (pid < 0)
break;
desc_list_len = get16(&p, p_end) & 0xfff;
if (desc_list_len < 0)
break;
desc_list_end = p + desc_list_len;
if (desc_list_end > p_end)
break;
for(;;) {
desc_tag = get8(&p, desc_list_end);
if (desc_tag < 0)
break;
if (stream_type == STREAM_TYPE_PRIVATE_DATA) {
if((desc_tag == 0x6A) || (desc_tag == 0x7A)) {
/*assume DVB AC-3 Audio*/
stream_type = STREAM_TYPE_AUDIO_AC3;
} else if(desc_tag == 0x7B) {
/* DVB DTS audio */
stream_type = STREAM_TYPE_AUDIO_DTS;
}
}
desc_len = get8(&p, desc_list_end);
desc_end = p + desc_len;
if (desc_end > desc_list_end)
break;
#ifdef DEBUG_SI
av_log(ts->stream, AV_LOG_DEBUG, "tag: 0x%02x len=%d\n",
desc_tag, desc_len);
#endif
switch(desc_tag) {
case DVB_SUBT_DESCID:
if (stream_type == STREAM_TYPE_PRIVATE_DATA)
stream_type = STREAM_TYPE_SUBTITLE_DVB;
language[0] = get8(&p, desc_end);
language[1] = get8(&p, desc_end);
language[2] = get8(&p, desc_end);
language[3] = 0;
get8(&p, desc_end);
comp_page = get16(&p, desc_end);
anc_page = get16(&p, desc_end);
break;
case 0x0a: /* ISO 639 language descriptor */
language[0] = get8(&p, desc_end);
language[1] = get8(&p, desc_end);
language[2] = get8(&p, desc_end);
language[3] = 0;
break;
default:
break;
}
p = desc_end;
}
p = desc_list_end;
#ifdef DEBUG_SI
av_log(ts->stream, AV_LOG_DEBUG, "stream_type=%d pid=0x%x\n",
stream_type, pid);
#endif
/* now create ffmpeg stream */
switch(stream_type) {
case STREAM_TYPE_AUDIO_MPEG1:
case STREAM_TYPE_AUDIO_MPEG2:
case STREAM_TYPE_VIDEO_MPEG1:
case STREAM_TYPE_VIDEO_MPEG2:
case STREAM_TYPE_VIDEO_MPEG4:
case STREAM_TYPE_VIDEO_H264:
case STREAM_TYPE_VIDEO_VC1:
case STREAM_TYPE_AUDIO_AAC:
case STREAM_TYPE_AUDIO_AC3:
case STREAM_TYPE_AUDIO_DTS:
case STREAM_TYPE_AUDIO_HDMV_DTS:
case STREAM_TYPE_SUBTITLE_DVB:
if(stream_type == STREAM_TYPE_AUDIO_HDMV_DTS && !has_hdmv_descr)
break;
if(ts->pids[pid] && ts->pids[pid]->type == MPEGTS_PES){
pes= ts->pids[pid]->u.pes_filter.opaque;
st= pes->st;
}else{
if (ts->pids[pid]) mpegts_close_filter(ts, ts->pids[pid]); //wrongly added sdt filter probably
pes = add_pes_stream(ts, pid, pcr_pid, stream_type);
if (pes)
st = new_pes_av_stream(pes, 0);
}
add_pid_to_pmt(ts, h->id, pid);
if(st)
av_program_add_stream_index(ts->stream, h->id, st->index);
break;
default:
/* we ignore the other streams */
break;
}
if (st) {
if (language[0] != 0) {
memcpy(st->language, language, 4);
}
if (stream_type == STREAM_TYPE_SUBTITLE_DVB) {
st->codec->sub_id = (anc_page << 16) | comp_page;
}
}
}
/* all parameters are there */
ts->stop_parse++;
mpegts_close_filter(ts, filter);
}
static void pat_cb(MpegTSFilter *filter, const uint8_t *section, int section_len)
{
MpegTSContext *ts = filter->u.section_filter.opaque;
SectionHeader h1, *h = &h1;
const uint8_t *p, *p_end;
