MPEG2 "header" information?

[easy2Bcheesy]

I'm currently re-evaluating my MPEG2 encoding set-up for my DVD products and want to reverse-engineer the DVDs produced by my competitors to see if I can learn anything from them and also to follow trends in development at rival studios.

I can usually look at an authored disk's structure and work out which authoring tool created it and have seen a slow migration from Spruce over to DVD Studio Pro, for example.

So I'm wondering if the MPEG2 streams contain any information with regards to the encoder that created it? Are there any apps available that give you clues as to how it was encoded?

At the moment I can only look at how the bitrate fluctuates throughout the stream which usually tells you if a cheapo hardware encoder was used or if they're using something like TMPEG or CCE.

[hank315]

Some encoders write a string in the user data section, this section starts with 00 00 01 B2 and can be found at the beginning of the video data.
TMPEG for instance does it, afaik CCE does not.
Videostreams are in general anonymous, if there's no information in the user data section it is hard to tell by which encoder it was created.

[easy2Bcheesy]

Interesting, thanks for that. Is there a tool that reads the user data section? Or should I just get hold of a hex editor and use that?

[SeeMoreDigital]

Why not have a chat with stegre, the creator of GSpot (http://forum.doom9.org/showthread.php?s=&threadid=82313). He's looking to add all kinds of implementations to his application. Where ever possible...


Cheers

[hank315]

I'm using Gspot version 2.52 beta01 and it gives you the user data in the section User Data/Metadata. If it is empty then there's no user data present.
But you can also use a Hex editor, the user data will in most cases be in the first 256 bytes.

[easy2Bcheesy]

Originally posted by hank315
I'm using Gspot version 2.52 beta01 and it gives you the user data in the section User Data/Metadata. If it is empty then there's no user data present.
But you can also use a Hex editor, the user data will in most cases be in the first 256 bytes.

Yes, Gspot is a very useful tool for all manner of uses so thanks very much to you guys for pointing it out to me. Thus far, only TMPEG streams seem to be identifiable from User Data.

[Arky]

ReStream (http://shh.sysh.de/pic/restream.png) also shows a little of this metadata, although of course this still assumes that the encoder opted to include relevant identification data during the encode.


Arky ;o)