[FFmpeg-devel] [PATCH] doc/ffmpeg: extend -dts_delta_threshold option description

[FFmpeg-devel] [PATCH] doc/ffmpeg: extend -dts_delta_threshold option description

[Stefano Sabatini]

---
 doc/ffmpeg.texi | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/doc/ffmpeg.texi b/doc/ffmpeg.texi
index 67b3294256..122f7e3387 100644
--- a/doc/ffmpeg.texi
+++ b/doc/ffmpeg.texi
@@ -1823,8 +1823,21 @@ results, but increase memory use and latency.
 
 The default value is 10 seconds.
 
-@item -dts_delta_threshold
-Timestamp discontinuity delta threshold.
+@item -dts_delta_threshold @var{threshold}
+Timestamp discontinuity delta threshold, expressed as a floating point
+number of @var{AV_TIME_BASE} units.
+
+If a timestamp discontinuity is detected whose absolute value is
+greater than @var{threshold} * @var{AV_TIME_BASE}, ffmpeg will remove the
+discontinuity by decreasing/increasing the current DTS and PTS by the
+corresponding delta value.
+
+Timestamp discontinuity correction can be inhibited by setting a big value for
+@var{threshold}, and is automatically disabled when employing the
+@code{-copy_ts} option.
+
+Default value is 10.
+
 @item -dts_error_threshold @var{seconds}
 Timestamp error delta threshold. This threshold use to discard crazy/damaged
 timestamps and the default is 30 hours which is arbitrarily picked and quite
-- 
2.25.1

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Re: [FFmpeg-devel] [PATCH] doc/ffmpeg: extend -dts_delta_threshold option description

[Gyan Doshi]

On 2023-01-25 06:37 am, Stefano Sabatini wrote:
> ---
>   doc/ffmpeg.texi | 17 +++++++++++++++--
>   1 file changed, 15 insertions(+), 2 deletions(-)
>
> diff --git a/doc/ffmpeg.texi b/doc/ffmpeg.texi
> index 67b3294256..122f7e3387 100644
> --- a/doc/ffmpeg.texi
> +++ b/doc/ffmpeg.texi
> @@ -1823,8 +1823,21 @@ results, but increase memory use and latency.
>   
>   The default value is 10 seconds.
>   
> -@item -dts_delta_threshold
> -Timestamp discontinuity delta threshold.
> +@item -dts_delta_threshold @var{threshold}
> +Timestamp discontinuity delta threshold, expressed as a floating point
> +number of @var{AV_TIME_BASE} units.
This is a CLI option and those users don't deal with AV_TIME_BASE . More 
useful to say it's in seconds.

> +
> +If a timestamp discontinuity is detected whose absolute value is
> +greater than @var{threshold} * @var{AV_TIME_BASE}, ffmpeg will remove the
> +discontinuity by decreasing/increasing the current DTS and PTS by the
> +corresponding delta value.

Might want to mention that this only applies to AV_FMT_DISCONT demuxers, 
or rather give a few examples, like MPEG-TS, HLS..etc.
For all other formats that users normally work with, clarify that only 
dts_error_threshold is relevant.

> +
> +Timestamp discontinuity correction can be inhibited by setting a big value for
> +@var{threshold}, and is automatically disabled when employing the
> +@code{-copy_ts} option.

For copy_ts, it is still applied for all negative deltas except the 
smallest.

Not blocking, but I'm reworking this code at present. Shouldn't really 
affect this patch. See 
https://ffmpeg.org/pipermail/ffmpeg-devel/2023-January/305539.html

Regards,
Gyan
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Re: [FFmpeg-devel] [PATCH] doc/ffmpeg: extend -dts_delta_threshold option description

[Stefano Sabatini]

[-- Attachment #1: Type: text/plain, Size: 1910 bytes --]

On date Wednesday 2023-01-25 10:47:20 +0530, Gyan Doshi wrote:
> 
> 
> On 2023-01-25 06:37 am, Stefano Sabatini wrote:
> > ---
> >   doc/ffmpeg.texi | 17 +++++++++++++++--
> >   1 file changed, 15 insertions(+), 2 deletions(-)
> > 
> > diff --git a/doc/ffmpeg.texi b/doc/ffmpeg.texi
> > index 67b3294256..122f7e3387 100644
> > --- a/doc/ffmpeg.texi
> > +++ b/doc/ffmpeg.texi
> > @@ -1823,8 +1823,21 @@ results, but increase memory use and latency.
> >   The default value is 10 seconds.
> > -@item -dts_delta_threshold
> > -Timestamp discontinuity delta threshold.
> > +@item -dts_delta_threshold @var{threshold}
> > +Timestamp discontinuity delta threshold, expressed as a floating point
> > +number of @var{AV_TIME_BASE} units.
> This is a CLI option and those users don't deal with AV_TIME_BASE . More
> useful to say it's in seconds.
> 
> > +
> > +If a timestamp discontinuity is detected whose absolute value is
> > +greater than @var{threshold} * @var{AV_TIME_BASE}, ffmpeg will remove the
> > +discontinuity by decreasing/increasing the current DTS and PTS by the
> > +corresponding delta value.
> 

> Might want to mention that this only applies to AV_FMT_DISCONT demuxers, or
> rather give a few examples, like MPEG-TS, HLS..etc.
> For all other formats that users normally work with, clarify that only
> dts_error_threshold is relevant.


> > +
> > +Timestamp discontinuity correction can be inhibited by setting a big value for
> > +@var{threshold}, and is automatically disabled when employing the
> > +@code{-copy_ts} option.
> 
> For copy_ts, it is still applied for all negative deltas except the
> smallest.

Which is a bit arbitrary.

> 
> Not blocking, but I'm reworking this code at present. Shouldn't really
> affect this patch. See
> https://ffmpeg.org/pipermail/ffmpeg-devel/2023-January/305539.html

Updated (had to review the code to get some clarity on the current
behavior).

Thanks.

[-- Attachment #2: 0002-ffmpeg-review-dts_delta_threshold-and-dts_delta_erro.patch --]
[-- Type: text/x-diff, Size: 12000 bytes --]

From 30ac56a14d66eb25428b71c9211f401f818bd057 Mon Sep 17 00:00:00 2001
From: Stefano Sabatini <stefasab@gmail.com>
Date: Fri, 1 Apr 2011 01:13:35 +0200
Subject: [PATCH 2/2] ffmpeg: review -dts_delta_threshold and -dts_delta_error
 options

Review handling of -dts_delta_threshold and -dts_delta_error options,
specify them as floating point expressed in seconds.

Also, review and simplify logic. Adjust values for tests, since in
some cases the new values does not trigger the correction logic.

