Re: Problems of capturing from 4 cameras
- From: Thore Karlsen [MVP DX] <sid@xxxxxxxx>
- Date: Tue, 12 Apr 2005 08:06:48 -0500
On Tue, 12 Apr 2005 02:29:02 -0700, "David Paps" <David
Paps@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>Hi,
>
>I'm using a videocapturing card which supports 4 cameras using 640x480. When
>I visualize the image of the 4 cameras at the same time, with the format
>RGB24 or YUY2, this image looks bad with the movement, apearing horitzontal
>lines, as if the buffer doesn't be well refreshed. The problem disapears
>using RGB555, or reducing the resolution, but I need 640x480. Does somebody
>have the same problem? Can you tell me if it's a problem of the directx or of
>the card I'm using?
It's probably a PCI bandwidth issue. I'm guessing that the capture chips
are BT878s or equivalent. These have a fairly short FIFO buffer, so if
it can't push the contents of that buffer out to the PCI bus quickly
enough, you'll see these lines all over the captured image. In my
experience there's not much that can be done about it except using a
machine with a better PCI bus, or reducing the bandwidth requirements by
e.g. lowering the framerate. Or using a card with a different capture
chip that doesn't have the same problem.
--
New to newsgroups? Read: http://dev.6581.com/newsgroups.html
.
- Follow-Ups:
- Re: Problems of capturing from 4 cameras
- From: David Paps
- Re: Problems of capturing from 4 cameras
- References:
- Problems of capturing from 4 cameras
- From: David Paps
- Problems of capturing from 4 cameras
- Prev by Date: Getting width from DVCam connected to VMR9
- Next by Date: Corrupted DV25 frame
- Previous by thread: Problems of capturing from 4 cameras
- Next by thread: Re: Problems of capturing from 4 cameras
- Index(es):
Relevant Pages
|
