5.1 Audio on Encore CS4 – Help Please!

[Stuart Baker]

Thanks, David. It sounds all too easy. I’ll give it a whirl and let you know how it shakes out.

Best,

Stuart

[Tommy Daquino]

I’ve got an HD MPEG-2 and a Dolby 5.1 AC3 in Encore for output to Blu-Ray. However, it’s only outputting a stereo audio track. The client had added some title slates to the front end of the project, lengthening the video track, without lengthening the audio file. I had to manually find a synch point in the audio which synch’s up and starts at about 28 seconds in to the video.

My question is, since the audio and video aren’t 1-to-1 for the entire length of the piece, is that causing Encore to decompress the AC3 file and re-render it to the length of the video file?

Thanks!
-Tommy

[Stuart Baker]

I am unsure what is happening with the lengthening of your audio, but I can tell you that if your timeline has multiple AC3 clips in the audio track, Encore needs to transcode your audio into a single file for muxing. Your 5.1 audio then becomes a stereo file, as Encore does not support the AC3 license for 5.1 encoding. At least that’s my understanding as to why, but the facts are certainly true: If you want to stay in 5.1 when you author, you need to have a single AC3 5.1 file in each timeline- no edits. I hope this is helpful.

[Tommy Daquino]

No… I’ve only got one AC3 file. It’s just that it isn’t exactly the same length as the video. In a 1 hr program, the audio file is about 30 seconds shorter than the video (at the head) and when I build the project, it’s only outputting a stereo signal.

Is there anyway to check to ensure that the file (the AC3) the client sent is a 5.1 file? I don’t know that I have anything on the Mac to check that.

[David Payne]

i found this thread really helpful, thanks to all involved. I had exactly the same problem putting all clips on the same timeline. I’m pretty confident if I join them I’ll get sync issues due to the length (over an hour) of the disc, but I’ll play around and if it does not work I’ll try to use separate timelines.

The only remaining issue I have is using 5.1 ac3 files for animated menu audio… is this possible? I’m having real problems getting the audio to play, fine when I use a wav, but when I clear cache and replace the wav with an ac3, it doesn’t play