PR: https://patchwork.ffmpeg.org/project/ffmpeg/list/?series=8252
---
 doc/ffmpeg.texi             | 36 ++++++++++++++++---
 fftools/ffmpeg.c            | 72 ++++++++++++++++++++-----------------
 fftools/ffmpeg.h            |  2 ++
 fftools/ffmpeg_demux.c      |  3 ++
 tests/fate/filter-audio.mak |  2 +-
 tests/fate/mpeg4.mak        |  2 +-
 6 files changed, 77 insertions(+), 40 deletions(-)

diff --git a/doc/ffmpeg.texi b/doc/ffmpeg.texi
index 67b3294256..ffffcdd1d7 100644
--- a/doc/ffmpeg.texi
+++ b/doc/ffmpeg.texi
@@ -1823,12 +1823,38 @@ results, but increase memory use and latency.
 
 The default value is 10 seconds.
 
-@item -dts_delta_threshold
-Timestamp discontinuity delta threshold.
+@item -dts_delta_threshold @var{threshold}
+Timestamp discontinuity delta threshold, expressed as a floating point
+number of seconds.
+
+The timestamp discontinuity correction enabled by this option is only
+applied to input formats accepting timestamp discontinuity (for which
+the @code{AV_FMT_DISCONT} flag is enabled), e.g. MPEG-TS and HLS, and
+is automatically disabled when employing the @code{-copy_ts} option
+(unless wrapping is detected).
+
+If a timestamp discontinuity is detected whose absolute value is
+greater than @var{threshold}, ffmpeg will remove the discontinuity by
+decreasing/increasing the current DTS and PTS by the corresponding
+delta value.
+
+The default value is 10.
+
 @item -dts_error_threshold @var{seconds}
-Timestamp error delta threshold. This threshold use to discard crazy/damaged
-timestamps and the default is 30 hours which is arbitrarily picked and quite
-conservative.
+Timestamp error delta threshold, expressed as a floating point number
+of seconds.
+
+The timestamp correction enabled by this option is only applied to
+input formats not accepting timestamp discontinuity (for which the
+@code{AV_FMT_DISCONT} flag is not enabled).
+
+If a timestamp discontinuity is detected whose absolute value is
+greater than @var{threshold}, ffmpeg will drop the PTS/DTS timestamp
+value.
+
+The default value is @code{3600*30} (30 hours), which is arbitrarily
+picked and quite conservative.
+
 @item -muxdelay @var{seconds} (@emph{output})
 Set the maximum demux-decode delay.
 @item -muxpreload @var{seconds} (@emph{output})
diff --git a/fftools/ffmpeg.c b/fftools/ffmpeg.c
index f722ae7632..cc58d98813 100644
--- a/fftools/ffmpeg.c
+++ b/fftools/ffmpeg.c
@@ -3411,62 +3411,68 @@ static void decode_flush(InputFile *ifile)
 static void ts_discontinuity_detect(InputFile *ifile, InputStream *ist,
                                     AVPacket *pkt)
 {
-    const int fmt_is_discont = ifile->ctx->iformat->flags & AVFMT_TS_DISCONT;
+    const int fmt_is_discont = !!(ifile->ctx->iformat->flags & AVFMT_TS_DISCONT);
     int disable_discontinuity_correction = copy_ts;
     int64_t pkt_dts = av_rescale_q_rnd(pkt->dts, ist->st->time_base, AV_TIME_BASE_Q,
                                        AV_ROUND_NEAR_INF | AV_ROUND_PASS_MINMAX);
 
+    av_log(NULL, AV_LOG_TRACE,
+           "ts discontinuity detection on stream #%d:%d pkt_dts:%s pkt_pts:%s next_dts:%s last_ts:%s fmt_discont:%d copy_ts:%d\n",
+           ist->file_index, ist->st->index,
+           av_ts2timestr(pkt->dts, &ist->st->time_base), av_ts2timestr(pkt->pts, &ist->st->time_base),
+           av_ts2timestr(ist->next_dts, &AV_TIME_BASE_Q), av_ts2timestr(ifile->last_ts, &AV_TIME_BASE_Q),
+           fmt_is_discont, copy_ts);
+
     if (copy_ts && ist->next_dts != AV_NOPTS_VALUE &&
         fmt_is_discont && ist->st->pts_wrap_bits < 60) {
         int64_t wrap_dts = av_rescale_q_rnd(pkt->dts + (1LL<<ist->st->pts_wrap_bits),
                                             ist->st->time_base, AV_TIME_BASE_Q,
                                             AV_ROUND_NEAR_INF|AV_ROUND_PASS_MINMAX);
-        if (FFABS(wrap_dts - ist->next_dts) < FFABS(pkt_dts - ist->next_dts)/10)
+        if (FFABS(wrap_dts - ist->next_dts) < FFABS(pkt_dts - ist->next_dts)/10) {
             disable_discontinuity_correction = 0;
+            av_log(NULL, AV_LOG_DEBUG,
+                   "wrapped ts detected in copy_ts, enabled discontinuity correction\n");
+        }
     }
 
