DVDA recompresses all audio that's included with the mpeg-2, doesn't have anything to do with the codec.

I use the render script so it's been a "meh" issue for me since Vegas 4.

"[I]A standard DVD is mpeg2 video with AC-3 sound.[/I]"

A DVD-Video disk can contain video, multiple audio streams as well as other types. Sony Creative Software didn't invent the standard though Sony participated.
https://en.wikipedia.org/wiki/DVD-Video

"[I]You don't need two rendering passes in Vegas...[/I]"

Audio renders are usually trivial compared to the process of assembling a DVD stream.

"[I]... you don't have to worry about identical naming...[/I]"

You don't have to name the video and audio the same. That was just done to make the DVD Architect process "automatic". You can name them anything to want and save them anywhere you want. In DVD Architect you can include files from any place named any thing as long as they meet the requirements, but it's up to you to locate them and add them to the project.

"[i] ...and you can use the .mpg directly for other purposes f.ex. direct viewing on the PC or uploading to youtube[/I]."

There are a number of programs available to multiplex elementary streams together for other uses. tsMuxer, for example.

Re: " ...There are a number of programs available to multiplex elementary streams together for other uses. tsMuxer, for example. .."

Why bother with creating separate files only to have to mix them later?

It doesn't take any longer to let DVDA encode the audio..

The advantages of separate elementary streams are multiple audio tracks (narrative, commentary, languages, even karaoke,) and the ability to replace the audio track quickly.

I don't think that the minor inconvenience of two renders outweighs the sum of the advantages.

"There are many advantages with two streams."
I suppose those advantages are good, but i'd also bet that a majority of Vegas->DVDA creations wouldn't see any advantage from them at all. Probably most of the DVD projects produced use only a single audio track.

"DVDA recompresses all audio that's included with the mpeg-2, doesn't have anything to do with the codec."
It doesn't have to. It could easily be programmed to recognize that the audio in the MPEG2 file is DVD-compliant and leave it alone. For that matter, it could be programmed to leave it alone even if it isn't compliant. It's not a law of nature; it's just a programming choice.

"A DVD-Video disk can contain video, multiple audio streams as well as other types. Sony Creative Software didn't invent the standard"
As mentioned earlier, while this is true, it's probably not the majority of cases. I'm sure most Vegas-produced DVDs contain no content other than what can be stored in a single MPEG2 file containing stereo audio.

"Audio renders are usually trivial compared to the process of assembling a DVD stream."
Trivial for the CPU, possibly, but still a duplication of effort for the user. Even if the time to run the audio render is tiny in comparison, i don't really count my time while the computer is running without me. I can go do lots of other things while the renders are running, but then if i have to come back and start a 2nd render, that's my time and effort.

OK, scripts that run both renders are helpful and eliminate most of the concerns. However, it's still completely valid to wish that Vegas/DVDA could perform the same task in one render if the result in question could be accomplished that way. This is especially true when all the reasons why separate renders might be better don't apply to the person asking the question.

DVD authoring programs vary. Some actually require separate streams and will not use an MPEG file that is muxed with audio. DVD Architect does not require separate streams, but if you feed it a an MPEG file with audio, it does demux it first, then muxes it back. So basically it is breaking the file down into two streams and then putting them together in a DVD format mux.

So although it seems you should be able to bring a muxed file into DVDA, the result is the same. It demuxes and remuxes so it would seem the best is to give it what it wants... separate streams.

Most other pro level DVD authoring packages will only accept separate streams. If you could examine a regular mpeg file with audio and a DVD video file with audio, you could see that the structure is quite different.

Thankyou for the many comments. All except Chienworks do not address the issue though saying I could do so many other things instead. Why is it desirable for some to prevent others to have more choices, well argumented choices at that. Others are welcome to use their own favorite other (more cumbersome) ways as in the old days.

So the suggestion stands for SonyCS to add a new template to Vegas which generates a .mpg containing the right stuff - mpeg2 video and AC-3 audio - in 1 go for DVDA.

@musicvid10
"There are many advantages with two streams.
Been done that way for a long time"

And you are so welcome to use two streams as many have done for a long time.
Why is that an argument against having a new more elegant way ALSO?

Well since you put it that way, I don't have a good answer for you.
I know that the AC3 license is part of the issue, but there is no physical constraint.

@musicvid10: Interesting about the license. But as there already is an AC3 rendering option I would guess the license has been paid or is it paid per template you think?

The license is included with DVDA, not with Vegas. If you don't have DVDA installed then there is no AC3 rendering available.

