This card consists of four USB devices, connected via a VIA USB bridge (USB2 mode, each tuner has a USB port dedicated to it), that demodulate DVB-t and produce a transport stream.
The tuners operate underneath the layer at which MPEG-4 and MHEG-5 appear so these two aspects of the question posed are not relevant to the device at all. It is relevant to any software that is used to view programming with, but given the large scope of software out there, 'how long is a piece of string'. DNTV-LIVE (I'm assuming renura will offer this as part of a bundle) does not appear to support MHEG-5 but given the almost total lack of MHEG-5 applets, apart from the freeview guide which is proprietary and licenced, this is of little consequence. DNTV-Live, if supplied with a MPEG-4 AVC decoder (ffdshow for instance) would be able to render MPEG-4 AVC video etc. At the moment, this too is of little consquence as there is no MPEG-4 AVC content transmitted at the moment. MPEG-2 still rules the roost of Australian FTA television.
DAB+ support is not so much 'onboard' as entirely 'off board'. The DAB+ side of things appears to be entirely implemented in the supplied radio application, with the tuners involvment being limited to providing a transport stream to the application. I'm not sure about FM reception, but it wouldn't at all surprise me to discover that FM too is demodulated entirely in software with the tuners outputting raw samples of the spectrum rather than a transport stream. Its also possible that the DSPs do FM demodulation or that there is even an actual FM demodulator section in the tuner with the resulting audio being sampled and provided as PCM to the supplied application.
As for DVB-T2, the DSP code embedded in the driver only appears to support DVB-T. Of course, if sufficient motivation were provided at the appropriate time, it may well be revealed that the DSP for each 'tuner' has sufficient resources to demodulate DVB-T2 and that DSP code capable of such has been provided by realtek.
For multiple program recording, most recording software isolates the user from the underlying receiver configuration. It is no more difficult to set a program, such as 'TV Scheduler Pro' or one of its derivatives, to record from 4 completely separate devices than it is to set it to record from a single device that has multiple receivers in it. renura supplies DNTV-Live and his variant of TV Scheduler, both of which operate in the manner described, ie the user doesn't need to know what lies beneath.
On other issues raised, a single USB2 (USB based DVB-t receivers are essentially exclusively USB2 capable) port is capable of carrying 480 megabits/sec or to put it another way, a single USB2 port can carry 20 x 24Mbit DVB-t transport streams. If that isn't sufficient capacity I'm afraid I don't know what would be. USB3, for what its worth, raises the bar to 5 gigabits
Recording every single DVB-t transmission in a given region would require at most 6 devices and the sum bit rate (144MBit/sec) of this is well within even a modest PC's capabilities (hard disks these days can sustain 700Mbit/sec). Sifting PIDs relevant to each program and outputting to separate files takes very little CPU time too. In fact, as an experiement I had an older spare PC doing just this. It had 4 USB2 tuners and a single PCI tuner card splitting and dumping all programs (ie ABC1, 2, 3, HD, SBS1, 2, HD, 7TWO, 7 SD, 7HD etc) without any problems at all.
Edited by DrP, 20 August 2010 - 06:27 AM.