[Gllug] Hardware requirements for video editing?

[Rich Walker]

Chris Bell <chrisbell at overview.demon.co.uk> writes:

> On Thu 10 Apr, Rich Walker wrote:
> > 
> 
> > 
> > hope this helps,
> > 
> > cheers, Rich
> > 
> 
> Many thanks for the info, much appreciated.
> 
> 
> Do standard camcorders aimed at the UK market run at 30 rather than 24/25
> frames per second?

I don't know; that's one of the speeds in the Firewire spec, ISTR. From
/usr/include/libdc1394/dc1394_control.h:

/* Enumeration of camera framerates */
enum 
{
    FRAMERATE_1_875= 32,
    FRAMERATE_3_75,
    FRAMERATE_7_5,
    FRAMERATE_15,
    FRAMERATE_30,
    FRAMERATE_60
};
#define FRAMERATE_MIN               FRAMERATE_1_875
#define FRAMERATE_MAX               FRAMERATE_60
#define NUM_FRAMERATES              (FRAMERATE_MAX - FRAMERATE_MIN + 1)

Now, what exactly the camcorders do I can't tell easily. However, doing
the *calculations* for "bigger than needed" is always a good bet:  the
next enum in that file is

/* Enumeration of camera modes for Format_0 */
enum 
{
    MODE_160x120_YUV444= 64,
    MODE_320x240_YUV422,
    MODE_640x480_YUV411,
    MODE_640x480_YUV422,
    MODE_640x480_RGB,
    MODE_640x480_MONO,
    MODE_640x480_MONO16
};

i.e. the frame size is slightly smaller than I thought.

As a "what are you using" - we've got an expensive Sony camcorder, an
expensive Sony mini-DV video, and 2 cheap (£75) UniBrain Fire-i
cameras. The Fire-i is a <1W device with 2 Firewire ports; it does 15fps
at 640x480x24, and 30fps on the 640x480xyuv4:1:1 format.

hope this helps,

cheers, Rich.


-- 
rich walker | technical person | Shadow Robot Company | rw at shadow.org.uk
front-of-tshirt space to let     251 Liverpool Road   |
                                 London  N1 1LX       | +UK 20 7700 2487

-- 
Gllug mailing list  -  Gllug at linux.co.uk
http://list.ftech.net/mailman/listinfo/gllug