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Topic: LAV video decoder and ffdshow raw filters for 10 bit

Hey there, while this issue isn't directly related to you guys, it's still somewhat relevant, since you suggest using LAV for decoding.
When playing back 10-bit files, normally madVR will do the conversion to 8-bit, since its the best at it. However, using ffdshow only for avisynth, it doesn't accept 10-bit input. This means that lav dithers the stream down and not madVR. Using ffdshow for decoding, this issue does not appear.

  • MAG79
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Re: LAV video decoder and ffdshow raw filters for 10 bit

heyer
And what the problem?

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Re: LAV video decoder and ffdshow raw filters for 10 bit

Well, the fact that LAV does the dithering instead of madVR, which supposedly is better at it. I really dunno how much you guys can do about it, just thought you might wanna know.

  • Rimsky
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Re: LAV video decoder and ffdshow raw filters for 10 bit

heyer
did you know that AviSynth works only with 8bit pictures? and with SVP all 10-bit video dithers to 8bit becouse it uses avs-script for making interpolation frames?

Re: LAV video decoder and ffdshow raw filters for 10 bit

Do you really see any difference?  hmm
10 bit is for encoding quality / file size, not for "i can see 10 bits on my LCD!" smile

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Re: LAV video decoder and ffdshow raw filters for 10 bit

Well, I dunno actually. If it doesn't make a difference, I guess it doesn't matter tongue

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Re: LAV video decoder and ffdshow raw filters for 10 bit

Btw Rimsky, are you sure about that? MadVR reports 10-bit input when using ffdshow as the decoder, even though SVP is on? The problem only occurs when using ffdshow as a raw filter

  • MAG79
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Re: LAV video decoder and ffdshow raw filters for 10 bit

heyer
SVP calculates new frames by Avisynth-script using avisynth SVP libraries.
Avisynth has restriction of color depth. It is 8 bit depth. Avisynth SVP libraries has restriction of color space. It is YV12.
ffdShow used by SVP to get videoframes on-the-fly and to pass it to the avisynth-script. At the avisynth-script input must be YV12 color-space. If not it is converted to YV12 (8 bit depth).

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Re: LAV video decoder and ffdshow raw filters for 10 bit

Thanks alot for the explanation smile
Then I'm guessing ffdshow upconverts it to 10-bit again after avisynth, thereby wasting CPU? That seems to be the only explanation to madVR reporting 10-bit, right?

  • Rimsky
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Re: LAV video decoder and ffdshow raw filters for 10 bit

heyer

thereby wasting CPU
yes, it a waste of CPU time

That seems to be the only explanation to madVR reporting 10-bit, right
maybe, 8bit, 10bit, no matter until mon/TV work in 8bit

  • MAG79
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Re: LAV video decoder and ffdshow raw filters for 10 bit

heyer
madVR reporting 10-bit
Where did you see that? Can you show screenshot?

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Re: LAV video decoder and ffdshow raw filters for 10 bit

MAG79
Well, I don't know how much a screenshot proves, but it can be easily replicated by using ffdshow as the main decoder, enabling SVP and using madVR. On the madVR overlay (ctrl-j) it will show 10-bit input.

  • MAG79
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Re: LAV video decoder and ffdshow raw filters for 10 bit

heyer
May be you are right. It is not important to me, I have not any 10-bit movie.