Opened 9 months ago

Closed 9 months ago

Last modified 9 months ago

#10521 closed defect (invalid)

ACC encoder speed degradation in version 5.x.x and above

Reported by: Vexs Owned by:
Priority: normal Component: undetermined
Version: Keywords: aac speed performance
Cc: Blocked By:
Blocking: Reproduced by developer: no
Analyzed by developer: no

Description (last modified by Vexs)

Summary of the bug:

AAC encoder speed is degraded in version 5.x and above

How to reproduce:

  1. Download test aac file ​https://filesamples.com/samples/audio/aac/sample4.aac
  1. Download ffmpeg version 4.4.1 from ​https://www.johnvansickle.com/ffmpeg/old-releases/ or compile from branch ​https://github.com/FFmpeg/FFmpeg/tree/release/4.4
  1. Download ffmpeg version 5.1.1 from ​https://www.johnvansickle.com/ffmpeg/old-releases/ or compile from branch ​https://github.com/FFmpeg/FFmpeg/tree/release/5.1
  1. Run command ffmpeg-5.1.1 -y -i sample4.aac -strict strict -b:a 128000 tmp.aac
  1. Run command ffmpeg-4.4.1 -y -i sample4.aac -strict strict -b:a 128000 tmp.aac
  1. Compare speed 5.1.1 speed=~26.5x vs 4.4.1 speed=~79.9x

Additional informations:

  1. It seems that only the aac format has this problem. Another audio codecs encoding speed is ok
  1. This only applies to encoding. AAC decoding speed looks ok
  1. In all 4.x.x version encoding speed is ok. Starting from 5.x.x speed is degraded

Change History (8)

comment:1 by Vexs, 9 months ago

Description: modified (diff)

comment:2 by Vexs, 9 months ago

Description: modified (diff)

comment:3 by Elon Musk, 9 months ago

Normal behavior, as you have not compared quality at all....
The aac default coder have been changed. Inspect aac encoder options next time.

comment:4 by Vexs, 9 months ago

Thanks, you have right, default value for -aac_coder was changed from fast to twoloop. When i set -aac_coder fast for 5.x.x the encoding speed is the same as 4.x.x

Last edited 9 months ago by Vexs (previous) (diff)

comment:5 by Balling, 9 months ago

Resolution: → invalid
Status: new → closed

There are quite horrible bugs in fast. Do not use it.

in reply to:  5 ; comment:6 by Vexs, 9 months ago

Replying to Balling:

There are quite horrible bugs in fast. Do not use it.

Thanks, is there a description of this problem somewhere, any issue or something?

in reply to:  6 ; comment:7 by Balling, 9 months ago

Replying to Vexs:

Replying to Balling:

There are quite horrible bugs in fast. Do not use it.

Thanks, is there a description of this problem somewhere, any issue or something?

#8066, #8505.

in reply to:  7 comment:8 by Vexs, 9 months ago

Replying to Balling:

Replying to Vexs:

Replying to Balling:

There are quite horrible bugs in fast. Do not use it.

Thanks, is there a description of this problem somewhere, any issue or something?

#8066, #8505.

Thanks

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