HD Downloads From iTunes

It’s Sunday afternoon here in jolly (but exhausted) old England. I just caught a post by George Ou at ZDNET called “Don’t believe the low bit-rate ‘HD’ lie.” It’s right on the money about the reality of downloading HD content as proposed by Apples new iTunes service.

There’s more to HD than spatial resolution. Just as a cheap digital camera might take pictures with a lot of pixels and nonetheless turn out lousy images. Bit rate matters, even given consideration for various compression schemes.


As I’ve said before the very best images you’ll ever see at home are going to be those delivered by HD-DVD or Blu Ray disk, which may hit 28-40 Mbps. Downloadable shows in 720p delivered at < 10 Mbps are simply not going too be anywhere near as good. Apple, like many others, think that no-one will notice or care.

Earlier this week I was asked to record an NBA game and bring it with me to the UK. They need to see an example of an American style broadcast for various reasons. I recorded Thursday evenings game to a Toshiba DVD recorder in SD and to TivoHD to have a widescreen & HD version. When I tried to record the 480i component analog output of the TivoHD to the DVD recorder it stopped due to DRM restrictions.

I was able to use the Tivo Desktop software to copy the game over to my PC and run it in Windows Media Player. The file from the 2 hours game was just shy of 20 GB. Now that’s MPEG2, which is less efficient than H.264. However, even the newer codecs would result in a file > 10GB. Since iTunes is not likely to deliver that sort of file size don’t expect the iTunes HD downloadables to be anywhere near as good image quality as Tivo.

Around our house we’ve taken to using the Amazon Unbox service which dovetails into our Tivo systems. The image quality is nowhere near what a typical DVD delivers, but the movie selection is good and the service is reliable. I hope that Amazon undertakes to remain competitive with iTunes in offering some HD content, hopefully at higher bit rates.

Perhaps there is an as yet unspoken upside to all of this. It will push the “Last Mile” technology deployed by ISPs and perhaps that will justify some investment in new network build out. Or perhaps, like Time Warner in Beaumont TX, they just start billing us by the byte?