On Mon, 2017-03-20 at 12:08 +0000, Russell King - ARM Linux wrote: > On Mon, Mar 20, 2017 at 12:55:26PM +0100, Philipp Zabel wrote: > > The above paragraph suggests we skip any rectangles that are not > > supported. In our case that would be 3. and 4., since the CSI can't > > compose into a larger frame. I hadn't realised that the crop selection > > currently happens on the source pad. > > I'd recommend viewing the documentation in its post-processed version, > because then you get the examples as pictures, and they say that a > picture is worth 1000 words. See > > https://linuxtv.org/downloads/v4l-dvb-apis/uapi/v4l/dev-subdev.html > > There is almost an exact example of what we're trying to do - it's > figure 4.6. Here, we have a sink pad with a cropping rectangle on > the input, which is then scaled to a composition rectangle (there's > no bounds rectangle, and it's specified that in such a case the > top,left of the composition rectangle will always be 0,0 - see quote > below). > > Where it differs is that the example also supports source cropping > for two source pads. We don't support that. > > The same document says: > > Scaling support is optional. When supported by a subdev, the crop > rectangle on the subdev's sink pad is scaled to the size configured > using the > :ref:`VIDIOC_SUBDEV_S_SELECTION <VIDIOC_SUBDEV_G_SELECTION>` IOCTL > using ``V4L2_SEL_TGT_COMPOSE`` selection target on the same pad. If the > subdev supports scaling but not composing, the top and left values are > not used and must always be set to zero. Right, this sentence does imply that when scaling is supported, there must be a sink compose rectangle, even when composing is not. I have previously set up scaling like this: media-ctl --set-v4l2 "'ipu1_csi0_mux':2[fmt:UYVY2X8/1920x1080@1/60]" media-ctl --set-v4l2 "'ipu1_csi0':2[fmt:AYUV32/960x540@1/30]" Does this mean, it should work like this instead? media-ctl --set-v4l2 "'ipu1_csi0_mux':2[fmt:UYVY2X8/1920x1080@1/60]" media-ctl --set-v4l2 "'ipu1_csi0':0[fmt:UYVY2X8/1920x1080@1/60,compose:(0,0)/960x540]" media-ctl --set-v4l2 "'ipu1_csi0':2[fmt:AYUV32/960x540@1/30]" I suppose setting the source pad format should not be allowed to modify the sink compose rectangle. regards Philipp
