Audio and video compression preferences for export to DVDSP

Question

Hi,
I have a few questions here. The first is regarding the internal use of compressor by DVD Studio Pro. It is my understanding from (limited experience with) past projects that quicktime movie files are automatically compressed to an mpeg2 format when imported into DVDSP. To what extent do I have control over the level of compression, and are the default mpegs that were made optimal quality? Where can I check this?
My second question is regarding compression of audio files. Whereas my video files were automatically compressed, I am not so sure about the audio. I was forced to compress the audio down to Dolby2 separately using the external compressor program, in order not to exceed the bitrate on my last project. Was this just a question of one or the other (video/audio) needing further compression than the default amount, or is there more to this issue?
I live and work with video in Europe, where I have recently been told that optimal audio is mp3? 4? rather than Dolby 5.1? Is this correct, and how much more space does dolby 5.1 take than dolby2? How significant an issue is this when making dvd's for musicians?
Lastly, can someone recommend the best quality audio-video compression solution for a dvd containing approx 40 minutes of audio and video footage for use in europe?? or explain how I might go about finding this out for myself?
Thanks a lot, and I look forward to reading your comments.
4 x 2.5 GHz PowerPC G5   Mac OS X (10.4.6)   8 GB DDR2 SDRam
4 x 2.5 GHz PowerPC G5   Mac OS X (10.4.6)   8 GB DDR2 SDRam

Answer 1

It is my understanding from (limited experience with) past projects that quicktime movie files are automatically compressed to an mpeg2 format when imported into DVDSP. To what extent do I have control over the level of compression, and are the default mpegs that were made optimal quality? Where can I check this?
Settings for DVDSP's internal encoder can be adjusted in DVDSP preferences. Press Command-, - that's the Apply and the comma keys - to bring those up, then select the Encoder tab. In your case, make sure you adjust the settings for SD DVD (and not HD-DVD). You will also be able to specify whether to encode in the background (basically, as soon as you import your file) or encode on build, at the bottom of that tab.
I was forced to compress the audio down to Dolby2 separately using the external compressor program, in order not to exceed the bitrate on my last project. Was this just a question of one or the other (video/audio) needing further compression than the default amount, or is there more to this issue?
I can't confess to have read any of your previous threads, but if you exceeded bit rate, that is a common reason to need to use Dolby compression for your audio. (unless you can afford to recompress your video files)
That is, if you video files use a high bit rate (say over 6 Mbps average), then it's usually necessity to use Dolby compression to make sure that all your footage fits on a single disc. (this is a simplification, of course, but I think you get the idea)
Or was there more to this question that I'm missing?
I live and work with video in Europe, where I have recently been told that optimal audio is mp3? 4? rather than Dolby 5.1? Is this correct, and how much more space does dolby 5.1 take than dolby2? How significant an issue is this when making dvd's for musicians?
Someone was mistaken when they told you that DVDs accept - let alone are optimized for - mp3 or mp4 files. That's flat out wrong.
As for the difference between Dolby 5.1 vs 2.0, that depends on your encoding rates. Typically, most folks encoder Dolby 2.0 at 192 kbps, with some choosing to up the bit rate to 224 kbps. Beyond 224 kbps, you're not actually improving audio quality for a 2.0 mix, you're just bloating your file size. When it comes to 5.1 audio, it's typical to encode your audio at 384 or 448 kbps.
When it comes to compressed audio vs uncompressed audio, it does matter when you're making DVDs for musicians. But that means that you'll probably need to lower the bit rate on your video files.
Lastly, can someone recommend the best quality audio-video compression solution for a dvd containing approx 40 minutes of audio and video footage for use in europe??
If you want to keep you audio as AIFF files, set your encode to 2 Pass VBR Best, with an Average bit rate of 5.0 Mbps and a Max bit rate of 7.0 Mbps. If you need things to happen a bit faster, use One Pass (not One Pass VBR) and use 5.5 Mbps as your bit rate.
If you want to have a firm grasp over how all these numbers work, there is a section at the back of DVDSP manual, that explains how to calculate bit rates (what we call bit budgeting in the business). Give that a quick once-over if you can.