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lavf: Provide a monotonic timestamp to the outside world

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Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This commit is contained in:
Harald Axmann 2012-12-02 19:27:21 +01:00 • committed by Michael Niedermayer
parent 388241efa2
commit 2d74dea84f
4 changed files with 198 additions and 60 deletions
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123
libavformat/utils.c
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@ -78,6 +78,27 @@ static int is_relative(int64_t ts) {
return ts > (RELATIVE_TS_BASE - (1LL<<48));
}
/**
* Wrap a given time stamp, if there is an indication for an overflow
*
* @param st stream
* @param timestamp the time stamp to wrap
* @return resulting time stamp
*/
static int64_t wrap_timestamp(AVStream *st, int64_t timestamp)
{
if (st->pts_wrap_behavior != AV_PTS_WRAP_IGNORE && st->pts_wrap_bits < 64 &&
st->pts_wrap_reference != AV_NOPTS_VALUE && timestamp != AV_NOPTS_VALUE) {
if (st->pts_wrap_behavior == AV_PTS_WRAP_ADD_OFFSET &&
timestamp < st->pts_wrap_reference)
return timestamp + (1LL<<st->pts_wrap_bits);
else if (st->pts_wrap_behavior == AV_PTS_WRAP_SUB_OFFSET &&
timestamp >= st->pts_wrap_reference)
return timestamp - (1LL<<st->pts_wrap_bits);
}
return timestamp;
}
/** head of registered input format linked list */
static AVInputFormat *first_iformat = NULL;
/** head of registered output format linked list */
@ -751,6 +772,8 @@ int ff_read_packet(AVFormatContext *s, AVPacket *pkt)
}
st= s->streams[pkt->stream_index];
pkt->dts = wrap_timestamp(st, pkt->dts);
pkt->pts = wrap_timestamp(st, pkt->pts);
force_codec_ids(s, st);
@ -900,8 +923,67 @@ static AVPacketList *get_next_pkt(AVFormatContext *s, AVStream *st, AVPacketList
return NULL;
}
static int update_wrap_reference(AVFormatContext *s, AVStream *st, int stream_index)
{
if (s->correct_ts_overflow && st->pts_wrap_bits != 64 &&
st->pts_wrap_reference == AV_NOPTS_VALUE && st->first_dts != AV_NOPTS_VALUE) {
int i;
// reference time stamp should be 60 s before first time stamp
int64_t pts_wrap_reference = st->first_dts - av_rescale(60, st->time_base.den, st->time_base.num);
// if first time stamp is not more than 1/8 and 60s before the wrap point, subtract rather than add wrap offset
int pts_wrap_behavior = (st->first_dts < (1LL<<st->pts_wrap_bits) - (1LL<<st->pts_wrap_bits-3)) ||
(st->first_dts < (1LL<<st->pts_wrap_bits) - av_rescale(60, st->time_base.den, st->time_base.num)) ?
AV_PTS_WRAP_ADD_OFFSET : AV_PTS_WRAP_SUB_OFFSET;
AVProgram *first_program = av_find_program_from_stream(s, NULL, stream_index);
if (!first_program) {
int default_stream_index = av_find_default_stream_index(s);
if (s->streams[default_stream_index]->pts_wrap_reference == AV_NOPTS_VALUE) {
for (i=0; i<s->nb_streams; i++) {
s->streams[i]->pts_wrap_reference = pts_wrap_reference;
s->streams[i]->pts_wrap_behavior = pts_wrap_behavior;
}
}
else {
st->pts_wrap_reference = s->streams[default_stream_index]->pts_wrap_reference;
st->pts_wrap_behavior = s->streams[default_stream_index]->pts_wrap_behavior;
}
}
else {
AVProgram *program = first_program;
while (program) {
