Why MPEG for High Def?

MohammeD T wrote on 10/16/2006, 10:29 PM

Am wondering, Why would High Defenition continue to use MPEG TS for compression, i read its smarter than MPEG2 and it cheets our eyes some how but why not take advantage of the new Media ment for HD such as blu-ray that could hold up to 25GB/50GB for DL ... why didnt they just leave it with the full quality of Video without compression, it would still fit a Blu-ray Disk!

i understand 13 GB for one hour DV required MPEG2 to fit on a 4.7 GB DVD.

why Compress HD when youv got 25 GB?

Comments

riredale wrote on 10/16/2006, 10:42 PM
Look at it this way:

1 hour of DV (compressed about 5:1 over "raw" video) = 13GB.

1 hour of HDV (pretty decent HD, though not pure HD, compressed about 25:1) =12GB

So a two-hour movie would need about 24GB if the HDV codec was used. More exotic codecs can reduce the space requirement by about a factor of 2.

You can run the numbers yourself...

30 frames per second
1080x1920 pixels per frame
each pixel needs 3 bytes of data (one for R, G, B each)

Conclusion: "raw" video, especially HD video, needs enormous amount of space UNLESS it is significantly compressed.
MohammeD T wrote on 10/16/2006, 10:57 PM
>>1 hour of HDV (pretty decent HD, though not pure HD, compressed about 25:1) =12GB

why wouldnt they put those 12 GB on Blu-ray Media and take advantage of the Storage capacity? why compress again,, i thought Blu-ray technology is a life saver for Video and would stop the heavy compression DV was getting.

Blu-ray Media is 5 times greater than x Media solutions, what did Video Quality in general benefit from this?
TLF wrote on 10/16/2006, 11:44 PM
I would guess that it's a means of getting consumers to switch to HD NOW rather than LATER.

Lets see... MIniDV tapes are available now for just a couple of $$, and they can hold an hour of HD (in MPEG TS). Likewise, hard drive recorders are available that can store hours of footage at relatively little cost.

But Blu-Ray... hmm. Where on earth can you buy a Blu-Ray disk, let alone a Blu-Ray recorder/player (at a price that consumers will accept)?

Blu-Ray isn't even an excepted standard yet.

I suspect that over the years, the way in which HD is captured will change as other technology changes and becomes affordable.

Worley
farss wrote on 10/17/2006, 12:18 AM
Well if you're talking about uncompressed HD, a BD disk will probably hold about 1 minutes worth. And it'd need to spin at oh, around 100,000 RPM to deliver the data fast enough.

The mpeg-2 compression used on SD DVDs can deliver a higher quality image than DV25, and the problem is not just data capacity but also data rates. A 4.7GB DVD can store a few minutes of uncompressed SD, it cannot deliver the data fast enough. Same goes for the next gen disks as well.
malowz wrote on 10/17/2006, 12:25 AM
i just wish a hdv version with 50mbps at 4:2:2

1920x1080 also....