jsolla / cec-decoder

Sigrok HDMI CEC protocol decoder

Sigrok HDMI CEC protocol decoder

Sigrok protocol decoder for HDMI CEC (Consumer Electronics Control)

Consumer Electronics Control (CEC) is a feature of HDMI designed to allow users to command and control devices connected through HDMI

CEC Bus can be found in PIN 13 of the HDMI connector:

Pulseview screenshots

Pulseview capture: CEC Ping frames

Pulseview capture: Vendor comand frame

Usage examples

Print all annotations (very verbose)

sigrok-cli -i data.sr -P cec:CEC=CEC

cec-1: ST
cec-1: 0
cec-1: 0
cec-1: 1
cec-1: 1
cec-1: 0
cec-1: 0
cec-1: 0
cec-1: 0
cec-1: 0x30
cec-1: EOM=N
cec-1: ACK
cec-1: 0
cec-1: 0
cec-1: 0
cec-1: 0
cec-1: 0
cec-1: 1
cec-1: 0
cec-1: 0
cec-1: 0x04
cec-1: EOM=Y
cec-1: ACK
cec-1: 30:04
cec-1: HDR: Tuner_1, TV | OPC: IMAGE_VIEW_ON | R: ACK

Print frames only

sigrok-cli -i data.sr -P cec:CEC=CEC -A cec=frames

cec-1: 30:04
cec-1: 35
cec-1: 35
cec-1: 3f:82:10:00
cec-1: 30:8f
cec-1: 03:90:01
cec-1: 30:44:6d
cec-1: 35
cec-1: 35
cec-1: 30:04
cec-1: 35
cec-1: 35
cec-1: 30:0d
cec-1: 35
cec-1: 35
cec-1: 35
cec-1: 35
cec-1: 30:04
cec-1: 35
cec-1: 35
cec-1: 30:8f
cec-1: 03:90:01
cec-1: 35
cec-1: 35
cec-1: 35
cec-1: 35
cec-1: 35
cec-1: 35
cec-1: 30:04

Print sections only

sigrok-cli -i data.sr -P cec:CEC=CEC -A cec=sections

cec-1: HDR: Tuner_1, TV | OPC: IMAGE_VIEW_ON | R: ACK
cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
cec-1: HDR: Tuner_1, Broadcast | OPC: ACTIVE_SOURCE | OPS: 0x10, 0x00 | R: ACK
cec-1: HDR: Tuner_1, TV | OPC: GIVE_DEVICE_POWER_STATUS | R: ACK
cec-1: HDR: TV, Tuner_1 | OPC: REPORT_POWER_STATUS | OPS: 0x01 | R: ACK
cec-1: HDR: Tuner_1, TV | OPC: USER_CONTROL_PRESSED | OPS: 0x6d | R: ACK
cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
cec-1: HDR: Tuner_1, TV | OPC: IMAGE_VIEW_ON | R: ACK
cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
cec-1: HDR: Tuner_1, TV | OPC: TEXT_VIEW_ON | R: ACK
cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
cec-1: HDR: Tuner_1, TV | OPC: IMAGE_VIEW_ON | R: ACK
cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
cec-1: HDR: Tuner_1, TV | OPC: GIVE_DEVICE_POWER_STATUS | R: ACK
cec-1: HDR: TV, Tuner_1 | OPC: REPORT_POWER_STATUS | OPS: 0x01 | R: ACK
cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
cec-1: HDR: Tuner_1, TV | OPC: IMAGE_VIEW_ON | R: ACK
cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
cec-1: HDR: Tuner_1, AudioSystem | OPC: PING | R: NACK
cec-1: HDR: Tuner_1, TV | OPC: GIVE_DEVICE_POWER_STATUS | R: ACK
cec-1: HDR: TV, Tuner_1 | OPC: REPORT_POWER_STATUS | OPS: 0x01 | R: ACK

Current status

The CEC protocol decoder is capable of the following:

• Decoding all low level parts: START, BITs, EOM, ACK / NACK
• Resolve names of all logical addresses
• Resolve names of all opcodes
• Detect (and warn) timing errors
• Detect (and warn) misplaced bits, etc

Pending:

• Operands of the opcodes are not parsed, only printed.