[FFmpeg-devel] [PATCH] libavfilter: created a new filter that obtains the average peak signal-to-noise ratio (PSNR) of two input video files in YUV format.

[Mark Himsley]

On 10/06/11 00:18, Stefano Sabatini wrote:
> On date Tuesday 2011-06-07 14:03:36 +0200, Roger Pau Monné encoded:

>> +    switch (inlink->format) {
>> +    case PIX_FMT_YUV410P:
>> +    case PIX_FMT_YUV411P:
>> +    case PIX_FMT_YUV420P:
>> +    case PIX_FMT_YUV422P:
>> +    case PIX_FMT_YUV440P:
>> +    case PIX_FMT_YUV444P:
>> +    case PIX_FMT_YUVA420P:
>
>> +        psnr->max[0] = 235;
>
> psnr->max[3] = 255;
>
> at least I suppose this is the max alpha value in
> psnr->YUVA420P, yes I forgot this in the lut filter

It is not. Alpha is always 0 - 255 (headroom is not required in an alpha 
signal, you can't have more than completely keyed on, or less than not 
keyed on at all)

>> +        psnr->max[1] = psnr->max[2] = 240;
>
>
>> +        break;
>> +    default:
>> +        psnr->max[0] = psnr->max[1] = psnr->max[2] = psnr->max[3] = 255;
>> +    }
>> +