[mythtv] Viaslice OSD

[Ivor Hewitt]

Hehe.

Ok I've had an entertaining afternoon watching colours wandering about
the screen, and am writing to report failure so far! Due to a slight
oversight on my part. i.e. ok I wasn't concentrating and forgot how mpeg
decompression works.. :-)

It's possible to manipulate the generated MPEG image directly so you can
overlay stuff on it in colour... and possibly more interesting you can
pull back the decompressed image.

However, obviously, when the next mpeg frame is decompressed it works it
out based on the previous frame, which I've just blatted all over with a
colour OSD and clock.. So you get some rather wacky visual effects as
the OSD gets MPEG manipulated across the screen!

I guess it would be possible to copy the existing contents of the MPEG
buffer into an offscreen buffer and put the OSD up, and then copy it
back before the next frame is decompressed... but I don't think that'll
do much for performance somehow.

I think I'll go back to grey, and just tint it a bit.

Cheers,
Ivor.


> -----Original Message-----
> From: mythtv-dev-bounces at mythtv.org 
> [mailto:mythtv-dev-bounces at mythtv.org] On Behalf Of Ivor Hewitt
> Sent: 28 December 2003 10:02
> To: 'Development of mythtv'
> Subject: [mythtv] Viaslice OSD
> 
> 
> I've been having a play with the OSD code and contrary to my 
> earlier comment Kenneth I think a colour OSD is possible.
> 
> Firstly I've got rid of the stuttering with the existing grey 
> OSD and it fades in and out fine now. I'll probably make a 
> little patch that fixes just that.
> 
> Then, with only a little bit more hacking I got the OSD to 
> draw itself into the MPEG buffer and it sort of drew with a 
> bit of colour... However I've got the yuv offsets all wrong 
> at the moment so it came out a bit funny :-)
> 
> The code is a bit of a, ahem mess, at the moment so I'll play 
> a bit more and see what I can come up with.
> 
> Cheers,
> Ivor. 
> 
> (currently working on a windows machine since the development vaio
> melted) :(
> 
>