splitmuxsink and timestamps

[Philippe De Muyter]

On Wed, Apr 19, 2017 at 01:05:40PM +1000, Jan Schmidt wrote:
> >> GST_BUFFER_TIMESTAMP is an alias for GST_BUFFER_PTS, so they're the same
> >> time.
> >>
> > Is it meant to contain the absolute capture timestamp of the frame ?
> > Or is another timestamp field available for that purpose ?
> 
> Short answer: No.
> Longer answer: PTS can contain whatever timestamp upstream decides -
> it's just an incrementing time with some arbitrary start point that
> increases according to the playback/capture rate of the video according
> to the clock it's being measured against..
> 
> > And when replaying h264 encoded files produced by splitmuxsink using splitmuxsrc,
> > is it possible to retrieve the original capture timestamps of the frames ?
> 
> You'll need to use timecodes for that. Hopefully someone else can
> answer, because I've never used them.
> 

Why timecode ?  Would that not make sense to add a third GST_BUFFER timestamp
to hold the capture time of the frame in timestamp, not timecode, format.

I am under the impression I am not the only one to see that as a needed
functionality.  Not every plugin should use it, but multifilesink, timeoverlay
and splitmuxsink are natural candidate users.

Philippe

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