Capturing DVB in PVA or MPEG 2

[tal-grazzja]

Which is the better way to capture DVB, in PVA format or MPEG2. This would be further processed up to DVD. Can you list some useful tutorials on the above which are found on doom9 or other websit sites.

[unixfs]

almost no program can read PVA, so MPEG2-PS is the preferred way to store your captures.

[tal-grazzja]

Is MPEG2-PS the same MPEG2 that DVDs are encoded with? Can you explain further please.

[unixfs]

DVD is a superset of MPEG2-PS; if you want to store on a DVD the content of a DVB broadcast, in some cases (when the resolution is DVD compatible) you only have to remux it with one of the many programs available (IFOedit is free, others such as TMPG DVD Author cost $50+ ), an operation that takes only few minutes, otherwise you have to re-encode it (slow).

Certain budget players (like mine) can also read non DVD-compatible MPEG2 (such as 480x576, 544x576). You should try to read a short clip
with yours.

[bb]

Originally posted by unixfs
DVD is a superset of MPEG2-PS; if you want to store on a DVD the content of a DVB broadcast, in some cases (when the resolution is DVD compatible) you only have to remux it with one of the many programs available (IFOedit is free, others such as TMPG DVD Author cost $50+ ), an operation that takes only few minutes, otherwise you have to re-encode it (slow).

Certain budget players (like mine) can also read non DVD-compatible MPEG2 (such as 480x576, 544x576). You should try to read a short clip
with yours.

I wouldn't call DVD a "superset" of MPEG2-PS. There are many flavours of MPEG-2 program streams that aren't compatible with the DVD standard, unfortunately quite a few of the remuxed DVB transport streams, too. Even if the resolution is DVD compatible you may encounter problems with GOP lengths > 15, bitrates not being set appropriately in the MPEG headers, and sometimes problems with the timecode, too. Well, despite of all the problems most DVB transport streams remuxed to program streams actually work on most DVD standalones, if you don't forget to correctly patch the bitrate and resolution in the headers.

But there's another thing you should be aware of: PVA has been designed to deal with errors and synch problems during DVB captures, so I'd always prefer to capture to PVA and convert to MPEG-2 PS later, preferably by ProjectX, ds.jar, or PVAstrumento. It is well-known that some of the DVB capture programs available have problems when capturing directly to MPEG-2. Thus I wouldn't dare to recommend capturing to MPEG-2 instead of PVA.

There are very good guides on the German board, so if you can read German, you will appreciate the stickies in:
http://www.gleitz.de/vbb3/forumdisplay.php?f=30

bb

[unixfs]

good to know, thank you!
But I don't understand why patching the resolution is supposed to work
(infact it never worked with my standalone, that reads anything else
you throw in its tray);
after all that process tricks the frame size, right?
Can you explain, please?

[bb]

Yes, it's a trick which works with some players. There are standalones having no problem at all with SVCD 480xYYY resolution, others work with the resolution patch, others don't work at all (then you have to re-encode to standard DVD resolutions).

If the trick works, it's usually sufficient to change the first GOP header only. But I've read that some people patch all headers.

bb