[mythtv] [mythtv-commits] Ticket #2649: Opengl video renderer

[Mark Kendall]

> What do you mean by "progressive scan versions of onefield, linearblend and
>  kerneldeint"?

(My apologies if this sounds like an egg sucking lesson)

They are frame rate doubling deinterlacers, taking each field in turn
and using different methods to guess the data in the missing rows to
produce a complete frame. If there is no motion detected, they just
use the data from the other field (i.e. 'perfect' quality). Otherwise,
linearblend interpolates the missing data from the rows above and
below, kerneldeint takes a view based on certain pixels above, below
and in the next and previous frames and onefield just uses the data
from the current field.

The latter is effectively an 'intelligent' bobdeint - it only 'bobs'
when motion is detected rather than applying it to the entire picture.
So no more flickering text etc.

Personally, I think the kerneldeint version gives the best results but
it can definitely be improved upon with better motion detection and
using edge detection/motion compensation techniques.

> What are your prospects in fixing the top-field deitnerlacing issue?

Easy enough - do you have some bottom field first samples that I can test with?

> Does this include a higher quality resize like has been discussed on
> this list before? (ie SD recordings and DVD playback resizing to 720p
> or 1080p resolution with all the filter goodies you seem to be
> implementing)

That's the plan. I'm just not sure how realistic it is yet. Assuming
quality is your objective, you'll want to use the best progressive,
deinterlacer (GPU demanding and double frame rate), followed by a
scaling operation (haven't figured out yet whether this is a simple
linear/bilinear scale or more complex), followed by applying some sort
of convolution kernel on your now much larger image. That last stage
is going to be really hard on your graphics hardware - to the extent
I'm even wondering whether it will run in realtime on reasonable
hardware.

> I've got a 6200TC on my dedicated frontend, which currently runs
> 0.20-fixes, is your work dependent on being compiled with SVN?

The patches are against the mythtv-vid branch.

> Finally, Thanks for your work! this looks to be some amazing
> advancements for us HDTV users.

My pleasure!

Mark