Tektronix & automated MPEG test, H264 and VC-1

I went to a Tektronix training seminar this morning and really got a lot out of it. The first session was led by a chap called Dr Mark Nicholls who amongst other things set me straight in my perception of the current cream of MPEG4-like codecs;

• MPEG4 implementations (DivX, XVID, WM9 etc.) score over previous DCT-schemas (MPEG2 principally) in that they allow forward and reverse reference to distinct macro-blocks rather than discrete frames. That is where the increased compressibility comes from and explains some of the weird effects you see in corrupt DivX files!
• More recent implementations (H.264 & VC-1) allow for variable size macroblocks as well - in effect the compression can track the detail better and really allocated data-space where things need it.
• No broadcasters currently implement PCR timing recovery in the transport stream - I wonder if this explains why the MS-DVR format files my homebrewed PVR produces are always 12-frames wrong sync-wise (i.e. there is no way of precisely timing each GOP)? You get this effect if you try and play the files outside the MediaPortal app or if you import them into VirtualDub.

The rest of the session was devoted to Cerify - a very clever system for automated QC of LAN/SAN-based media - Rupert had a look at the API and is convinced it would be a cinch to make Artbox drive it. It really was a very impressive demo and I imagine it will be the kind of thing that lots of broadcasters would buy into in coming years. A kind of n x virtual-WVR7100s continually hoovering up new media and analyzing it for all video/audio and transmission parameters (including perceived parameter - measurement of compression PSNR for example).
Anyhow - it's probably copyright, but all the training notes are here.