int sid, pmt_pid;
#ifdef DEBUG_SI
av_log(ts->stream, AV_LOG_DEBUG, "PAT:\n");
av_hex_dump_log(ts->stream, AV_LOG_DEBUG, (uint8_t *)section, section_len);
#endif
p_end = section + section_len - 4;
p = section;
if (parse_section_header(h, &p, p_end) < 0)
return;
if (h->tid != PAT_TID)
return;
clear_programs(ts);
for(;;) {
sid = get16(&p, p_end);
if (sid < 0)
break;
pmt_pid = get16(&p, p_end) & 0x1fff;
if (pmt_pid < 0)
break;
#ifdef DEBUG_SI
av_log(ts->stream, AV_LOG_DEBUG, "sid=0x%x pid=0x%x\n", sid, pmt_pid);
#endif
if (sid == 0x0000) {
/* NIT info */
} else {
av_new_program(ts->stream, sid);
ts->stop_parse--;
mpegts_open_section_filter(ts, pmt_pid, pmt_cb, ts, 1);
add_pat_entry(ts, sid);
add_pid_to_pmt(ts, sid, 0); //add pat pid to program
add_pid_to_pmt(ts, sid, pmt_pid);
}
}
/* not found */
ts->stop_parse++;
mpegts_close_filter(ts, filter);
}
static void mpegts_set_service(MpegTSContext *ts)
{
mpegts_open_section_filter(ts, PAT_PID,
pat_cb, ts, 1);
}
static void sdt_cb(MpegTSFilter *filter, const uint8_t *section, int section_len)
{
MpegTSContext *ts = filter->u.section_filter.opaque;
SectionHeader h1, *h = &h1;
const uint8_t *p, *p_end, *desc_list_end, *desc_end;
int onid, val, sid, desc_list_len, desc_tag, desc_len, service_type;
char *name, *provider_name;
#ifdef DEBUG_SI
av_log(ts->stream, AV_LOG_DEBUG, "SDT:\n");
av_hex_dump_log(ts->stream, AV_LOG_DEBUG, (uint8_t *)section, section_len);
#endif
p_end = section + section_len - 4;
p = section;
if (parse_section_header(h, &p, p_end) < 0)
return;
if (h->tid != SDT_TID)
return;
onid = get16(&p, p_end);
if (onid < 0)
return;
val = get8(&p, p_end);
if (val < 0)
return;
for(;;) {
sid = get16(&p, p_end);
if (sid < 0)
break;
val = get8(&p, p_end);
if (val < 0)
break;
desc_list_len = get16(&p, p_end) & 0xfff;
if (desc_list_len < 0)
break;
desc_list_end = p + desc_list_len;
if (desc_list_end > p_end)
break;
for(;;) {
desc_tag = get8(&p, desc_list_end);
if (desc_tag < 0)
break;
desc_len = get8(&p, desc_list_end);
desc_end = p + desc_len;
if (desc_end > desc_list_end)
break;
#ifdef DEBUG_SI
av_log(ts->stream, AV_LOG_DEBUG, "tag: 0x%02x len=%d\n",
desc_tag, desc_len);
#endif
switch(desc_tag) {
case 0x48:
service_type = get8(&p, p_end);
if (service_type < 0)
break;
provider_name = getstr8(&p, p_end);
if (!provider_name)
break;
name = getstr8(&p, p_end);
if (name) {
AVProgram *program = av_new_program(ts->stream, sid);
if(program)
av_set_program_name(program, provider_name, name);
}
break;
default:
break;
}
p = desc_end;
}
p = desc_list_end;
}
}
/* scan services in a transport stream by looking at the SDT */
static void mpegts_scan_sdt(MpegTSContext *ts)
{
mpegts_open_section_filter(ts, SDT_PID,
sdt_cb, ts, 1);
}
