[FFmpeg-devel] adding RGBA and BGRA to nvenc.c

Nicolas George george at nsup.org
Thu Sep 8 20:34:52 EEST 2016

Le tridi 23 fructidor, an CCXXIV, Carl Eugen Hoyos a écrit :
> xcb is slower?

Looking at the code, I see that xcbgrab allocates and frees the shared
memory segment for each frame, while x11grab only allocates it once at the
beginning. xcbgrab does that so that it can wrap the segment in a refcounted

On the other hand, x11grab seems to be returning the shared memory segment
as the packet payload as is. If I am not mistaken, this is just invalid, and
works just by luck. It could be tested with the following procedure: grab a
packet, dump it, grab a second packet, dump the first one again.

Still, it is probably possible to do something faster than xcbgrab while
still correct: only allocate a new segment if the first one is still in use.


  Nicolas George
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