View Single Post
Posts: 2,152 | Thanked: 1,490 times | Joined on Jan 2006 @ Czech Republic
#26
Originally Posted by Serge View Post
The process of copying from system memory to framebuffer with color format conversion is a small gap, where graphics bus is not used (and graphics bus bandwidth is a scarce resource). Fortunately copying is quite fast and does not take too much time, but improvements in this area can help to avoid some framedrops for high resolution movies playback with tearsync enabled (and tearsync is always enabled for video). We could use something like 'page flipping' if we had enough framebuffer memory.
I guess you tried to start copying earlier to narrow the gap? It just needs to write to framebuffer data which is already transferred and do not outrun the DMA in progress. Maybe some timestamp when DMA transfer started could help with timing this? But this would need modified kernel anyway (unless the timestamp can be figured out somehow) so we could also preallocate second framebuffer in such kernel too (but this eats memory). Is the timing worth the effort?
__________________
Newbies click here before posting. Thanks.

If you really need to PM me with troubleshooting question please consider posting it to the forum instead. It is OK to PM me a link to such post then. Thank you.