-    if (ist->next_dts != AV_NOPTS_VALUE && !disable_discontinuity_correction) {
-        int64_t delta = pkt_dts - ist->next_dts;
+#define CHECK_INVALID_TS(delta_, ts_type_, ts_)                         \
+    if (FFABS(delta_) > ist->dts_error_threshold) {                     \
+        av_log(NULL, AV_LOG_WARNING, "drop invalid " #ts_type_ " ts:%s delta:%s > dts_error_threshold:%s\n", \
+               av_ts2timestr(ts_, &ist->st->time_base),                 \
+               av_ts2timestr(delta_, &AV_TIME_BASE_Q),                  \
+               av_ts2timestr(ist->dts_error_threshold, &AV_TIME_BASE_Q)); \
+        ts_ = AV_NOPTS_VALUE;                                           \
+    }
+
+    if (!disable_discontinuity_correction) {
+        int64_t delta;
+
         if (fmt_is_discont) {
-            if (FFABS(delta) > 1LL * dts_delta_threshold * AV_TIME_BASE ||
-                pkt_dts + AV_TIME_BASE/10 < FFMAX(ist->pts, ist->dts)) {
+            delta =
+                ist->next_dts != AV_NOPTS_VALUE ? pkt_dts - ist->next_dts :
+                ifile->last_ts != AV_NOPTS_VALUE ? pkt_dts - ifile->last_ts :
+                AV_NOPTS_VALUE;
+
+            if (delta != AV_NOPTS_VALUE && FFABS(delta) > ist->dts_delta_threshold) {
                 ifile->ts_offset_discont -= delta;
                 av_log(NULL, AV_LOG_DEBUG,
-                       "timestamp discontinuity for stream #%d:%d "
-                       "(id=%d, type=%s): %"PRId64", new offset= %"PRId64"\n",
-                       ist->file_index, ist->st->index, ist->st->id,
-                       av_get_media_type_string(ist->par->codec_type),
-                       delta, ifile->ts_offset_discont);
+                       "ts offset corrected ts_offset_discont:%s delta:%s > dts_delta_threshold:%s\n",
+                       av_ts2timestr(ifile->ts_offset_discont, &AV_TIME_BASE_Q),
+                       av_ts2timestr(delta, &AV_TIME_BASE_Q),
+                       av_ts2timestr(ist->dts_delta_threshold, &AV_TIME_BASE_Q));
                 pkt->dts -= av_rescale_q(delta, AV_TIME_BASE_Q, ist->st->time_base);
                 if (pkt->pts != AV_NOPTS_VALUE)
                     pkt->pts -= av_rescale_q(delta, AV_TIME_BASE_Q, ist->st->time_base);
             }
-        } else {
-            if (FFABS(delta) > 1LL * dts_error_threshold * AV_TIME_BASE) {
-                av_log(NULL, AV_LOG_WARNING, "DTS %"PRId64", next:%"PRId64" st:%d invalid dropping\n", pkt->dts, ist->next_dts, pkt->stream_index);
-                pkt->dts = AV_NOPTS_VALUE;
-            }
-            if (pkt->pts != AV_NOPTS_VALUE){
+        } else if (ist->next_dts != AV_NOPTS_VALUE) {
+            delta = pkt_dts - ist->next_dts;
+            CHECK_INVALID_TS(delta, dts, pkt->dts);
+            if (pkt->pts != AV_NOPTS_VALUE) {
                 int64_t pkt_pts = av_rescale_q(pkt->pts, ist->st->time_base, AV_TIME_BASE_Q);
                 delta = pkt_pts - ist->next_dts;
-                if (FFABS(delta) > 1LL * dts_error_threshold * AV_TIME_BASE) {
-                    av_log(NULL, AV_LOG_WARNING, "PTS %"PRId64", next:%"PRId64" invalid dropping st:%d\n", pkt->pts, ist->next_dts, pkt->stream_index);
-                    pkt->pts = AV_NOPTS_VALUE;
-                }
+                CHECK_INVALID_TS(delta, pts, pkt->pts);
             }
         }
-    } else if (ist->next_dts == AV_NOPTS_VALUE && !copy_ts &&
-               fmt_is_discont && ifile->last_ts != AV_NOPTS_VALUE) {
-        int64_t delta = pkt_dts - ifile->last_ts;
-        if (FFABS(delta) > 1LL * dts_delta_threshold * AV_TIME_BASE) {
-            ifile->ts_offset_discont -= delta;
-            av_log(NULL, AV_LOG_DEBUG,
-                   "Inter stream timestamp discontinuity %"PRId64", new offset= %"PRId64"\n",
-                   delta, ifile->ts_offset_discont);
-            pkt->dts -= av_rescale_q(delta, AV_TIME_BASE_Q, ist->st->time_base);
-            if (pkt->pts != AV_NOPTS_VALUE)
-                pkt->pts -= av_rescale_q(delta, AV_TIME_BASE_Q, ist->st->time_base);
-        }
     }
 
     ifile->last_ts = av_rescale_q(pkt->dts, ist->st->time_base, AV_TIME_BASE_Q);
diff --git a/fftools/ffmpeg.h b/fftools/ffmpeg.h
index 5527dbe49b..14ad1a10ee 100644
--- a/fftools/ffmpeg.h
+++ b/fftools/ffmpeg.h
@@ -352,6 +352,8 @@ typedef struct InputStream {
     int64_t       next_pts;  ///< synthetic pts for the next decode frame (in AV_TIME_BASE units)
     int64_t       pts;       ///< current pts of the decoded frame  (in AV_TIME_BASE units)
     int           wrap_correction_done;
+    int64_t       dts_delta_threshold; ///< dts_delta_threshold value rescaled to AV_TIME_BASE units
+    int64_t       dts_error_threshold; ///< dts_error_threshold value rescaled to AV_TIME_BASE units
 
     // the value of AVCodecParserContext.repeat_pict from the AVStream parser
     // for the last packet returned from ifile_get_packet()
diff --git a/fftools/ffmpeg_demux.c b/fftools/ffmpeg_demux.c
index 71ce7d9a02..c7323c4adc 100644
--- a/fftools/ffmpeg_demux.c
+++ b/fftools/ffmpeg_demux.c
@@ -736,6 +736,9 @@ static void add_input_streams(const OptionsContext *o, Demuxer *d)
         ist->filter_in_rescale_delta_last = AV_NOPTS_VALUE;
         ist->prev_pkt_pts = AV_NOPTS_VALUE;
 
+        ist->dts_delta_threshold = 1LL * dts_delta_threshold * AV_TIME_BASE;
+        ist->dts_error_threshold = 1LL * dts_error_threshold * AV_TIME_BASE;
+
         ist->dec_ctx = avcodec_alloc_context3(ist->dec);
         if (!ist->dec_ctx)
             report_and_exit(AVERROR(ENOMEM));
diff --git a/tests/fate/filter-audio.mak b/tests/fate/filter-audio.mak
index eff32b9f81..a0d8a78cb4 100644
--- a/tests/fate/filter-audio.mak
+++ b/tests/fate/filter-audio.mak
@@ -220,7 +220,7 @@ tests/data/hls-list-append.m3u8: ffmpeg$(PROGSSUF)$(EXESUF) | tests/data
         -f lavfi -i "aevalsrc=cos(2*PI*t)*sin(2*PI*(440+4*t)*t):d=20" -f segment -segment_time 10 -map 0 -flags +bitexact -codec:a mp2fixed \
         -segment_list $(TARGET_PATH)/$@ -y $(TARGET_PATH)/tests/data/hls-append-out-%03d.ts 2>/dev/null; \
         $(TARGET_EXEC) $(TARGET_PATH)/$< -nostdin \
-        -f lavfi -i "aevalsrc=cos(2*PI*t)*sin(2*PI*(440+4*t)*t):d=20" -f hls -hls_time 10 -map 0 -flags +bitexact \
+        -f lavfi -i "aevalsrc=cos(2*PI*t)*sin(2*PI*(440+4*t)*t):d=20" -f hls -hls_time 10 -map 0 -flags +bitexact -dts_delta_threshold 1 \
         -hls_flags append_list -codec:a mp2fixed -hls_segment_filename $(TARGET_PATH)/tests/data/hls-append-out-%03d.ts \
         $(TARGET_PATH)/tests/data/hls-list-append.m3u8 2>/dev/null
 
diff --git a/tests/fate/mpeg4.mak b/tests/fate/mpeg4.mak
index 4cec21c547..ece5829aee 100644
--- a/tests/fate/mpeg4.mak
+++ b/tests/fate/mpeg4.mak
@@ -1,7 +1,7 @@
 
