Re: [libdv-dev] [ libdv-Bugs-419875 ] YUV still overloading the lookup tables

[Stefan L. <Ste...@sn...>]

On Son, 29 Apr 2001, Nobody/Anonymous wrote:
> Bugs item #419875, was updated on 2001-04-28 16:41
> You can respond by visiting: 
> http://sourceforge.net/tracker/?func=detail&atid=104393&aid=419875&group_id=4393

Hopefully you are subscriber to this list.

> 
> Category: None
> Group: None
> Status: Open
> Resolution: None
> Priority: 5
> Submitted By: Nobody/Anonymous (nobody)
> Assigned to: Nobody/Anonymous (nobody)
> Summary: YUV still overloading the lookup tables
> 
> Initial Comment:
> In YUY2.c the Ytmp and cbcr_frame values still overload
> the lookup tables and produce artifacts when
> decompressing car break lights and fluorescent signs at
> night.  The artifacts are very difficult to see unless
> you watch the video in fullscreen.

So I think it's best to provide a short 1 frame dv file for
download, so that we can view your false decoded frame too.

>  Also the lookup
> tables  seem to clamp between 16 and 240. 

Y values should be clamped to 16 and 235,
Cr,Cb values should be clamped to 16 .. 240 (see SMPTE-314 page 22).

Y clamp table (line 73) should be set to:
    else if(i > (235-128)) value = 235;
instead of:
    else if(i > (235-128)) value = 240;

> Camcorders
> store information in these super black and super white
> regions which videographers often need for color
> correction and rounding.
Could you provide more information about that color correction.

> 
> ----------------------------------------------------------------------
> 
> You can respond by visiting: 
> http://sourceforge.net/tracker/?func=detail&atid=104393&aid=419875&group_id=4393
> 
> _______________________________________________
> libdv-dev mailing list
> lib...@li...
> http://lists.sourceforge.net/lists/listinfo/libdv-dev
-- 

mfg

  Stefan Lucke (Ste...@sn...)