static int64_t get_pts(const uint8_t *p)
{
int64_t pts = (int64_t)((p[0] >> 1) & 0x07) << 30;
pts |= (AV_RB16(p + 1) >> 1) << 15;
pts |= AV_RB16(p + 3) >> 1;
return pts;
}
/* return non zero if a packet could be constructed */
static void mpegts_push_data(MpegTSFilter *filter,
const uint8_t *buf, int buf_size, int is_start)
{
PESContext *pes = filter->u.pes_filter.opaque;
MpegTSContext *ts = pes->ts;
const uint8_t *p;
int len, code;
if(!ts->pkt)
return;
if (is_start) {
pes->state = MPEGTS_HEADER;
pes->data_index = 0;
}
p = buf;
while (buf_size > 0) {
switch(pes->state) {
case MPEGTS_HEADER:
len = PES_START_SIZE - pes->data_index;
if (len > buf_size)
len = buf_size;
memcpy(pes->header + pes->data_index, p, len);
pes->data_index += len;
p += len;
buf_size -= len;
if (pes->data_index == PES_START_SIZE) {
/* we got all the PES or section header. We can now
decide */
#if 0
av_hex_dump_log(pes->stream, AV_LOG_DEBUG, pes->header, pes->data_index);
#endif
if (pes->header[0] == 0x00 && pes->header[1] == 0x00 &&
pes->header[2] == 0x01) {
/* it must be an mpeg2 PES stream */
code = pes->header[3] | 0x100;
if (!((code >= 0x1c0 && code <= 0x1df) ||
(code >= 0x1e0 && code <= 0x1ef) ||
(code == 0x1bd) || (code == 0x1fd)))
goto skip;
if (!pes->st) {
/* allocate stream */
new_pes_av_stream(pes, code);
}
pes->state = MPEGTS_PESHEADER_FILL;
pes->total_size = AV_RB16(pes->header + 4);
/* NOTE: a zero total size means the PES size is
unbounded */
if (pes->total_size)
pes->total_size += 6;
pes->pes_header_size = pes->header[8] + 9;
} else {
/* otherwise, it should be a table */
/* skip packet */
skip:
pes->state = MPEGTS_SKIP;
continue;
}
}
break;
/**********************************************/
/* PES packing parsing */
case MPEGTS_PESHEADER_FILL:
len = pes->pes_header_size - pes->data_index;
if (len > buf_size)
len = buf_size;
memcpy(pes->header + pes->data_index, p, len);
pes->data_index += len;
p += len;
buf_size -= len;
if (pes->data_index == pes->pes_header_size) {
const uint8_t *r;
unsigned int flags;
flags = pes->header[7];
r = pes->header + 9;
pes->pts = AV_NOPTS_VALUE;
pes->dts = AV_NOPTS_VALUE;
if ((flags & 0xc0) == 0x80) {
pes->pts = get_pts(r);
r += 5;
} else if ((flags & 0xc0) == 0xc0) {
pes->pts = get_pts(r);
r += 5;
pes->dts = get_pts(r);
r += 5;
}
/* we got the full header. We parse it and get the payload */
pes->state = MPEGTS_PAYLOAD;
}
break;
case MPEGTS_PAYLOAD:
if (pes->total_size) {
len = pes->total_size - pes->data_index;
if (len > buf_size)
len = buf_size;
} else {
len = buf_size;
}
if (len > 0) {
AVPacket *pkt = ts->pkt;
if (pes->st && av_new_packet(pkt, len) == 0) {
memcpy(pkt->data, p, len);
pkt->stream_index = pes->st->index;
pkt->pts = pes->pts;
pkt->dts = pes->dts;
/* reset pts values */
