[FFmpeg-devel] [PATCH] more libx264 parameters

[Michael Niedermayer]

On Thu, Mar 18, 2010 at 04:50:31PM +0000, Loren Merritt wrote:
> On Thu, 18 Mar 2010, Michael Niedermayer wrote:
>> On Wed, Mar 17, 2010 at 05:06:59PM -0700, Baptiste Coudurier wrote:
>>>
>>> -flags2 +psy (activated by default)
>>
>> but first, do we need a psy flag, is not setting some of the float 
>> parameters
>> to 0 naturally disabling it? no i am not upto date with x264 encoding 
>> options
>
> The psy flag also affects a number of minor psy optimizations that don't 
> have their own strength variables.

ok then


>
>>> +#define CODEC_FLAG2_SSIM          0x00100000 ///< Compute SSIM during 
>>> encoding
>>
>> is the value made available through AVFrame.error[] or just printed
>> to the terminal, printf would be a bit annoying, in light of av_log()
>> expectance of applications.
>
> Only printed, though libx264 supports an av_log callback to replace printf.

i guess some GUIs (and us too for consistency to how we handle psnr)
would love to have this accessable per frame and overall at the end
in some struct

for now we could just add a note to 
CODEC_FLAG2_SSIM that the error[] values are undefined if this flag is set
if we plan to i the future store them there or maybe we could use a seperate
ssim[] for that dunno?


>
>>> +    /**
>>> +     * AQ strength
>>> +     * Reduces blocking and blurring in flat and textured areas. [1.0]
>>> +     */
>>> +    float aq_strength;
>>
>> is this semantically different from our *cplx_mask fields?
>
> It's a different algorithm, has a different range of valid inputs, and I 
> recommend that people do use x264's aq but not use spatial_cplx_masking.
> Other than that, no.

i wont reject this extra field but i would prefer if someone could just
port x264s algorithm (if its better which i assume) so that we have just
one field. This would keep the API from exploding into many codec specific
fields that will confuse everyone.
We could call that field aq_strength and put the old under #if version <...


[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

The bravest are surely those who have the clearest vision
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