Size of file when you capture video

[pbuscher]

Ok. I'm a bit confused. I know you can capture video a different quality but the megabits and megabytes are kind of confusing me. What is an "ok" capture rate per second and what is a very good DVD quality capture rate per second? Do they record by bits or bytes?

Basically, what size of a hard drive would I need to capture video in either "ok" quality and perfect DVD quality for one hour?

Thanks

[gll99]

Data rates are expressed in kilobits per second.

A DVD may be up to 7000 to 9000 kilobits per second or so excluding audio.

7000 kilobits x 60 (seconds in a minute) x 60 (min in an hour) = 25,200,000 kilobits / (divided by ) 8 for bytes = 3,150,000,000 bytes

Therefore every hour would require approx 3.150 gigagytes of video.

There is some overhead but that basically it.

Also remember in the calculation that kilo bits is 1000 bits.

A file encoded (video only) at 1000 kbs (kilobits per second
(1,000,000 bits x 60 x 60) /8 generates a file of approx 450 mb + audio for each hour.

[gll99]

1 more point:

Technically that's how many bits of data go through the encoder/decoder but the file size is usually pretty close on average.

If you use this to calculate filesize then err on the side of caution since other factors can affect file size.