| Message ID | 20230411201847.26564-1-jeebjp@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | [FFmpeg-devel] avfilter/vsrc_ddagrab: add option to control pts offset removal | expand |
| Context | Check | Description |
|---|---|---|
| andriy/make_x86 | success | Make finished |
| andriy/make_fate_x86 | success | Make fate finished |
On Tue, 11 Apr 2023, Jan Ekström wrote: > This keeps the default behavior as-is by defaulting to true, > while allowing to start the timestamps with the offset from > av_gettime_relative epoch start. This allows for synchronization > with other capture modules that utilize the same epoch start, such > as DShow audio capture. I don't think an option is needed. The zero based pts should simply be changed to wallclock based pts, most capture devices already work that way. ffmpeg.c can make pts 0 based if needed. Also, there were arguments in the past for using av_gettime() for pts values and av_gettime_relative() for elapsed time measurement, and most capture devices tend to follow that unless I am mistaken. Regards, Marton > --- > libavfilter/vsrc_ddagrab.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/libavfilter/vsrc_ddagrab.c b/libavfilter/vsrc_ddagrab.c > index 042842104f..14fb4abd10 100644 > --- a/libavfilter/vsrc_ddagrab.c > +++ b/libavfilter/vsrc_ddagrab.c > @@ -100,6 +100,7 @@ typedef struct DdagrabContext { > int out_fmt; > int allow_fallback; > int force_fmt; > + int start_pts_at_zero; > } DdagrabContext; > > #define OFFSET(x) offsetof(DdagrabContext, x) > @@ -123,6 +124,8 @@ static const AVOption ddagrab_options[] = { > OFFSET(allow_fallback), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, FLAGS }, > { "force_fmt", "exclude BGRA from format list (experimental, discouraged by Microsoft)", > OFFSET(force_fmt), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, FLAGS }, > + { "start_pts_at_zero", "start timestamps at PTS=0, removing any initial offset", > + OFFSET(start_pts_at_zero), AV_OPT_TYPE_BOOL, { .i64 = 1 }, 0, 1, FLAGS }, > { NULL } > }; > > @@ -913,7 +916,7 @@ static int ddagrab_request_frame(AVFilterLink *outlink) > av_usleep(delay); > } > > - if (!dda->first_pts) > + if (dda->start_pts_at_zero && !dda->first_pts) > dda->first_pts = now; > now -= dda->first_pts; > > -- > 2.40.0 > > _______________________________________________ > ffmpeg-devel mailing list > ffmpeg-devel@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel > > To unsubscribe, visit link above, or email > ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe". >
diff --git a/libavfilter/vsrc_ddagrab.c b/libavfilter/vsrc_ddagrab.c index 042842104f..14fb4abd10 100644 --- a/libavfilter/vsrc_ddagrab.c +++ b/libavfilter/vsrc_ddagrab.c @@ -100,6 +100,7 @@ typedef struct DdagrabContext { int out_fmt; int allow_fallback; int force_fmt; + int start_pts_at_zero; } DdagrabContext; #define OFFSET(x) offsetof(DdagrabContext, x) @@ -123,6 +124,8 @@ static const AVOption ddagrab_options[] = { OFFSET(allow_fallback), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, FLAGS }, { "force_fmt", "exclude BGRA from format list (experimental, discouraged by Microsoft)", OFFSET(force_fmt), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, FLAGS }, + { "start_pts_at_zero", "start timestamps at PTS=0, removing any initial offset", + OFFSET(start_pts_at_zero), AV_OPT_TYPE_BOOL, { .i64 = 1 }, 0, 1, FLAGS }, { NULL } }; @@ -913,7 +916,7 @@ static int ddagrab_request_frame(AVFilterLink *outlink) av_usleep(delay); } - if (!dda->first_pts) + if (dda->start_pts_at_zero && !dda->first_pts) dda->first_pts = now; now -= dda->first_pts;