Why HD movie downloads are a big lie

[admin]

http://blogs.zdnet.com/Ou/?p=511

[Chewy]

very interesting blog, I wish I really understood it better

I have seen(3 years ago) divx/xvid duplicate the quality of a 3 hour mpeg2 by shrinking the file size to a 1/3 the size

Now H264 improves upon that, slightly, but the examples seem to be larger for the run time(1.4gig for 1 1/2 hours)

1400MB/5400sec is only 259KB/s ????????????

Is bluray/HD that much better?

[drfsupercenter]

I guess it all depends on the source. Animated stuff compresses easier (if you use XviD cartoon mode), and can look as good as, if not better than, the source DVD. I have tried this with some Pokémon episodes, 195MB for a typical 23min episode turns out great looking.

Unfortunately, live action has to be bigger to get that same quality, so if these companies are locked in on file size, I guess it isn't gonna be that good quality!

[admin]

High def DVD bitrates tend to vary a lot, for example The Brothers Grimm Blu-ray with AVC encoding only uses 16 Mbps, while Identity Blu-ray also with AVC encoding uses 28.5 Mbps. Click with MPEG-2 uses nearly 36 Mbps, Fantastic Four also with MPEG-2 uses only 16 Mbps. More bitrates listed here.

In comparison, DVD only uses around 4 to 7 Mbps, but that's to be expected since 1080p holds 5 times as much information as 480/576. So you really do need about 20 to 30 GB to store the movie, just to keep it the same "bitrate per pixel" as DVD. Downloading a Blu-ray/HD DVD is just not worth the time/effort/cost at the moment.

I think 1.3 Mbps for a 720p is far too little - 1.3 Mbps will get you a very good quality AVC encode at DVD resolution, but that's not nearly enough for a 720p clip (more than twice as much information compared to DVD resolution) - 720p needs 4 Mbps or above. Even then, you get downloads comparable to the size of a DVD - acceptable for some people, but only once or twice per month.

I think the studios should concentrate on delivering DVD resolution content first (using the more advanced codecs), before thinking about HD. People will accept 1 to 1.5 GB downloads, but not much bigger than that at the moment due to net speed and quotas (especially people, like me, in less developed countries in terms of ADSL).

[Chewy]

especially people, like me, in less developed countries

sad state of affairs in Oz

[anonymez]

1.3mbps is a joke. But then so is the idea of a suitable bitrate, since it's not really practical for most people.

1400MB/5400sec is only 259KB/s ?

In kilobits, 2.17mbps. At least 4mpbs is needed, and we're talking 2-pass x264. Higher for Quicktime.