if (program->pts_wrap_reference != AV_NOPTS_VALUE) {
pts_wrap_reference = program->pts_wrap_reference;
pts_wrap_behavior = program->pts_wrap_behavior;
break;
}
program = av_find_program_from_stream(s, program, stream_index);
}
// update every program with differing pts_wrap_reference
program = first_program;
while(program) {
if (program->pts_wrap_reference != pts_wrap_reference) {
for (i=0; i<program->nb_stream_indexes; i++) {
s->streams[program->stream_index[i]]->pts_wrap_reference = pts_wrap_reference;
s->streams[program->stream_index[i]]->pts_wrap_behavior = pts_wrap_behavior;
}
program->pts_wrap_reference = pts_wrap_reference;
program->pts_wrap_behavior = pts_wrap_behavior;
}
program = av_find_program_from_stream(s, program, stream_index);
}
}
return 1;
}
return 0;
}
static void update_initial_timestamps(AVFormatContext *s, int stream_index,
int64_t dts, int64_t pts)
int64_t dts, int64_t pts, AVPacket *pkt)
{
AVStream *st= s->streams[stream_index];
AVPacketList *pktl= s->parse_queue ? s->parse_queue : s->packet_buffer;
@ -943,6 +1025,16 @@ static void update_initial_timestamps(AVFormatContext *s, int stream_index,
pktl->pkt.dts= pts_buffer[0];
}
}
if (update_wrap_reference(s, st, stream_index) && st->pts_wrap_behavior == AV_PTS_WRAP_SUB_OFFSET) {
// correct first time stamps to negative values
st->first_dts = wrap_timestamp(st, st->first_dts);
st->cur_dts = wrap_timestamp(st, st->cur_dts);
pkt->dts = wrap_timestamp(st, pkt->dts);
pkt->pts = wrap_timestamp(st, pkt->pts);
pts = wrap_timestamp(st, pts);
}
if (st->start_time == AV_NOPTS_VALUE)
st->start_time = pts;
}
@ -1088,7 +1180,7 @@ static void compute_pkt_fields(AVFormatContext *s, AVStream *st,
/* PTS = presentation timestamp */
if (pkt->dts == AV_NOPTS_VALUE)
pkt->dts = st->last_IP_pts;
update_initial_timestamps(s, pkt->stream_index, pkt->dts, pkt->pts);
update_initial_timestamps(s, pkt->stream_index, pkt->dts, pkt->pts, pkt);
if (pkt->dts == AV_NOPTS_VALUE)
pkt->dts = st->cur_dts;
@ -1125,7 +1217,7 @@ static void compute_pkt_fields(AVFormatContext *s, AVStream *st,
if (pkt->pts == AV_NOPTS_VALUE)
pkt->pts = pkt->dts;
update_initial_timestamps(s, pkt->stream_index, pkt->pts,
pkt->pts);
pkt->pts, pkt);
if (pkt->pts == AV_NOPTS_VALUE)
pkt->pts = st->cur_dts;
pkt->dts = pkt->pts;
@ -1142,7 +1234,7 @@ static void compute_pkt_fields(AVFormatContext *s, AVStream *st,
pkt->dts= st->pts_buffer[0];
}
if(st->codec->codec_id == AV_CODEC_ID_H264){ // we skipped it above so we try here
update_initial_timestamps(s, pkt->stream_index, pkt->dts, pkt->pts); // this should happen on the first packet
update_initial_timestamps(s, pkt->stream_index, pkt->dts, pkt->pts, pkt); // this should happen on the first packet
}
if(pkt->dts > st->cur_dts)
st->cur_dts = pkt->dts;
@ -1629,6 +1721,7 @@ int ff_add_index_entry(AVIndexEntry **index_entries,
int av_add_index_entry(AVStream *st,
int64_t pos, int64_t timestamp, int size, int distance, int flags)
{
timestamp = wrap_timestamp(st, timestamp);
return ff_add_index_entry(&st->index_entries, &st->nb_index_entries,
&st->index_entries_allocated_size, pos,
timestamp, size, distance, flags);
@ -1675,6 +1768,12 @@ int av_index_search_timestamp(AVStream *st, int64_t wanted_timestamp,
