nvenc 2pass

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nvenc 2pass

JUGGALO BEAVIS
How to do a 2pass encode using the NVENC codec ?
is it a single command, for example:
ffmpeg -i INPUT.mp4 -c:v nvenc -preset hq -profile:v main -c:a aac -strict experimental -b:v 500000 -b:a 128k -cbr 1 -2pass 1 -y OUTPUT.mp4
or, do we need multiple pass commands as with h264 ?
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Re: nvenc 2pass

Moritz Barsnick
On Mon, Jul 27, 2015 at 17:28:28 +0000, JUGGALO BEAVIS wrote:
> is it a single command, for example:
> ffmpeg -i INPUT.mp4 -c:v nvenc -preset hq -profile:v main -c:a aac -strict experimental -b:v 500000 -b:a 128k -cbr 1 -2pass 1 -y OUTPUT.mp4
> or, do we need multiple pass commands as with h264 ?

ffmpeg does not iterate over a video itself. You need to call ffmpeg
twice, with "-pass 1" and "-pass 2".

Moritz
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Re: nvenc 2pass

JUGGALO BEAVIS
Thank you.
nvenc codec seems to have it's own -2pass parameter, with possible values being -1,0,1 (default -1)
Would this be the proper way to combine the nvenc's -2pass parameter with ffmpeg's -pass parameter ?
ffmpeg -i INPUT.mp4 -c:v nvenc -preset hq -profile:v main -an -b:v 500000 -cbr 1 -pass 1 -2pass 1 -y OUTPUT.mp4
ffmpeg -i INPUT.mp4 -c:v nvenc -preset hq -profile:v main -c:a aac -strict experimental -b:v 500000 -b:a 128k -cbr 1 -pass 2 -2pass 1 -y OUTPUT.mp4
My biggest concern is the value of -2pass parameter in each command.


     On Monday, July 27, 2015 2:44 PM, Moritz Barsnick <[hidden email]> wrote:
   

 On Mon, Jul 27, 2015 at 17:28:28 +0000, JUGGALO BEAVIS wrote:
> is it a single command, for example:
> ffmpeg -i INPUT.mp4 -c:v nvenc -preset hq -profile:v main -c:a aac -strict experimental -b:v 500000 -b:a 128k -cbr 1 -2pass 1 -y OUTPUT.mp4
> or, do we need multiple pass commands as with h264 ?

ffmpeg does not iterate over a video itself. You need to call ffmpeg
twice, with "-pass 1" and "-pass 2".

Moritz
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Re: nvenc 2pass

Moritz Barsnick
On Mon, Jul 27, 2015 at 19:54:11 +0000, JUGGALO BEAVIS wrote:
> Thank you.
> nvenc codec seems to have it's own -2pass parameter, with possible values being -1,0,1 (default -1)

Oh, I wasn't aware of that. Due to lack of access to nvenc and its
documentation, I take my answer back in favor of someone else giving a
proper answer.

Moritz
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