[FFmpeg-user] Reduce CPU usage to match VLC

Anshul anshul.ffmpeg at gmail.com
Mon Feb 10 20:12:14 CET 2014



Loadlinx <limiteddi at gmail.com> wrote:
>Tried with 5 processes and it breaks the picture.
>
>
>On Mon, Feb 10, 2014 at 10:58 AM, Reindl Harald
><h.reindl at thelounge.net>wrote:
>
>> do you *think* that or have you tried it?
>>
>> you can't calculate "booh CPU usage multiplied with cores gives
>streams"
>> the one and only question is if the overall load can handle
>> the streams without drop frames and how the OS will schedule
>> the threads and processes
>>
>> the final goal is that any of your cores are 100% loaded and
>> nothing breaks down
>>
>> Am 10.02.2014 16:51, schrieb Loadlinx:
>> > At 120% i am still limited to only ~4 transcoding sessions.
>> > Maybe the quality is not the same and maybe ffmpeg is faster.
>> >
>> > I am willing to sacrifice quality for lower CPU usage. Is this
>possible?
>> I
>> > tried -preset:ultrafast but no difference in CPU usage observed.
>> >
>> >
>> > On Mon, Feb 10, 2014 at 10:46 AM, Carl Eugen Hoyos
><cehoyos at ag.or.at>
>> wrote:
>> >
>> >> Loadlinx <limiteddi <at> gmail.com> writes:
>> >>
>> >>> /vlc -vvv http://192.168.1.50:6002 --sout
>> >>> '#transcode{venc=x264{preset=ultrafast}
>> >>                                ^^^^^^^^^
>> >>
>> >>> ./ffmpeg -i http://192.168.1.50:6002 <http://162.219.0.246:12709>
>> >>> -vcodec libx264 -vb 1500k -s 480x320 -acodec libfdk_aac -ab 32k
>> >>> -f flv rtmp://192.168.1.50:1935/live/709
>> >>
>> >> (Complete, uncut console output missing.)
>> >>
>> >> Aren't these two completely different things?
>> >> Or does libx264 nowadays default to ultrafast?
>> >>
>> >>> Quality seems to me somewhat the same
>> >>
>> >> somewhat: maybe
>> >> the same: most likely not
>>
>>
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>>
>>
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Please try to match the encoder parameters of vlc and ffmpeg.
Since ffmpeg and vlc both use libx264(same code). I have assumed
That your codec is h264.

On mailing list please try to top post.
As specified by carl please post the uncut logs from ffmpeg, that way we can understand your problem better
Like in your case I am not sure what codec is used and what were the configuration.

I dont guaranty the solution, since I dont know how vlc is working

-Anshul
-- 
Sent from my Android device with K-9 Mail. Please excuse my brevity.


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