pes->pts = AV_NOPTS_VALUE;
pes->dts = AV_NOPTS_VALUE;
ts->stop_parse = 1;
return;
}
}
buf_size = 0;
break;
case MPEGTS_SKIP:
buf_size = 0;
break;
}
}
}
static AVStream* new_pes_av_stream(PESContext *pes, uint32_t code)
{
AVStream *st;
int codec_type, codec_id;
switch(pes->stream_type){
case STREAM_TYPE_AUDIO_MPEG1:
case STREAM_TYPE_AUDIO_MPEG2:
codec_type = CODEC_TYPE_AUDIO;
codec_id = CODEC_ID_MP3;
break;
case STREAM_TYPE_VIDEO_MPEG1:
case STREAM_TYPE_VIDEO_MPEG2:
codec_type = CODEC_TYPE_VIDEO;
codec_id = CODEC_ID_MPEG2VIDEO;
break;
case STREAM_TYPE_VIDEO_MPEG4:
codec_type = CODEC_TYPE_VIDEO;
codec_id = CODEC_ID_MPEG4;
break;
case STREAM_TYPE_VIDEO_H264:
codec_type = CODEC_TYPE_VIDEO;
codec_id = CODEC_ID_H264;
break;
case STREAM_TYPE_VIDEO_VC1:
codec_type = CODEC_TYPE_VIDEO;
codec_id = CODEC_ID_VC1;
break;
case STREAM_TYPE_AUDIO_AAC:
codec_type = CODEC_TYPE_AUDIO;
codec_id = CODEC_ID_AAC;
break;
case STREAM_TYPE_AUDIO_AC3:
codec_type = CODEC_TYPE_AUDIO;
codec_id = CODEC_ID_AC3;
break;
case STREAM_TYPE_AUDIO_DTS:
case STREAM_TYPE_AUDIO_HDMV_DTS:
codec_type = CODEC_TYPE_AUDIO;
codec_id = CODEC_ID_DTS;
break;
case STREAM_TYPE_SUBTITLE_DVB:
codec_type = CODEC_TYPE_SUBTITLE;
codec_id = CODEC_ID_DVB_SUBTITLE;
break;
default:
if (code >= 0x1c0 && code <= 0x1df) {
codec_type = CODEC_TYPE_AUDIO;
codec_id = CODEC_ID_MP2;
} else if (code == 0x1bd) {
codec_type = CODEC_TYPE_AUDIO;
codec_id = CODEC_ID_AC3;
} else {
codec_type = CODEC_TYPE_VIDEO;
codec_id = CODEC_ID_MPEG1VIDEO;
}
break;
}
st = av_new_stream(pes->stream, pes->pid);
if (st) {
av_set_pts_info(st, 33, 1, 90000);
st->priv_data = pes;
st->codec->codec_type = codec_type;
st->codec->codec_id = codec_id;
st->need_parsing = AVSTREAM_PARSE_FULL;
pes->st = st;
}
return st;
}
static PESContext *add_pes_stream(MpegTSContext *ts, int pid, int pcr_pid, int stream_type)
{
MpegTSFilter *tss;
PESContext *pes;
/* if no pid found, then add a pid context */
pes = av_mallocz(sizeof(PESContext));
if (!pes)
return 0;
pes->ts = ts;
pes->stream = ts->stream;
pes->pid = pid;
pes->pcr_pid = pcr_pid;
pes->stream_type = stream_type;
tss = mpegts_open_pes_filter(ts, pid, mpegts_push_data, pes);
if (!tss) {
av_free(pes);
return 0;
}
return pes;
}
/* handle one TS packet */
static void handle_packet(MpegTSContext *ts, const uint8_t *packet)
{
AVFormatContext *s = ts->stream;
MpegTSFilter *tss;
int len, pid, cc, cc_ok, afc, is_start;
const uint8_t *p, *p_end;
pid = AV_RB16(packet + 1) & 0x1fff;
if(pid && discard_pid(ts, pid))
return;
is_start = packet[1] & 0x40;
tss = ts->pids[pid];
if (ts->auto_guess && tss == NULL && is_start) {
add_pes_stream(ts, pid, -1, 0);
tss = ts->pids[pid];
}
if (!tss)
return;
/* continuity check (currently not used) */
