[Mjpeg-users] Re: 1.6.1.93: Bad quality

[Ray C. <ray...@ea...>]

Some observations that I did make about .93 (haven't necessarily run all of these same tests on .92, so I have no idea if this is 'different' from .92 or not, but it seems odd to me):

1) Changing from -r 16 to -r 32 produced a larger .m2v file by about 3%.  I would have thought it'd be smaller.  -r 24 seemed to produce the smallest file compared to -r 8, -r 16 (which is understandable), and -r 32 (say what?)

2) Changing -4 2 to -4 3 produced a smaller file by about 2%, which also seems really strange.  I would have thought the file size would have dropped with a lower -2 and -4 value (same happened when I upped -2 - file got smaller...)

-- Ray


On Fri, 23 Jan 2004 19:55:03 -0600
Ray Cole <ray...@ea...> wrote:

> With the same parameters as 1.6.1.92, I'm seeing terrible quality problems.
> 
> Parameters used:
> mpeg2enc  -f 8 -q 5 -a 2 -g 6 -G 18 -E -10 -N 1.0 -z t -4 2 -2 2 -r 16 -o file.m2v
> 
> I'm seeing very poor quality on still scenes.  Faces are very blotchy.  Now I also use yuvdenoise - I haven't made any determination as to whether it is the newer mpeg2enc or newer yuvdenoise killing me, but it feels more like an mpeg2enc issue more than anything else.  I also haven't tried using -R 2 - that is certainly a major difference between 92 and 93.  I'll try that as well.  Anyone else experienced a major decline in quality?
> 
> I'll let you know the result of some additional experiments.
> 
> -- Ray