Hi / MPEG2-PS/TS question

[georgekellerman]

Hi, members of the doom9 board!

I'm a newbie with a lot of questions, and I hope I won't be too impolite if I debut with one... and many others to follow. I come from a non-technical field, so it's likely that I won't be able to answer deep questions myself. But I will be a help for other newbies, should I know the answer. Promised. :)



I simply can't figure it out from other discussions at the board. Are MPEG2-PS and MPEG2-TS containers, just like .mp4 or avi? I ask this because of the following: AFAIK there are no PS and TS container(?) specs for AVC. The .mp4-container is considered as the AVC-container. And this leads to both, my first question above and to another one: As I understand it, AVC is open (LINK (http://www.chiariglione.org/mpeg/faq/mp4-sys/sys-faq-esm.htm#ESM-4) - "4. What is the delivery layer?") in terms of the way it is playing. Only the interface for "grabbing" the more or less raw AVC video data is specified. When it comes to HDTV broadcasting, AVC video is in an MPEG2-TS container(?). Is this all correct? If so, is an MPEG2-TS container really used, because there's indeed no ACV-container besides .mp4? And is .mp4 not a good container for broadcasting (or unable to serve as a broadcast container)?

Thank you so much!! :)

[Guest]

Are MPEG2-PS and MPEG2-TS containers, just like .mp4 or avi? "Just like" is rather vague. The answer is likely "no".

AFAIK there [is] no TS container(?) spec for AVC. Sure there is:

http://neuron2.net/library/avc/T-REC-H[1].222.0-200403-I!Amd3!PDF-E.pdf

When it comes to HDTV broadcasting, AVC video is in an MPEG2-TS container(?). Yes.

[georgekellerman]

Thanks for the link, neuron2! Wow, I didn't know that. So ITU is fully, officially considering MPEG2-TS as the broadcast-"container".

And how do PS/TS differ from real containers? And, just to see clearer, why isn't the .mp4-container being used for broadcasting? Is that possible at all technically?

[Guest]

Containers like MP4 and AVI have one-time data structures that appear once in the file. But for broadcast you need to be able to join the stream at any time. So the differences derive from the difference between file storage and streaming.

[georgekellerman]

So in other words: If that's the difference, MPEG2-PS is a usual container and TS is not, because TS holds streams with different time stamps. So practically TS is a container as well, but instead of being a standard one, it's like a "Superman" of a container. Does this sound correct?

[Guest]

So in other words: If that's the difference, MPEG2-PS is a usual container and TS is not, because TS holds streams with different time stamps. So practically TS is a container as well, but instead of being a standard one, it's like a "Superman" of a container. Does this sound correct?Don't get hung up on the word "container"; it has no precise definition. Just understand that different environments, e.g., broadcasting versus file storage, have different packaging needs.

[georgekellerman]

Yeah, I see. That's right, without a question. Before closing the issue from my part, I just would like to know the following other things:


Is "Full TS" an "official" term? And official or not, what does it mean exactly? Is it:
- more than 1 x video + audio + evetually epg or whatever data in one TS?
- simply that some data (epg or whatever) is present in the TS in addition to video + audio?
- ALL PIDs of the frequency received in a TS?


And: I assume that it's impossible to mux raw streams (MPEG2-ES streams in case of MPEG2) to MPEG2-TS/MPEG2-PS. The muxer always makes MPEG2-PES streams before muxing to MPEG2-TS/MPEG2-PS. How is it when muxing MPEG2-ES video and audio to .mp4? After the .mp4-muxer did it's work, are then MPEG2-ES or MPEG2-PES streams muxed in that file? Is there a tool that shows ES/PES info for muxed(!) MPEG2/AVC (ts and mp4)?

[Guest]

Your questions are answered in the specs. You should read them if you are interested in the details.

[georgekellerman]

Yes. I will try to find those and check everything out. Many thanks again neuron2 for all your answers above! :)