CommandCam

The original author of CommandCam is Ted Burke. This repository is a fork of tedburke/CommandCam and contains an enhanced version of the original. CommandCam is published under the GNU General Public License (version 3) and is completely free to download and use. You can download the precompiled version of CommandCam for Windows along with source code from here: CommandCam-2.7.zip

Features

CommandCam is a simple and easy to use command line webcam image grabber for Windows. It captures a single image from a webcam and stores it in a local file. CommandCam is ideal for use in batch files and other situations where you want a very simple way to automate image capture. CommandCam uses Microsoft's DirectShow API to access webcams, so it should work with most USB cameras.

Currently it can capture and decode the following image formats from webcams:

• RGB 24 bits (RGB888)
• YUY2 16 bits (4:2:2)
• I420 12 bits (4:2:0 planar)
• MJPG 24 bits

To check which format your webcam uses, use the /details option.

You can select which webcam to use (by number or by name), which resolution to use and which format to select (if there are more). For the YUV image formats (YUY2, I420, ...) you can also select the color conversion parameters according to the ITU-R recommendation (BT.601 or BT.709). For more on this see Video Rendering with 8-Bit YUV Formats from Microsoft and Wikipedia:YUV.

Usage

CommandCam doesn't have any GUI and is intended for use in a command line window or in batch files. You can open command line window by running cmd or via Start > Accessories > Command Prompt. Move to the directory where you downloaded CommandCam.exe (for example, My Documents\Downloads), type CommandCam and if the webcam is connected, the image will be captured and stored in the file capture.bmp on the same directory.

You can specify the following options to the CommandCam:

• /delay <DELAY_IN_MILLISECONDS>
  Specify a time delay between the camera being turned on and the image being grabbed (recommended!).
  Default: 2000 ms (2 s)

• /filename <OUTPUT_FILENAME>
  Specify different filename for the grabbed image. If the filename contains spaces, enclose it in quotes. Filename currently shouldn't contain any Unicode characters.
  Default: capture.bmp (for RGB) or capture.jpg (for MJPG)

• /devnum <DEVICE_NUMBER>
  If you want to use a particular webcam (if you have more than one), check it's number with /devlist and use it with /devnum.
  Default: 1^st in list

• /devname <DEVICE_NAME>
  Same as above, but with the full webcam name (as printed in /devlist).

• /size <WIDTH>x<HEIGHT>
  If the default resolution of captured image is not what you wanted, use /details and select one of the supported resolutions listed for selected webcam.
  Default: 1^st in list

• /fourcc <FOURCC>
  If your webcam supports more than one image format at the same resolutions, you can select specific format as listed in /details. Typical formats would be RGB (best quality), YUY2 (less than RGB), I420 (less than YUY2) and MJPG (less than all above).
  Default: RGB, for more about this see What is FOURCC? and YUV pixel formats

• /colors <BT.601 | BT.709>
  Specifying this is meaningful only if your webcam outputs one of the YUV image formats (YUY2, I420, ...). BT.601 is the older color conversion (for SDTV, still very common) and BT.709 is newer (for HDTV). The difference is minimal.
  Default: BT.601

• /preview
  By default, CommandCam does not display any video on the screen before capturing the image. However, you can enable a short (1 s) video preview window using the /preview option.

• /devlist
  To list the available capture devices, for example to check which device number corresponds to which device, use the /devlist option.
  Example output:

Available capture devices:
  1. Logitech QuickCam Connect
  2. UScreenCapture

• /details
  This option lists all available capture devices along with their "pins" and capabilities:

  • video format, fourcc code, color depth in bits, resolution in pixels and frame rate/second

  Typical "pins" for the webcam would be:

  • "Capture", "Still" and "Video Camera Terminal" (unusable)

  Example output:

Available capture devices:
  1. Logitech QuickCam Connect
     Pin: Capture, 9 caps
       Cap  0: FORMAT_VideoInfo, RGB, 24 bits, 160x120 @ 30 fps
       Cap  1: FORMAT_VideoInfo, RGB, 24 bits, 320x240 @ 15 fps
       Cap  2: FORMAT_VideoInfo, RGB, 24 bits, 640x480 @ 15 fps
       Cap  3: FORMAT_VideoInfo, RGB, 24 bits, 960x720 @ 7 fps
       Cap  4: FORMAT_VideoInfo, I420, 12 bits, 160x120 @ 30 fps
       Cap  5: FORMAT_VideoInfo, I420, 12 bits, 320x240 @ 15 fps
       Cap  6: FORMAT_VideoInfo, I420, 12 bits, 640x480 @ 15 fps
       Cap  7: FORMAT_VideoInfo, I420, 12 bits, 960x720 @ 7 fps
     Pin: Video Camera Terminal
     Pin: Still, 9 caps
       Cap  0: FORMAT_VideoInfo, RGB, 24 bits, 160x120 @ 1 fps
       Cap  1: FORMAT_VideoInfo, RGB, 24 bits, 320x240 @ 1 fps
       Cap  2: FORMAT_VideoInfo, RGB, 24 bits, 640x480 @ 1 fps
       Cap  3: FORMAT_VideoInfo, RGB, 24 bits, 960x720 @ 1 fps
       Cap  4: FORMAT_VideoInfo, I420, 12 bits, 160x120 @ 1 fps
       Cap  5: FORMAT_VideoInfo, I420, 12 bits, 320x240 @ 1 fps
       Cap  6: FORMAT_VideoInfo, I420, 12 bits, 640x480 @ 1 fps
       Cap  7: FORMAT_VideoInfo, I420, 12 bits, 960x720 @ 1 fps
  2. UScreenCapture
     Pin: Capture, 1 caps
       Cap  0: FORMAT_VideoInfo, RGB, 24 bits, 1920x1080 @ 15 fps

• /quiet
  To suppress the text normally printed to the console by CommandCam (version and progress information), use the /quiet option. Error messages will still be printed to the screen.

How to compile

CommandCam can be compiled with Microsoft C++ or MinGW g++ using supplied Makefiles or directly:

• Microsoft C++
  cl CommandCam.cpp ole32.lib strmiids.lib oleaut32.lib
• MinGW g++
  g++ CommandCam.cpp -lole32 -lstrmiids -loleaut32 -static -o CommandCam.exe