[FFmpeg-user] Help: transform 'asyncts=first_pts=0' into new 'aresample' filter

Frank Häfemeier ffmpeg at frank.haefemeier.eu
Sun Jan 27 03:37:09 CET 2013

Am Sonntag, den 20.01.2013, 23:38 +0100 schrieb Stefano Sabatini:
> On date Sunday 2013-01-20 22:36:35 +0100, Frank Häfemeier wrote:
> > Who know how to transform the filter 'asyncts=first_pts=0' into the new
> > one? Is it possible? I am not familiar enough and searching an
> > experienced user.
> What I used when I need the same functionality:
> min_comp=0.001:min_hard_comp=0.1
> Exegesis:
> delta = |input PTS - expected PTS|
> min_comp=d
> basically enables soft/hard compensation in case delta >= d.
> Compensation consists in applying one of these:
> stretching/squeezing (soft compensation)
> filling or trimming (hard compensation)
> Since you want to enable *filling*/padding in this case,
> min_hard_comp=0.1 will add samples if delta >= 0.1 (this happens in
> case of big delay at the beginning of the file), soft compensation in
> case of "small" (<0.1 seconds) gaps. Since min_hard_comp=0.1 is the
> default, you can simply set equivalently:
> aresample=min_comp=0.001
Thanks for the explanation. I will try it. The conclusion is, I need
more tests, how to configure the filter to get the correct result for my
> See the ffmpeg-resampler(1) manual for more info.
> There is no way to exactly duplicate the asyncts functionality -
> padding *only* at the file beginning. asyncts can be enabled with
> --enable-libavresample when building.
The library is enabled and asyncts is available, but creates some
tearing noise at the beginning of the video (see my posting 'Get a
tearing noise by using filter asyncts'). The result of the refered one
was the motivation for this mail.
> See also asetpts, ashowinfo, aselect filters.
I will have a look on it.


More information about the ffmpeg-user mailing list