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recompressing audio; why?
I loaded an uncompressed NTSC AVI file, 48k stereo 16-bit audio into DVD Architect 5.0 and chose PCM audio for the project settings (in all locations). When I went to Optimize, I noticed a message that said the audio would be recompressed because it did not match the required settings for the disc (SD DVD). Any idea if this is a bogus message or why DVD-A would want to recompress the audio, which is in excatly the right format?
I went ahead and ran the job, then when I looked at the VOB file for the movie, Vegas said both the audio and video were MPEG2 – so I really can’t tell what is going on.
Thanks for any help.
Dennis -
4 Replies
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I am surprised that no one has replied yet, but you are doing wt least two things the hard way.
Yes the message is correct because the audio in a DVD is AC3, so DVDA needs to re-encode it.
First, using DVDA to encode the MPEG is a compromise of everything. Encode the video and audio separately in Vegas. It’s in the “Render As” menu, though you are encoding, not rendering. Use the DVD Architect MPEG2 template for the video and the AC3 template for the audio. (Yes, you have to encode twice, but the audio is pretty quick). Drag the MPEG file into Architect and it will find the AC3 file.
Steve Mann
MannMade Digital Video
http://www.mmdv.com -
> Yes the message is correct because the audio in a DVD is AC3, so DVDA needs to re-encode it.
Nope. He said that he selected PCM audio for the DVD Architect project so it should not be converting to AC3. PCM is a valid format for DVD’s and is higher quality than AC3.
My guess is that it is simply taking the audio from the AVI file and transcoding it to wave with no real recompression. Had you used a separate wave file you probably would not have gotten that warning. I’m surprised the warning came up which is why I didn’t respond initially.
~jr
http://www.johnrofrano.com
http://www.vasst.com -
I agree with John. In addition, it could be that your audio files are not stored as avi or wav, but multiplexed into the VOB. So that “conversion” could be what the dialog box was about too. Again, no real signal change, but rather the was it is stored and presented.
Tech-T Productions
http://www.technical-t.com -
Thanks to all for the help. I was able to get it working by splitting out the audio file from the AVI as a WAV file as suggested. But I never let DVD-A convert my WAV files to AC3 because it has so few options/settings (though 5.0 is better than previous version). Instead, I use Vegas to make the AC3 file without any attenuation, then load that as the audio file.
Thanks again for the help.
Best.
D.
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