Posted by Frank on 01/15/06 23:07

On Sun, 15 Jan 2006 20:58:29 GMT, in 'rec.video.production',
in article <Re: How much space does an hour of HD take up?>,
"PTravel" <ptravel@travelersvideo.com> wrote:

>
>"David McCall" <david.mccall@comcast.net> wrote in message
>news:DIxyf.6402$C%3.4086@trndny03...
>>
>> "Happ Sapp7" <nononono2@spam.com> wrote in message
>> news:r_wyf.2232$xk1.50603@news20.bellglobal.com...
>> >I know that an hour of SD DV takes up approx. 13 GB on my hard drive, or
>> >one miniDV tape at SP speed.
>> >
>> > Thinking of HD vameras, and wanted to know how much space an hour of
>video
>> > in HD format takes up....from what i gathered, it still uses miniDV
>tapes.

Yes, the same tapes or better yet, special higher-grade,
lower-dropout-rate tapes such as JVC's M-DV63HD tape and Sony's
DVM-63HD or PHDVM-63DM tapes.

>> There are many HD formats and compression schemes, so the size
>> could vary widely. I think you are asking specifically about HDV, which
>> is a High Definition variant of DV. I believe that the tape, and data-rate
>> are the same as DV. That being true, then the disk space requirement
>> would be the same as for DV.
>
>HDV uses mpeg2 and, I'm almost certain, uses a variable bit rate. As such,
>I don't think it's possible to tie specific file sizes to specific times.

HDV video is always MPEG-2 CBR (constant bit rate). HDV comes,
however, in two flavors, 720p and 1080i. The 720p flavor of HDV is
written at an approximate 19.7 Mbps data rate. The 1080i flavor of HDV
is written at an approximate 25 Mbps data rate, the same as DV
(including Sony's DVCAM and Panasonic's DVCPRO variants of DV).
Therefore, when stored on a hard disk drive in its native .m2t (MPEG-2
Transport Stream) format, the 1080i flavor of HDV has approximately
the same storage requirements as DV content with the same running
time.

In contrast, Panasonic's DVCPRO HD flavor of HD, which is usually
stored in the form of an .mxf file, has a data rate of approximately
100 Mbps, so its storage requirements would be approximately four
times that of DV, DVCAM, DVCPRO, or 1080i HDV content with the same
running time. The storage requirements for Sony's HDCAM and HDCAM SR
formats, owing to their much higher data rates, would be even greater.
The data transfer rate of an HD-SDI link, by the way, is in excess of
1 Gbps, just to put this in perspective.

>> If you are going to edit it, then the question becomes more complicated.
>> HDV adds complexity to editing, from a programming standpoint.
>> Many people prefer to convert the HDV file to a less compressed format
>> for editing, and this makes for much bigger files.
>
>Is that true? I'm not working in HDV yet so I haven't tried it, but Adobe
>Premiere Pro, for example, has the ability to import HDV directly.
>
>
>>
>> David

--
Frank, Independent Consultant, New York, NY
[Please remove 'nojunkmail.' from address to reply via e-mail.]
Read Frank's thoughts on HDV at http://www.humanvalues.net/hdv/

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