kern/38208: bktr(4) stuck at 12.5 fps in PAL mode with RGB pixel format

[scw%netbsd.org@localhost]

>Number:         38208
>Category:       kern
>Synopsis:       bktr(4) stuck at 12.5 fps in PAL mode with RGB pixel format
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    kern-bug-people
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Sun Mar 09 16:15:03 +0000 2008
>Originator:     Steve Woodford
>Release:        NetBSD 4.99.49
>Organization:
        
>Environment:
        
        
System: NetBSD joe.mctavish.co.uk 4.99.49 NetBSD 4.99.49 (JOE) #3: Thu Feb 7 
13:55:32 GMT 2008 
steve%horace.mctavish.co.uk@localhost:/export/netbsd/local/netbsd/sys/arch/i386/compile/JOE
 i386
Architecture: i386
Machine: i386
>Description:
When sampling PAL video in RGB mode, the bktr(4) driver (using
METEOR_CAP_CONTINOUS) does not supply frames at the full 25 fps rate.
The frames are, instead, supplied at 12.5 fps. If switched to YUV mode,
the driver works correctly; the application receives video at 25 fps.

I don't have an NTSC source so I can't tell for sure if this problem is
specific to PAL. Looking at the driver however, different RISC code is
used for PAL/SECAM RGB compared to NTSC RGB (it's different again for YUV)
which leads me to believe that this problem could be caused by a bug in
the PAL RGB RISC code. There's additional stuff in the PAL RGB code to
deal with VBI data...
>How-To-Repeat:
Try to sample a PAL video in RGB mode. Note that you get 12.5 fps instead
of 25.
>Fix:
Unknown.

>Unformatted:
 bktr(4) stuck at 12.5 fps in PAL mode with RGB pixel format