[MPlayer-dev-eng] Darkening of picture on most mplayer outputs

[Haakon Riiser]

[Compn]

> the only thing i can think of, is that its a swscale problem
> 
> ijpg > video = [swscaler @ 0096C510]SwScaler: BICUBIC scaler, from
> yuv444p to yuv420p using MMX2
> 
> ffmjpeg > video = [swscaler @ 0096C510]SwScaler: BICUBIC scaler, from
> rgb24 to yuv420p using MMX2
> 
> ffmjpeg > yuv4mpeg = [swscaler @ 0096C510]SwScaler: BICUBIC scaler,
> from yuv444p to yuv420p using MMX2

Yeah, about that:

Why does it say "rgb24 to yuv420p" when -vo is not yuv4mpeg?
The frame's pixel format is yuv444p, so unless mplayer has
requested ffmpeg to decode and convert to rgb24, there's no
reason why this would happen.  Does mplayer use rgb24 internally
(for post-processing filters), and therefore requests this format
whenever there _might_ be filters involved later on (even though
there isn't in this case)?
  
Anyway, from the above, it looks like the darkening could be
happening either at ffmpeg's yuv444p -> rgb24 conversion, or at
mplayer's rgb24 -> yuv420p conversion.  Shouldn't be hard to just
insert some debugging code in mplayer to dump the pixel data to disk
before and after each operation to find out where it happens.

I don't have time to do this right now, but I can take a look
at it tomorrow (unless (hopefully) someone more familiar with
mplayer's internals beats me to it :-)).

> -vo yuv4mpeg is also dark for me. strange...

Is it dark when you do this:

 $ mplayer -vo yuv4mpeg 1.avi
 $ sed 1,2d stream.yuv | convert -size 640x480 yuv:- output.jpg

?

When I compare output.jpg to the original source.jpg that was used
to generate 1.avi, I see the same brightness.

-- 
 Haakon