creating mpeg2 / aiff audio files in Compressor 3

[David Roth weiss]

Phil,

AC3 audio is now quite correctly the only option in the DVD presets. Aiff should really never be used on a DVD anyway. Don’t know why you’re using Toast rather than DVDSP, but Toast works just fine with AC3.

David

David Roth Weiss
Director/Editor/Post-production Supervisor
David Weiss Productions, Inc.
Los Angeles

POST-PRODUCTION WITHOUT THE USUAL INSANITY

[Michael Gissing]

David, what a strange comment to make. AC3 is but one of four options for audio on a DVD. Uncompressed PCM, DTS and Mpeg2 multichannel are the other three perfectly valid options to put on a DVD.

When I put my Led Zepllin DVD on, I love to use the DTS or PCM sound tracks that they have. AC3 is a poor codec and my least favourite as an audio professional. For the record, the Compressor presets that I have used so far include aif and AC3. Not sure which one you are trying but many of mine in 5.1.4 and 6.0.1 have aif.

If you can’t find them, make an aif mixdown in FCP and then import that into DVD SP. You can happily put an aif file in DVD SP.

[Phil Muri]

Hi Michael,

Thanks for your reply. What kind of throws me is that (it seems to me, anyways that) in previous versions of Compressor, the presets in the DVD folder, contained a setting for MPEG-2 AND aiff. But now, the DVD-presets show only AC-3 for audio encoding… David posted that Compressor 3 now only offers AC-3 in the DVD-presets. Are you manually selecting aiff audio from a custom preset?

Either way, I want to use Toast 8 to burn my DVD since its one-track, short show and do not want to fuss with all the extras in DVDSP.

My AC-3 asset file is slightly shorter in duration than my MPEG-2 asset file… Does this make any sense? It seems to me that Toast will only apply the AC-3 file as the audio track for the MPEG-2 file if the two are the same duration…?

Thanks for your input.

-Phil

[David Roth weiss]

Come on Michael, you’re going to confuse 99% of the people here and throughout the Cow, the vast majority of whom should be using AC3 audio for their video DVDs.

Take a poll and see how many are making Led Zeplin DVDs. Next, see how many create problem DVDs that skip or become pixelated because they’re use of PCM audio causes their dics to exceed the throughput limitations of their set top players.

Seriously, if you simply look around across the forums you will see that the vast majority of questions are not about how to make DVDs that sound great to audiophiles, but rather how to make DVDs that play in set top players without problems. Suggesting the use of AC3 audio works in many, many cases.

David

David Roth Weiss
Director/Editor/Post-production Supervisor
David Weiss Productions, Inc.
Los Angeles

POST-PRODUCTION WITHOUT THE USUAL INSANITY

[David Roth weiss]

[Pseudojag] “Either way, I want to use Toast 8 to burn my DVD since its one-track, short show and do not want to fuss with all the extras in DVDSP.

My AC-3 asset file is slightly shorter in duration than my MPEG-2 asset file… Does this make any sense? It seems to me that Toast will only apply the AC-3 file as the audio track for the MPEG-2 file if the two are the same duration…?”

First, you don’t use all the extras in DVDSP, its perfectly capable of making great DVDs without even as much as a simple menu. Don’t let it intimidate you, just take ten minutes to learn how to use its most simple features. DVDSP makes much better DVDs than Toast.

Next, your audio and video assets should be exactly the same length as your video assets. Are you saying that you encoded both audio and video at the same time from the same files and they came out differently?

David

David Roth Weiss
Director/Editor/Post-production Supervisor
David Weiss Productions, Inc.
Los Angeles

POST-PRODUCTION WITHOUT THE USUAL INSANITY

[Michael Gissing]

Just make your aif file from FCP directly not using Compressor. Use the same in out markers and the file length will be the same as your video mpeg2 file. If Compressor 3 has dropped aif, then mores the pity.

I have both 5.1.4 and 6.0.1 but haven’t used Compressor 3 yet so I was unaware that they had dropped the aif option.

[Michael Gissing]

David, exceeding the bandwidth that set top players are throttled at is possible with any DVD if you don’t get the balance of audio and video data rates correct. AC3 is not the magic bullet to getting that balance right. Knowledge of data limitations and ways to get the balance right using any of the audio options is important. If a desire to correct oversimplifications is going to confuse the forum then my apologies.

If it was about bandwidth, then no-one would use AC3 over MPEG variable bit rate audio. AC3 is fixed bit rate and uses far too much data for the ordinary sound it produces. Years ago (1997 from memory,)I did a test disk with an AC3 2.0 and an mpeg stereo track. This was played to the Australian Screen Sound Guild in a blind listening test. 100% of the audience chose the mpeg stereo over the AC3. The files sizes? AC3 file was twice the size of the mpeg.

The reason that the Motion Pictures Expert Group original rejected Dolby AC3 should not be forgotten. There are many out there that have forced Dolby encoding on DVDs and digital broadcasts. It never should be considered anything other than optional.

By all means share your winning formula for making bullet proof DVDs, but please don’t proclaim that Dolby is rightly the only audio format for DVDs.