RepoMirrors/ffmpeg
1
0
Fork 0
mirror of https://git.ffmpeg.org/ffmpeg.git synced 2024-12-25 08:42:39 +00:00
Code Issues Projects Releases Wiki Activity
36aa7bc27f
ffmpeg/libavformat/mpegts.c
Ivan Schreter 4c6b49bf74 Change TS seeking so it returns position/timestamp of a key frame. 
Patch by Ivan Schreter, schreter gmx net

Originally committed as revision 17665 to svn://svn.ffmpeg.org/ffmpeg/trunk
2009-02-28 18:35:53 +00:00

1561 lines
45 KiB
C
Raw Blame History

/*
* 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 "libavutil/crc.h"
#include "libavutil/intreadwrite.h"
#include "avformat.h"
#include "mpegts.h"
#include "internal.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);
enum MpegTSFilterType {
MPEGTS_PES,
MPEGTS_SECTION,
};
typedef struct MpegTSFilter MpegTSFilter;
typedef void PESCallback(MpegTSFilter *f, const uint8_t *buf, int len, int is_start, int64_t pos);
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;
unsigned int check_crc:1;
unsigned 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
struct Program {
unsigned int id; //program id/service id
unsigned int nb_pids;
unsigned int pids[MAX_PIDS_PER_PROGRAM];
};
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;
struct Program *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;
int64_t ts_packet_pos; /**< position of first TS packet of this PES packet */
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)
{
struct Program *p;
void *tmp = av_realloc(ts->prg, (ts->nb_prg+1)*sizeof(struct Program));
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;
struct Program *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;
struct Program *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) {
/* referenced private data will be freed later in
* av_close_input_stream */
if (!((PESContext *)filter->u.pes_filter.opaque)->st) {
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-3; i++){
if(buf[i] == 0x47 && !(buf[i+1] & 0x80) && (buf[i+3] & 0x30)){
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;
int has_dirac_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;
case REGISTRATION_DESCRIPTOR: /*MPEG-2 Registration descriptor */
{
uint8_t bytes[4];
bytes[0] = get8(&p, desc_end);
bytes[1] = get8(&p, desc_end);
bytes[2] = get8(&p, desc_end);
bytes[3] = get8(&p, desc_end);
if(bytes[0] == 'd' && bytes[1] == 'r' &&
bytes[2] == 'a' && bytes[3] == 'c')
has_dirac_descr = 1;
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_VIDEO_DIRAC:
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)
|| (stream_type == STREAM_TYPE_VIDEO_DIRAC && !has_dirac_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) {
av_metadata_set(&st->metadata, "language", language);
}
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_metadata_set(&program->metadata, "name", name);
av_metadata_set(&program->metadata, "provider_name", provider_name);
}
}
av_free(name);
av_free(provider_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,
int64_t pos)
{
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;
pes->ts_packet_pos = pos;
}
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->dts = 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;
/* store position of first TS packet of this PES packet */
pkt->pos = pes->ts_packet_pos;
/* 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;
enum CodecID codec_id;
enum CodecType codec_type;
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_VIDEO_DIRAC:
codec_type = CODEC_TYPE_VIDEO;
codec_id = CODEC_ID_DIRAC;
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_PROBE;
}
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;
int64_t pos;
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;
pos = url_ftell(ts->stream->pb);
ts->pos47= pos % 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 {
// Note: The position here points actually behind the current packet.
tss->u.pes_filter.pes_cb(tss,
p, p_end - p, is_start, pos - ts->raw_packet_size);
}
}
/* 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;
int check_count= size / TS_FEC_PACKET_SIZE;
#define CHECK_COUNT 10
if (check_count < CHECK_COUNT)
return -1;
score = analyze(p->buf, TS_PACKET_SIZE *check_count, TS_PACKET_SIZE , NULL)*CHECK_COUNT/check_count;
dvhs_score= analyze(p->buf, TS_DVHS_PACKET_SIZE*check_count, TS_DVHS_PACKET_SIZE, NULL)*CHECK_COUNT/check_count;
fec_score = analyze(p->buf, TS_FEC_PACKET_SIZE *check_count, TS_FEC_PACKET_SIZE , NULL)*CHECK_COUNT/check_count;
// 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 90kHz PCR and the extension for the 27MHz 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[5*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;
clear_programs(ts);
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",
NULL_IF_CONFIG_SMALL("MPEG-2 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|AVFMT_TS_DISCONT,
};
AVInputFormat mpegtsraw_demuxer = {
"mpegtsraw",
NULL_IF_CONFIG_SMALL("MPEG-2 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|AVFMT_TS_DISCONT,
};
Reference in New Issue View Git Blame Copy Permalink