[pvrusb2] Capture video without black bars

[Jan Ceuleers]

Dear list,

I'm using a bunch of HVR1900 devices to record video/audio using MythTV:
two are connected to STBs, so I'm using the composite video input and
the analogue audio inputs, and two more are connected to analogue cable.

When playing these recordings back on a 16:9 TV which has overscan
disabled there are black bars of various widths around the picture: 2cm
on the left, 0.5cm on the right, some at the bottom but none at the top.

MythTV offers a setting for the size of the picture, which is expressed
in pixels, and which is currently set to 720x576. But I am not aware of
a way to tell MythTV (or indeed of a way for MythTV to tell the driver)
which part of the picture we're interested in so that the video gets
captured without the black bars.

I'm aware that I can fix this problem at the playback end of the chain,
by setting appropriate X/Y offset and zoom values in the frontend. But
if I do so I also lose the corresponding bits of the picture when I play
back videos and discs.

So here's the question: can I tell the driver at what offset relative to
horizontal and vertical sync the picture begins at the top and the left?
I could then use the size settings in Myth to remove the black bars from
the bottom and the right.

Thanks, Jan