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fftools/ffmpeg: move packet timestamp processing to demuxer thread 

Discontinuity detection/correction is left in the main thread, as it is
entangled with InputStream.next_dts and related variables, which may be
set by decoding code.

Fixes races e.g. in fate-ffmpeg-streamloop after
aae9de0cb2.
This commit is contained in:
Anton Khirnov 2022-08-10 17:15:06 +02:00
parent 3b2beceae1
commit 6ded80af92
2 changed files with 57 additions and 52 deletions
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52
fftools/ffmpeg.c
View File

@ -3792,7 +3792,6 @@ static int process_input(int file_index)
InputStream *ist;
AVPacket *pkt;
int ret, i, j;
int64_t duration;
is = ifile->ctx;
ret = ifile_get_packet(ifile, &pkt);
@ -3847,37 +3846,6 @@ static int process_input(int file_index)
if (ist->discard)
goto discard_packet;
if (debug_ts) {
av_log(NULL, AV_LOG_INFO, "demuxer -> ist_index:%d type:%s "
"next_dts:%s next_dts_time:%s next_pts:%s next_pts_time:%s pkt_pts:%s pkt_pts_time:%s pkt_dts:%s pkt_dts_time:%s duration:%s duration_time:%s off:%s off_time:%s\n",
ifile->ist_index + pkt->stream_index,
av_get_media_type_string(ist->st->codecpar->codec_type),
av_ts2str(ist->next_dts), av_ts2timestr(ist->next_dts, &AV_TIME_BASE_Q),
av_ts2str(ist->next_pts), av_ts2timestr(ist->next_pts, &AV_TIME_BASE_Q),
av_ts2str(pkt->pts), av_ts2timestr(pkt->pts, &ist->st->time_base),
av_ts2str(pkt->dts), av_ts2timestr(pkt->dts, &ist->st->time_base),
av_ts2str(pkt->duration), av_ts2timestr(pkt->duration, &ist->st->time_base),
av_ts2str(input_files[ist->file_index]->ts_offset),
av_ts2timestr(input_files[ist->file_index]->ts_offset, &AV_TIME_BASE_Q));
}
if(!ist->wrap_correction_done && is->start_time != AV_NOPTS_VALUE && ist->st->pts_wrap_bits < 64){
int64_t stime, stime2;
stime = av_rescale_q(is->start_time, AV_TIME_BASE_Q, ist->st->time_base);
stime2= stime + (1ULL<<ist->st->pts_wrap_bits);
ist->wrap_correction_done = 1;
if(stime2 > stime && pkt->dts != AV_NOPTS_VALUE && pkt->dts > stime + (1LL<<(ist->st->pts_wrap_bits-1))) {
pkt->dts -= 1ULL<<ist->st->pts_wrap_bits;
ist->wrap_correction_done = 0;
}
if(stime2 > stime && pkt->pts != AV_NOPTS_VALUE && pkt->pts > stime + (1LL<<(ist->st->pts_wrap_bits-1))) {
pkt->pts -= 1ULL<<ist->st->pts_wrap_bits;
ist->wrap_correction_done = 0;
}
}
/* add the stream-global side data to the first packet */
if (ist->nb_packets == 1) {
for (i = 0; i < ist->st->nb_side_data; i++) {
@ -3898,26 +3866,6 @@ static int process_input(int file_index)
}
}
if (pkt->dts != AV_NOPTS_VALUE)
pkt->dts += av_rescale_q(ifile->ts_offset, AV_TIME_BASE_Q, ist->st->time_base);
if (pkt->pts != AV_NOPTS_VALUE)
pkt->pts += av_rescale_q(ifile->ts_offset, AV_TIME_BASE_Q, ist->st->time_base);
if (pkt->pts != AV_NOPTS_VALUE)
pkt->pts *= ist->ts_scale;
if (pkt->dts != AV_NOPTS_VALUE)
pkt->dts *= ist->ts_scale;
duration = av_rescale_q(ifile->duration, ifile->time_base, ist->st->time_base);
if (pkt->pts != AV_NOPTS_VALUE) {
pkt->pts += duration;
ist->max_pts = FFMAX(pkt->pts, ist->max_pts);
ist->min_pts = FFMIN(pkt->pts, ist->min_pts);
}
if (pkt->dts != AV_NOPTS_VALUE)
pkt->dts += duration;
// detect and try to correct for timestamp discontinuities
ts_discontinuity_process(ifile, ist, pkt);

