04 July, 2007

Video wars part MXXLIV

A town in miniature

High Noon Thursday 21 June 2007



Main Street, New Effington SD

First thought – why is he trying not to swear? 2nd thought, what the heck was Old Effington like? I don’t think I want to even know where it is/was.

I’m not sure how that works

This is what brings me to this isolated area, the latest battle in the distribution wars between cable, satellite and Telcos, well not the SimulSat dish but some equipment that takes its feeds from the LNB’s in the focal arc.

Unless you are only watching analog over the air television (you do know about 19 February 2009 don’t you?) most television distribution from content providers to your TV set involves digital compression technologies for both the audio and video portions reducing the bandwidth required to transmit. Current deployed systems use what is referred to as MPEG-2.

MPEG 2 is now a bit over 15 years old now, in terms of space saving an uncompressed standard definition video signal has a bandwidth requirement of 270Mbps (video & audio) after compression the same signal now requires only 2~6Mbps (for most content) similar ratios of compression are also on the High Definition side, as uncompressed HD is 1.39Gbps and compresses down to 12~19Mbps, impressive when you consider you are in essence taking only 1 bit out of a hundred or so and still have (hopefully) pristine pictures and sound.

This is the same technology used in your DVD player or if you get your service from DirecTv or Dish, same with Digital Cable, in the RF space of one analog channel you can fit 12 to14 standard definition compressed services. Until recently all distribution was over some sort of RF network, these days there is also another method of distribution Video over IP (that’s Internet Protocol not Intellectual Property although lately I’m often involved in conversations where both terms are used) or IPTV.

IP networks are funny things, to an old broadcast engineer there are lies, dammed lies and IP network specifications – take your typical Ethernet connection, the first was 10BaseT and has a raw data spec of 10 Mbps, of course you can’t actually get anywhere near that in throughput. Coupled with the various limitations of copper wiring for “long distance” (thousands of feet) such as DSL, ADSL, ADSL2+ means that the Telco attempting to do IPTV has serious challenges in attempting to deliver MPEG 2 SD let alone HD and internet and VoIP.

Enter MPEG4, specifically part 10 h.264 AVC, now in its initial deployments. Currently it halves the bandwidth requirements of MPEG2 (and costs at least twice as much) and promises even more bandwidth savings. However it is still in the early stages of deployment which means interoperability between the various different bits in the system (from different vendors) is still a work in progress.

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