HDMI CEC

https://etwiki.sys.comcast.net/display/CE/%5bShared%5d+HDMI-CEC

https://rdkwiki.com/rdk/display/RDK/HDMI+Input

https://www.teamccp.com/confluence/display/CPE/RDK+HDMI+Input+Architecture

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

• Send raw or formatted CEC messages on behalf of application
• Provide received CEC messages to registered application listener
• Get information about a device connected to HDMI input
• Autonomously handle subset of CEC messages
• Provide list of connected CEC capable device to application
• Send "Feature Abort" response if message is not handled autonomously by RDK and message is not handled by application listener

Device Applicability

This feature applies to the following devices:

• Hybrid
• IP

Architecture Overview

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 SoC CEC library from CEC Protocol Library

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

• Provide HDMI event notification

• Read/Modify/Write EDID

• Add dsRegisterHdmiListener

• Add dsSelectVideoSource

• Add dsScaleVideoSource

SoC Video Pipeline

• Source video from HDMI input

Design Details

Methods

"CECAddresses" : {
 "physicalAddress": Array of 4 bytes [byte0, byte1, byte2, byte3],
 "logicalAddresses" : Array of <CECLogicalAddress>
}

"CECLogicalAddress" : {
 "deviceType" : <string> 
 "logicalAddress": <integer>
}

Events