Video Streams Question

[Tolwyn]

Not sure if this is the right forum, I'm taking my "Best Guess" approach...

Can someone explain to me, or point me to a guide that discusses the different types of streams an MPEG file can be?

For example...
I don't know what makes a Elementary Stream different from any other stream. I know that my lame version of Sony's DVD Authoring Studio doesn't like these kinds of streams... and seems to balk at any file I send at it that I've multiplexed with TMPGEnc.

[daamon]

Hi Tolwyn,

An Elementary Stream, as I understand, contains just one thing - either audio or video - and has an extension to identify it as such (e.g. audio.ac3/mp2 or video.m2v).

A System Stream is footage.mpg and, again I believe, can have both audio and video together in the one file, but sometimes just the video only.

I hope that sheds some light on it...

[Tolwyn]

Yeah, a little bit. Thanks.
I'm still back to the cold, dark, sinister truth that my DVD Authoring program of "choice" hates any damn stream that hasn't been encoded using Sony's encoder. And Sony's encoder simply doesn't have the features and flexibility I need.

I wonder why DVD Architect Studio doesn't think my stream is compliant and wants to re-encode even the video.

I took video.m2v and multiplexed it with audio.mp2 to make footage.mpg and Sony wants to re-encode the video.

Arrrgh!

[lordsmurf]

Not authoring... moved to GENERAL forum...

[daamon]

Mmmm..... I'm not familiar with your authoring app, so can only make some basic suggestions:

1. Find out what the specs must be for footage.mpg to be acceptable without re-encoding. See if you can encode video.m2v and audio.mp2 to meet those, whilst being acceptable to you.

2. Try an authoring app that doesn't re-encode by default...

3. Hang in there and see if anyone else can help you on this better than I.

Good luck...

[Tolwyn]

It's just a limitation of my authoring application. But being that we're talking about authoring, the topic is moved. So I have to try to be more clever next time talking about... authoring. Hmmm. ? :P

Something is up though.
If I frameserve out to TMPGEnc and encode with using Layer 2, Sony DVDAS thinks the NTSC stream is a-okay; even though it wants to re-compress the audio to PCM.

If I MULTIPLEX a mv2 and mp2 together using TMPGEnc, Sony does NOT think the NTSC stream is a-okay.

Now that has me perplexed. Am I not using the multiplexing utility correct? Is it changing the stream to a non-comforming (according to Sony, anyways) stream?

[SaSi]

Going back to your original question - I think - will straight things a bit.

MPEG streams can be one of three kinds:

1. Elementary streams
2. Program streams
3. System streams

Elementary streams - as the name suggests - contain any single entity that can be video, audio or "private" streams - like subtitles.

Program streams are a multiplexed incarnation of elementary streams, in which any number of elementary streams (1 or more video and 0 or more audio + private streams) can be combined. It is more than the sum of elementary streams since they also contain an "envelope" with information as to what they contain and how to figure out where to find what.
Program streams are mainly what VOB files are.

System streams are a different version of the above. They are not compatible with DVD or authoring programs. I am not totaly sure of their purpose, but my understanding is that digital video broadcast is in the form of a system stream. Their main difference from program streams is that they contain "a better envelope" with resync capabilities - guess in case of bad reception from the receiver.

Some authoring applications MUST have elementary streams as input, while others MUST have program streams, and finaly, some can take both (like DVDLab).

None will take a system stream as input.

[Tolwyn]

Thank you very much.

I'm still unclear as to why Sony's DVDA-S wants to re-encode the video of 2 multiplexed elementary streams; yet doesn't want to re-encode the video when it was created as a Program Stream.

Using any other authoring application works just fine, of course.

[SaSi]

Thank you very much.

I'm still unclear as to why Sony's DVDA-S wants to re-encode the video of 2 multiplexed elementary streams; yet doesn't want to re-encode the video when it was created as a Program Stream.

Using any other authoring application works just fine, of course.

Well, we have to consider the (even remote) possibility that some tools may be stupid.

[Tolwyn]

Your consideration is...

Most logical. :P

[TBoneit]

It's just a limitation of my authoring application. But being that we're talking about authoring, the topic is moved. So I have to try to be more clever next time talking about... authoring. Hmmm. ? :P

Something is up though.
If I frameserve out to TMPGEnc and encode with using Layer 2, Sony DVDAS thinks the NTSC stream is a-okay; even though it wants to re-compress the audio to PCM.

If I MULTIPLEX a mv2 and mp2 together using TMPGEnc, Sony does NOT think the NTSC stream is a-okay.

Now that has me perplexed. Am I not using the multiplexing utility correct? Is it changing the stream to a non-comforming (according to Sony, anyways) stream?

I think the clue is the above where it wants to encode the audio ro LPCM. TMPGEnc Plus for example creates a mp2 audio and thus when that is muxed into the video the Sony App wants to encode the muxed file because the audio is non DVD compliant per spec. IE LPCM or AC3

Or IOWs I think the root cause is the audio format.
Therefor convert the audio to AC3 (LPCM) or use something that encodes to AC3 audio (Example TMPGenc Xpress with the AC3 plug-in) or switch to something that can handle MP2 audio. Example TMPGenc DVD Author Program.

Hope this helps, Feel free to let us Videohelp users know if this helps for future reference.

Thanks