webcam with MJPG image format

I'm working with C# and a usb webcam that supports YUY2 or MJPG image formats. Thus far I've always had i开发者_高级运维t in YUY2 mode and that works fine. Recently I tried changing the format to MJPG thinking that it would then feed my program one JPEG image per frame capture. It appears to almost do that. When I try to display the buffer, my app always takes an exception which is vague, but seems to indicate that the stream is invalid. I then copied one of the buffers to a file and tried to view it with IrfanView and it tells me that there is no huffman table. Looking at the buffer with a binary editor, I see it does have the SOI and EOF JPEG markers (and several others); however, it doesn't contain a huffman table marker. Any ideas what I'm doing wrong here? I've read a bit about JPEG and apparently there are cases where images can use a standard huffman table to reduce file size; however, if that's the case, how do I insert this into the image (if appropriate)? This is with reference to Microsoft Lifecam by the way.

Part of the Motion-JPEG standard for AVI files is that a fixed Huffman table will be used so that it doesn't have to be stored in every frame.