Reply To: scaling filters

Home Forums OSSC OSSC – Discussion and support scaling filters Reply To: scaling filters



I rewrote the sampling phase alignment and filtering code this past weekend along with merging it with the latest from the release tree. This included changes to support a 4x 1K line buffer with filtering or an effective 2x 2K line buffer without filtering. linex3 M2 and M3 modes work great with and without filtering. Reset or reacquiring sync doesn’t result in a random 180 degree phase shift. But I’ve introduced some bugs:

1) linex2 and linex3 M0/M1 modes randomly drop frames (flicker) on a xcapture-1. my projector doesn’t exhibit the problem
2) linex2 scaling filters have flickering pixels.
3) 2x 2K linebuffer mode draws a column of seemingly random pixels (usually all black) when it crosses into the next physical 1k buffer.

For (1), the flickering doesn’t coincide with a tvp sync loss. I’m pretty sure the problem was introduced by the phase alignment changes.

I’m not sure what to do about (2). I allow a programmable amount of difference between pixels for comparison in the filtering logic, but changing this doesn’t result in a reduction in the amount or degree pixels flicker.

(3) seems like an off-by-one error. What’s interesting is sometimes the column of pixels isn’t black and it extends through the masked regions.

I may also need to further pipeline the filtering logic to fix timing problems.