 MPEG4_RESOLUTION_CHANGE = down-down down-up up-down up-up
 
-fate-mpeg4-resolution-change-%: CMD = framemd5 -flags +bitexact -idct simple -i $(TARGET_SAMPLES)/mpeg4/resize_$(@:fate-mpeg4-resolution-change-%=%).h263 -sws_flags +bitexact
+fate-mpeg4-resolution-change-%: CMD = framemd5 -flags +bitexact -idct simple -i $(TARGET_SAMPLES)/mpeg4/resize_$(@:fate-mpeg4-resolution-change-%=%).h263 -sws_flags +bitexact -dts_delta_threshold 1
 
 FATE_MPEG4-$(call FRAMEMD5, M4V, MPEG4, SCALE_FILTER) := $(addprefix fate-mpeg4-resolution-change-, $(MPEG4_RESOLUTION_CHANGE))
 
-- 
2.25.1


[-- Attachment #3: Type: text/plain, Size: 251 bytes --]

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Re: [FFmpeg-devel] [PATCH] doc/ffmpeg: extend -dts_delta_threshold option description

[Gyan Doshi]

On 2023-02-06 06:55 am, Stefano Sabatini wrote:
> On date Wednesday 2023-01-25 10:47:20 +0530, Gyan Doshi wrote:
>> For copy_ts, it is still applied for all negative deltas except the
>> smallest.
> Which is a bit arbitrary.

Possibly, but I imagine there was some trac ticket which prompted that 
handling. Does git blame shed any light?

Regards,
Gyan

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Re: [FFmpeg-devel] [PATCH] doc/ffmpeg: extend -dts_delta_threshold option description

[Michael Niedermayer]

[-- Attachment #1.1: Type: text/plain, Size: 4319 bytes --]

On Mon, Feb 06, 2023 at 02:25:23AM +0100, Stefano Sabatini wrote:
> On date Wednesday 2023-01-25 10:47:20 +0530, Gyan Doshi wrote:
> > 
> > 
> > On 2023-01-25 06:37 am, Stefano Sabatini wrote:
> > > ---
> > >   doc/ffmpeg.texi | 17 +++++++++++++++--
> > >   1 file changed, 15 insertions(+), 2 deletions(-)
> > > 
> > > diff --git a/doc/ffmpeg.texi b/doc/ffmpeg.texi
> > > index 67b3294256..122f7e3387 100644
> > > --- a/doc/ffmpeg.texi
> > > +++ b/doc/ffmpeg.texi
> > > @@ -1823,8 +1823,21 @@ results, but increase memory use and latency.
> > >   The default value is 10 seconds.
> > > -@item -dts_delta_threshold
> > > -Timestamp discontinuity delta threshold.
> > > +@item -dts_delta_threshold @var{threshold}
> > > +Timestamp discontinuity delta threshold, expressed as a floating point
> > > +number of @var{AV_TIME_BASE} units.
> > This is a CLI option and those users don't deal with AV_TIME_BASE . More
> > useful to say it's in seconds.
> > 
> > > +
> > > +If a timestamp discontinuity is detected whose absolute value is
> > > +greater than @var{threshold} * @var{AV_TIME_BASE}, ffmpeg will remove the
> > > +discontinuity by decreasing/increasing the current DTS and PTS by the
> > > +corresponding delta value.
> > 
> 
> > Might want to mention that this only applies to AV_FMT_DISCONT demuxers, or
> > rather give a few examples, like MPEG-TS, HLS..etc.
> > For all other formats that users normally work with, clarify that only
> > dts_error_threshold is relevant.
> 
> 
> > > +
> > > +Timestamp discontinuity correction can be inhibited by setting a big value for
> > > +@var{threshold}, and is automatically disabled when employing the
> > > +@code{-copy_ts} option.
> > 
> > For copy_ts, it is still applied for all negative deltas except the
> > smallest.
> 
> Which is a bit arbitrary.
> 
> > 
> > Not blocking, but I'm reworking this code at present. Shouldn't really
> > affect this patch. See
> > https://ffmpeg.org/pipermail/ffmpeg-devel/2023-January/305539.html
> 
> Updated (had to review the code to get some clarity on the current
> behavior).
> 
> Thanks.

>  doc/ffmpeg.texi             |   36 ++++++++++++++++++----
>  fftools/ffmpeg.c            |   72 +++++++++++++++++++++++---------------------
>  fftools/ffmpeg.h            |    2 +
>  fftools/ffmpeg_demux.c      |    3 +
>  tests/fate/filter-audio.mak |    2 -
>  tests/fate/mpeg4.mak        |    2 -
>  6 files changed, 77 insertions(+), 40 deletions(-)
> 55e91624524749274a62bdc43cacdf8e47dd3598  0002-ffmpeg-review-dts_delta_threshold-and-dts_delta_erro.patch
> From 30ac56a14d66eb25428b71c9211f401f818bd057 Mon Sep 17 00:00:00 2001
> From: Stefano Sabatini <stefasab@gmail.com>
> Date: Fri, 1 Apr 2011 01:13:35 +0200
> Subject: [PATCH 2/2] ffmpeg: review -dts_delta_threshold and -dts_delta_error
>  options
> 
> Review handling of -dts_delta_threshold and -dts_delta_error options,
> specify them as floating point expressed in seconds.
> 
> Also, review and simplify logic. Adjust values for tests, since in
> some cases the new values does not trigger the correction logic.
> 
> PR: https://patchwork.ffmpeg.org/project/ffmpeg/list/?series=8252
> ---
>  doc/ffmpeg.texi             | 36 ++++++++++++++++---
>  fftools/ffmpeg.c            | 72 ++++++++++++++++++++-----------------
>  fftools/ffmpeg.h            |  2 ++
>  fftools/ffmpeg_demux.c      |  3 ++
>  tests/fate/filter-audio.mak |  2 +-
>  tests/fate/mpeg4.mak        |  2 +-
>  6 files changed, 77 insertions(+), 40 deletions(-)

This seems to break a case with concat and vsync
./ffmpeg -y -i 'concat:///home/michael/videos/angels.mpg|/home/michael/videos/angels.mpg'  -vsync 0 -an file.avi

...
cpb: bitrate max/min/avg: 0/0/200000 buffer size: 0 vbv_delay: N/A
[mpeg4 @ 0x55e051b8d4c0] Invalid pts (0) <= last (11)00.00 bitrate=N/A speed=   0x    
[vost#0:0/mpeg4 @ 0x55e051b9d700] Error submitting video frame to the encoder
Conversion failed!


