[FFmpeg-devel] yadif: Don't process progressive frames and select proper pix format

Nicolas George nicolas.george at normalesup.org
Sat May 5 10:51:04 CEST 2012

Le septidi 17 floréal, an CCXX, Robert Nagy a écrit :
> 1. It will auto-insert a scale filter to ensure format compatibility with
> yadif, even if fed with a progressive stream with auto_enable==true, e.g.
> progressive bgra stream will be converted to yuv420, for no reason.

Is there a fundamental reason that would make yadif impossible to port to
RGB formats? If not, that would be a much better solution IMHO. Ans since
yadif already supports YUV444P, i.e. a 3-components format with no
subsampling, it should only be a matter of handling packed formats.

> 2. Incorrect auto-insert scale filters, e.g. bgra -> yadif, will become,
> bgra -> yuv420 -> yadif, instead of more appropriate bgra -> yuva420 ->
> yadif.

This is not yadif-specific: automatic conversions should try to choose a
more conservative format. I thought it was already done.

> The attached patch tries to address these issues by moving format handling
> into the yadif filter. However, the problem with this hack solution is that
> one need to add an explicit scale filter after any yadif filter in order to
> not confuse the filter graph about formats.'

I am not really happy about that solution: that makes a lot of duplicated
code, and furthermore it makes an additional case where automatic conversion
happens, and this is not good when people want to control conversion


  Nicolas George
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