[mythtv] [patch] ViaSlice Interlaced Playback

[Steven Cruysberghs]

Kenneth Aafløy wrote:

>On Wednesday 23 June 2004 19:55, Steven Cruysberghs wrote:
>  
>
>>Hi Kenneth,
>>
>>Great work on the Viaslice stuff. I just got my epia M10k a few days ago
>>and managed to get the hardware decoding to work (kernel 2.4.26-epia1
>>that proved v4l_via.drv, CVS unichrome driver for via_drv.o and the
>>opensource libddmpeg, PVR250 capture and X-resolution = 720x576). Today
>>I tried adding this Interlaced playback patch and the qmatrix one from
>>june 20.
>>
>>It works but I'm afraid I the only difference I notice is a flickering
>>OSD when using the patches. Quality doesn't seem to improve.
>>The image on the TV still seems deinterlaced to me.
>>    
>>
>[snip]
>
>The qMatrix patch should yeild a sharper image, because only half of the 
>tables was copied into the hw decoder before.
>
>The interlacing patch was tested with a recorded pan sequence, which I put up 
>at http://kenneth.aafloy.net/test-pan.mpg If you try to edit the line in 
>videoout_viaslice.cpp: VideoOutputVIA::Show that says
>
>	if (cur->progressive_sequence)
>to
>	if (0 || cur->progressive_sequence)
>
>and recompile it will quickly disable the new interlacing code. Play the file 
>a couple of times without interlacing enabled, then edit, recompile and watch 
>the difference. It might be a little sluggish, because it's a fast moving 
>scene, but the image quality is much better (vertical lines is gone).
>
>The OSD is overlaid on top of the mpeg suface, and thus this deinterlacing 
>does not apply.
>
>The patch could certainly be improved on by blending (not overlaying) the OSD 
>onto the MPEG surface, which also would give us color OSD, but this will 
>require a driver patch. It has the sideeffect that MPEG2 decoding will be a 
>little slower, because we need to copy the current frame to the (always) 
>displaying frame, then blend the osd, and display this frame. It must be done 
>this way because the hw mpeg decoder uses reference all frames as reference 
>frames, and if we mess with one we mess with prediction.
>
>Hope this'll change your list a bit :)
>
>Kenneth
>
>  
>
Had more time to test and must say tvout quality improves quite a bit 
with your patches. The image is scharper and things like newstickers run 
verry smooth.
Switched between the PVR350 and the Via's TVout a couple of times and 
it's getting hard (even for the girlfriend) to tell the difference (as 
long as OSD isn't displaying that is :-)

Thanks
Steven