Ill mail you the angels.mpg, i think its online somewhere but i cant
find it

thx

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

"Nothing to hide" only works if the folks in power share the values of
you and everyone you know entirely and always will -- Tom Scott


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Re: [FFmpeg-devel] [PATCH] doc/ffmpeg: extend -dts_delta_threshold option description

[Stefano Sabatini]

[-- Attachment #1: Type: text/plain, Size: 2065 bytes --]

On date Thursday 2023-02-09 00:41:18 +0100, Michael Niedermayer wrote:
> On Mon, Feb 06, 2023 at 02:25:23AM +0100, Stefano Sabatini wrote:
[...]
> > Subject: [PATCH 2/2] ffmpeg: review -dts_delta_threshold and -dts_delta_error
> >  options
> > 
> > Review handling of -dts_delta_threshold and -dts_delta_error options,
> > specify them as floating point expressed in seconds.
> > 
> > Also, review and simplify logic. Adjust values for tests, since in
> > some cases the new values does not trigger the correction logic.
> > 
> > PR: https://patchwork.ffmpeg.org/project/ffmpeg/list/?series=8252
> > ---
> >  doc/ffmpeg.texi             | 36 ++++++++++++++++---
> >  fftools/ffmpeg.c            | 72 ++++++++++++++++++++-----------------
> >  fftools/ffmpeg.h            |  2 ++
> >  fftools/ffmpeg_demux.c      |  3 ++
> >  tests/fate/filter-audio.mak |  2 +-
> >  tests/fate/mpeg4.mak        |  2 +-
> >  6 files changed, 77 insertions(+), 40 deletions(-)
> 
> This seems to break a case with concat and vsync
> ./ffmpeg -y -i 'concat:///home/michael/videos/angels.mpg|/home/michael/videos/angels.mpg'  -vsync 0 -an file.avi
> 
> ...
> cpb: bitrate max/min/avg: 0/0/200000 buffer size: 0 vbv_delay: N/A
> [mpeg4 @ 0x55e051b8d4c0] Invalid pts (0) <= last (11)00.00 bitrate=N/A speed=   0x    
> [vost#0:0/mpeg4 @ 0x55e051b9d700] Error submitting video frame to the encoder
> Conversion failed!
>
> 
> Ill mail you the angels.mpg, i think its online somewhere but i cant
> find it

Fixed, now the code should be equivalent to the previous
implementation.

What happened in this case (and apparently in the other fate tests
failing), is that some sort of limit correction is applied:

detected dts:-0.041711 < dts_limit:0.358789
ts delta 0.5005 applied => ts_offset_discont:0.5005 dts:0.458789

preventing the invalid pts error.

The limit correction, hardcoded in the ffmpeg.c code, is completely
unrelated to the dts_delta_threshold value, no idea if it would make
sense to make this parametric (but at least now it should be a bit
more clear from the code/logs).

[-- Attachment #2: 0001-ffmpeg-review-dts_delta_threshold-and-dts_delta_erro.patch --]
[-- Type: text/x-diff, Size: 10917 bytes --]

From 8e23638cbcfcf1e47d4b7d582d4eb12a29ad4f57 Mon Sep 17 00:00:00 2001
From: Stefano Sabatini <stefasab@gmail.com>
Date: Fri, 1 Apr 2011 01:13:35 +0200
Subject: [PATCH] ffmpeg: review -dts_delta_threshold and -dts_delta_error
 options

Review handling of -dts_delta_threshold and -dts_delta_error options
in order to simplify a bit the logic and improve logging.

Also extend documentation.

PR: https://patchwork.ffmpeg.org/project/ffmpeg/list/?series=8252
---
 doc/ffmpeg.texi        | 36 +++++++++++++---
 fftools/ffmpeg.c       | 98 ++++++++++++++++++++++++++----------------
 fftools/ffmpeg.h       |  2 +
 fftools/ffmpeg_demux.c |  3 ++
 4 files changed, 96 insertions(+), 43 deletions(-)

diff --git a/doc/ffmpeg.texi b/doc/ffmpeg.texi
index d9d4b75567..63be7951e6 100644
--- a/doc/ffmpeg.texi
+++ b/doc/ffmpeg.texi
@@ -1837,12 +1837,38 @@ results, but increase memory use and latency.
 
 The default value is 10 seconds.
 
-@item -dts_delta_threshold
-Timestamp discontinuity delta threshold.
+@item -dts_delta_threshold @var{threshold}
+Timestamp discontinuity delta threshold, expressed as a floating point
+number of seconds.
+
+The timestamp discontinuity correction enabled by this option is only
+applied to input formats accepting timestamp discontinuity (for which
+the @code{AV_FMT_DISCONT} flag is enabled), e.g. MPEG-TS and HLS, and
+is automatically disabled when employing the @code{-copy_ts} option
+(unless wrapping is detected).
+
+If a timestamp discontinuity is detected whose absolute value is
+greater than @var{threshold}, ffmpeg will remove the discontinuity by
+decreasing/increasing the current DTS and PTS by the corresponding
+delta value.
+
+The default value is 10.
+
 @item -dts_error_threshold @var{seconds}
-Timestamp error delta threshold. This threshold use to discard crazy/damaged
-timestamps and the default is 30 hours which is arbitrarily picked and quite
-conservative.
+Timestamp error delta threshold, expressed as a floating point number
+of seconds.
+
+The timestamp correction enabled by this option is only applied to
+input formats not accepting timestamp discontinuity (for which the
+@code{AV_FMT_DISCONT} flag is not enabled).
+
+If a timestamp discontinuity is detected whose absolute value is
+greater than @var{threshold}, ffmpeg will drop the PTS/DTS timestamp
+value.
+
+The default value is @code{3600*30} (30 hours), which is arbitrarily
+picked and quite conservative.
+
 @item -muxdelay @var{seconds} (@emph{output})
 Set the maximum demux-decode delay.
 @item -muxpreload @var{seconds} (@emph{output})
diff --git a/fftools/ffmpeg.c b/fftools/ffmpeg.c
index 064ec6d4b3..e88a78872a 100644
--- a/fftools/ffmpeg.c
+++ b/fftools/ffmpeg.c
@@ -3671,62 +3671,84 @@ static void decode_flush(InputFile *ifile)
 static void ts_discontinuity_detect(InputFile *ifile, InputStream *ist,
                                     AVPacket *pkt)
 {
-    const int fmt_is_discont = ifile->ctx->iformat->flags & AVFMT_TS_DISCONT;
+    const int fmt_is_discont = !!(ifile->ctx->iformat->flags & AVFMT_TS_DISCONT);
     int disable_discontinuity_correction = copy_ts;
     int64_t pkt_dts = av_rescale_q_rnd(pkt->dts, ist->st->time_base, AV_TIME_BASE_Q,
                                        AV_ROUND_NEAR_INF | AV_ROUND_PASS_MINMAX);
 
