MPEG4 vs MPEG2 hours 622/722

[ncted]

Sorry if this has been asked previously. I did some searches, but did not find the answer I was looking for. I have a 722 which is supposed to hold "up to 55 hours" of HD programming. Is that assuming all HD programming is MPEG4 ?

My HR10-250 could hold up to 30 hours of HD with a 250GB drive. Given the size of the drive in the 722 and the potential space savings for MPEG4, I would expect more than 55 hours.

Thanks,

 

[8bitbytes]

I believe it is based on MPEG2. You do get more space on the 722 drive but remember, Dish saves part of the drive of OS and VOD. You could see up to twice the 55 hours though if you keep to all MPEG4.

The external drive archive option gives you acess to very nearly the entire drive. Some thing to consider...

 

[ncted]

I believe it is based on MPEG2. You do get more space on the 722 drive but remember, Dish saves part of the drive of OS and VOD. You could see up to twice the 55 hours though if you keep to all MPEG4.

The external drive archive option gives you acess to very nearly the entire drive. Some thing to consider...

Thanks for your response. 55 Hours of MPEG2 HD or over 100 Hours of MPEG4 HD should be plenty for me in general, but I am going to be out of town of a couple of weeks, so I wasn't sure if I should add the USB HDD and move all my existing recordings to it prior to leaving.

Ted

 

[ncted]

After some brief anecdotal testing, it would appear an hour of MPEG4 HD is about 65% to 80% of an "HD hour" recording with respect to disk usage. After deleting Wednesday's Grey's Anatomy of which I recorded 64 minutes, I recovered 42 minutes of recording time. CSI:NY was also 64 minutes, and I recovered 50 minutes.

Of course, there are many factors that go into size, like 720p vs. 1080i, compressability of pillarbox side bars on commercials, amount of change between key frames, etc. I am recording some OTA programming to compare, and I will post my results here.

Ted

 

[8bitbytes]

If you have an external hard disk and have transferred content to it, you will see that MPEG4 is actually 40 to 65% the size of MPEG2.

 

[ncted]

Apparently the Available recording time is just a very vague estimate. I recorded Without a Trace last night off OTA. When I deleted the 64 minute show, I got back 87 minutes. Obviously, the estimate is some sort of average of MPEG4 and MPEG2 recording times. Also, the SD estimate is incorrect as well. A 64 minute TopGear recorded on BBC America represented 84 minutes of "Available" time when I deleted it.

Ted

 

[LER]

welcome to the world of variable bit rate and statistical multiplexing.

It'll never be 100% accurate, as the sizes are very content dependent.

LER