Question about Transport Streams

[Cyberia]

I really haven't done much with transport streams, but I want to learn. What streams are supported by DGMPGDec?

What are the native resolutions of those streams? Do transport streams also come with (4/3) and (16/9) PARs? The audio appears to be demuxed differently.

Should I know anything else about them? Basically, they are just higher resolution DVDs and everything else works the same?

[Guest]

DGMPGDec currently supports DVB transport streams having 188 byte packets and adhering to ISO 13818-1 (available in the Library at my site).

The streams may be 4:3 or 16:9 as per MPEG2 video spec. Currently, only MPEG audio and AC3 audio are demuxed because ATSC (US digital TV standard -- also used in other places) transport uses only AC3. Demuxing of other audio types may be added in the future.

The whole point of a transport stream is to multiplex multiple programs. For example, your dish receives a transport stream from a satellite transponder. You can select from several programs and even from alternate audio (different languages). To allow for this, the streams are broken into 188-byte packets and the packet header carries a packet ID (PID). To choose a particular program, you set the PIDs for the streams you want. Then the transport parser delivers only those streams to the decoder.

EDIT: Corrected statement about audio as pointed out by len0x below.

[len0x]

Originally posted by neuron2
Currently, only AC3 audio is demuxed

That's not true. MPA audio can be demuxed with current version of DGIndex without any problems.

[Guest]

@len0x

Oops, yes, of course, that is correct.

[nnigam]

I seem to be working mostly with TS streams. My work hours (working on a case in trial) makes me miss a lot of my favorite tv shows, so I started capturing them. At 9gb an hour, my hd started getting filled very fast, so I started converting them to avi. (gb comes out to about 650mb as an AVI at 768x432. I am finding that 1080i @29.97fps are the easiest to process and 720p at 59.94 give the most problems due to audio synch errors. Many 720p streams have both a 16x9 and 4x3 video streams in them, you have to select the correct PID. 1080i generally have only 1 pid.

I finally broke down and bought a 160gig drive to store ts files that I could not convert, but it is getting filled fast.

[hakko504]

DVB transport streams (sometimes) uses DTS for multichannel audio nowadays.