WMV audio to ac3 v..e..r..y slow

PeterWright wrote on 11/2/2010, 7:22 PM

I downloaded a wmv file, and am using Vegas to render it to DVD format.

The clip is 1 hr 21 mins long, and it took 59 minutes to render just the audio to ac3.

This seems incredibly slow - the computer is generally functioning normally. The only slow down factor was that the wmv and rendered ac3 were on the same drive, but this doesn't usually make a huge difference.

Does anyone know if there is something about wmv audio which makes it difficult to convert to ac3 format?

Comments

fldave wrote on 11/2/2010, 7:45 PM

My history with WMV is to immediately convert it to something else. Encoding directly from WMV to anything else is atrocious.

farss wrote on 11/2/2010, 7:57 PM

WMV does take a bit to decode and ac3 also is pretty heavy on the CPU to encode. Add in that there's possibly a sample rate conversion going on as well and the time involved doesn't seem that over the top to me.
I do agree about converingt any of the high compression lossy codecs to uncompressed audio for editing, probably nothing to be gained if just doing a vanilla transcode though.

Bob.

PeterWright wrote on 11/2/2010, 8:10 PM

Thanks Dave and Bob,

I've just tried another wmv clip from the same series - this one was 9 min long, and encoding to ac3 only took 42 secs, so I think there must have been something about the first clip that was "unusual" to have taken that long.