Converting (10hr) mp3 to m4a, converter file is 40m

[dreadjr]

When converting a 10hr/~500mb .mp3 audio file to aac (vbr), the resulting file is 40m long and ~50mb.

Encoding = Apple AAC
Target = Quality (VBR)
Quality = 103
LC AAC
DSP Effects =

When I click "1 file" in the UI it says
Source Type = MPEG-1 Layer 3
Source length = 10 hours
Estimated Size = 961.3 MB

[Spoon-]

Re: Converting (10hr) mp3 to m4a, converter file is 40m

Can anything play that 10 hour mp3 as 10 hours?

Try converting mp3 to mp3, what is the length?