|
|
Posted by PTravel on 10/15/87 11:37
"Frank" <frank@nojunkmail.humanvalues.net> wrote in message
news:07kls1lnjv8isg7qa4r55dkre81gaab007@4ax.com...
> 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).
I didn't know that, thanks.
> 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.
Interesting that 720p HDV actually has a lower bit rate than DV-25.
>
> 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.
>
> >> 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/
Navigation:
[Reply to this message]
|