NTSC spec doesn't require support for MPEG-1 layer II audio, only PCM & Dolby Digital have to be supported.
PAL spec on the other hand is to support MPEG audio as well.

I don't think that is your problem though. It is more than likely in the setup menu for audio in your player. I don't know about your player but mine can't output from digital & analogue at the same time, I have to select one or other !

[Sonic Solution's MyDVD will only output audio as PCM .wav file regardless of whther you put in compressed audio or not.]

Hmm . . . My DVD player does have some settings for the audio format (dolby digital, stream, or PCM) but changing the settings doesn't help.

Could it be that I have to convert the audio to an AC3 file and burn it using a DVD authoring software that supports AC3 format? Do you have success using MyDVD to burn directly from an MPEG file with an embedded Mpeg-1 layer 2 audio stream, and playing back on a DVD player through the digital output into a reciver that supports dolby digital? I was just thinking that maybe the reciever is only looking for an AC3 encoded stream, and ignores the MPEG-1 layer 2 stream even though the DVD player can read the stream, and sends it out of the analog outs. What do you guys think?? Thanks!!

Peter Dribble

like I said if you've got a NTSC player it probably will not support MPEG audio only PCM (.wav) or AC-3. MyDVD will not support AC-3. The cheapest program I know that does is DVDit PE ( that will be about a $600 upgrade for you)
I've never used MyDVD but I have used DVDit. What DVDit would do with your MPEG file is to demultiplex it to give you seperate audio & video streams. It would then re-encode your resultant audio file into .wav file so that NTSC would support it.
The difference between the AC-3 and .wav is that the .wav file is about x10 the size and that will obviously eat into your project size.

What are you doing with your project. Are you loading an .avi file into MyDVD and letting it do all the transcoding/encoding ? Are you loading an MPG (video/audio) stream into MyDVD & letting it do the transcoding ? Are you loading seperate streams of video & audio ?

Have you tried the DVDit/MyDVD forums ?

If audio is playing out of your analogue outs then whatever audio the DVD player is playing should come out of the digital outs provided you have selected that in your players settings.
My DVD player will play PCM,MPEG,DD or DTS from whatever one output I select. I can have the audio out of analogue, or out of digital but not both at the same time.
I have similar choices with the the video signal, it can be out of scart,component,S-Video or composite.

What are you connecting your digital out to when you are getting no sound ?
If it is an amp/receiver does it have a decoder ?
Maybe your problem is that when you use the analogue out your DVD player is doing the decoding , but when you use the digital out it is not decoding as it is upto the amp/receiver to do it.

I agree with the posters so far who have stated that the NTSC DVD spec does not require MPEG audio decoding, and therefore that's probably why you're not getting any analog audio from your DVD player.

I'm surprised that our MPEG encoder doesn't offer PCM audio interleaving, and I'll look into that.

In the meantime, you might try outputting separate elementary streams, and then also rendering a PCM .WAV files, and having your DVD authoring / writing software interleave those together into an MPEG program stream, which is what you'd burn on the DVD. Since PCM is a required playback format for any NTSC DVD player, that should work.

///d@

Sorry, didn't notice MyDVD was the authoring tool here in my first reply - wouldn't have started off the MPEG audio thing if I had....

Unless it's changed recently, MyDVD converts all the audio to 48kHz PCM on the DVD, even if the source files have MPEG audio - if I remember correctly it does say this somewhere in the manual/help system. You can confirm this if the player displays the audio stream type - some do. I agree with Vonhosen that this looks like a player or amp/receiver problem.

SonicDennis - Yes, I'm surprised that the VV3 encoder can't generate a muxed stream with PCM audio, especially since some other implementations of the Mainconcept encoder appear to have the facility (e.g. Ulead VS6, Puremotion MPEGXS).

Tony

I talked to the fellow who implemented the Vegas MPEG output using the MainConcept SDK, and here's what he had to say:

"According to the MPEG spec, there is no such thing as an MPEG file with PCM audio (i.e. PCM audio isn't defined of the MPEG spec). PCM audio is defined by the DVD spec for creation of VOBs (not MPEGs). The DVD spec has extended the MPEG spec to support this.

With that said, the latest version of MainConcept's SDK supports PCM audio (at least to some degree) and it may make sense to add PCM support to the plug-in for a future release."

So, with Vegas 3, either use a DVD burning app that creates a PCM stream from MPEG audio (such as the one you mention), or do two renders (an MPEG video stream and a PCM .WAV audio stream) and have your VOB encoder weave them together. At least, that's my understanding. I'm told that only Spruce and Scenarist require this.

///d@

That's what I do with mine.
Encode a video only stream through MC encoder or TMPGEnc (.m2v file or similar)
& then another render this time of audio from timeline as 48KHz .wav file

Load both into authoring program and link them to the same button to play them.

Yes high end systems like Scenarist may REQUIRE this, but it's advisable to do it this way if you can as it eliminates any problems authoring program may have demuxing & re-encoding, not to mention saving the time it would take the authoring program to do it all !