0.4.1&0.4.0 Linux&Windows client MPEG2 PS&TS broken?

Johann Hanne jonny at 1409.org
Tue Jul 9 21:43:11 CEST 2002


> > Well, you could "simply" use the first video and audio stream in the TS 
> > and play it?
> NO, it could be the second or third or fourth or fifth. You get the 
> idea? ;-)
But if the TS includes only one audio and one video stream, you could do 
it?

> > However, I have modified the program to record PID 0 (PAT), PID 100 (PMT), 
> > PID 110 (video and PCR) and PID 120 (audio). The result is still the same. 
> > Of course not all PMT-PIDs given in the PAT are available. Is this a 
> > problem? Should I modify the PAT to only include the reference to PID 100?
> The PAT and PMT should match the SP-TS (Single Program Transport 
> Stream). Otherwise a MPEG decoder does not know which program to decode.
What does that mean? What streams does a SPTS include? Only one video and 
one audio stream? Each with a specific SPTS-PID? Or also PAT and PMT?!

> Vlc can play MPEG-TS files from disk. It also can read them when there 
> is a MP-TS (Multi Program Transport Stream) PAT and PMT's. Then you have 
> to choose the right PMT from the menu View|Program. This might work.
When I try to play the stream, the View|Program option is greyed out, i.e. 
not selectable.

> > Has anybody actually tried out to play MPEG TS from a file? What should 
> > vlc actually do? Shouldn't there be an option for choosing a program 
> > number (i've tried the --program parameter without success)?
> Did you fill in the PMT PID number?
I've tried the program number from the PAT (28006) as well as the 
referenced PMT PID (100).

> Reading a SP-TS from file is no problem as long as it is a *valid* 
> SP-TS. Officially a SP-TS with the original PAT and PMT in it is no 
> SP-TS.
Can you give me some hints what a SPTS actually includes? Until now I 
thought that it consists only of one video and one audio stream with the 
PCR included in the video stream?! I wasn't able to find much information 
on the net about it :-(

> It would be better to modify the PAT to only include the PMT of 
> the program that is recorded. Also correct the CRC32 in there if you are 
> at it.
I have extended the program to do that. It now replaces all incoming PAT 
packets with some predefined PAT (the CRC32 is calculated and then 
re-checked, so it should be ok). This PAT only includes program number 1 
referencing PMT PID 100. Apart from PID 0 (PAT) the recorded file now 
only includes the referenced PMT PID 100 and all PIDs referenced in that 
PMT. So it should now be a *complete* transport stream. However, vlc still 
doesn't even open a video output window. Do you have some further ideas?!

> This all will work provided that the DVB card produces a valid Mpeg-TS 
> stream. With that I limit the DVB cards to Hauppage Win-TV Nova model 
> 542. If you are using a DVB-S or probably even a DVB-C card, then there 
> are more problems.
I *have* a DVB-C. But as far as I have understood the only (?) problem is, 
that the full-featured DVB-cards (not-Nova) cannot pass the complete TS 
through, but only up to 8 (?) single PIDs. So if I modify the PAT to only 
reference one program, the TS should be "complete" again?

> I suggest to continue this discussion which is highly development 
> oriented on vlc-devel at videolan.org, instead of the user mailing list for 
> vlc.
Ok. I've also sent this message to vlc-devel and deleted vlc from the 
recipient list.

Cheers, Jonny <jonny at 1409.org>


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