Chapter 1. Common API Elements

Table of Contents

1.1. Opening and Closing Devices
1.1.1. Device Naming
1.1.2. Related Devices
1.1.3. Multiple Opens
1.1.4. Shared Data Streams
1.1.5. Functions
1.2. Querying Capabilities
1.3. Application Priority
1.4. Video Inputs and Outputs
1.5. Audio Inputs and Outputs
1.6. Tuners and Modulators
1.6.1. Tuners
1.6.2. Modulators
1.6.3. Radio Frequency
1.6.4. Satellite Receivers
1.7. Video Standards
1.8. User Controls
1.9. Extended Controls
1.9.1. Introduction
1.9.2. The Extended Control API
1.9.3. Enumerating Extended Controls
1.9.4. Creating Control Panels
1.9.5. MPEG Control Reference Generic MPEG Controls CX2341x MPEG Controls
1.9.6. Camera Control Reference
1.9.7. FM Transmitter Control Reference
1.10. Data Formats
1.10.1. Data Format Negotiation
1.10.2. Image Format Enumeration
1.11. Image Cropping, Insertion and Scaling
1.11.1. Cropping Structures
1.11.2. Scaling Adjustments
1.11.3. Examples
1.12. Streaming Parameters

Programming a V4L2 device consists of these steps:

In practice most steps are optional and can be executed out of order. It depends on the V4L2 device type, you can read about the details in Chapter 4, Interfaces. In this chapter we will discuss the basic concepts applicable to all devices.