What may be possible is the license that Sony Creative Software has Dolby for including it in their software may have restrictions on what templates are allowed to use it. This is pure conjecture on my part though.

"[I]Sony Creative Software - please add a "Ready for DVDArchitect authoring"-template to create an out-of-the-box .mpg ready for use in DVDArchitect![/I]"

Now that you've heard different points of view on the subject consider availing yourself of the Product Suggestion which will go to Sony Creative Software. Most of the members of this forum are not connected with SCS.

@John Dennis: Good point - and I already did yesterday!

"An MPEG-2 container can contain the mpeg2 video stream AND an AC-3 audio stream. My question is: why is there no template in Vegas Pro that can create a .mpg file containing the AC-3 audio stream?"

It's a licensing issue.
If you notice, vegas can not create ANY file with (pro) AC3 already muxed. The Pro ac3 encoder is licensed to DVDa in order to create "compliant" discs.

As for DVDa, it will not create a "non compliant" file/disc and .mpg with ac3 is non compliant.
Vegas and DVDa need to follow the rules since they are profit generating programs while programs like Tsmuxer are non profit (free).

RE: " ... As for DVDa, it will not create a "non compliant" file/disc and .mpg with ac3 is non compliant. "


Now I'm ( more ) confused?? I thought that creating an .mpg file with ac3 is what DVDa is doing..

"[i]I thought that creating an .mpg file with ac3 is what DVDa is doing.. [/I]"

In the strictest sense of the word, DVD Architect creates a series of VOBs. I scratched my head the first time someone told me to just rename the .vob to .mpg to put it back on the Vegas timeline.

"I scratched my head the first time someone told me to just rename the .vob to .mpg to put it back on the Vegas timeline."

That will work so long as the vob contains only one audio track and no sub tracks.

Unlike MPG, a VOB may contain multiple audio and sub tracks. A VOB also can not exceed 1 gig while a MPG can

@Rob Franks:

- "vegas can not create ANY file with (pro) AC3 already muxed".
Correct - that is why I raised the request!!

- "The Pro ac3 encoder is licensed to DVDa".
How can that be true, when Vegas CAN create an AC3 file? I just ask for an option to have it muxed in the .mpg ready for use in DVDa instead of being forced to two render passes in Vegas. It gives the most simple workflow. Is there a "law" against muxing AC3 in Vegas? If it costs a penny or a pound more then SonyCS is most welcome to ask and I will pay screaming with joy.

It cries to high heaven that a ready muxed file cannot be created when two separate files CAN be created. It saves valuable person-time at the computer. Two passes takes double person-time, one pass just gives ~double rendering time which you can use for doing other work.

I am suprised by the many twists and turns and misunderstandings introduced in this discussion, just from me suggesting a more simple workflow from components inarguably already present. I hoped for some (massive) support in raising the simple wish towards SonyCS.

"How can that be true, when Vegas CAN create an AC3 file?"

It can only create an AC3 (pro) file when DVDa (pro) is on your machine. You can not create an AC3 file without DVDa. In other words Vegas can create an AC3 file which is SUPPOSED to be solely for DVDa

There are templates there for creating other file with ac3 but these use the studio encoder version which is not a true AC3 encoder. DVDa in fact will reencode ac3 files created in the studio version because they are non compliant.

As for mpg and ac3.... It's a non compliant file and you would most likely need Dolby's permission. As far as I know Sony has Dolby's permission to create compliant discs, but non compliant files or files not geared for disc are a different story.

You have to remember that a (real) AC3 file is not yours, mine, or Sony's. The rights are in Dolby's hands and you can't (shouldn't) do things with it that are not approved directly by Dolby.

"The rights are in Dolby's hands and you can't (shouldn't) do things with it that are not approved directly by Dolby."

I'm sure a large part of the reason for that is because Dolby prides themselves on being purely professional and they don't ever want to face a situation where someone makes something that doesn't work just quite right in professional environment that contains something tagged from Dolby Labs. They know what always works best when making a DVD with AC3 audio, and while some folks may have occasional sorts of success with other methods, they don't want to risk the cases where people have less than success.

Wideseen, i suggest you look at some of the free and easy scripts that combine the two renders into a single user operation. That way you get the best result according to Dolby by doing it the right way, and in a single step so that you don't have double person-time. It's a win-win for you.

Personally i still do it in two steps because, honestly, i might author 4 or 5 DVDs a year these days. It's not worth my effort to worry about it. I do the audio render first because it only takes a few minutes, during which time i get up and stretch and refill my glass. By the time i'm back it's done and i start the video render.