1.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later 2 3.. _common: 4 5################### 6Common API Elements 7################### 8Programming a V4L2 device consists of these steps: 9 10- Opening the device 11 12- Changing device properties, selecting a video and audio input, video 13 standard, picture brightness a. o. 14 15- Negotiating a data format 16 17- Negotiating an input/output method 18 19- The actual input/output loop 20 21- Closing the device 22 23In practice most steps are optional and can be executed out of order. It 24depends on the V4L2 device type, you can read about the details in 25:ref:`devices`. In this chapter we will discuss the basic concepts 26applicable to all devices. 27 28 29.. toctree:: 30 :maxdepth: 1 31 32 open 33 querycap 34 app-pri 35 video 36 audio 37 tuner 38 standard 39 dv-timings 40 control 41 extended-controls 42 ext-ctrls-camera 43 ext-ctrls-flash 44 ext-ctrls-image-source 45 ext-ctrls-image-process 46 ext-ctrls-codec 47 ext-ctrls-codec-stateless 48 ext-ctrls-jpeg 49 ext-ctrls-dv 50 ext-ctrls-rf-tuner 51 ext-ctrls-fm-tx 52 ext-ctrls-fm-rx 53 ext-ctrls-detect 54 ext-ctrls-colorimetry 55 fourcc 56 format 57 planar-apis 58 selection-api 59 crop 60 streaming-par 61