Fast(er) transcoding from aac to mp3.

[dinkypumpkin]

Not really comparing like-for-like, but with 2010 Macbook Pro (2.66 Ghz Core i7, 8Gb) and ffmpeg HEAD, transcoding a 3-hour program gives these numbers:

real	5m7.197s
user	4m56.078s
sys	0m6.127s

Just for kicks, in a 32-bit 1-CPU Ubuntu 10.10 VM (via VMWare Fusion) on the same machine I get this for the same file:

real	5m48.907s
user	5m30.741s
sys	0m11.337s

ffmpeg saturated one of the CPU cores in both cases, so the difference is more-or-less from the VM overhead.  That's OK for my purposes, but it's not hard to see how it could be pokey on older hardware.

On 18 Mar 2011, at 12:52, bat guano wrote:

> I downloaded a 3-hour show (Steve Wright in the Afternoon*) and calculated the time taken
> to convert it using ffmpeg.
> This is the command:-
> time ffmpeg -i filename.aac -acodec libmp3lame -ab 128k test1.mp3
> 
> The result:-
> real    20m42.369s
> user    17m40.318s
> sys    0m56.812s