How to determine whether a MJPEG-AVI is coded as YV12 or YUY2?

[scharfis_brain]

As the title says:

I got plenty of MJPEG-AVI video clips derived from digital photo cameras.

Now I am uncertain whether they are stored as YUV 4:2:2 (YUY2) or as YUV 4:2:0 (YV12), cause all decoders I know of just convert to the output colorspace I had set up earlier.

So how can I analyse this issue properly?

Anyways, one thing for sure:
digital photo cameras store the full luma range of 0...255 into YUV, so one has to correct it to 16...235 in order to be able to see all dark and bright details.

[JohnnyMalaria]

Dig into the AVI file to extract a single JPEG and examine its header. The JPEG header structure can be found at:

http://www.obrador.com/essentialjpeg/headerinfo.htm

Part of it describes the H and V subsampling.

(I'd use a simple hex editor to open the AVI file and look for the tell-tale markers.)

[scharfis_brain]

hmmm. I used VDubs internal HexEditor to look up an AVI. But I wasn't able the spot any JFIF String.

So isn't there an application that tells me the JPEG specific parameter in a human readable format?