[Libav-user] Performance of Slice Based Processing

[Robert Beattie]

I am not sure what I did wrong. Maybe I did not use enough frames but it
makes sense now. I get about 40% reduction going from 4 slices to 8. That's
not unreasonable given htop shows the cpu utilisation has dropped a little.
Apologies for the noise.

Thanks
Rob.

On Thu, 29 Jun 2023 at 17:04, Paul B Mahol <onemda at gmail.com> wrote:

>
>
> On Thu, Jun 29, 2023 at 5:45 PM Robert Beattie <
> robert.scott.beattie at gmail.com> wrote:
>
>> I am curious as to why the performance (throughput) does not increase
>> linearly with the number of slices. I am using a scale filter
>> (scale=1280:720:flags=bilinear) to convert from 1080 to 720p in a stand
>> alone app.
>>
>> When I go from 1 to 2 slices and 2 to 4 slices I see a large increase in
>> throughput. However, going from 4 to 8 slices there is almost no change at
>> all. Can anyone enlighten me as to the reason for this? There are plenty of
>> cores available on the machines I tried it on.
>>
>
> By increasing number of cores you increase number of slices and at same
> time decrease amount of work each core needs to do for each slice as slices
> are smaller and smaller.
>
>
>>
>> Thanks
>> Rob
>>
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