Here's what I found on the subject:

"MJPEG in AVIs having the MJPG fourcc, is restricted JPEG with a fixed -- and *omitted* -- Huffman table. The JPEG must be YCbCr colorspace, it must be 4:2:2, and it must use basic Huffman encoding, not arithmetic or progressive. "

This means it should be quite easy to get the cam to output right format as long as you can force the huffman table to standard and then omit it in the stream.

"MJPEG in AVIs having the MJPG fourcc, is restricted JPEG with a fixed -- and *omitted* -- Huffman table. The JPEG must be YCbCr colorspace, it must be 4:2:2, and it must use basic Huffman encoding, not arithmetic or progressive. "

This means it should be quite easy to get the cam to output right format as long as you can force the huffman table to standard and then omit it in the stream.