DVD-A Studio 2.0 does not recompress, 4.0 does

jdachik wrote on 4/12/2007, 8:31 AM
Hi everyone,
This is a copy of an e-mail I sent to Tech support, but I'd thought I'd see if any of you had any insights:

We have FlipFactory here for transcoding, and it creates two types of MPEG-2 files - Transport stream (TS) and Program stream (PS). DVDAS 2.0 would not accept the TS files without recompression, but would accept PS. I downloaded the Demo version of DVDAS 4.0 with the hopes of using the AC-3 capability of the upgrade, but 4.0 wants to recompress both TS and PS type files.

Is there a reason why DVDAS 2.0 could accept Program Streams, but now 4.0 will not? Is this possibly just a bug in the demo version?

Thanks for you help guys.

Comments

MPM wrote on 4/12/2007, 10:05 PM
I don't know about the studio version, but previous versions of DVDA would not accept mpg2 streams not rendered to the DVDA template in Vegas unless they were muxed without an audio file -- this was/is easily done by muxing in TMPGEnc's MpgTools & not supplying an audio file.

Otherwise some mpg2 video has the initial bit rate flag too high -- reducing the reported bit rate in the 1st header only, using DVDPatcher seems to always work there.

Have no idea if that'll help or not but good luck
jdachik wrote on 4/13/2007, 8:15 AM
Sorry, I should have mentioned that these are all multiplexed (video and audio, with .mpg extension), and that Transport stream and Program stream are just types of MPEG-2 files.

All of the files that I've been testing have been well below DVD spec for max bit rate, usually 4.0 MB/s.

So, again, the multiplexed, 4.0 MB/s Program Stream MPEG-2 files are accpeted (without recompression) by DVDAS 2.0, but need to be recompressed by DVDAS 4.0 (at least the demo version).

I have sent a test file, as they had requested, to Tech support for testing, and I'll let you guys know what I hear.
MPM wrote on 4/13/2007, 10:22 AM
Totally FWIW & in case it's of interest as tech support is checking a sample stream...

Sorry my guesses were so far off, but those were the only bad experiences I've had with DVD compliant files in DVDA; I'm sure Sony tech will track it down.

In DVD-centric circles it's less common to work with muxed files [authoring software just has to demux before render], so possibly something there we haven't heard about is responsible. The only thing I recall reading is problems if the audio length is too far off, though in an *extremely* quick look at your encoder's site I saw something about proprietary audio...

If it turns out to be the result of something like enhanced compliance checking in the newer Studio version, and your files need to be corrected, the end result will be a better, more universally compliant DVD [I do realize that's putting a happy face on having to do more work though -- sorry]. If you do find yourself in that situation, perhaps some of the software tools at videohelp.com might help.

The mpg2 specs aren't that tight, & the actual structure of the files can vary quite a bit, plus many applications are pretty forgiving so errors in the stream aren't that uncommon. Thankfully there are quite a few programs made to deal with & fix it.

Again, good luck.