ac3 import into VMS10HDPlat

Jack S wrote on 4/26/2011, 9:56 AM

My home videos are split into sections (ie vacation 1, vacation 2, etc). I need to render them as individual mpg files so I can check them for errors using DVD AS. I used to render the AVI sections as Mainconcept MPEG, check them out and if there was a mistake I could just modify the relevant section then render it again. When I was satisfied that all the sections were correct I would then render them all together avoiding recompression and bring the one file into DVD AS.
Now, I read in this forum that to avoid recompression of the audio I should render 2 seperate streams (Video and ac3 audio) so that DVD AS wouldn't recompress the audio. My problem now is, I have rendered the sections as video and audio but I can't pull the ac3 tracks into VMS, the format is invalid. Unless someone out there has an answer to this I'll have to go back to the old way of doing it and put up with the audio recompression.

Comments

Khat wrote on 4/26/2011, 11:53 AM

Not sure if this is a codec problem or not. If AC3 can be played back in Windows without problems then you should be ok. If you're using something that has internal filters such as VLC then you may need to try using FFDSHOW to decode the stream.

http://www.free-codecs.com/download/ffdshow.htm

Get it and set the option for AC3 to be decoded using libavcodec and then try again. If this fails then I don't know what else to tell you. What this will do is call for FFDSHOW when the AC3 stream is detected. My Vegas suddenly wont open so I can't even test it out and confirm before telling you.

Find the option after installing under the FFDSHOW AUDIO configuration. Hope this helps.

Jack S wrote on 4/26/2011, 1:47 PM

Thanks for the response. You misunderstood my question though. I'm trying to pull both the mpeg video stream and the ac3 audio stream into Vegas Movie Studio not DVD Architect Studio. If I can do this I can pull all my sections in and render a new full length video and ac3 audio stream. I want to do this to avoid the long pauses between titles when played back on my DVD player
Sorry for the confusion.

Khat wrote on 4/27/2011, 11:14 PM

I thought Vegas supported AC3 natively? I could be wrong. If I don't get a reply that works to my own problem by this weekend then I'll format/reinstall and test it out myself then get back to you.

TOG62 wrote on 4/28/2011, 2:49 AM

Why would you re-render the output from the individual projects, rather than rendering from the source files, once all the corrections have been made? That would give better quality.

Chienworks wrote on 4/28/2011, 3:13 AM

Or assuming the source files are DV .avi then all the pieces should be rendered as DV. avi to avoid loss all together. Wait until the very last render to convert to MPEG/AC3.

Jack S wrote on 4/28/2011, 9:26 AM

Thanks Guys. The source files are AVI. I just wanted to save time re-rendering the full sequence of sections in a joined up project. I used to render each AVI section into dual stream (video and audio) mpeg files then check them out in my DVD player after putting them through DVD Architect Studio as a single movie. If there was a problem I just needed to rectify the problem section and re-render it. When I had all the sections correct I would bring them all into VMS10 and smart render them into one dual stream mpeg file. I would then use this to make my menu based DVD. The problem started when I tried to bring the sections into VMS after they had been rendered as 2 single streams (mpeg and ac3). I had changed my original workflow to avoid recompression of mpeg audio into ac3 by DVD Architect Studio as I had been told in this forum that this would further degrade the audio. I have been unable to bring a dual stream (mpeg and ac3) file into VMS (VMS states that ac3 is an invalid format). I can see now that this isn't possible and I will have to revert back to my original workflow or do as Chienworks suggests and tolerate the extra rendering time involved.
Once again, thanks guys for your suggestions.

Khat wrote on 5/7/2011, 5:52 AM

Based on what you would like to do, maybe you could join the files using free software beforehand and then have a single file and do a direct stream copy for what you want to keep and a re-compress for what you want to change (audio). Free tools include FormatFactory and WinFF. Others are there if you'd like me to list them. Hopefully this helps.

Once completed you can then drag into VMS and export to DVD-AS and do as you please.

Jack S wrote on 5/7/2011, 11:24 AM

Thanks Khat

I'll have to decide whether the extra steps in my workflow justify avoiding the tolerable degradation of the audio from mpeg to ac3.

Thanks for your input.

musicvid10 wrote on 5/7/2011, 12:04 PM

"I had changed my original workflow to avoid recompression of mpeg audio into ac3 by DVD Architect Studio as I had been told in this forum that this would further degrade the audio. "

Mpeg Layer II Audio is vastly inferior to AC3 to begin with. You will not notice any further degradation by encoding it to AC3 whether it be done in Vegas or DVDA Studio.