Hi,

I've been using MPEG2 for my recordings for numerous reasons. Yet some of my channels (even updated/rescanned) provide nonstandard MPEG2 frames compared to standard IbbPbbPbbPbbI (uncapitalized for counting) structure.

The nonstandardization can be anything within the same stream like: IPPPPIIPbbPbbII... (I can even provide short clips which can demonstrate this). This causes the size of MPEG2 go twice or more depending how much the B-frames are replaced with P-frames even worse with I-frames...

The similar channels; where everything else is same (e.g:720x756,4/3,192kbps,1ch ....) except this behavior, provide reasonable recording sizes with the standard frame structure.

So I'd like to ask what can be cause of this? I don't suspect the following; LNB, Dish, cable, SS2 or other hardware since this phenomenon affects only 3-4 channels among 200+ AFAIK. What's left is; TechniSat v4.4 Drivers, ProgDVB v4 latest, Transponders and the Broadcast itself...

Can anyone please explain or even better guide me on this?

Thank you...

I guess the channels/service providers
set their own standard of mpeg2 which type and bitrate
vary from channel to channel they pay for a certain amount
of bandwith so to say...

Lets say that 5min would take 100mb on the "orginal software that the card has been shipped with"

How big would the file be with progdvb then cant really beleive it can get so much bigger.

I use an compro videomate s-350 card my self with progdvb and cant get it
to become so much bigger lets say the tolerance on file size is approx 2-3%

Channel i recorded: Ocko tv on astra 19,2e

Compro: 43,0 MB (45 088 768 bytes) 1m59s
ProgDVB: 43,8 MB (46 002 176 bytes) 2m00s

Files can be downloaded here if you like:

http://www.hagis2k.se/progdvb/rec

And i am using progdvb: 5.0.9.2
Driver is: VMHybrid_1.3.4.5b

//Hagis

All DVB software products simply write the originally transmitted into a file container. Size may just depen d on number of streams included, possible padding stream included or not.
And you can't precisely compare recordings from different times even on the same station, as video streams are coded with VBR, different stations on one transponder have different priority and, of course, channel / stream data rate requirements also depend on the content. But all of those together have to suit the transponder data rate (allowed), last bit of headroom existing in the VBR buffer fullness then.

The frame structure is defined by the provider.
It does not have to be exactly DVD standards compatible, as DVB allows a bunch of varieties more than the decades old DVD system. Limits on GOP structure and length depend on system defined minimum hardware requirements, like on buffer RAM size.