From: Anton Khirnov <anton@khirnov.net>
To: ffmpeg-devel@ffmpeg.org
Subject: [FFmpeg-devel] [PATCH 9/9] fftools/ffmpeg: move packet timestamp processing to demuxer thread
Date: Wed, 10 Aug 2022 18:25:45 +0200
Message-ID: <20220810162545.21382-9-anton@khirnov.net> (raw)
In-Reply-To: <20220810162545.21382-1-anton@khirnov.net>
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
aae9de0cb2887e6e0bbfda6ffdf85ab77d3390f0.
---
fftools/ffmpeg.c | 52 --------------------------------------
fftools/ffmpeg_demux.c | 57 ++++++++++++++++++++++++++++++++++++++++++
2 files changed, 57 insertions(+), 52 deletions(-)
diff --git a/fftools/ffmpeg.c b/fftools/ffmpeg.c
index 8d85af1c97..71a7e0b837 100644
--- a/fftools/ffmpeg.c
+++ b/fftools/ffmpeg.c
@@ -3791,7 +3791,6 @@ 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);
@@ -3846,37 +3845,6 @@ 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++) {
@@ -3897,26 +3865,6 @@ 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);
diff --git a/fftools/ffmpeg_demux.c b/fftools/ffmpeg_demux.c
index d15cee614d..6dfb5bb35b 100644
--- a/fftools/ffmpeg_demux.c
+++ b/fftools/ffmpeg_demux.c
@@ -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);
--
2.34.1
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prev parent reply other threads:[~2022-08-10 16:27 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-08-10 16:25 [FFmpeg-devel] [PATCH 1/9] fftools/ffmpeg: mark all encode sync queues as done before flushing encoders Anton Khirnov
2022-08-10 16:25 ` [FFmpeg-devel] [PATCH 2/9] fftools/ffmpeg_mux: avoid leaking pkt on errors Anton Khirnov
2022-08-10 16:25 ` [FFmpeg-devel] [PATCH 3/9] fftools/ffmpeg: move stream-dependent starttime correction to transcode_init() Anton Khirnov
2022-08-10 22:33 ` Michael Niedermayer
2022-08-11 7:45 ` [FFmpeg-devel] [PATCH] " Anton Khirnov
2022-08-12 15:43 ` Michael Niedermayer
2022-08-10 16:25 ` [FFmpeg-devel] [PATCH 4/9] fftools/ffmpeg: pre-compute the streamcopy start pts before transcoding starts Anton Khirnov
2022-08-10 16:25 ` [FFmpeg-devel] [PATCH 5/9] fftools/ffmpeg: move timestamp discontinuity correction out of process_input() Anton Khirnov
2022-08-10 16:25 ` [FFmpeg-devel] [PATCH 6/9] fftools/ffmpeg: move inter-stream ts discontinuity handling to ts_discontinuity_process() Anton Khirnov
2022-08-10 16:25 ` [FFmpeg-devel] [PATCH 7/9] fftools/ffmpeg: simplify conditions in ts_discontinuity_process Anton Khirnov
2022-08-10 16:25 ` [FFmpeg-devel] [PATCH 8/9] fftools/ffmpeg: use a separate variable for discontinuity offset Anton Khirnov
2022-08-10 16:25 ` Anton Khirnov [this message]
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