cc = (packet[3] & 0xf);
cc_ok = (tss->last_cc < 0) || ((((tss->last_cc + 1) & 0x0f) == cc));
tss->last_cc = cc;
/* skip adaptation field */
afc = (packet[3] >> 4) & 3;
p = packet + 4;
if (afc == 0) /* reserved value */
return;
if (afc == 2) /* adaptation field only */
return;
if (afc == 3) {
/* skip adapation field */
p += p[0] + 1;
}
/* if past the end of packet, ignore */
p_end = packet + TS_PACKET_SIZE;
if (p >= p_end)
return;
ts->pos47= url_ftell(ts->stream->pb) % ts->raw_packet_size;
if (tss->type == MPEGTS_SECTION) {
if (is_start) {
/* pointer field present */
len = *p++;
if (p + len > p_end)
return;
if (len && cc_ok) {
/* write remaining section bytes */
write_section_data(s, tss,
p, len, 0);
/* check whether filter has been closed */
if (!ts->pids[pid])
return;
}
p += len;
if (p < p_end) {
write_section_data(s, tss,
p, p_end - p, 1);
}
} else {
if (cc_ok) {
write_section_data(s, tss,
p, p_end - p, 0);
}
}
} else {
tss->u.pes_filter.pes_cb(tss,
p, p_end - p, is_start);
}
}
/* XXX: try to find a better synchro over several packets (use
get_packet_size() ?) */
static int mpegts_resync(ByteIOContext *pb)
{
int c, i;
for(i = 0;i < MAX_RESYNC_SIZE; i++) {
c = url_fgetc(pb);
if (c < 0)
return -1;
if (c == 0x47) {
url_fseek(pb, -1, SEEK_CUR);
return 0;
}
}
/* no sync found */
return -1;
}
/* return -1 if error or EOF. Return 0 if OK. */
static int read_packet(ByteIOContext *pb, uint8_t *buf, int raw_packet_size)
{
int skip, len;
for(;;) {
len = get_buffer(pb, buf, TS_PACKET_SIZE);
if (len != TS_PACKET_SIZE)
return AVERROR(EIO);
/* check paquet sync byte */
if (buf[0] != 0x47) {
/* find a new packet start */
url_fseek(pb, -TS_PACKET_SIZE, SEEK_CUR);
if (mpegts_resync(pb) < 0)
return AVERROR_INVALIDDATA;
else
continue;
} else {
skip = raw_packet_size - TS_PACKET_SIZE;
if (skip > 0)
url_fskip(pb, skip);
break;
}
}
return 0;
}
static int handle_packets(MpegTSContext *ts, int nb_packets)
{
AVFormatContext *s = ts->stream;
ByteIOContext *pb = s->pb;
uint8_t packet[TS_PACKET_SIZE];
int packet_num, ret;
ts->stop_parse = 0;
packet_num = 0;
for(;;) {
if (ts->stop_parse>0)
break;
packet_num++;
if (nb_packets != 0 && packet_num >= nb_packets)
break;
ret = read_packet(pb, packet, ts->raw_packet_size);
if (ret != 0)
return ret;
handle_packet(ts, packet);
}
return 0;
}
static int mpegts_probe(AVProbeData *p)
{
#if 1
const int size= p->buf_size;
int score, fec_score, dvhs_score;
#define CHECK_COUNT 10
if (size < (TS_FEC_PACKET_SIZE * CHECK_COUNT))
return -1;
score = analyze(p->buf, TS_PACKET_SIZE *CHECK_COUNT, TS_PACKET_SIZE, NULL);
dvhs_score = analyze(p->buf, TS_DVHS_PACKET_SIZE *CHECK_COUNT, TS_DVHS_PACKET_SIZE, NULL);
fec_score= analyze(p->buf, TS_FEC_PACKET_SIZE*CHECK_COUNT, TS_FEC_PACKET_SIZE, NULL);
