[Mplayer-advusers] [Bug] (6/6) mplayer mis-calculates the resolution when pre-scaling

[Magnus Pfeffer]

Hi,

I use nuppelvideo to record tv shows. To reduce noise, I found it useful to 
record all the PAL lines (576) and reduce the resolution afterwards when 
converting the video to VCD.

mplayer plays the nuppelvideo files fine, but does a mis-calculation when it 
applies pre-scaling. My 480x576 videos are considered 4:3 aspect movies 
(which is correct), but are upscaled to 766x576, which gives a 1.32986111 
aspect. 

The reason for this seems to be a very limited aspect precision in the 
pre-scaling algorithm: It appears that exactly 1.33 is used as the aspect 
ration instead of 4:3 (1.333333....). If I use -aspect 4:3 or -aspect 
1.33333 mplayer calculates the correct upscale resolution of 768x576.

After some searching I found the culprit:

In line 249 of libmpdemux/demux_nuv.c

                sh_video->aspect = (float) 1.33;

is used. It should be changed to 4.0/3.0 or similar, I think.


Magnus