+#define BASE_TS(ts_) av_ts2timestr(ts_, &AV_TIME_BASE_Q)
+#define PKT_TS(ts_) av_ts2timestr(ts_, &ist->st->time_base)
+
+    av_log(NULL, AV_LOG_TRACE,
+           "ts discontinuity detection on stream #%d:%d pkt_dts:%s pkt_pts:%s next_dts:%s last_ts:%s fmt_discont:%d copy_ts:%d\n",
+           ist->file_index, ist->st->index,
+           PKT_TS(pkt->dts), PKT_TS(pkt->pts),
+           BASE_TS(ist->next_dts), BASE_TS(ifile->last_ts),
+           fmt_is_discont, copy_ts);
+
     if (copy_ts && ist->next_dts != AV_NOPTS_VALUE &&
         fmt_is_discont && ist->st->pts_wrap_bits < 60) {
         int64_t wrap_dts = av_rescale_q_rnd(pkt->dts + (1LL<<ist->st->pts_wrap_bits),
                                             ist->st->time_base, AV_TIME_BASE_Q,
                                             AV_ROUND_NEAR_INF|AV_ROUND_PASS_MINMAX);
-        if (FFABS(wrap_dts - ist->next_dts) < FFABS(pkt_dts - ist->next_dts)/10)
+        if (FFABS(wrap_dts - ist->next_dts) < FFABS(pkt_dts - ist->next_dts)/10) {
             disable_discontinuity_correction = 0;
+            av_log(NULL, AV_LOG_DEBUG,
+                   "wrapped ts detected in copy_ts, enabled discontinuity correction\n");
+        }
     }
 
-    if (ist->next_dts != AV_NOPTS_VALUE && !disable_discontinuity_correction) {
-        int64_t delta = pkt_dts - ist->next_dts;
+#define CHECK_INVALID_TS(delta_, ts_type_, ts_)                         \
+    if (FFABS(delta_) > ist->dts_error_threshold) {                     \
+        av_log(NULL, AV_LOG_WARNING,                                    \
+               "drop invalid " #ts_type_ ":%s delta:%s > dts_error_threshold:%s\n", \
+               PKT_TS(ts_), BASE_TS(delta), BASE_TS(ist->dts_error_threshold)); \
+        ts_ = AV_NOPTS_VALUE;                                           \
+    }
+
+    if (!disable_discontinuity_correction) {
+        int64_t delta;
+
         if (fmt_is_discont) {
-            if (FFABS(delta) > 1LL * dts_delta_threshold * AV_TIME_BASE ||
-                pkt_dts + AV_TIME_BASE/10 < FFMAX(ist->pts, ist->dts)) {
-                ifile->ts_offset_discont -= delta;
-                av_log(NULL, AV_LOG_DEBUG,
-                       "timestamp discontinuity for stream #%d:%d "
-                       "(id=%d, type=%s): %"PRId64", new offset= %"PRId64"\n",
-                       ist->file_index, ist->st->index, ist->st->id,
-                       av_get_media_type_string(ist->par->codec_type),
-                       delta, ifile->ts_offset_discont);
-                pkt->dts -= av_rescale_q(delta, AV_TIME_BASE_Q, ist->st->time_base);
-                if (pkt->pts != AV_NOPTS_VALUE)
-                    pkt->pts -= av_rescale_q(delta, AV_TIME_BASE_Q, ist->st->time_base);
-            }
-        } else {
-            if (FFABS(delta) > 1LL * dts_error_threshold * AV_TIME_BASE) {
-                av_log(NULL, AV_LOG_WARNING, "DTS %"PRId64", next:%"PRId64" st:%d invalid dropping\n", pkt->dts, ist->next_dts, pkt->stream_index);
-                pkt->dts = AV_NOPTS_VALUE;
+            delta =
+                ist->next_dts != AV_NOPTS_VALUE ? pkt_dts - ist->next_dts :
+                ifile->last_ts != AV_NOPTS_VALUE ? pkt_dts - ifile->last_ts :
+                AV_NOPTS_VALUE;
+
+            if (delta != AV_NOPTS_VALUE) {
+                char fix_delta = 0;
+                int64_t dts_limit = FFMAX(ist->pts, ist->dts) - AV_TIME_BASE/10;
+
+                if (FFABS(delta) > ist->dts_delta_threshold) {
+                    av_log(NULL, AV_LOG_DEBUG,
+                           "detected dts:%s delta:%s > dts_delta_threshold:%s\n",
+                           BASE_TS(pkt_dts), BASE_TS(delta), BASE_TS(ist->dts_delta_threshold));
+                    fix_delta = 1;
+                } else if (ist->next_dts != AV_NOPTS_VALUE && pkt_dts < dts_limit) {
+                    av_log(NULL, AV_LOG_DEBUG, "detected dts:%s < dts_limit:%s\n",
+                           BASE_TS(pkt_dts), BASE_TS(dts_limit));
+                    fix_delta = 1;
+                }
+
+                if (fix_delta) {
+                    ifile->ts_offset_discont -= delta;
+                    pkt->dts -= av_rescale_q(delta, AV_TIME_BASE_Q, ist->st->time_base);
+                    if (pkt->pts != AV_NOPTS_VALUE)
+                        pkt->pts -= av_rescale_q(delta, AV_TIME_BASE_Q, ist->st->time_base);
+                    av_log(NULL, AV_LOG_DEBUG,
+                           "ts delta %s applied => ts_offset_discont:%s dts:%s\n",
+                           BASE_TS(-delta), BASE_TS(ifile->ts_offset_discont), PKT_TS(pkt->dts));
+                }
             }
-            if (pkt->pts != AV_NOPTS_VALUE){
+        } else if (ist->next_dts != AV_NOPTS_VALUE) {
+            delta = pkt_dts - ist->next_dts;
+            CHECK_INVALID_TS(delta, dts, pkt->dts);
+            if (pkt->pts != AV_NOPTS_VALUE) {
                 int64_t pkt_pts = av_rescale_q(pkt->pts, ist->st->time_base, AV_TIME_BASE_Q);
                 delta = pkt_pts - ist->next_dts;
-                if (FFABS(delta) > 1LL * dts_error_threshold * AV_TIME_BASE) {
-                    av_log(NULL, AV_LOG_WARNING, "PTS %"PRId64", next:%"PRId64" invalid dropping st:%d\n", pkt->pts, ist->next_dts, pkt->stream_index);
-                    pkt->pts = AV_NOPTS_VALUE;
-                }
+                CHECK_INVALID_TS(delta, pts, pkt->pts);
             }
         }
-    } else if (ist->next_dts == AV_NOPTS_VALUE && !copy_ts &&
-               fmt_is_discont && ifile->last_ts != AV_NOPTS_VALUE) {
-        int64_t delta = pkt_dts - ifile->last_ts;
-        if (FFABS(delta) > 1LL * dts_delta_threshold * AV_TIME_BASE) {
-            ifile->ts_offset_discont -= delta;
-            av_log(NULL, AV_LOG_DEBUG,
-                   "Inter stream timestamp discontinuity %"PRId64", new offset= %"PRId64"\n",
-                   delta, ifile->ts_offset_discont);
-            pkt->dts -= av_rescale_q(delta, AV_TIME_BASE_Q, ist->st->time_base);
-            if (pkt->pts != AV_NOPTS_VALUE)
-                pkt->pts -= av_rescale_q(delta, AV_TIME_BASE_Q, ist->st->time_base);
-        }
     }
 
