On 03/04/2014 08:38 AM, Archit Taneja wrote: > Hi Hans, > > On Monday 03 March 2014 01:20 PM, Hans Verkuil wrote: >> Hi Archit! >> >> On 03/03/2014 08:33 AM, Archit Taneja wrote: >>> Add crop ioctl ops. For VPE, cropping only makes sense with the input to VPE, or >>> the V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE buffer type. >>> >>> For the CAPTURE type, a S_CROP ioctl results in setting the crop region as the >>> whole image itself, hence making crop dimensions same as the pix dimensions. >>> >>> Setting the crop successfully should result in re-configuration of those >>> registers which are affected when either source or destination dimensions >>> change, set_srcdst_params() is called for this purpose. >>> >>> Some standard crop parameter checks are done in __vpe_try_crop(). >> >> Please use the selection ops instead: if you implement cropping with those then you'll >> support both the selection API and the old cropping API will be implemented by the v4l2 >> core using the selection ops. Two for the price of one... > > > When using selection API, I was finding issues using the older cropping > API. The v4l_s_crop() ioctl func assumes that "crop means compose for > output devices". However, for a m2m device. It probably makes sense to > provide the following configuration: > > for V4L2_BUF_TYPE_VIDEO_OUTPUT (input to the mem to mem HW), use CROP > target(to crop the input buffer) > > and, for V4L2_BUF_TYPE_VIDEO_CAPTURE(output of the mem to mem HW), use > COMPOSE target(to place the HW output into a larger region) > > Don't you think forcing OUTPUT devices to 'COMPOSE' for older cropping > API is a bit limiting? Yes, and that's why the selection API was created to work around that limitation :-) The old cropping API was insufficiently flexible for modern devices, so we came up with this replacement. Another reason why you have to implement the selection API: it's the only way to implement your functionality. Regards, Hans -- 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
