Feature Summary

The HDMI_CEC API defines the ability to get connected HDMI devices, send messages to those devices, and to be notified when messages are received from HDMI devices.

HDMI-CEC is a protocol that provides high-level control functions between audio-visual devices connected over HDMI. CEC is a one-wire bidirectional serial bus based on industry-standard AV.Link protocol to perform control functions. All audio-visual sources are connected directly or indirectly to a display device as the ‘root’ in a tree-like structure.

Feature Summary

• Hardware support for HDMI-CEC as specified in HDMI 1.4a

  • CEC 4 – Electrical Specification
  • CEC 5 – Signaling and Bit Timings
  • CEC 6 – Frame Description
  • CEC 7 – Reliable Communication Mechanisms
  • CEC 8 – Protocol Extensions
  • CEC 9 – CEC Arbitration
  • CEC 10.1 – Physical Address Discovery
  • CEC 11 – Switch Requirements

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Component Impacts

CEC Protocol Library

• Translate application commands to CEC commands
• Receive CEC commands and provide to application listeners
• Autonomously respond to a subset of CEC messages

HDMI-CEC HAL

• Abstract Abstracts SoC HDMI-CEC driver from higher level components that means it will abstract SoC CEC library from CEC Protocol Library
• it allow transmits/receives HDMI-CEC messages

SoC CEC Driver

• Serialize and send CEC commands
• Receive CEC commands and provide to CEC Protocol Library

• Send EDID to HDMI source

• Provide HDMI input connect notification

Service Manager

• Provide HDMI input connect notification via State Observer API.

• Select select video source

Device Settings HAL

Device Settings APIs that SoC vendors implement.  It provides primitive and hardware specific implementation for each controllable aspect of the SoC.  This level API is considered single-app mode only, even though its SoC implementation may potentially support multiple-app mode.

• Initialize and terminate device inputs and outputs.
• Determine device settings capabilities (e.g. supported video resolutions, audio modes, etc).
• Modify device settings (e.g. audio encoding).
• Modify front panel LEDs.

• Provide HDMI event notification

• Read/Modify/Write EDID

• Add dsRegisterHdmiListener

• Add dsSelectVideoSource

• Add dsScaleVideoSource

SoC Video Pipeline

• Source video from HDMI input

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