25fps AAC to 23.976fps AAC (slowdown)

[pub]

I have a video that was originally 23.976fps, but sped up to 25fps, including the audio. I can slowdown the video just fine, but I can't seem to slowdown the AAC audio.

eac3to requires some Nero plugins I don't have and have no idea how to get those. I could make a WAV with faad and then slow it down, but I still can't output a AAC file (AC3 will work). Also it might reduce the quality.
Audacity isn't an option either, because it casues background (white?) noice. Switching between WASAPI/MME/etc. doesn't work

Is there another way to slow the audio down (pitch+speed) while re-encoding as little as possible (AAC->AAC instead of AAC->WAV->AAC)?

[newpball]

I have a video that was originally 23.976fps, but sped up to 25fps,

Are you sure it was not simply sped up from 24p?

[poisondeathray]

nero aac codec is a free download. Although nero took it down from their site, many websites - even this one - still have it available to download

Is there another way to slow the audio down (pitch+speed) while re-encoding as little as possible (AAC->AAC instead of AAC->WAV->AAC)?

This is exactly the same operation. You're not losing anything extra. When you go AAC => AAC, there is a WAV step in between. You might not see or be exposed to what is happening depending on what program you are using, but it is occurring in the background. Compressed audio has to be decoded (decompressed) before re-compression. The same is true for compressed video (it has to be decoded as well)

[pub]

I have a video that was originally 23.976fps, but sped up to 25fps,

Are you sure it was not simply sped up from 24p?

Yes, I'm sure

nero aac codec is a free download. Although nero took it down from their site, many websites - even this one - still have it available to download

Is there another way to slow the audio down (pitch+speed) while re-encoding as little as possible (AAC->AAC instead of AAC->WAV->AAC)?

This is exactly the same operation. You're not losing anything extra. When you go AAC => AAC, there is a WAV step in between. You might not see or be exposed to what is happening depending on what program you are using, but it is occurring in the background. Compressed audio has to be decoded (decompressed) before re-compression. The same is true for compressed video (it has to be decoded as well)

I've put the neroAacDec.exe, neroAacEnc.exe and neroAacTag.exe in the same folder as eac3to, but I'm getting these errors:

G:\eac3to>eac3to a.aac an.m4a -slowdown
AAC, 2.0 channels, 48kHz
Decoding with DirectShow (Nero Audio Decoder 2)...
Getting "Nero Audio Decoder 2" instance failed.
Aborted at file position 262144.

G:\eac3to>eac3to a.aac an.m4a -slowdown -nero
AAC, 2.0 channels, 48kHz
I'd like to use the Nero decoder, but it doesn't seem to work.

Using .aac instead of m4a doesn't work either.

[poisondeathray]

While the Nero AAC encoder is free, the decoder is not, and you don't have it installed. You can force a eac3to to use free decoder like libav . There is no problem decoding AAC with libav .

-libav

[pub]

While the Nero AAC encoder is free, the decoder is not, and you don't have it installed. You can force a eac3to to use free decoder like libav . There is no problem decoding AAC with libav .

-libav

I now get this error:

G:\eac3to>eac3to a.aac an.m4a -slowdown -libav
AAC, 2.0 channels, 48kHz
Unfortunately libav doesn't contain an (LGPL) AAC decoder.

Changing aac to m4a or every variation on that doesn't work either.

[poisondeathray]

I guess you need the nero decoder installed for eac3to

Another option is to use megui, which has presets for slowdown/speedup . You have the option to use neroaac, or qaac (arguably better)

[pub]

It worked with MeGUI and qaac, thanks!