// av_log(NULL, AV_LOG_DEBUG, "score: %d, dvhs_score: %d, fec_score: %d \n", score, dvhs_score, fec_score);
// we need a clear definition for the returned score otherwise things will become messy sooner or later
if (score > fec_score && score > dvhs_score && score > 6) return AVPROBE_SCORE_MAX + score - CHECK_COUNT;
else if(dvhs_score > score && dvhs_score > fec_score && dvhs_score > 6) return AVPROBE_SCORE_MAX + dvhs_score - CHECK_COUNT;
else if( fec_score > 6) return AVPROBE_SCORE_MAX + fec_score - CHECK_COUNT;
else return -1;
#else
/* only use the extension for safer guess */
if (match_ext(p->filename, "ts"))
return AVPROBE_SCORE_MAX;
else
return 0;
#endif
}
/* return the 90 kHz PCR and the extension for the 27 MHz PCR. return
(-1) if not available */
static int parse_pcr(int64_t *ppcr_high, int *ppcr_low,
const uint8_t *packet)
{
int afc, len, flags;
const uint8_t *p;
unsigned int v;
afc = (packet[3] >> 4) & 3;
if (afc <= 1)
return -1;
p = packet + 4;
len = p[0];
p++;
if (len == 0)
return -1;
flags = *p++;
len--;
if (!(flags & 0x10))
return -1;
if (len < 6)
return -1;
v = AV_RB32(p);
*ppcr_high = ((int64_t)v << 1) | (p[4] >> 7);
*ppcr_low = ((p[4] & 1) << 8) | p[5];
return 0;
}
static int mpegts_read_header(AVFormatContext *s,
AVFormatParameters *ap)
{
MpegTSContext *ts = s->priv_data;
ByteIOContext *pb = s->pb;
uint8_t buf[1024];
int len;
int64_t pos;
if (ap) {
ts->mpeg2ts_compute_pcr = ap->mpeg2ts_compute_pcr;
if(ap->mpeg2ts_raw){
av_log(s, AV_LOG_ERROR, "use mpegtsraw_demuxer!\n");
return -1;
}
}
/* read the first 1024 bytes to get packet size */
pos = url_ftell(pb);
len = get_buffer(pb, buf, sizeof(buf));
if (len != sizeof(buf))
goto fail;
ts->raw_packet_size = get_packet_size(buf, sizeof(buf));
if (ts->raw_packet_size <= 0)
goto fail;
ts->stream = s;
ts->auto_guess = 0;
if (s->iformat == &mpegts_demuxer) {
/* normal demux */
/* first do a scaning to get all the services */
url_fseek(pb, pos, SEEK_SET);
mpegts_scan_sdt(ts);
mpegts_set_service(ts);
handle_packets(ts, s->probesize);
/* if could not find service, enable auto_guess */
ts->auto_guess = 1;
#ifdef DEBUG_SI
av_log(ts->stream, AV_LOG_DEBUG, "tuning done\n");
#endif
s->ctx_flags |= AVFMTCTX_NOHEADER;
} else {
AVStream *st;
int pcr_pid, pid, nb_packets, nb_pcrs, ret, pcr_l;
int64_t pcrs[2], pcr_h;
int packet_count[2];
uint8_t packet[TS_PACKET_SIZE];
/* only read packets */
st = av_new_stream(s, 0);
if (!st)
goto fail;
av_set_pts_info(st, 60, 1, 27000000);
st->codec->codec_type = CODEC_TYPE_DATA;
st->codec->codec_id = CODEC_ID_MPEG2TS;
/* we iterate until we find two PCRs to estimate the bitrate */
pcr_pid = -1;
nb_pcrs = 0;
nb_packets = 0;
for(;;) {
ret = read_packet(s->pb, packet, ts->raw_packet_size);
