Hello,

I'm writing an article about some codec comparison, I'll focus on MP3, WMA, FLAC and AAC (eAAC+)

How can I compare waveform of decoded encoded-file with the origin PCM file extract by EAC. I heard somewhere that Adobe Audition can do it, but I can't find out how to do it or my Trial version just have that feature disabled?

Compare in what way?

Let's say, I have an origin PCM file ripped by EAC.

And an eAAC+ file encoded by Enhanced AACPlus (CLI).

I decode the eAAC+ file to PCM again.

Import them to Adobe Audition, then hi-light the differences between them two.

Like this: http://www.audioholics.com/techtips/specsf...mages/sacd7.gif

This image, AFAIK, is the comparison between left-channel and right-channel waveforms. I want to compare 1st source left-channel to 2nd source left-channel and the same to the right-channel.

Do you realise that's not able to show audible differences between them? Double-blind testing is necessary.

Well I just want to compare their waveforms between the two, please help.

Frzzman,
The image you linked to is only the spectrum analyzer in AA. It shows the difference in amplitude at various frequencies between the left and right channels.
From memory, the blue is the right channel and the red is the left channel.
Even your PCM file will show discrepencies, because that's what stereo is all about... different information in the left and right channels.
What you could do in AA is do a null test between the PCM and the encoded file, but all you'll hear is some low level facsimile of the original, which will sound like it's been filtered to buggery!
Personally, I don't know what it is you're trying to prove (whether to yourself or to someone else), but it sure seems like a helluva lot of work for no discernible return!