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Sky HD clips reviewed

Sky's HD clips are there for all to see – provided you have a decent spec PC and a quality screen. But if you can't access them - here's a quick review.

I paired up the Philips HD friendly Media Center PC the MCP9350I/05 with the Philips 37PF9830 screen downloaded the four 50MB files and hit play in Windows Media. All four clips are certainly good quality, but I suspect they aren't high definition in way that we’ll get to see it properly via satellite, cable and of course through Blu-ray and HD DVD. The clips are encoded using Windows Media 10 while Sky’s satellite footage will be in the better quality MPEG4 derivative H.264.

Of the four the best is the Rugby in the rain. The detail on the faces of the players is excellent, the colours are really rich and you can actually see the droplets as they fall. The other Rugby clip – the Haka is slightly lees impressive.

The two National Geographic channel clips both look fine, but you are more blown away by the quality of the colours rather than the richness of the detail. Two other things to note are firstly that the clips are in the 4:3 format – very strange as ideally Sky will want people to view these clips on wide and flat TVs. Secondly they are in the 1440 x 1080 resolution as opposed to 1920 x 1080 which will be standard for some of Sky’s HD footage.

Can we have some football now please?

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Posted by Shiny Media on February 20, 2006

Comments

The Sky HD clips can be adjusted to fit into widescreen by passing them through windows media encoder and converting to 1920 x 1080 resolution. Then they look fine on a TV.

Regards

Mark

Posted by: Mark Heath | February 20, 2006 6:11 PM

The Sky HD clips aren't 4:3 - the video within them is 16:9 - but encoded anamorphically (just as 4:3 and 16:9 DVDs both use the same non-square pixel/sample 720x576 system).

However they have been encoded at 1440x1080 with non-square pixels/samples, rather than the more common square-pixel 1920x1080, probably to save bandwith and allow quicker download. They are also encoded in WMV rather than MPEG4 H264 AVC, which is what Sky will be using for their HD broadcasts. They seem to be encoded at around 11Mbs.

Also none of them are encoded in 50i or 50p - they are all running at the lower 25p or similar - so don't show fluid motion. (One Rugby clip is all slow mo, the other doesn't really show much action - so this isn't a problem for the demos) I suspect that most PCs would have choked decoding double the frame/field rate...

1440x1080 is used in Aus for 16:9 HD - to save bandwith over 1920x1080. The same format is also used for HDV Camcorders, and the early HDCam broadcast HD VTRs, again to save bandwith. (HDCam SR and HD-D5 uses the full 1920x1080 format)

However - the clips are surely just a "this is what HD is like" rather than "this is exactly what Sky HD will look like" marketing thing. After all - many expect Sky to be 1280x720/50p for sport - not 1920x1080/50i (and they certainly won't be 25p I'd hope!)

Posted by: Steve | February 23, 2006 11:27 AM

By the way - the clips play fine streamed from a Windows Media Center PC to an XBox 360 - though you do have to alter the ZOOM setting to stretch the 1440x1080 to fill the 16:9 display (otherwise it displays as tall/thin video in a 4:3 pillarbox).

I get the feeling Windows Media doesn't always cope with non-square pixels that well. (Many codecs signal the pixel aspect ratio in addition to the resolution)

Posted by: steve | February 23, 2006 11:29 AM

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