[FFmpeg-devel] [PATCH 3/3] avformat/mpegts: use av_unlikely for detecting unknown streams

Marton Balint cus at passwd.hu
Fri Jan 25 03:03:14 EET 2019



On Fri, 25 Jan 2019, Carl Eugen Hoyos wrote:

> 2019-01-24 21:38 GMT+01:00, Marton Balint <cus at passwd.hu>:
>> Strangely the previous commit caused a slowdown in overall performance
>> and this fixes it. I used gcc 7.3.1. Does anybody else see this?
>
> No, but since this command exists nearly immediately for me
> I see a 5% deviation even without your patch.

Thanks for checking it. I tested my series on top of 
1b126ec4087ab5d87d413116bee666495b0d2d3e, and can still reproduce the 
speedup on it. On the other hand, on current git head, I can no longer 
reproduce the speedup. Whatever this is, the fact that using av_unlikely 
fixed it is probably just luck.

So considering the mixed feelings about av_(un)likely in general, I'll 
just drop patch 1 and 3.

Thanks,
Marton


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