GlasgowDavy said:
where does the 1795 number come from
Simple answer : From the MHEG stream.
Detailed answer : When a channel is broadcast is can have audio, video, and data. Many channels just have A/V - the radio channels just have A/D where the data is usually a logo and a little info text.
For Red Hot, and other "MHEG protected channels" - they have all three - however you can't simply turn off the teletext data to see the channel underneath and you have to enter a PIN code to get the box to redirect it to "see" the A/V.
The MHEG data contains both the logo & text you see when first turning on a channel, and also a Set of Codes and what to do with them. The instructions in the stream tell your box to use the codes to generate a random pair of Viewer ID and PIN, and to display the Viewer ID - it will also check the PIN you enter against its generated PIN and if they match process the REVEAL command (i.e. so you see the picture and audio).
As everything is broadcast unencrypted, it is possible (with the correct equipment/software) for anyone to read the MHEG data on a computer. If you can read the MHEG, you can then see the Set of Codes included in it - these are what your box uses to create the viewer ID & PIN. So it is possible to easy replicate what your box does and create a Viewer ID from any PIN (or vice versa - which is really more use if you want to watch on a TV)
So
Q- where does the 1795 number come from
A- its one of the Set of Codes broadcast on that day
Q-are all these ref numbers the same for the whole month?
A-No, only until they change the broadcast signal. In the terms of RH they change the signal each day. In the terms of SS, they change every half hour.
Q-So I have to do it each time?
A-Yes. Though technically only each time you want to go from the MHEG screen to the picture underneath(**), as once your box is watching the correct Picture/Audio a change in the MHEG shouldn't matter. (*)
(*) If you put the correct pin in when Setanta starts broadcasting you don't need to enter the pin again even though the MHEG codes change twice after that (**) before the match (unless you lose the data - e.g. turning box off or in the case of some boxes into standby, or changing channel)
(**)In the case of Red Hot because the channel goes off-air if you've left it on the channel it loads new data when it starts broadcasting again. It is possible (well reported by someone else) to watch each night without entering codes again IF you unplug the aerial before it finishes broadcasting and plug it back in after the next broadcast has started (assuming you've not turned your box off nor changed channel) this is because its a signal loss problem but your box is still tuned to the correct Video/Audio PID from the night before. I've no idea if this works on every box as some may lose the data after time.
Q-Whats the correct equipment?
A-Something to receive the broadcast signal Transport Stream (usually a Digital Terrestrial TV card/USB-stick), and software that knows what to do with the MHEG portion of the Program Stream (one channel from the TS).
Q-So if I want to watch these channels I need a DTT card to then get the codes?
A-No, only if you want to get the codes yourself to then use to watch the channel on an idTV or TV+box. If you want to watch on your PC you don't need the codes, just to be able to manually tell it where to loook to "see" the picture (i.e. enter in PIDs). If you got the codes off someone else or from somewhere else (e.g. a forum of some kind where nice people were) then you can use them to view your TV without needing any extra equipment.
Q- I Don't remember all these questions
A- No I made most of them up - just to clarify it for all.