[gst-devel] Support for Plextor ConvertX PX-TV402U/PX-M402U

[Fredrik Persson]

The Plextor ConvertX PX-TV402U/PX-M402U is a very neat USB2.0 device
with hardware support for MPEG1, MPEG2, MPEG4 and MJPEG compression. I
fell in love with this device in 10 seconds! On-the-fly MPEG4
compression of full-blown PAL, 720x576 at 25fps, in full color depth, with
great result, is awesome.

Now, this device is a v4l2 device, and as such, should be handled by the
v4l2src element. It implements all the functions a v4l2 device needs to
implement, the driver is provided by Plextor and can be found here:

http://oss.wischip.com/

On my Ubuntu machine, I can confirm that the driver and the device works
flawlessly with the provided command-line test-app from plextor,
"gorecord".

With gstreamer I was not so lucky. At one point, I managed to have it
display video with the cvs version of v4l2src using its built-in MJPEG
compression. Most of the time, though, I got a message "input/output
error" and if I tried to run gstreamer with it again, my computer
hangs. 

So, I am willing to invest some work in having this thing run under
gstreamer, but I need help from the people who generally maintains the
v4l2src code.

Please, download the driver source code from the link provided above.
Take a look in the README, where the non-v4l2 stuff is documented. Also,
have a look in the go7007.h header file where it is... also documented.
Is this doable, can gstreamer support this? Also, what kind of work is
involved? Any pointers would be greatly appreciated. 

>From what I can see, it is the special compression settings that needs
to be supported. v4l2 device normally don't have those. We need to be
able to tell the device what compression to use and with what
parameters. After that, I assume, the v4l2src should be able to read
frames just as from any other v4l2 device, and feed them into a
pipeline. Probably right into a decodebin, of course.

/Fredrik Persson