if (ret < 0)
return -1;
pid = AV_RB16(packet + 1) & 0x1fff;
if ((pcr_pid == -1 || pcr_pid == pid) &&
parse_pcr(&pcr_h, &pcr_l, packet) == 0) {
pcr_pid = pid;
packet_count[nb_pcrs] = nb_packets;
pcrs[nb_pcrs] = pcr_h * 300 + pcr_l;
nb_pcrs++;
if (nb_pcrs >= 2)
break;
}
nb_packets++;
}
/* NOTE1: the bitrate is computed without the FEC */
/* NOTE2: it is only the bitrate of the start of the stream */
ts->pcr_incr = (pcrs[1] - pcrs[0]) / (packet_count[1] - packet_count[0]);
ts->cur_pcr = pcrs[0] - ts->pcr_incr * packet_count[0];
s->bit_rate = (TS_PACKET_SIZE * 8) * 27e6 / ts->pcr_incr;
st->codec->bit_rate = s->bit_rate;
st->start_time = ts->cur_pcr;
#if 0
av_log(ts->stream, AV_LOG_DEBUG, "start=%0.3f pcr=%0.3f incr=%d\n",
st->start_time / 1000000.0, pcrs[0] / 27e6, ts->pcr_incr);
#endif
}
url_fseek(pb, pos, SEEK_SET);
return 0;
fail:
return -1;
}
#define MAX_PACKET_READAHEAD ((128 * 1024) / 188)
static int mpegts_raw_read_packet(AVFormatContext *s,
AVPacket *pkt)
{
MpegTSContext *ts = s->priv_data;
int ret, i;
int64_t pcr_h, next_pcr_h, pos;
int pcr_l, next_pcr_l;
uint8_t pcr_buf[12];
if (av_new_packet(pkt, TS_PACKET_SIZE) < 0)
return AVERROR(ENOMEM);
pkt->pos= url_ftell(s->pb);
ret = read_packet(s->pb, pkt->data, ts->raw_packet_size);
if (ret < 0) {
av_free_packet(pkt);
return ret;
}
if (ts->mpeg2ts_compute_pcr) {
/* compute exact PCR for each packet */
if (parse_pcr(&pcr_h, &pcr_l, pkt->data) == 0) {
/* we read the next PCR (XXX: optimize it by using a bigger buffer */
pos = url_ftell(s->pb);
for(i = 0; i < MAX_PACKET_READAHEAD; i++) {
url_fseek(s->pb, pos + i * ts->raw_packet_size, SEEK_SET);
get_buffer(s->pb, pcr_buf, 12);
if (parse_pcr(&next_pcr_h, &next_pcr_l, pcr_buf) == 0) {
/* XXX: not precise enough */
ts->pcr_incr = ((next_pcr_h - pcr_h) * 300 + (next_pcr_l - pcr_l)) /
(i + 1);
break;
}
}
url_fseek(s->pb, pos, SEEK_SET);
/* no next PCR found: we use previous increment */
ts->cur_pcr = pcr_h * 300 + pcr_l;
}
pkt->pts = ts->cur_pcr;
pkt->duration = ts->pcr_incr;
ts->cur_pcr += ts->pcr_incr;
}
pkt->stream_index = 0;
return 0;
}
static int mpegts_read_packet(AVFormatContext *s,
AVPacket *pkt)
{
MpegTSContext *ts = s->priv_data;
ts->pkt = pkt;
return handle_packets(ts, 0);
}
static int mpegts_read_close(AVFormatContext *s)
{
MpegTSContext *ts = s->priv_data;
int i;
for(i=0;i<NB_PID_MAX;i++)
if (ts->pids[i]) mpegts_close_filter(ts, ts->pids[i]);
return 0;
}
static int64_t mpegts_get_pcr(AVFormatContext *s, int stream_index,
int64_t *ppos, int64_t pos_limit)
{
MpegTSContext *ts = s->priv_data;
int64_t pos, timestamp;
uint8_t buf[TS_PACKET_SIZE];
int pcr_l, pcr_pid = ((PESContext*)s->streams[stream_index]->priv_data)->pcr_pid;
const int find_next= 1;
