WebCam Video Format Problem

Question

Hi,
I'm trying to change the video format of my webcam using JMF from it's default of 320x240 to 640x480 which it does support. However I am having problems. Can anyone help please?
I am running on Windows. My code looks like this:
//ml = a medialocator pointing to vfw://0
DataSource dataSource = javax.media.Manager.createDataSource(ml);
CaptureDevice theCamera = ((CaptureDevice) dataSource);
FormatControl formatControls = (theCamera.getFormatControls())[0];
availableFormats = formatControls.getSupportedFormats();
//Print out all formats my camera supports
for(int i=0;i<availableFormats.length;i++){
       System.err.println(i+":"+availableFormats);
}//end for
At this stage the I get the following formats reported:
0:YUV Video Format: Size = java.awt.Dimension[width=320,height=240] MaxDataLengt
h = 115200 DataType = class [B yuvType = 2 StrideY = 320 StrideUV = 160 OffsetY
= 0 OffsetU = 76800 OffsetV = 96000
1:YUV Video Format: Size = java.awt.Dimension[width=160,height=120] MaxDataLengt
h = 28800 DataType = class [B yuvType = 2 StrideY = 160 StrideUV = 80 OffsetY =
0 OffsetU = 19200 OffsetV = 24000
2:YUV Video Format: Size = java.awt.Dimension[width=640,height=480] MaxDataLengt
h = 460800 DataType = class [B yuvType = 2 StrideY = 640 StrideUV = 320 OffsetY
= 0 OffsetU = 307200 OffsetV = 384000
I then disconnect from the camera, attempt to change format and reconnect.
[code]
dataSource.disconnect();
System.err.println("ret="+ formatControls.setFormat(availableFormats[2]));
System.err.println(formatControls.getFormat());
dataSource.connect();
The "ret=" line returns the 640x480 format as exptected. However the getFormat print line returns the format.....
RGB, 320x240, FrameRate=15.0, Length=230400, 24-bit, Masks=3:2:1, PixelStride=3, LineStride=960, Flipped
.....which is not on the list of available formats. I am confused as to why this is so. It is also not what I tried to set the format to.
The connect fails with "java.io.IOException: Could not connect to capture device". If I don't try and set the format, the connect succeeds.
Any ideas?
With Thanks
LJ

Answer 1

Hi,
I'm trying to change the video format of my webcam
using JMF from it's default of 320x240 to 640x480
which it does support. However I am having problems.
Can anyone help please?
To specify the format, try using the following:
player = Manager.createRealizedProcessor(new ProcessorModel(new Format[] { playerFormat }, null));
Where playerFormat is a VideoFormat object from the list of formats.