[vlc-devel] [PATCH 1/2] transcode: add support for flush operations

[Rémi Denis-Courmont]

Le maanantaina 15. helmikuuta 2021, 13.49.55 EET Francois Cartegnie a écrit :
> Le 15/02/2021 à 12:38, Alaric Senat a écrit :
> > Previously flushing the transcode stream was left unimplemented.
> > Flushing out the stream while transcoding makes sense especially to
> > support seeking operations.
> > 
> > While seeking in transcoding is far from being fully supported in vlc
> > this allows to at least change the starting time before transcoding a
> > media without major modifications to the input loop.
> 
> As I've mentioned before, there's no concept of flushing in a sout
> chain. Only individual defined flush control is possible: Decoders,
> packetizers. A generic flush has no meaning.

It has a meaning: to expedite output abort, as opposed to draining which waits 
for proper and clean end. This is the same meaning as with the audio output. 
However I do agree that it makes no general sense at it is nonrecoverable.

> What do I do when it hits, for example, muxers ?

As with everything else, drop buffers if possible in reasonably simple manner.

> Trying to solve an asynchronous random access discontinuity handling
> issue with a synchronous command can't work without breaking the concept
> of stream.

I agree. We should assert that nothing happens after flush (other than 
deactivate).

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