Re: [Linux-uvc-devel] uvcview videograbber with preview available for testing

[Laurent P. <lau...@sk...>]

> Yes, I've made it to uncompress mjpeg data from an avi, and mov file for my
> gallery program (photon) written in python. I known it's not the best
> langage to play with bitstream, but it's working i recreate a full jpeg
> header from the stream. Else, i dont' known how to decode jpeg data +
> huffman table without the libjpeg.

You definitely need a library to decode MJPEG. libjpeg might be a bit too big 
to do the job (MJPEG is a small subset of all possible JPEG formats), but 
it's the easiest to use for prototyping.

> I'll look Qt. For now, i only do conversion for the YVY2 format.

The Qt patch I wrote modifies the Qt JPEG codec which uses libjpeg, so you 
will be able to reuse the code in Gnomemeeting. Be careful about licensing 
issues though. pwlib is licensed under the Mozilla Public License 1.1 and Qt 
under the GNU Public License. You can reuse my code in pwlib (I grant you the 
right to use it under the MPL), but not Qt code.

> > Why did you need to modify the driver ?
>
> To support ENUM_STD. Only to not return -EINVAL. But it failed somewhere
> after that ... This is why i don't send the patch. Here the patch use:

Mmmmm... Shouldn't mplayer be fixed instead ? V4L2 v0.8 doesn't make it 
mandatory to support ENUM_STD:

(1.7. Video Standards)

"Here the driver shall set the std field of struct v4l2_input and struct 
v4l2_output to zero, the VIDIOC_G_STD, VIDIOC_S_STD, VIDIOC_QUERYSTD and 
VIDIOC_ENUMSTD ioctls shall return the EINVAL error code."

Laurent Pinchart