[FFmpeg-devel] [PATCH] Add AAC FATE encode tests.

Reimar Döffinger Reimar.Doeffinger at gmx.de
Fri Apr 6 22:39:39 CEST 2012


On Fri, Apr 06, 2012 at 04:29:05PM -0400, Derek Buitenhuis wrote:
> On 06/04/2012 4:24 PM, Reimar Döffinger wrote:
> > What exactly do you want to know? The tiny_psnr tool prints as last
> > statistics two size values, and the size tolerance is the difference
> > between these.
> > If you want to know why there is a difference in size between decoded
> > file and reference that is generally due to encoder/decoder delay
> > creating addition 0-samples in front, the encoder rounding the size
> > to whatever block size it needs and here also the "shift" value
> > influencing the "size" value that tiny_psnr calculates - which may
> > or may not make sense.
> > Large values tend to mean that the encoder/decoder aren't particularly
> > good, since I think for most formats that issue can be minimized.
> 
> I was just wondering how you derived 2464 and 3560.
> 
> As in where do those numbers come from.

As said in the start, you take the last two numbers tiny_psnr prints and
subtract them from each other.


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