HD-DVRs

[Ilmater]

So the DVR I use is the Scientific Atlantic 8300. It has a 160GB HD, and can store up to 20 hours of HD programming. So... simple math... 8GBs PER HOUR?!?!

How is that possible? Does HD content really take THAT much bandwidth?

 

[xanis]

I didn't know it took up 8GB and hour, but it honestly doesn't surprise me. Why do you think HD content is being put on larger-capacity sotrage mediums like BluRay and HD-DVD? The high quality and rich details don't magically fit into the same space.

 

[techs]

Originally posted by: Ilmater
So the DVR I use is the Scientific Atlantic 8300. It has a 160GB HD, and can store up to 20 hours of HD programming. So... simple math... 8GBs PER HOUR?!?!

How is that possible? Does HD content really take THAT much bandwidth?

Yes.
And thats WITH compression.

 

[Rage187]

pfft, thats compressed

 

[KLin]

Originally posted by: Ilmater
So the DVR I use is the Scientific Atlantic 8300. It has a 160GB HD, and can store up to 20 hours of HD programming. So... simple math... 8GBs PER HOUR?!?!

How is that possible? Does HD content really take THAT much bandwidth?

Yes.

/thread

 

[lokiju]

My Comcast HD-DVR uses 4x the space as non HD content according to Comcast.

 

[Demon-Xanth]

For 1080i:
1920x1080=2,073,600 pixels 30 times per second (We'll just round it since 2MB=2,097,152)
Lets say we want to capture in 24 bit color.
2M*30*3B=180MB/sec
3600 seconds in an hour=648GB uncompressed.

8GB doesn't seem so bad now, does it?

 

[Ilmater]

Originally posted by: Demon-Xanth
For 1080i:
1920x1080=2,073,600 pixels 30 times per second (We'll just round it since 2MB=2,097,152)
Lets say we want to capture in 24 bit color.
2M*30*3B=180MB/sec
3600 seconds in an hour=648GB uncompressed.

8GB doesn't seem so bad now, does it?

I know it's big uncompressed, I'm still just amazed it's compressed that much. I have an entire season of 24 at home, and that's 8GB compressed for the entire season... 16 hours. I'm just amazed they can't come somewhere between 8GB and 500MB with the compression on those things.

Edit: BTW, your math is wrong. 1080i only draws 1/2 the lines every frame. 324GB uncompressed. Still huge, but 1/2 what you figured up.

 

[Demon-Xanth]

Originally posted by: Ilmater
I know it's big uncompressed, I'm still just amazed it's compressed that much. I have an entire season of 24 at home, and that's 8GB compressed for the entire season... 16 hours. I'm just amazed they can't come somewhere between 8GB and 500MB with the compression on those things.

Edit: BTW, your math is wrong. 1080i only draws 1/2 the lines every frame. 324GB uncompressed. Still huge, but 1/2 what you figured up.

It redraws half every 60th of a second. So it is 30 times per second.

 

[Ilmater]

Originally posted by: Demon-Xanth
It redraws half every 60th of a second. So it is 30 times per second.

You win. I did not know that.