On Fri, 2009-06-26 at 11:33 -0500, Mike Isely wrote: > On Fri, 26 Jun 2009, jmdk wrote: > > > Hello, > > > > I have a Hauppauge HVR-1900 which works fine with the pvrusb2 driver. > > However because most TV channels now air with 16:9 content inside 4:3 > > images, I would like to crop out the top and bottom black bars before > > encoding via the hardware MPEG2 encoder. I tried using the ctl_crop_top > > and ctl_crop_height in /sysfs as well as the --set-crop option of > > v4l2-ctrl but only received error messages indicating a value out of range. > > > > The card has a cx25843 which should support cropping. Does anyone know > > how to get this feature to work ? > > > > Thanks in advance for the help, > > Unfortunately the cx25840 driver does not implement any cropping > capability and the recent change to the v4l-subdevice architecture > currently lacks the API entrypoints to make such a thing possible :-( > > A pvrusb2 user a while back (it's in the pvrusb2 list archives) came up > with some patches to the cx25840 driver that implement cropping. He > also generated corresponding patches for the pvrusb2 driver. I merged > his pvrusb2 patches (which is why you see that support in the driver) > but not the cx25840 patches since I'm not an expert on that chip and I > don't have the ability to verify that the patches preserve correct > behavior for all the other devices that use the same chip. I did pass > the cx25840 patches to Hans Verkuil and he tried them out at the time > and basically pronounced them "ok" but I think even he wasn't sure if it > was doing everything right. > > That was a while ago and the cx25840 driver has undergone enough other > changes to make merging those patches a lot more difficult - plus the > v4l-subdevice stuff needs additional changes to support the extra > cropping API. Not only that, doing cropping with the CX2584x chips and friends appears to break VBI extraction in interaction with the CX2341x encoding engine. A good bit of experimentation would need to be done to keep VBI working with cropping. Regards, Andy > -Mike -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
