JMF capture Audio and video (ii)

6. About video Capture

6.1VFW (video for Windows)

Before we explain how to identify video capture devices, we first introduce the VFW concept:

VFW is a Microsoft software toolkit for developing video applications under the Windows platform, providing a range of application programming interfaces (APIs) that enable users to easily implement common features such as video capture, video editing, and video playback. You can also use callback functions to develop more complex video applications. It is characterized by the fact that video playback does not require a dedicated hardware device, and the application of flexible, can meet the needs of video application development. The Windows operating system itself carries VFW, and the related components of VFW are automatically installed when the system is installed.

The following table is the functional module for VFW

/tr>

module	feature
avicap. The DLL
msvideo. The DLL
mciavi. DRV
avifile. The DLL
icm	compression manager, for pipe Video compression/decompression compiler (CODEC)
Audio Compression Manager, provides services similar to ICM, for waveform audio

6.2 The relationship between JMF and VFW:

Note the following code:

String str1 = "vfw:Logitech USB Video Camera:0";
String str2 = "vfw:Microsoft WDM Image Capture (Win32):0";
device = CaptureDeviceManager.getDevice(str2);
medialocator = device.getLocator();

As long as the device information at the beginning of the VFW can be identified and used for the JMF architecture. You can write code to identify this device.

In JMF, when detect Capture devices is used, it is possible to find a more device name in Capture devices: