1*4882a593Smuzhiyun.. SPDX-License-Identifier: GPL-2.0 2*4882a593Smuzhiyun 3*4882a593SmuzhiyunThe Virtual Media Controller Driver (vimc) 4*4882a593Smuzhiyun========================================== 5*4882a593Smuzhiyun 6*4882a593SmuzhiyunThe vimc driver emulates complex video hardware using the V4L2 API and the Media 7*4882a593SmuzhiyunAPI. It has a capture device and three subdevices: sensor, debayer and scaler. 8*4882a593Smuzhiyun 9*4882a593SmuzhiyunTopology 10*4882a593Smuzhiyun-------- 11*4882a593Smuzhiyun 12*4882a593SmuzhiyunThe topology is hardcoded, although you could modify it in vimc-core and 13*4882a593Smuzhiyunrecompile the driver to achieve your own topology. This is the default topology: 14*4882a593Smuzhiyun 15*4882a593Smuzhiyun.. _vimc_topology_graph: 16*4882a593Smuzhiyun 17*4882a593Smuzhiyun.. kernel-figure:: vimc.dot 18*4882a593Smuzhiyun :alt: Diagram of the default media pipeline topology 19*4882a593Smuzhiyun :align: center 20*4882a593Smuzhiyun 21*4882a593Smuzhiyun Media pipeline graph on vimc 22*4882a593Smuzhiyun 23*4882a593SmuzhiyunConfiguring the topology 24*4882a593Smuzhiyun~~~~~~~~~~~~~~~~~~~~~~~~ 25*4882a593Smuzhiyun 26*4882a593SmuzhiyunEach subdevice will come with its default configuration (pixelformat, height, 27*4882a593Smuzhiyunwidth, ...). One needs to configure the topology in order to match the 28*4882a593Smuzhiyunconfiguration on each linked subdevice to stream frames through the pipeline. 29*4882a593SmuzhiyunIf the configuration doesn't match, the stream will fail. The ``v4l-utils`` 30*4882a593Smuzhiyunpackage is a bundle of user-space applications, that comes with ``media-ctl`` and 31*4882a593Smuzhiyun``v4l2-ctl`` that can be used to configure the vimc configuration. This sequence 32*4882a593Smuzhiyunof commands fits for the default topology: 33*4882a593Smuzhiyun 34*4882a593Smuzhiyun.. code-block:: bash 35*4882a593Smuzhiyun 36*4882a593Smuzhiyun media-ctl -d platform:vimc -V '"Sensor A":0[fmt:SBGGR8_1X8/640x480]' 37*4882a593Smuzhiyun media-ctl -d platform:vimc -V '"Debayer A":0[fmt:SBGGR8_1X8/640x480]' 38*4882a593Smuzhiyun media-ctl -d platform:vimc -V '"Sensor B":0[fmt:SBGGR8_1X8/640x480]' 39*4882a593Smuzhiyun media-ctl -d platform:vimc -V '"Debayer B":0[fmt:SBGGR8_1X8/640x480]' 40*4882a593Smuzhiyun v4l2-ctl -z platform:vimc -d "RGB/YUV Capture" -v width=1920,height=1440 41*4882a593Smuzhiyun v4l2-ctl -z platform:vimc -d "Raw Capture 0" -v pixelformat=BA81 42*4882a593Smuzhiyun v4l2-ctl -z platform:vimc -d "Raw Capture 1" -v pixelformat=BA81 43*4882a593Smuzhiyun 44*4882a593SmuzhiyunSubdevices 45*4882a593Smuzhiyun---------- 46*4882a593Smuzhiyun 47*4882a593SmuzhiyunSubdevices define the behavior of an entity in the topology. Depending on the 48*4882a593Smuzhiyunsubdevice, the entity can have multiple pads of type source or sink. 49*4882a593Smuzhiyun 50*4882a593Smuzhiyunvimc-sensor: 51*4882a593Smuzhiyun Generates images in several formats using video test pattern generator. 52*4882a593Smuzhiyun Exposes: 53*4882a593Smuzhiyun 54*4882a593Smuzhiyun * 1 Pad source 55*4882a593Smuzhiyun 56*4882a593Smuzhiyunvimc-debayer: 57*4882a593Smuzhiyun Transforms images in bayer format into a non-bayer format. 58*4882a593Smuzhiyun Exposes: 59*4882a593Smuzhiyun 60*4882a593Smuzhiyun * 1 Pad sink 61*4882a593Smuzhiyun * 1 Pad source 62*4882a593Smuzhiyun 63*4882a593Smuzhiyunvimc-scaler: 64*4882a593Smuzhiyun Scale up the image by a factor of 3. E.g.: a 640x480 image becomes a 65*4882a593Smuzhiyun 1920x1440 image. (this value can be configured, see at 66*4882a593Smuzhiyun `Module options`_). 67*4882a593Smuzhiyun Exposes: 68*4882a593Smuzhiyun 69*4882a593Smuzhiyun * 1 Pad sink 70*4882a593Smuzhiyun * 1 Pad source 71*4882a593Smuzhiyun 72*4882a593Smuzhiyunvimc-capture: 73*4882a593Smuzhiyun Exposes node /dev/videoX to allow userspace to capture the stream. 74*4882a593Smuzhiyun Exposes: 75*4882a593Smuzhiyun 76*4882a593Smuzhiyun * 1 Pad sink 77*4882a593Smuzhiyun * 1 Pad source 78*4882a593Smuzhiyun 79*4882a593Smuzhiyun 80*4882a593SmuzhiyunModule options 81*4882a593Smuzhiyun-------------- 82*4882a593Smuzhiyun 83*4882a593SmuzhiyunVimc has a module parameter to configure the driver. 84*4882a593Smuzhiyun 85*4882a593Smuzhiyun* ``sca_mult=<unsigned int>`` 86*4882a593Smuzhiyun 87*4882a593Smuzhiyun Image size multiplier factor to be used to multiply both width and 88*4882a593Smuzhiyun height, so the image size will be ``sca_mult^2`` bigger than the 89*4882a593Smuzhiyun original one. Currently, only supports scaling up (the default value 90*4882a593Smuzhiyun is 3). 91