should I decompress ac3 before compressing to mp3?

[rakan]

Just wondering what the best practice is for encoding audio. Should I decompress that .ac3 file before compressing it to AAC, OGG, or MP3? Or is this unnecessary? Thanks.

[obieobieobie]

Uh, if your conversion software can read AC3 files, it will of course decompress it on the fly when it encodes it to the new format.

[rakan]

Thanks obieobieobie

Is that true of all conversion software? I was just wondering because from time to time I will use AutoGK for a quick backup and I noticed that it uses Azid AC3 decoder followed by Normalize 0.253 before it uses LAME to encode to MP3. So if LAME converts to the WAV on the fly, why does it need Azid AC3 decoder?

[buzzqw]

lame take the wav and encode to mp3...

lame isn't able to read the ac3 ... so autogk decompress ac3 to wav, normalize the volume, then lame is ABLE to take wav and output mp3

BHH

P.S. another approach could be using ffmpeg.exe for direct piping or direct encoding (use the search button)

[rakan]

Ahhhh, I understand. Thanks for the explanation.