Hello!

I would like to record some tv shows with my ProgDVB. But when I start recording and 1 hour is gone, I do have nearly 3-4 GB of space for just one little film. Is that normal or am I able to set this more "hdd friendly" to a size of about perhaps 500 MB or so?

Thanks in advance!

its normal ...

DVB software records the streams as they are transmitted. So the file size depends on the data rate the provider uses for that channel, resp. the streams you've selected to record.
Good signals are transmitted in DVD like data rate, but some providers may reduce data and quality below that level, more or less, resulting in smaller recordings as well.
Also possible, and noticed that several times, retransmissions using lower data rate and quality. Happened on german ARD stations several times, obviously their retransmissions were either recompressed, compared with original live signals, or recorded from DVB-T instead of DVB-S, which in many cases also reduces for it's transmission path.