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

[Paul B Mahol]

Dana 25. 7. 2015. 20:31 osoba "Tomáš Hnyk" <tomashnyk at gmail.com> napisala
je:
>
>
>
> Hello,
> I created initial captions with fade ins and outs like this:
>
> ffmpeg -i in.mov \
> -framerate 24 -loop 1 -i a/01.png \
> -framerate 24 -loop 1 -i a/02.png \
> -framerate 24 -loop 1 -i a/03.png \
> -framerate 24 -loop 1 -i a/04.png \
> -framerate 24 -loop 1 -i a/05.png \
> -framerate 24 -loop 1 -i a/06.png \
> -framerate 24 -loop 1 -i a/07.png \
> -framerate 24 -loop 1 -i a/08.png \
> -framerate 24 -loop 1 -i a/09.png \
> -filter_complex \
> "[1:v]fade=in:0:d=0.2,fade=out:20:d=0.2[fad1]; \
> [2:v]fade=in:28:d=0.2,fade=out:48:d=0.2[fad2]; \
> [3:v]fade=in:56:d=0.2,fade=out:76:d=0.2[fad3]; \
> [4:v]fade=in:84:d=0.2,fade=out:104:d=0.2[fad4]; \
> [5:v]fade=in:112:d=0.2,fade=out:132:d=0.2[fad5]; \
> [6:v]fade=in:140:d=0.2,fade=out:160:d=0.2[fad6]; \
> [7:v]fade=in:168:d=0.2,fade=out:188:d=0.2[fad7]; \
> [8:v]fade=in:196:d=0.2,fade=out:216:d=0.2[fad8]; \
> [9:v]fade=in:224:d=0.2,fade=out:265:d=0.2[fad9]; \
> [0:v][fad1]overlay=0:0:enable='between(t,0,1)'[tmp1]; \
> [tmp1][fad2]overlay=0:0:enable='between(t,1.2,2.2)'[tmp2]; \
> [tmp2][fad3]overlay=0:0:enable='between(t,2.4,3.4)'[tmp3]; \
> [tmp3][fad4]overlay=0:0:enable='between(t,3.6,4.6)'[tmp4]; \
> [tmp4][fad5]overlay=0:0:enable='between(t,4.8,5.8)'[tmp5]; \
> [tmp5][fad6]overlay=0:0:enable='between(t,6,  7  )'[tmp6]; \
> [tmp6][fad7]overlay=0:0:enable='between(t,7.2,8.2)'[tmp7]; \
> [tmp7][fad8]overlay=0:0:enable='between(t,8.4,9.4)'[tmp8]; \
> [tmp8][fad9]overlay=0:0:enable='between(t,9.6,11.2)'[tmp9]; \
> [tmp9]ass=../subtitles.ass[outv]" \
> -map [outv] -map a:0 \
> -c libx264 -preset slow  -profile:v high -crf 19 \
> -strict -2 -c:a aac -b:a 192k \
> -f mov -y out.mov
>
> It encodes at 5.5 fps if I let it run for five minutes (the video is
almost two hours)
> If I instead do:
>
> ffmpeg -i in.mov \
> -i a/01.png -i a/02.png -i a/03.png -i a/04.png -i a/05.png -i a/06.png
-i a/07.png -i a/08.png -i a/09.png \
> -filter_complex \
> "[0:v][1:v]overlay=0:0:enable='between(t,0,1)'[tmp1]; \
> [tmp1][2:v]overlay=0:0:enable='between(t,1.2,2.2)'[tmp2]; \
> [tmp2][3:v]overlay=0:0:enable='between(t,2.4,3.4)'[tmp3]; \
> [tmp3][4:v]overlay=0:0:enable='between(t,3.6,4.6)'[tmp4]; \
> [tmp4][5:v]overlay=0:0:enable='between(t,4.8,5.8)'[tmp5]; \
> [tmp5][6:v]overlay=0:0:enable='between(t,6,  7  )'[tmp6]; \
> [tmp6][7:v]overlay=0:0:enable='between(t,7.2,8.2)'[tmp7]; \
> [tmp7][8:v]overlay=0:0:enable='between(t,8.4,9.4)'[tmp8]; \
> [tmp8][9:v]overlay=0:0:enable='between(t,9.6,11.2)'[tmp9]; \
> [tmp9]ass=../neposunute.ass[outv]" \
> -map [outv] -map a:0 \
> -c libx264 -preset slow  -profile:v high -crf 19 \
> -strict -2 -c:a aac -b:a 192k \
> -f mov -y  out.mov
>
> 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?

> Regards,
> Tomas
> _______________________________________________
> ffmpeg-user mailing list
> ffmpeg-user at ffmpeg.org
> http://ffmpeg.org/mailman/listinfo/ffmpeg-user