A better AAC encoder: FDK-AAC

  • In version 1.2.0 the built-in AAC encoder of FFMpeg seems to be broken. I will look into this, yes.

    But there is an alternative / workaround:

    • Simply extract the libfdk-aac-2.dll file from the attached zip archive to your C:\windows\system32\ directory.

    You will then have the Fraunhofer AAC encoder available in Voukoder. This will work - maybe even better.

    For licensing reasons both needs to be separated.


    • libfdk-aac.zip

      (729.88 kB, downloaded 108 times, last: )

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  • By default FDK-AAC cuts of anything above 17kHz when using CBR mode. It's possible to change it.

    Vouk could you perhaps add button that changes this to 20kHz?

    Workaround for this is to use ("VBR" In Voukoder) Quality Mode 5. Downside to this is that it has lower maximum bitrate.


  • Also discovered:
    FDK-AAC on Voukoder uses wrong format profile according to mediainfo:

    Sampling rate also seems to be wrong.

  • Looked into it:

    1. Default profile in my case is "LC" (Low Complexity)
    2. Bit Rate is 48kbit/s on (auto) but does match to each setting i make
    3. Sampling Rate is 48KHz which looks also good

    Maybe you can reset you parameter cache? I also don't know about your sequence/project settings.

    Trying to find a fix for the noise with AAC now ...

    Edit: When using FFMpeg 4.0 AAC audio is fine. When using 4.1 its distorted. The higher the framerate, the worse.

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  • They have some wierd theory behind the delay and apparently it is intentional, even though FFMPEG's standard AAC doesn't do it, neither does Adobe's AAC or any other video-editing suite with AAC support for that matter.

    It isn't an issue with FFMPEG, its by design inside FDK... the delay can be noticed in very highly sychronized fast action video by those who actually create the video... for example my better half says she can't tell the difference.

    But where it really becomes apparent is when you re-import the mp4 with FDKAAC stream into Premiere and you will see the delay in the sample view.

    Unless someone seriously into dissecting code was to fork FDKAAC and engineered their own changes in, I'm afraid it would be wise to just stick with alternative options, for now I just stick with raw 24 bit pcm and let the transcoding server deal with the distribution formats.


    Just want to add for newcomers to AAC... The standard AAC built into FFMPEG is actually BETTER than FDK-AAC at higher than 128kb bitrates. FDKAAC comes into its own below 128k and in part at 128k. But Nero is still the best IMO at all bitrates, but I don't think Vouk will ever add functionality to allow us to use the neroaacencode.exe binary?...

  • Simple question, maybe. How can I check if libfdk-aac-2.dll is being picked up or not? I don't see an added option in the audio panel drop down. Using ProcessExplorer it's not attached to the PPro process as a library.