pos = ((*ppos + ts->raw_packet_size - 1 - ts->pos47) / ts->raw_packet_size) * ts->raw_packet_size + ts->pos47;
if (find_next) {
for(;;) {
url_fseek(s->pb, pos, SEEK_SET);
if (get_buffer(s->pb, buf, TS_PACKET_SIZE) != TS_PACKET_SIZE)
return AV_NOPTS_VALUE;
if ((pcr_pid < 0 || (AV_RB16(buf + 1) & 0x1fff) == pcr_pid) &&
parse_pcr(&timestamp, &pcr_l, buf) == 0) {
break;
}
pos += ts->raw_packet_size;
}
} else {
for(;;) {
pos -= ts->raw_packet_size;
if (pos < 0)
return AV_NOPTS_VALUE;
url_fseek(s->pb, pos, SEEK_SET);
if (get_buffer(s->pb, buf, TS_PACKET_SIZE) != TS_PACKET_SIZE)
return AV_NOPTS_VALUE;
if ((pcr_pid < 0 || (AV_RB16(buf + 1) & 0x1fff) == pcr_pid) &&
parse_pcr(&timestamp, &pcr_l, buf) == 0) {
break;
}
}
}
*ppos = pos;
return timestamp;
}
static int read_seek(AVFormatContext *s, int stream_index, int64_t target_ts, int flags){
MpegTSContext *ts = s->priv_data;
uint8_t buf[TS_PACKET_SIZE];
int64_t pos;
if(av_seek_frame_binary(s, stream_index, target_ts, flags) < 0)
return -1;
pos= url_ftell(s->pb);
for(;;) {
url_fseek(s->pb, pos, SEEK_SET);
if (get_buffer(s->pb, buf, TS_PACKET_SIZE) != TS_PACKET_SIZE)
return -1;
// pid = AV_RB16(buf + 1) & 0x1fff;
if(buf[1] & 0x40) break;
pos += ts->raw_packet_size;
}
url_fseek(s->pb, pos, SEEK_SET);
return 0;
}
/**************************************************************/
/* parsing functions - called from other demuxers such as RTP */
MpegTSContext *mpegts_parse_open(AVFormatContext *s)
{
MpegTSContext *ts;
ts = av_mallocz(sizeof(MpegTSContext));
if (!ts)
return NULL;
/* no stream case, currently used by RTP */
ts->raw_packet_size = TS_PACKET_SIZE;
ts->stream = s;
ts->auto_guess = 1;
return ts;
}
/* return the consumed length if a packet was output, or -1 if no
packet is output */
int mpegts_parse_packet(MpegTSContext *ts, AVPacket *pkt,
const uint8_t *buf, int len)
{
int len1;
len1 = len;
ts->pkt = pkt;
ts->stop_parse = 0;
for(;;) {
if (ts->stop_parse>0)
break;
if (len < TS_PACKET_SIZE)
return -1;
if (buf[0] != 0x47) {
buf++;
len--;
} else {
handle_packet(ts, buf);
buf += TS_PACKET_SIZE;
len -= TS_PACKET_SIZE;
}
}
return len1 - len;
}
void mpegts_parse_close(MpegTSContext *ts)
{
int i;
for(i=0;i<NB_PID_MAX;i++)
av_free(ts->pids[i]);
av_free(ts);
}
AVInputFormat mpegts_demuxer = {
"mpegts",
"MPEG2 transport stream format",
sizeof(MpegTSContext),
mpegts_probe,
mpegts_read_header,
mpegts_read_packet,
mpegts_read_close,
read_seek,
mpegts_get_pcr,
.flags = AVFMT_SHOW_IDS,
};
AVInputFormat mpegtsraw_demuxer = {
"mpegtsraw",
"MPEG2 raw transport stream format",
sizeof(MpegTSContext),
NULL,
mpegts_read_header,
mpegts_raw_read_packet,
mpegts_read_close,
read_seek,
mpegts_get_pcr,
.flags = AVFMT_SHOW_IDS,
};
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