To Investigate - Revision history

Paul Blankenbaker: /* Web Cam Image Capturing */

2013-01-13T15:33:50Z

Web Cam Image Capturing

← Older revision		Revision as of 11:33, 13 January 2013
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	NOTE: It's been hit and miss for me related to the use of the ''streamer'' rate parameter (often is seems like it is ignored and images are captured very quickly - especially at the initial start of the capture).		NOTE: It's been hit and miss for me related to the use of the ''streamer'' rate parameter (often is seems like it is ignored and images are captured very quickly - especially at the initial start of the capture).

			The mplayer and ffmpeg packages can be used to capture still frames like:

			yum install mplayer ffmpeg
			mplayer -tv device=/dev/video0:width=640:height=480:outfmt=rgb24 -frames 60 -vo jpeg:outdir=/var/nst/image-capture2 tv://

			This definitely is a simple method to grab a snapshot or two. Here are some things to note:

			* The user be a member of the ''video'' group.
			* The first couple of frames may be completely bad (on my netbook I see two solid green frames before the images start coming in).
			* It may take many frames until the web camera's "auto adjustments" (white balance, etc) result in decent pictures (on my web cam things started looking decent at frame 10 and by frame 20 things looked like they had stabilized).

			Ideally, this sounds to me like if you were using the mplayer approach it would be best if you could leave the web cam in a on state after capture (I think this would reduce the number of frames required to get a good image the next time).

			The ZoneMinder package (http://www.zoneminder.com/) is available under Fedora and creating a setup/management page in the NST WUI would be possible.

Paul Blankenbaker: /* Data Visualizer */

2013-01-13T15:32:17Z

Data Visualizer

← Older revision		Revision as of 11:32, 13 January 2013
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	http://gephi.org/		http://gephi.org/


			== Web Cam Image Capturing ==

			The v4l-utils package includes a lot of web cam utilities. Including the ''v4l2-ctl'' command line tool which allows you to query and adjust the web cam settings from the command line. Try:

			yum install v4l-utils
			v4l2-ctl --all
			v4l2-ctl --list-ctrls

			Here are some examples which query and then change the frame size:

			[root@cayenne image-capture]# v4l2-ctl --all
			Driver Info (not using libv4l2):
			Driver name : uvcvideo
			Card type : USB 2.0 Camera
			Bus info : usb-0000:00:1d.7-2
			Driver version: 3.6.11
			Capabilities : 0x04000001
			Video Capture
			Streaming
			Format Video Capture:
			Width/Height : 640/480
			Pixel Format : 'YUYV'
			Field : None
			Bytes per Line: 1280
			Size Image : 614400
			Colorspace : SRGB
			Crop Capability Video Capture:
			Bounds : Left 0, Top 0, Width 640, Height 480
			Default : Left 0, Top 0, Width 640, Height 480
			Pixel Aspect: 1/1
			Video input : 0 (Camera 1: ok)
			Streaming Parameters Video Capture:
			Capabilities : timeperframe
			Frames per second: 30.000 (30/1)
			Read buffers : 0
			[root@cayenne image-capture]# v4l2-ctl --list-framesizes=YUYV
			ioctl: VIDIOC_ENUM_FRAMESIZES
			Size: Discrete 640x480
			Size: Discrete 352x288
			Size: Discrete 320x240
			Size: Discrete 176x144
			Size: Discrete 160x120
			Size: Discrete 640x480
			[root@cayenne image-capture]# v4l2-ctl --set-fmt-video=width=352,height=288,pixelformat=YUYV
			[root@cayenne image-capture]# v4l2-ctl --get-fmt-videoFormat Video Capture:
			Width/Height : 352/288
			Pixel Format : 'YUYV'
			Field : None
			Bytes per Line: 704
			Size Image : 202752
			Colorspace : SRGB
			[root@cayenne image-capture]#


			The ''streamer'' tool from the xawtv package can be used to capture still frames at periodic intervals. For example, the following will capture 10 frames total at a capture rate of 0.2 seconds per frame (5 seconds between each image):

			streamer -w 2.0 -t 10 -r 0.2 -s 640x480 -o /var/nst/image-capture/image-00.jpeg

			NOTE: It's been hit and miss for me related to the use of the ''streamer'' rate parameter (often is seems like it is ignored and images are captured very quickly - especially at the initial start of the capture).

Paul Blankenbaker: /* Data Visualizer */

2010-10-29T18:45:03Z

Data Visualizer

← Older revision		Revision as of 14:45, 29 October 2010
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	Gephi is a generic visualizer that allows one to look at node/edge based graphs visually. Might be useful for visualized network traffic, intrusion detection data, etc.		Gephi is a generic visualizer that allows one to look at node/edge based graphs visually. Might be useful for visualized network traffic, intrusion detection data, etc.

	http://~~code~~.~~google.com/p/phpvirtualbox~~/		http://gephi.org/

Paul Blankenbaker: Created page with 'This page contains interesting tools that might be useful for future inclusion in the Network Security Toolkit. == Data Visualizer == Gephi is a generic visualizer that allows …'

2010-10-29T13:54:54Z

Created page with 'This page contains interesting tools that might be useful for future inclusion in the Network Security Toolkit. == Data Visualizer == Gephi is a generic visualizer that allows …'

New page

This page contains interesting tools that might be useful for future inclusion in the Network Security Toolkit.

== Data Visualizer ==

Gephi is a generic visualizer that allows one to look at node/edge based graphs visually. Might be useful for visualized network traffic, intrusion detection data, etc.

http://code.google.com/p/phpvirtualbox/