     ifile->last_ts = av_rescale_q(pkt->dts, ist->st->time_base, AV_TIME_BASE_Q);
diff --git a/fftools/ffmpeg.h b/fftools/ffmpeg.h
index f1412f6446..686d38c934 100644
--- a/fftools/ffmpeg.h
+++ b/fftools/ffmpeg.h
@@ -368,6 +368,8 @@ typedef struct InputStream {
     int64_t       next_pts;  ///< synthetic pts for the next decode frame (in AV_TIME_BASE units)
     int64_t       pts;       ///< current pts of the decoded frame  (in AV_TIME_BASE units)
     int           wrap_correction_done;
+    int64_t       dts_delta_threshold; ///< dts_delta_threshold value rescaled to AV_TIME_BASE units
+    int64_t       dts_error_threshold; ///< dts_error_threshold value rescaled to AV_TIME_BASE units
 
     // the value of AVCodecParserContext.repeat_pict from the AVStream parser
     // for the last packet returned from ifile_get_packet()
diff --git a/fftools/ffmpeg_demux.c b/fftools/ffmpeg_demux.c
index 98da0678f5..18f8ed8946 100644
--- a/fftools/ffmpeg_demux.c
+++ b/fftools/ffmpeg_demux.c
@@ -736,6 +736,9 @@ static void add_input_streams(const OptionsContext *o, Demuxer *d)
         ist->filter_in_rescale_delta_last = AV_NOPTS_VALUE;
         ist->prev_pkt_pts = AV_NOPTS_VALUE;
 
+        ist->dts_delta_threshold = 1LL * dts_delta_threshold * AV_TIME_BASE;
+        ist->dts_error_threshold = 1LL * dts_error_threshold * AV_TIME_BASE;
+
         ist->dec_ctx = avcodec_alloc_context3(ist->dec);
         if (!ist->dec_ctx)
             report_and_exit(AVERROR(ENOMEM));
-- 
2.25.1


[-- Attachment #3: Type: text/plain, Size: 251 bytes --]

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Re: [FFmpeg-devel] [PATCH] doc/ffmpeg: extend -dts_delta_threshold option description

[Stefano Sabatini]

[-- Attachment #1: Type: text/plain, Size: 2318 bytes --]

On date Saturday 2023-02-11 03:30:00 +0100, Stefano Sabatini wrote:
> On date Thursday 2023-02-09 00:41:18 +0100, Michael Niedermayer wrote:
> > On Mon, Feb 06, 2023 at 02:25:23AM +0100, Stefano Sabatini wrote:
> [...]
> > > Subject: [PATCH 2/2] ffmpeg: review -dts_delta_threshold and -dts_delta_error
> > >  options
> > > 
> > > Review handling of -dts_delta_threshold and -dts_delta_error options,
> > > specify them as floating point expressed in seconds.
> > > 
> > > Also, review and simplify logic. Adjust values for tests, since in
> > > some cases the new values does not trigger the correction logic.
> > > 
> > > PR: https://patchwork.ffmpeg.org/project/ffmpeg/list/?series=8252
> > > ---
> > >  doc/ffmpeg.texi             | 36 ++++++++++++++++---
> > >  fftools/ffmpeg.c            | 72 ++++++++++++++++++++-----------------
> > >  fftools/ffmpeg.h            |  2 ++
> > >  fftools/ffmpeg_demux.c      |  3 ++
> > >  tests/fate/filter-audio.mak |  2 +-
> > >  tests/fate/mpeg4.mak        |  2 +-
> > >  6 files changed, 77 insertions(+), 40 deletions(-)
> > 
> > This seems to break a case with concat and vsync
> > ./ffmpeg -y -i 'concat:///home/michael/videos/angels.mpg|/home/michael/videos/angels.mpg'  -vsync 0 -an file.avi
> > 
> > ...
> > cpb: bitrate max/min/avg: 0/0/200000 buffer size: 0 vbv_delay: N/A
> > [mpeg4 @ 0x55e051b8d4c0] Invalid pts (0) <= last (11)00.00 bitrate=N/A speed=   0x    
> > [vost#0:0/mpeg4 @ 0x55e051b9d700] Error submitting video frame to the encoder
> > Conversion failed!
> >
> > 
> > Ill mail you the angels.mpg, i think its online somewhere but i cant
> > find it
> 
> Fixed, now the code should be equivalent to the previous
> implementation.
> 
> What happened in this case (and apparently in the other fate tests
> failing), is that some sort of limit correction is applied:
> 
> detected dts:-0.041711 < dts_limit:0.358789
> ts delta 0.5005 applied => ts_offset_discont:0.5005 dts:0.458789
> 
> preventing the invalid pts error.
> 
> The limit correction, hardcoded in the ffmpeg.c code, is completely
> unrelated to the dts_delta_threshold value, no idea if it would make
> sense to make this parametric (but at least now it should be a bit
> more clear from the code/logs).

Moving the refactoring changes to a dedicated thread.

Updating the doc extensions.

[-- Attachment #2: 0003-doc-ffmpeg-extend-documentation-for-dts_delta_thresh.patch --]
[-- Type: text/x-diff, Size: 2324 bytes --]

From f7df77c9d488fa0f470eba064cdcce915c519ca3 Mon Sep 17 00:00:00 2001
From: Stefano Sabatini <stefasab@gmail.com>
Date: Sat, 11 Feb 2023 17:18:39 +0100
Subject: [PATCH 3/3] doc/ffmpeg: extend documentation for -dts_delta_threshold
 and -dts_error_threshold

PR: https://patchwork.ffmpeg.org/project/ffmpeg/list/?series=8252
---
 doc/ffmpeg.texi | 36 +++++++++++++++++++++++++++++++-----
 1 file changed, 31 insertions(+), 5 deletions(-)

diff --git a/doc/ffmpeg.texi b/doc/ffmpeg.texi
index d9d4b75567..63be7951e6 100644
--- a/doc/ffmpeg.texi
+++ b/doc/ffmpeg.texi
@@ -1837,12 +1837,38 @@ results, but increase memory use and latency.
 
