[FFmpeg-devel] [PATCH] (for discussion): cuvid: allow to crop and resize in decoder

Timo Rothenpieler timo at rothenpieler.org
Sun Mar 5 17:36:25 EET 2017


Am 01.03.2017 um 11:58 schrieb Timo Rothenpieler:
>>> We recently just had all sorts of discussions what decoders should and
>>> should not do, I don't think scaling in a decoder is a good thing to
>>> start doing here.
>>
>> scaling in some decoders is mandated by some specs
>> some standards support reduced resolution which can switch from frame
>> to frame without the decoder output changing
>> There is also the possiblity of scalability where the reference stream
>> has lower resolution IIRC.
>>
>> This is kind of different of course but, scaling code in decoders is
>> part of some specifications.
>
> Would like to bring this back up.
> I'd like to merge this, as specially the scaling is freely done by the
> video asic, offering a possibility to scale without requiring non-free
> libnpp. And cropping so far is not possible at all.
>
> Yes, scaling and cropping is not something a decoder usually does, but
> it exposes a hardware feature that has no other way of accessing it,
> which offers valuable functionality to users.
>

With the lazy filter init now merged, this patch can be simplified.
Rewrote most of it, currently on github: 
https://github.com/BtbN/FFmpeg/commit/f856fa509278392a88c754b8c7755a575e5aeb41

I'm still doing some testing with it, but intend to push it if no issues 
are found.


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