CBR vs VBR

[CVANR]

This may sound like a dumb question but how can you tell if a file was encoded with a VBR or a CBR I have looked at screen shots of files and have not been able to tell?

[setarip]

Load the file into VirtualDub. From the "File" dropdown menu, select "File Information". If the audio format was CBR, the number of audio frames will be equal to or less than the number of video frames. If the audio format was VBR, the number of audio frames will be significantly greater than the number of video frames...