media/v4l/dev-subdev.rst

77 Pad-level Formats
82     Pad-level formats are only applicable to very complex devices that
124 can expose pad-level image format configuration to applications. When
128 negotiate formats on a per-pad basis.
136 Pad-level image format configuration support can be tested by calling
137 the :ref:`VIDIOC_SUBDEV_G_FMT` ioctl on pad
138 0. If the driver returns an ``EINVAL`` error code pad-level format
184 or active format is set on a pad, corresponding formats on other pads of
190    a format on a source pad should not modify the format on any sink
191    pad.
207 list entity names and pad numbers).
303 1. Initial state. The sensor source pad format is set to its native 3MP
306    values, as well as the compose rectangle on the scaler's sink pad.
308 2. The application configures the frontend sink pad format's size to
310    driver propagates the format to the frontend source pad.
312 3. The application configures the scaler sink pad format's size to
315    on the sink pad is set to V4L2_MBUS_FMT_SGRBG_1X8. The driver
317    scaler's sink pad, and the format to the scaler source pad.
320    rectangle of the scaler's sink pad 1280x960. The driver propagates
321    the size to the scaler's source pad format.
349 As for pad formats, drivers store try and active rectangles for the
352 On sink pads, cropping is applied relative to the current pad format.
353 The pad format represents the image size as received by the sub-device
364 rectangle on the subdev's sink pad is scaled to the size configured
367 using ``V4L2_SEL_TGT_COMPOSE`` selection target on the same pad. If the
373 COMPOSE rectangle on the sink pad. In both sink and source pads, the
409 the sink pad towards the source pad. This is also reflected in the order
422 1. Sink pad format. The user configures the sink pad format. This format
424    pad for further processing.
426 2. Sink pad actual crop selection. The sink pad crop defines the crop
427    performed to the sink pad format.
429 3. Sink pad actual compose selection. The size of the sink pad compose
431    pad crop rectangle. The location of the compose rectangle specifies
435 4. Source pad actual crop selection. Crop on the source pad defines crop
438 5. Source pad format. The source pad format defines the output pixel
441    by the size of the source pad actual crop selection.
447 selection will refer to the sink pad format dimensions instead.
458 In the above example, the subdev supports cropping on its sink pad. To
460 pad. Now the actual crop rectangle can be set on the sink pad --- the
464 pad.