[FFmpeg-devel] [PATCH] Added QSV based VPP filter - second try

wm4 nfxjfg at googlemail.com
Thu Nov 5 13:42:30 CET 2015


On Thu, 5 Nov 2015 12:49:50 +0100
"Sven Dueking" <sven at nablet.com> wrote:

> > > +            } else if (ret == MFX_WRN_DEVICE_BUSY) {
> > > +                av_usleep(500);  
> > 
> > What. Use proper event-based waiting.  
> 
> That´s the same behavior as we have in the qsv encoder and decoder.
> And as far as I know this is how Intel recommends to handle this.

That's just ridiculous. Can you send some hate-mail to Intel and tell
them what a bad idea this is? Half a millisecond is an eternity for a
CPU. What if the device is blocked only for 10 microseconds? Then it
will waste time by spending 490 microseconds idly.

Software engineers recognized that polling is a bad idea half a century
ago. Why can't Intel do this right?

Or does MFX have some sort of async mode that works without polling?


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