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24bit – 96khz Audio or highest level audio possible
I am currently editing LIVE concert footage for a national-level string quartet. They would like the audio to be of the highest quality possible. The audio engineer gave me DVD quality audio (24bit 96khz – AIF file) to sync up with the video. He said he does not want me to compress it if possible. If I have to compress it keep it at the 24bit/96khz level. I have yet to do this with Vegas 6 and DVDA 3. If anyone out there has experience with high level audio projects I would appreciate your feed back. This DVD will most likely be reviewed and the emphasis will be on the audio. Thanks for your time.
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8 Replies
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For a DVD with audio AND video, you’ve got two choices. Dolby AC-3 compression, which is what most people use because it’s small, works well and sounds good, and PCM (wav) which is uncompressed and can sound better, but uses more storage on the disk and more of the bitrate during playback.
24/96 is one of the rez you can get with DVD PCM audio. Look up PCM in the DVDA help file. Bear in mind that you’ll get a little less than the typical 90 minutes of video to fit on a DVD, and additional bitrate you use in audio will take some away from video playback quality.
You’ll compress MPEG-2 for DVDA video stream as usual out of Vegas, but use a bitrate calculator that will make allowance for the 24/96 audio.
Then you’ll render audio to WAV 24/96 out of Vegas.
Build your dvd in DVDA. When preparing the DVD, use the “optimize” button to select PCM audio. I think that’s it.
You can also have DVDA do the MPEG compression by giving it a DV-AVI file. Just make sure it picks up the audio from your WAV file.
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Thanks much Seth. I’ll be talking this over with the audio engineer – we may have more questions. Also, I know there are a lot of bitrate calculators out there but could you recommend one that I could download and use from my desktop?
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Well, the one I use is here and is available as a download or to use on the site.
However, I’m not sure what bitrate a stereo PCM at 24/96 is. This is info you need to use a calculator… somewhere I’ve a spreadsheet with the math, but can’t lay my hands on it right now. It might be 4608Kbps. Has someone got this info?
Otherwise (without bitrate info) you can still have DVDA do your video compression to MPEG2 as above. If you specify PCM and give it a 24/96 file, it should take the required bitrate into account when it sizes the video.
A brief discussion of player compatibility with 24/96 is here. Some players will truncate 24/96 to 48KHz, and some to 20 bit.
BTW, doing some 24 bit recording myself, to me the biggest gain was from going to 24 bit – I record in 24/48. If you have a concern about size or bitrate, you might discuss with the engineer the possibility of 24/48.
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Right now I have 24/96 AIF files and I can’t import them into Vegas. Am i doing something wrong or should I have them converted to PCM files first?
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oops, I forgot to change my sign in information.
I’m trying to import 24/96 .aif files into Vegas and Vegas gives me error messages. Do these files have to be converted to PCM in order to bring them into Vegas? Exactly how can I get 24/96 rez audio into Vegas?
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I have no problem importing 24/96 .aif files – work fine in vegas, just dragging them from the explorer to the timeline.
Possibly you have an incomplete install of quicktime. A standard “default” install isn’t enough. Reinstall QT from apple.com/quicktime/download/win.html, select custom and make sure the authoring components are installed.
If that doesn’t work it’s possible there’s a codec issue, but the engineer should be giving you straight uncompressed .aif, and vegas doesn’t expose any QT audio codecs (thinking speculating and typing…)
Perhaps if none of the above helps, you would need a .wav pcm from the engineer, which should be a lossless conversion. Or if you have Sound Forge you might try opening it there (but do the QT install first).
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Seth – I finally got around to the rendering stage of my project and now when I try to render the audio as a 24bit/96khz WAVE (microsoft) file from Vegas 6 I received an error message.
“The file being rendered has exceeded the maximum size allowed for the selected format.”
If you know what this error message means please let me know.
I have a dual layer DVD burner. I was planning to burn these files onto a DVD-9. Is that possible with DVDA3? Any suggestions? Thanks for your time. Rick
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I don’t have the information at my fingertips, but there is a quasi-limitation of Windows for WAV file sizes. Is it 2gb? Don’t remember but I think so. Perhaps this message indicates that you’ve exceeded the limit.
I say “quasi-limitation” because some audio apps ignore it, working just fine, even though the windows spec says that’s it.
If this is the case, you’re going to need to work around. Experiment to find the max length for one audio render, then do some sort of split and join. You might be able to join in DVDA, or try audacity or any other app you have.
Or recut your source media for DVDA into smaller chapters.
If it isn’t the wav size limitation I don’t really know what’s going on, but the error message seems to point to it.
Sorry I don’t have experience with double-layer yet.
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