[FFmpeg-devel] [PATCH] lavdevice: Add VideoToolbox output device.

[Nicolas George]

Thilo Borgmann (12020-06-08):
> How do you avoid the auto-scaler to be scaling to alsa's default
> format of pcm_s16 on the command line?

We cannot, not with your original version, not with how alsa_enc does
and the new version.

Because they are not sample formats, they are codecs, and converting
from a codec to another is more complex than just a resampler. And even
if in these particular cases they are trivial codecs, they could easily
not be: ALSA supports S/PDIF, so it could be AC3 or something.

The solution to have format negotiation would be to make sure all output
devices have a matching lavfi sink. Unfortunately, for now, I am not
sure lavfi's scheduling work with non-buffer sinks. And it has other
drawbacks, including preventing S/PDIF.

Regards,

-- 
  Nicolas George
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