af_scaletempo: output minimally sized audio frame

This helps the filter to adapt much faster to speed changes. Before this
commit, the filter just converted and output the full input frame, which
could cause problems with large input frames. This was made worse by
certain filters like dynaudnorm or loudnorm outputting pretty large
frames.

This commit changes the filter from trying to convert all input at once
to only outputting a single internally filtered frame. Internally, this
filter already output data in units of 60ms by default (controlled by
the "stride" sub-option), and concatenated as many output frames as
necessary to consume all input.

Behavior is still kind of bad when inserting the filter. This is because
the large frames can be buffered up after the insertion point, so the
speed change will be performed with a larger latency. The scaletempo
filter can't do anything against this, although it can be fixed by
inserting scaletempo as user filter as part of --af.

0 files changed, 0 insertions, 0 deletions