[FFmpeg-user] libvpx and libx264 problematic frame accuracy

Franz Klinger klingerfranz827 at gmail.com
Mon Jan 21 13:13:35 CET 2013

Am 20.01.2013 03:02, schrieb Carl Eugen Hoyos:
> Franz Klinger<klingerfranz827<at>  gmail.com>  writes:
>> ffmpeg.exe -i akiyo-352x288-29.970.avi -c:v libvpx
>> -quality good -speed 0 -vb 300k -y
>> akiyo-vp8-none-352x288-29.970-good-cbr-300.webm
>> I get a file with which I can't  properly measure
>> psnr or ssim. It seems that when using e.g. msu
>> video quality measurment tool (which seem to use
>> DirectShowSource2 for webm files) the frames are
>> shifted.
> I may misunderstand but the output you posted
> indicates that frames are neither dropped nor
> duplicated so "shifting" seems unlikely.
> Did you test by encoding both the original
> and the encoded video to images and compare
> them?
Seems to be no problem directly related to ffmpeg. I created indexes 
with FFMpegsource2 for frame accurate parsing and now the metric values 
seem to be correct.

Franz Klinger

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