AC3 for Dolby 5.1 vs. WAV
 

Something I think I have overlooked in my project workflow is making sure I'm preserving the Dolby 5.1 audio as originally recorded by the camera (SONY Handycam HDR-SR11 60Gb HDD for 1080 60i NTSC 1920x1080 recording including Dolby 5.1 surround-sound audio).

This was preserved during the downconversion to MPEG-2, but I'm wondering if when I imported this MPEG-2to VirtualDub for the video conversion to AVI, that I should have done something different then merely save the audio conversion as WAV. I have not had the opportunity to listen to the DVD authored product output yet, as I'm still thinking through the authoring software options out there (see my other post today).

I know VirtualDub couldn't convert the audio off the MPEG-2 until I installed the AC3 Filter codec. Was the Dolby 5.1 audio passed along properly to the WAV (multi-channel PCM)? Now, having accomplished the export from Adobe Premiere 6.5 using the MainConcept 1.3 MPEG Encoder, would this have properly re-encoded the surround-sound audio, or should I have done something else along the way?

I can put hamburger on a fancy plate, cut it with a steak knife, and charge $25 for it --- but it's still not ever going to be a steak. The same can be said for consumer-level 5.1 AC3 audio. I can dump sound into all 6 channels, but that doesn't make it true 5.1 Dolby.

That camera's audio is a perfect example of a consumer gimmick. Given how it was recorded from a teeny tiny on-camera microphone (or cheapie external mic) -- correct me if I'm wrong -- there's no way this is surround sound. It's just mono or stereo crammed into 6 channels. Any good TV receiver does that already -- often better than the computer software or camera processing.

If you really want to go to all that work of preserving the camera's false 5.1, then DVDWS2 will pass it just fine. What I don't know about, however, is Premiere. Standard PCM audio is 2-channel. You can make 6-channel PCM, but I don't do it very often. It's an option in Besweet, for example.

The only time I work with 5.1 is when I'm downconverting it for studio projects, off their master sources, for special projects.

To make 5.1, you need to hand mix it. It takes a lot of skill, and it's not something automatic.

No doubt the "Dolby 5.1" audio recording on this camera is nothing like the professional effort you describe. The sound seems disctinct by channel and the result is nothing like stereo - even if not Dolby 5.1 compliant - but stuff is heard behind you as recorded in the field while something else is heard in front right, etc. A good field example is the recording of "Katey Did" cicadas in the middle of a deep woods. The cicadas are easily distinguishable (voicing, rythym) so when it's happening, you know it. The omni-directional voices are captured and the recording effectively "locates" the sound of an individual in a surround context. I can't speak to the fidelity of the process though. Whatever the gimmick, it satisfies me enough.

It's probably just a good false recording, unless there are multiple tiny sub-microphones that are more directional in their recording.

As far as the throughput for 5.1 audio, I'm afraid I'd have to defer to the Premiere documentation (the program's help file). I'd look it up myself, but that computer is currently encoding.