[MPlayer-dev-eng] enhancement for yuv4mpeg output driver

[D Richard Felker III]

On Wed, Jan 19, 2005 at 12:41:05AM -0800, Steven M. Schultz wrote:
> 	Increasing the number of vertical lines is done by interpolation
> 	isn't it and with interlaced material upscaling vertically is to
> 	be avoided.  A sight downsampling horizontally would be better for
> 	the quality (and the graphics card might even help out).

MPlayer simply DOES NOT SUPPORT interlaced video playback. So there's
no point in making special considerations for it in the vo behavior.
Downscaling loses information and isn't even [properly] supported by
some video cards. Upscaling loses (almost) nothing.

> 	Leave the vertical dimension alone would be A Real Good Thing.

Only if you support interlaced video, which requires syncing to the
video refresh and all...

> +	fprintf(yuv_out, "YUV4MPEG2 W%d H%d ", image_width, image_height);
> +	if(image_fps>23.975973976 && image_fps<23.976073976) 
> +		fprintf(yuv_out, "F24000:1001 ");
> +	else if(image_fps>29.96997997 && image_fps<29.97007997) 
> +		fprintf(yuv_out, "F30000:1001 ");

There are already good fraction reducing routines in mplayer (or
lavc?) that let you specify maximum magnitude for the denominator.
They'll make mplayer's stupid float crap into correct values like
30000/1001.

Rich