MJPEG Quantization Matrix

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MJPEG Quantization Matrix

Dsoccer16
Hi everyone,
I'm using mjpeg to code an uncommon type of yuv files. I would like to use a customized quantization matrix, anyone knows if it is possible?
Thanks in advance.
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Re: MJPEG Quantization Matrix

Carl Eugen Hoyos
Dsoccer16 <josepedro.16 <at> hotmail.com> writes:

> I'm using mjpeg to code an uncommon type of yuv files.
> I would like to use a customized quantization matrix,
> anyone knows if it is possible?

See -intra_matrix and -chroma_intra_matrix

Carl Eugen

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Re: MJPEG Quantization Matrix

Dsoccer16
Thank you very much.
It works but there are two things I don't understand.
Why can't I set all the coefficients equal 1? Is it possible to use a custom quantization matrix and at the same time control the coefficients using the q parameter?

José Peixeiro
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Re: MJPEG Quantization Matrix

Robert Krüger-2
On Wed, Sep 16, 2015 at 4:40 PM, Dsoccer16 <[hidden email]> wrote:

> Thank you very much.
> It works but there are two things I don't understand.
> Why can't I set all the coefficients equal 1? Is it possible to use a
> custom
> quantization matrix and at the same time control the coefficients using the
> q parameter?
>
>
If you succeed doing this, it would be nice if you could share your
findings here. I failed a few years ago to use custom matrices to drive
bitrate up higher than with qmin 1 qmax 1.
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