The AV7710 and AV7111 ARM-based MPEG-2 Decoders were designed by Texas Instruments. They have been discontinued. They have some serious design limitations. The most important is probably that you are not able to get the unmodified, original data stream from cards using this decoder without hardware modifications. There have been many reports from users of these cards on the linux-dvb Mailinglist as this piece of hardware is a quite sensitive beast and hangs often. Some cards with these chips have thermal problems. On the other hand these cards have the advantage that a relatively slow computer beginning at 400MHz (less noise) is able to record and play MPEG streams.
Used in TechnoTrend-designed cards, namely the Hauppauge WinTV-NEXUS-S and the TechnoTrend / Fujitsu Siemens Rev 1.3/1.5/1.6/2.1/2.2 DVB-S/C/T. Unfortunately VDR, one of the most sophisticated Linux-STB software projects, has been designed around the way these cards work. The VDR Software Decoder Plugin has been available for VDR for quite a while, but unfortunately it is not yet installed by default.
According to the used Firmware, a possible limitation could be a drop of the 4 bytes MPEG-2 header from Transport Stream.
Please add more technical Details if known...