57
fftools/ffmpeg_demux.c
View File

@ -114,6 +114,61 @@ static int seek_to_start(InputFile *ifile)
return ret;
}
static void ts_fixup(InputFile *ifile, AVPacket *pkt)
{
InputStream *ist = input_streams[ifile->ist_index + pkt->stream_index];
const int64_t start_time = ifile->ctx->start_time;
int64_t duration;
if (debug_ts) {
av_log(NULL, AV_LOG_INFO, "demuxer -> ist_index:%d type:%s "
"pkt_pts:%s pkt_pts_time:%s pkt_dts:%s pkt_dts_time:%s duration:%s duration_time:%s\n",
ifile->ist_index + pkt->stream_index,
av_get_media_type_string(ist->st->codecpar->codec_type),
av_ts2str(pkt->pts), av_ts2timestr(pkt->pts, &ist->st->time_base),
av_ts2str(pkt->dts), av_ts2timestr(pkt->dts, &ist->st->time_base),
av_ts2str(pkt->duration), av_ts2timestr(pkt->duration, &ist->st->time_base));
}
if (!ist->wrap_correction_done && start_time != AV_NOPTS_VALUE &&
ist->st->pts_wrap_bits < 64) {
int64_t stime, stime2;
stime = av_rescale_q(start_time, AV_TIME_BASE_Q, ist->st->time_base);
stime2= stime + (1ULL<<ist->st->pts_wrap_bits);
ist->wrap_correction_done = 1;
if(stime2 > stime && pkt->dts != AV_NOPTS_VALUE && pkt->dts > stime + (1LL<<(ist->st->pts_wrap_bits-1))) {
pkt->dts -= 1ULL<<ist->st->pts_wrap_bits;
ist->wrap_correction_done = 0;
}
if(stime2 > stime && pkt->pts != AV_NOPTS_VALUE && pkt->pts > stime + (1LL<<(ist->st->pts_wrap_bits-1))) {
pkt->pts -= 1ULL<<ist->st->pts_wrap_bits;
ist->wrap_correction_done = 0;
}
}
if (pkt->dts != AV_NOPTS_VALUE)
pkt->dts += av_rescale_q(ifile->ts_offset, AV_TIME_BASE_Q, ist->st->time_base);
if (pkt->pts != AV_NOPTS_VALUE)
pkt->pts += av_rescale_q(ifile->ts_offset, AV_TIME_BASE_Q, ist->st->time_base);
if (pkt->pts != AV_NOPTS_VALUE)
pkt->pts *= ist->ts_scale;
if (pkt->dts != AV_NOPTS_VALUE)
pkt->dts *= ist->ts_scale;
duration = av_rescale_q(ifile->duration, ifile->time_base, ist->st->time_base);
if (pkt->pts != AV_NOPTS_VALUE) {
pkt->pts += duration;
ist->max_pts = FFMAX(pkt->pts, ist->max_pts);
ist->min_pts = FFMIN(pkt->pts, ist->min_pts);
}
if (pkt->dts != AV_NOPTS_VALUE)
pkt->dts += duration;
}
static void *input_thread(void *arg)
{
InputFile *f = arg;
@ -176,6 +231,8 @@ static void *input_thread(void *arg)
}
}
ts_fixup(f, pkt);
msg.pkt = av_packet_alloc();
if (!msg.pkt) {
av_packet_unref(pkt);