We called mp_pin_out_request_data() if there was input _and_ output.
This is not how it should be: we should request new input only if output
was requested, but we could not produce any output.
On the other hand, the upper half of the process() function will request
new input if output is required, but all input was consumed. But this
requires calling mp_filter_internal_mark_progress(), as otherwise the
general filter logic would not know that we can continue.
If the speed is changed by a large amount, we need to effectively change
the output rate by a large amount, and swr_set_compensation() is
apparently not designed to handle such large changes well. So it's
better to reinitialize the resampler on all large changes.
Also, strictly reinitialize the resampler if the rate changes, otherwise
it could happen that libavresample (which does not automatically
initialize resampling if avresample_set_compensation() is used) would
never apply speed changes properly.
Also document some conditions better that handle corner cases (remove
the inline condition from the if gating the compensation code).
It also appears that we crashed with very large compensation ratios
(when raising audio speed quickly by keeping the "[" key down), and this
commit accidentally mitigates it by not allowing large compensation.
Similar to the previous commit, and for the same reasons. Unlike with
af_scaletempo, resampling does not have a natural frame size, so we set
an arbitrary size limit on output frames. We add a new option to control
this size, although I'm not sure whether anyone will use it, so mark it
for testing only.
Note that we go through some effort to avoid buffering data in
libswresample itself. One reason is that we might have to reinitialize
the resampler completely when changing speed, which drops the buffered
data. Another is that I'm not sure whether the resampler will do the
right thing when applying dynamic speed changes.
zc62
wm4