Differences between version 16 and predecessor to the previous major change of OV519WebCam.
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| Newer page: | version 16 | Last edited on Wednesday, September 21, 2005 1:00:17 pm | by IanMcDonald | Revert |
| Older page: | version 14 | Last edited on Thursday, June 16, 2005 3:48:56 pm | by IanMcDonald | Revert |
@@ -2,9 +2,9 @@
This [USB] WebCam supports 640x480 resolution images at 15fps, and video at 25fps, according to the box.
!Linux Support
-The 2.6 series LinuxKernel (as of 2.6.7 at least) come with support for webcams
that use the similar OV511 chip, but not these [WebCam]s.
+The 2.6 series LinuxKernel (as of 2.6.7 at least) come with support for [WebCam]s
that use the similar OV511 chip, but not these [WebCam]s.
The 'lsusb' program shows:
05a9:8519 ~OmniVision Technologies, Inc.
@@ -12,22 +12,23 @@
from http://alpha.dyndns.org/ov511/download.html#ov51x - the module will be called ov51x. It should work with 2.2, 2,4 and 2.6 kernels.
The camera's built-in microphone is detected by the kernel's USB [ALSA] drivers, but it doesn't actually seem to work - a new sound device is registered (/dev/dsp1) but reading from this device doesn't do anything.
-Unfortunately, these cameras serve images up in [JPEG] format only, and this
-linux
seems to handle this (yet - at least for V4L version 1). The source code for the driver (linked above) comes with a small program that can grab and save jpeg
images from the camera. JohnMcPherson has a modified version of this program that will display captured video in an X window -
+Unfortunately, these cameras serve images up in [JPEG] format only, and this behaviour will require application-level support. No webcam software for [Linux]
seems to handle this (yet - at least for [
V4L]
version 1). The source code for the driver (linked above) comes with a small program that can grab and save [JPEG]
images from the camera. JohnMcPherson has a modified version of this program that will display captured video in an X window -
grab the "showvideo" package from [our software archive|http://www.wlug.org.nz/archive/software/ov51x/].
-Best bet (for now) is to get a camera with better linux
support.
+Best bet (for now) is to get a camera with better [Linux]
support.
You can also code the decompression in the kernel space! Take a look at the decompression for ov518: it is very very close to JPEG decompression.
But there are patents about JPEG decompression and that is why - as far as I understand - the module doesn't handle JPEG decompression in kernel space..
But an individual that coded it for himself (and his friends ;) ) would not have to fear those patents... and the ov519 would work anywhere no mater with what app!
One such driver is now available for download from the following website: http://www.rastageeks.org/ov51x-jpeg/
--- The kernel
maintainers would not allow something like jpeg
decompression inside a kernel module... they will argue (correctly) that this is something that should be done in userspace.
+-- The [LinuxKernel]
maintainers would not allow something like [JPEG]
decompression inside a kernel module... they will argue (correctly) that this is something that should be done in userspace.
-- That is not totally correct. Web camera decompression is being done in kernel but the biggest obstacle has been (and why it keeps coming out of kernel) is that code was not clean room. Also note about patents is not correct - you can still be prosecuted as an individual - less likely but you still can. Having seen John's comment below it confirms my memory that the problem was people stealing code from Philips and not [JPEG] being the issue. IanMcDonald
-- [JPEG] is not a patent-encumbered format, [AFAIK]. JohnMcPherson
+
+-- [JPEG] itself may not be patented - it is a rather common mathematical compression BTW, but the file format that uses that compression, the [JFIFF] is patented [AFAIK]. Romain Beauxis
