[MPlayer-dev-eng] different brightness

[Michael Hess]

Hi there,

when I play a file directly from the disk
mplayer -noascpect -fps 23.98 -vo jpeg -jpeg
noprogressive:optimize=0:smooth=0:quality=100 test.mp4
I got a lot of pictures.
When I play the file as a stream (streamed with Darwin 5.0 on a other PC)
with
mplayer -noascpect -fps 23.98 -vo jpeg -jpeg
noprogressive:optimize=0:smooth=0:quality=100 rtsp://192.168.2.11/test.mp4

the pictures mplayer is saving are not so bright. Since I want to compare
the quality of this pictures with the universal image quality index and
this index is also depending on the brightness, I get bad results. I have
compiled the live.com libraries and mplayer is using them.
Does anybody have an idea, why the brightness is different ?
As far as I understood, mplayer has serval plugins for the input (live.com
and file in my case) and from the plugins the data is put to a demuxer,
demuxed and then decoded. So as far as I understand, the decoder is the
same, and should be feeded with the same data. But this seems not to be
the case.

Another thing which desturbed me in the beginning, that the jpgs are
numberd, and if a frame is dropped, the number says just nothing. I now
have patched the mplayer so the files are named by the time they should be
played (from the sh_video->timer) and this is working good. Also with the
original source the problem still exists. I have downloaded the
cvssnapshoot at 12.12.2003 and today (7.1.2004) and with both the problem
exists.
Maybe this problem has not been realized yet, because the difference is
not big, but if you look really good at the pictures, it is there (and
with that, the universal quality index is unusable).

Thanks in advance,

Michael Hess