wanted_timestamp, flags);
}
static int64_t ff_read_timestamp(AVFormatContext *s, int stream_index, int64_t *ppos, int64_t pos_limit,
int64_t (*read_timestamp)(struct AVFormatContext *, int , int64_t *, int64_t ))
{
return wrap_timestamp(s->streams[stream_index], read_timestamp(s, stream_index, ppos, pos_limit));
}
int ff_seek_frame_binary(AVFormatContext *s, int stream_index, int64_t target_ts, int flags)
{
AVInputFormat *avif= s->iformat;
@ -1750,7 +1849,7 @@ int64_t ff_gen_search(AVFormatContext *s, int stream_index, int64_t target_ts,
if(ts_min == AV_NOPTS_VALUE){
pos_min = s->data_offset;
ts_min = read_timestamp(s, stream_index, &pos_min, INT64_MAX);
ts_min = ff_read_timestamp(s, stream_index, &pos_min, INT64_MAX, read_timestamp);
if (ts_min == AV_NOPTS_VALUE)
return -1;
}
@ -1766,7 +1865,7 @@ int64_t ff_gen_search(AVFormatContext *s, int stream_index, int64_t target_ts,
pos_max = filesize - 1;
do{
pos_max -= step;
ts_max = read_timestamp(s, stream_index, &pos_max, pos_max + step);
ts_max = ff_read_timestamp(s, stream_index, &pos_max, pos_max + step, read_timestamp);
step += step;
}while(ts_max == AV_NOPTS_VALUE && pos_max >= step);
if (ts_max == AV_NOPTS_VALUE)
@ -1774,7 +1873,7 @@ int64_t ff_gen_search(AVFormatContext *s, int stream_index, int64_t target_ts,
for(;;){
int64_t tmp_pos= pos_max + 1;
int64_t tmp_ts= read_timestamp(s, stream_index, &tmp_pos, INT64_MAX);
int64_t tmp_ts= ff_read_timestamp(s, stream_index, &tmp_pos, INT64_MAX, read_timestamp);
if(tmp_ts == AV_NOPTS_VALUE)
break;
ts_max= tmp_ts;
@ -1821,7 +1920,7 @@ int64_t ff_gen_search(AVFormatContext *s, int stream_index, int64_t target_ts,
pos= pos_limit;
start_pos= pos;
ts = read_timestamp(s, stream_index, &pos, INT64_MAX); //may pass pos_limit instead of -1
ts = ff_read_timestamp(s, stream_index, &pos, INT64_MAX, read_timestamp); //may pass pos_limit instead of -1
if(pos == pos_max)
no_change++;
else
@ -1850,9 +1949,9 @@ int64_t ff_gen_search(AVFormatContext *s, int stream_index, int64_t target_ts,
ts = (flags & AVSEEK_FLAG_BACKWARD) ? ts_min : ts_max;
#if 0
pos_min = pos;
ts_min = read_timestamp(s, stream_index, &pos_min, INT64_MAX);
ts_min = ff_read_timestamp(s, stream_index, &pos_min, INT64_MAX, read_timestamp);
pos_min++;
ts_max = read_timestamp(s, stream_index, &pos_min, INT64_MAX);
ts_max = ff_read_timestamp(s, stream_index, &pos_min, INT64_MAX, read_timestamp);
av_dlog(s, "pos=0x%"PRIx64" %s<=%s<=%s\n",
pos, av_ts2str(ts_min), av_ts2str(target_ts), av_ts2str(ts_max));
#endif
@ -3191,6 +3290,8 @@ AVStream *avformat_new_stream(AVFormatContext *s, const AVCodec *c)
st->cur_dts = s->iformat ? RELATIVE_TS_BASE : 0;
st->first_dts = AV_NOPTS_VALUE;
st->probe_packets = MAX_PROBE_PACKETS;
st->pts_wrap_reference = AV_NOPTS_VALUE;
st->pts_wrap_behavior = AV_PTS_WRAP_IGNORE;
/* default pts setting is MPEG-like */
avpriv_set_pts_info(st, 33, 1, 90000);
@ -3230,6 +3331,8 @@ AVProgram *av_new_program(AVFormatContext *ac, int id)
program->discard = AVDISCARD_NONE;
}
program->id = id;
program->pts_wrap_reference = AV_NOPTS_VALUE;
program->pts_wrap_behavior = AV_PTS_WRAP_IGNORE;
program->start_time =
program->end_time = AV_NOPTS_VALUE;