Is the audio delay for AC3 files also required for WAV?

[anthony.d]

Greetings all,

I don't fully understand the whole concept of audio delay, so I have some issues with it's application. Using DVD2AVI, I can create AC3 audio files that have a "delay" parameter in the filename. It's easy enough to figure out what to do with these. However, when I use DVD2AVI to create WAV files, there is no "delay" specified in the filename. Has the delay been added to the wav? Do I still need to add the delay when encoding? The delays with the files I'm using are quite small (~100ms) so it's hard for me to tell by just listening.

Also, a slightly related question: What is the best way to convert AC3 audio to mono MP3? Should I just use the "-m m" parameter with lame? (I'm using Gordian Knot)

Thanks!

[digitalman]

If you are using DVD2AVI to create .d2v files for an MPEG2 or MPEG1 encode you are going to do, don't mess with the delay. When you go and mux the MPEG2 video and audio file together everything will be matched up. If you start messing with the delay the voices will not match the mouth movements. Maybe at the start but after a few minutes they will be off. The same should go for the WAVs files, whatever DVD2AVI encodes them to, leave them alone, don't change the delay.

[anthony.d]

I'm not trying to mess with the delay. The issue is that there is no delay specified for WAV files. For example, here are the filenames for audio files DVD2AVI created from the same DVD source:

movie1 AC3 T01 2_0ch 192Kbps DELAY -116ms.ac3
movie1 AC3 T01 2_0ch 192Kbps 44.1KHz.wav

No delay specified for the wav... Was it encoded into the wav file? Do I need to manually specify -116ms when using the wav?

[manono]

Hi-

An educated guess tells me that the delay will stay the same even after the WAV conversion, because there's no way to adjust the delay in DVD2AVI. However, you should only be getting the AC3 from DVD2AVI, and not the WAV. You are much better off getting the WAV, if that's what you really want, and not MP3 or MP2 or whatever, in BeSweet or HeadAC3he. Please see Question 19 of the DVD2AVI FAQ. (http://forum.doom9.org/showthread.php?s=&threadid=59272)