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Posted by Frank on 10/18/92 11:37
On Sun, 15 Jan 2006 23:39:47 GMT, in 'rec.video.production',
in article <Re: How much space does an hour of HD take up?>,
"PTravel" <ptravel@travelersvideo.com> wrote:
>> HDV video is always MPEG-2 CBR (constant bit rate).
>
>I didn't know that, thanks.
That's because you didn't read my Web page. :)
>> 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).
>Interesting that 720p HDV actually has a lower bit rate than DV-25.
Less data (after lossy compression, that is) = lower data rate.
>> 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.
>
>Do you think HDCAM will be supported in any prosumer machines? I was under
>the impression that Sony was drawing a clear dividing line between HDV,
>which will be an amateur/prosumer format, and HDCAM which, much like DVCAM,
>will be for higher end pro units.
I do indeed believe that a dividing line has been drawn (Sony needs to
protect the HDCAM and HDCAM SR product lines while simultaneously
offering XDCAM gear and promoting HDV), but I also wouldn't be too
surprised if Sony didn't come out with both HDV camcorders and HDV
VCRs with more professionally-oriented features. Look what they did
with DV in terms of DVCAM. The DSR-2000, for example, sells for about
U.S. $12,000, which doesn't exactly make it an amateur/prosumer
product.
What I wonder about is whether Ikegami plans to get into the high-end
HDV market.
--
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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