162306a36Sopenharmony_ci.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later 262306a36Sopenharmony_ci 362306a36Sopenharmony_ci.. _common: 462306a36Sopenharmony_ci 562306a36Sopenharmony_ci################### 662306a36Sopenharmony_ciCommon API Elements 762306a36Sopenharmony_ci################### 862306a36Sopenharmony_ciProgramming a V4L2 device consists of these steps: 962306a36Sopenharmony_ci 1062306a36Sopenharmony_ci- Opening the device 1162306a36Sopenharmony_ci 1262306a36Sopenharmony_ci- Changing device properties, selecting a video and audio input, video 1362306a36Sopenharmony_ci standard, picture brightness a. o. 1462306a36Sopenharmony_ci 1562306a36Sopenharmony_ci- Negotiating a data format 1662306a36Sopenharmony_ci 1762306a36Sopenharmony_ci- Negotiating an input/output method 1862306a36Sopenharmony_ci 1962306a36Sopenharmony_ci- The actual input/output loop 2062306a36Sopenharmony_ci 2162306a36Sopenharmony_ci- Closing the device 2262306a36Sopenharmony_ci 2362306a36Sopenharmony_ciIn practice most steps are optional and can be executed out of order. It 2462306a36Sopenharmony_cidepends on the V4L2 device type, you can read about the details in 2562306a36Sopenharmony_ci:ref:`devices`. In this chapter we will discuss the basic concepts 2662306a36Sopenharmony_ciapplicable to all devices. 2762306a36Sopenharmony_ci 2862306a36Sopenharmony_ci 2962306a36Sopenharmony_ci.. toctree:: 3062306a36Sopenharmony_ci :maxdepth: 1 3162306a36Sopenharmony_ci 3262306a36Sopenharmony_ci open 3362306a36Sopenharmony_ci querycap 3462306a36Sopenharmony_ci app-pri 3562306a36Sopenharmony_ci video 3662306a36Sopenharmony_ci audio 3762306a36Sopenharmony_ci tuner 3862306a36Sopenharmony_ci standard 3962306a36Sopenharmony_ci dv-timings 4062306a36Sopenharmony_ci control 4162306a36Sopenharmony_ci extended-controls 4262306a36Sopenharmony_ci ext-ctrls-camera 4362306a36Sopenharmony_ci ext-ctrls-flash 4462306a36Sopenharmony_ci ext-ctrls-image-source 4562306a36Sopenharmony_ci ext-ctrls-image-process 4662306a36Sopenharmony_ci ext-ctrls-codec 4762306a36Sopenharmony_ci ext-ctrls-codec-stateless 4862306a36Sopenharmony_ci ext-ctrls-jpeg 4962306a36Sopenharmony_ci ext-ctrls-dv 5062306a36Sopenharmony_ci ext-ctrls-rf-tuner 5162306a36Sopenharmony_ci ext-ctrls-fm-tx 5262306a36Sopenharmony_ci ext-ctrls-fm-rx 5362306a36Sopenharmony_ci ext-ctrls-detect 5462306a36Sopenharmony_ci ext-ctrls-colorimetry 5562306a36Sopenharmony_ci fourcc 5662306a36Sopenharmony_ci format 5762306a36Sopenharmony_ci planar-apis 5862306a36Sopenharmony_ci selection-api 5962306a36Sopenharmony_ci crop 6062306a36Sopenharmony_ci streaming-par 61