[mythtv] My ongoing quest for a stable bobdeint setup...

[Jeroen Brosens]

My motivations in this context:

- I want full field rate in video playback; to my knowledge, using 
bobdeint is the only way to achieve this;
- bobdeint requires a form of vertical sync, which as far as I know the 
SiS driver cannot support.

In my ongoing quest to find an X setup that gives me jitter-free video 
using bobdeint I stumbled upon a new option, found on the SiS X driver 
website (http://www.winischhofer.at/linuxsispart1.shtml): 
<http://www.winischhofer.at/linuxsispart1.shtml>

> *2. Video blitter method*
>
> This second method is only supported on the SiS M650, 651, (M)661, 
> (M)741, 330 and (M)760, not any older chipsets. It works entirely 
> different to the overlay method: The video blitter simply copies video 
> data from the video application into the framebuffer (eg. a window), 
> thereby converting the data from the video color space (some YUV 
> format) to RGB. All this is done by the 2D acceleration engine.
>
> The following color space formats are supported: YV12, I420, UYVY, 
> YUY2, YVYU, NV12, NV21. The maximum video source size is 2046x2046.
>
> The video blitter is only very little slower than the Xv method. 
> However, it's worst disadvantage is that it cannot scale the video. 
> The video will always be shown in its original size; if the video is 
> larger than the visible screen, it will be cropped. If it smaller, a 
> black border will be drawn. Furthermore, there are no video properties 
> such as contrast, brightness, etc.
>

So, when I enable this as the video output, bobdeint starts acting like 
it does when you give "bobdeint" as an argument to the "Custom Filters" 
option in the Setup > Tv Settings > Playback menu; which is splitting 
the screen horizontally in two halves, each displaying one field. Of 
course, this is due to the fact that bobdeint only works on Xv or XvMC 
output. Using this Video blitter method, the output comes from the 
framebuffer, as stated above.

My experience up till now has been that the combination of SiS + Xv + 
bobdeint gives vertical jitter (now and then) because there is no 
(driver or OpenGL) Vsync support. My question: can the source code of 
either bobdeint or the the non-Xv video output (which one handles this?) 
be modified to have the screen built up correctly, that is with the 
fields interweaved and not split screen?

Thanks,
-- Jeroen
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mythtv.org/pipermail/mythtv-dev/attachments/20050223/45ee61bd/attachment.htm