[FFmpeg-user] multiple fade out slow down encoding about two to three times

[Tomáš Hnyk]

On Sat, 25 Jul 2015 22:18:43 +0200, Paul B Mahol <onemda at gmail.com> wrote:

> Dana 25. 7. 2015. 20:31 osoba "Tomáš Hnyk" <tomashnyk at gmail.com> napisala
> je:
>>
>>
>>
>> It encodes in roughly 14 fps. But fade ins and outs occur only at the
> very beginning (in the first 11 seconds), yet the slow down is preserved  
> (I
> also run the compilation for about five minuts). Is this a performance  
> bug?
>
> What ffmpeg version you are using?
> Fade filter can use multiple cores to speed up filtering.
> What fps speed you want?
>
The version is:
ffmpeg version 2.5.7-0ubuntu0.15.04.1 Copyright (c) 2000-2015 the FFmpeg  
developers
   built with gcc 4.9.2 (Ubuntu 4.9.2-10ubuntu13)

All my 4 cores were used to the fullest. I want the same fps as without  
the fade filter in the parts of the video where there is no fading. The  
video is 105 minutes long. Fade ins and outs are all in the first eleven  
seconds. I do not mind if these first eleven seconds are rendered  
super-slowly, but why does the whole encoding process (for the whole  
105-minute-long video) take about 2.5 as long as without the fade filter?
Tomas