[FFmpeg-devel] [PATCH] libavfilter/af_atempo: offset output frames' pts by first_frame_pts / tempo

[Pavel Koshevoy]

On Thu, Jan 24, 2019 at 8:01 AM Gyan <ffmpeg at gyani.pro> wrote:
>
>
>
> On 24-01-2019 08:18 PM, Paweł Wegner wrote:
> >
> > This fixes seeking when I have video playback sped up in ffplay like this:
> > ffplay -vf "setpts=0.5 * PTS" -af "atempo=2" input
>
> The better way to run this is
>
>      ffplay -vf "setpts=0.5 * (PTS - STARTPTS)" -af "atempo=2" input
>
>


yeah, why not just do this... no code changes required.  I'd prefer it
if atempo stayed simple.  This way you can still use a separate pts
transform filter to adjust audio pts if necessary and without
hard-coding an assumption into atempo.

Pavel.