[FFmpeg-user] VBR setting is unsupported in libfdk_aac

[Gyan]

On 26-12-2019 03:11 pm, Ashish Jha wrote:
> for aac_low profile as well, I am getting the same error. PFB error

It's a warning, not an error. It is *always* printed when ffmpeg detects 
the use of -vbr or -qscale:a / -q:a with libfdk-aac.

fdk-aac is an external encoder, so it, not ffmpeg, makes the decision on 
which rate control mode to ultimately use. Unfortunately, ffmpeg can't 
detect whether VBR mode was chosen, hence the warning is always printed.

However, in your 2nd command, the output does look to be VBR.

FTR, these are the target bitrates and accepted profiles for VBR as per 
its value:

1:        32 kbps mono   AAC-LC + SBR + PS
2:        64 kbps stereo AAC-LC + SBR
3:        80 - 96 kbps stereo AAC-LC
4:        128 kbps stereo AAC-LC
5:        192 kbps stereo AAC-LC

VBR looks to be unsupported with HE-AAC.

Gyan

(Avoid top-posting; see https://trac.ffmpeg.org/wiki/MailingListEtiquette)