[Libav-user] Threading a h264 video decoder - timing is odd.

Jesper Taxbøl jesper at taxboel.dk
Fri Jun 3 14:41:39 CEST 2016


It is different streams (seperate video files). Thats the funny thing.

2016-06-03 14:22 GMT+02:00 Karel Vorechovsky <k.vorechovsky at gmail.com>:

> "threaded video reader to spread the decode workload on some more cores
> and gain some speed"
>
> Decoding of the same stream must happen within one codec context. If you
> want speedup, read and buffer packets in one thread and do decoding in
> another. If that's not enough, look for faster decoder.
>
> Karel
>
>
> Dne 3.6.2016 v 14:09 Jesper Taxbøl napsal(a):
>
>> Hi Guys,
>>
>> I am working on a threaded video reader to spread the decode workload on
>> some more cores and gain some speed. My source is included below:
>>
>> The thing is that I dont see a time improvement when starting two
>> processes instead of one. On a 80mb mp4 file it takes 6 seconds to decode
>> the video, while doing two in parallel takes 12 seconds. I can see that two
>> cores's are used 100 percent. Im on a fast SSD disk so I dont think im IO
>> limited.
>>
>> What could be the case. Is it the same decoder taht is doing all the
>> work? Do I perhaps need to instantiate a context or something?
>>
>> kind regards
>>
>> --
>> Jesper Taxbøl
>>
>> _______________________________________________
>> Libav-user mailing list
>> Libav-user at ffmpeg.org
>> http://ffmpeg.org/mailman/listinfo/libav-user
>>
>
> _______________________________________________
> Libav-user mailing list
> Libav-user at ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/libav-user
>



-- 
Jesper Taxbøl
+45 61627501
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://ffmpeg.org/pipermail/libav-user/attachments/20160603/86d32075/attachment.html>


More information about the Libav-user mailing list