audio error some clips play audio others don't

Question

audio error some clips play audio others don't

Hi, I am in the middle of updating a DVD - it is a demo of my cinematography work made up of commercials. Each commercial has been separately encoded a library of commercials, encoded in ac3 at 256KB and .m2v files (highest quality) - all encoded in compressor. I am working on a macbook pro 2.33 Intel Core 2 Duo and DVDSP 4.1.2

I build the reel but then only half of the commercials play with sound. I check them with the inspector and they all are ac3 files at the same bit rate. In fact the first couple of commercials have no sound and then then the sound picks up and then goes away.

Are there problems with mixing ac3 files coming from various versions of compressor? I have been using DVDSP since V1.0 But I have never had this problem before.

thanks,

Steve

MacBookPro 2.33 Intel Core 2 Duo, Mac OS X (10.4.10), DVDSP 4.2.1

Posted on Aug 7, 2007 6:54 PM

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Answer 1

Drew13

Level 6

12,387 points

Aug 7, 2007 7:32 PM in response to Steven Moses2

Steve

I think maybe you are onto something.

I started using newer versions of Compressor and then DVD SP 3 would not simulate or build properly with sound.

In DVD SP 4 (pre UB) it then worked for awhile then muxing would produce builds that would not play sound in Apple DVD Player.

Compiling in the newest UB on another computer seemed to work.

Cleared out prefs on the other computer in DVD SP and Apple Player and DVD SP worked again for awhile, but then the builds and playback became suspect again (bad compiles/playback.)

I am not quite sure of what pattern seems to have cause this and one of the ones I was thinking about was maybe the various versions of Compressor/DVD SP/Apple DVD Player. As an aside I am also noticing more issues with AC3 files in general. Seems to be more pops/glitches. I still have not figured out whether it is realted to some of my standalone players or TVs. (I actually think the pops are related to one tv I test on.)

I also think there was something happening depending on how I encoded the audio - either directly from FCP, self contained then encode in Compressor or self contained and then encoded with bitVice and then encode the audio.

It is strange and have not tracked down the combination I can say for sure is the one. (Also people have mentioned some issues with Quicktime, think maybe 7.2)

Thinking back a bit I think the issue started in the DVD SP 3/4 side when I took AC3 files from my Intel machine.

I know not much there as answer but perhaps there is something similar in your patterns that may match up.

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Answer 2

Aug 7, 2007 10:39 PM in response to Drew13

Well, I caved in and rounded up all of my sources from my archives and encoded them all again, saving a .aif file with each one and put the project back together from scratch. I also noticed that my old titles which were inserted as as .m2v files with no audio now cause some problems with sound overlaps coming up under the silent title cards. I added some silent .ac3 files under the title cards and now they behave well too. Thanks for the support on this one. I have been doing all my encoding from self-contained quicktimes because I have sources coming in in various flavors of HD, SD & DV -

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