 The default value is 10 seconds.
 
-@item -dts_delta_threshold
-Timestamp discontinuity delta threshold.
+@item -dts_delta_threshold @var{threshold}
+Timestamp discontinuity delta threshold, expressed as a floating point
+number of seconds.
+
+The timestamp discontinuity correction enabled by this option is only
+applied to input formats accepting timestamp discontinuity (for which
+the @code{AV_FMT_DISCONT} flag is enabled), e.g. MPEG-TS and HLS, and
+is automatically disabled when employing the @code{-copy_ts} option
+(unless wrapping is detected).
+
+If a timestamp discontinuity is detected whose absolute value is
+greater than @var{threshold}, ffmpeg will remove the discontinuity by
+decreasing/increasing the current DTS and PTS by the corresponding
+delta value.
+
+The default value is 10.
+
 @item -dts_error_threshold @var{seconds}
-Timestamp error delta threshold. This threshold use to discard crazy/damaged
-timestamps and the default is 30 hours which is arbitrarily picked and quite
-conservative.
+Timestamp error delta threshold, expressed as a floating point number
+of seconds.
+
+The timestamp correction enabled by this option is only applied to
+input formats not accepting timestamp discontinuity (for which the
+@code{AV_FMT_DISCONT} flag is not enabled).
+
+If a timestamp discontinuity is detected whose absolute value is
+greater than @var{threshold}, ffmpeg will drop the PTS/DTS timestamp
+value.
+
+The default value is @code{3600*30} (30 hours), which is arbitrarily
+picked and quite conservative.
+
 @item -muxdelay @var{seconds} (@emph{output})
 Set the maximum demux-decode delay.
 @item -muxpreload @var{seconds} (@emph{output})
-- 
2.25.1


[-- Attachment #3: Type: text/plain, Size: 251 bytes --]

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Re: [FFmpeg-devel] [PATCH] doc/ffmpeg: extend -dts_delta_threshold option description

[Gyan Doshi]

On 2023-02-11 09:58 pm, Stefano Sabatini wrote:
> On date Saturday 2023-02-11 03:30:00 +0100, Stefano Sabatini wrote:
>> On date Thursday 2023-02-09 00:41:18 +0100, Michael Niedermayer wrote:
>>> On Mon, Feb 06, 2023 at 02:25:23AM +0100, Stefano Sabatini wrote:
>> [...]
>>>> Subject: [PATCH 2/2] ffmpeg: review -dts_delta_threshold and -dts_delta_error
>>>>   options
>>>>
>>>> Review handling of -dts_delta_threshold and -dts_delta_error options,
>>>> specify them as floating point expressed in seconds.
>>>>
>>>> Also, review and simplify logic. Adjust values for tests, since in
>>>> some cases the new values does not trigger the correction logic.
>>>>
>>>> PR: https://patchwork.ffmpeg.org/project/ffmpeg/list/?series=8252
>>>> ---
>>>>   doc/ffmpeg.texi             | 36 ++++++++++++++++---
>>>>   fftools/ffmpeg.c            | 72 ++++++++++++++++++++-----------------
>>>>   fftools/ffmpeg.h            |  2 ++
>>>>   fftools/ffmpeg_demux.c      |  3 ++
>>>>   tests/fate/filter-audio.mak |  2 +-
>>>>   tests/fate/mpeg4.mak        |  2 +-
>>>>   6 files changed, 77 insertions(+), 40 deletions(-)
>>> This seems to break a case with concat and vsync
>>> ./ffmpeg -y -i 'concat:///home/michael/videos/angels.mpg|/home/michael/videos/angels.mpg'  -vsync 0 -an file.avi
>>>
>>> ...
>>> cpb: bitrate max/min/avg: 0/0/200000 buffer size: 0 vbv_delay: N/A
>>> [mpeg4 @ 0x55e051b8d4c0] Invalid pts (0) <= last (11)00.00 bitrate=N/A speed=   0x
>>> [vost#0:0/mpeg4 @ 0x55e051b9d700] Error submitting video frame to the encoder
>>> Conversion failed!
>>>
>>>
>>> Ill mail you the angels.mpg, i think its online somewhere but i cant
>>> find it
>> Fixed, now the code should be equivalent to the previous
>> implementation.
>>
>> What happened in this case (and apparently in the other fate tests
>> failing), is that some sort of limit correction is applied:
>>
>> detected dts:-0.041711 < dts_limit:0.358789
>> ts delta 0.5005 applied => ts_offset_discont:0.5005 dts:0.458789
>>
>> preventing the invalid pts error.
>>
>> The limit correction, hardcoded in the ffmpeg.c code, is completely
>> unrelated to the dts_delta_threshold value, no idea if it would make
>> sense to make this parametric (but at least now it should be a bit
>> more clear from the code/logs).
> Moving the refactoring changes to a dedicated thread.
>
> Updating the doc extensions.

LGTM.

Regards,
Gyan

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Re: [FFmpeg-devel] [PATCH] doc/ffmpeg: extend -dts_delta_threshold option description

[Anton Khirnov]

Quoting Stefano Sabatini (2023-02-11 03:30:00)
> On date Thursday 2023-02-09 00:41:18 +0100, Michael Niedermayer wrote:
> > On Mon, Feb 06, 2023 at 02:25:23AM +0100, Stefano Sabatini wrote:
> [...]
> > > Subject: [PATCH 2/2] ffmpeg: review -dts_delta_threshold and -dts_delta_error
> > >  options
> > > 
> > > Review handling of -dts_delta_threshold and -dts_delta_error options,
> > > specify them as floating point expressed in seconds.

Maybe it's a bit nitpicky, but these are decimal numbers, not floating
point.

-- 
Anton Khirnov
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Re: [FFmpeg-devel] [PATCH] doc/ffmpeg: extend -dts_delta_threshold option description

[Stefano Sabatini]

On date Monday 2023-02-20 18:57:44 +0100, Anton Khirnov wrote:
> Quoting Stefano Sabatini (2023-02-11 03:30:00)
> > On date Thursday 2023-02-09 00:41:18 +0100, Michael Niedermayer wrote:
> > > On Mon, Feb 06, 2023 at 02:25:23AM +0100, Stefano Sabatini wrote:
> > [...]
> > > > Subject: [PATCH 2/2] ffmpeg: review -dts_delta_threshold and -dts_delta_error
> > > >  options
> > > > 
> > > > Review handling of -dts_delta_threshold and -dts_delta_error options,
> > > > specify them as floating point expressed in seconds.
> 
> Maybe it's a bit nitpicky, but these are decimal numbers, not floating
> point.

Fixed and pushed, thanks.
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