CEC volume control of TV and AVR

MaxMustermann · June 21, 2024 at 7:37 PM

Hi,

this might be a topic for the Kodi Forum, but I have read more detailed technical CEC threads here, so I think this is the real home of CEC experts.

I am running LE12 stable on a RPi 5.

This is my HDMI setup:

The Pi is connected to my TV (LG G4)
The AVR (Yamaha) is connected to my TV as well
Sound is passed through from the Pi to the AVR using ARC

This is the current CEC topology:

Code

htpc:~ # cec-ctl -S
Driver Info:
    Driver Name                : vc4_hdmi
    Adapter Name               : vc4-hdmi-0
    Capabilities               : 0x0000010e
        Logical Addresses
        Transmit
        Passthrough
        Connector Info
    Driver version             : 6.6.28
    Available Logical Addresses: 1
    DRM Connector Info         : card 1, connector 32
    Physical Address           : 4.0.0.0
    Logical Address Mask       : 0x0002
    CEC Version                : 1.4
    Vendor ID                  : 0x001582 (Pulse-Eight)
    OSD Name                   : ''
    Logical Addresses          : 1 (Allow Fallback to Unregistered)
      Logical Address          : 1 (Recording Device 1)
        Primary Device Type    : Record
        Logical Address Type   : Record
        All Device Types       : Record
        RC TV Profile          : None
        Device Features        :
        None
    System Information for device 0 (TV) from device 1 (Recording Device 1):
        CEC Version                : 1.4
        Physical Address           : 0.0.0.0
        Primary Device Type        : TV
        Vendor ID                  : 0x00e091 (LG)
        OSD Name                   : Tx, OK, Rx, OK, Feature Abort
        Menu Language              : ger
        Power Status               : On
    System Information for device 5 (Audio System) from device 1 (Recording Device 1):
        CEC Version                : 1.4
        Physical Address           : 2.0.0.0
        Primary Device Type        : Audio System
        Vendor ID                  : 0x00a0de (Yamaha)
        OSD Name                   : 'RX-V381'
        Power Status               : Standby
    Topology:
        0.0.0.0: TV
            2.0.0.0: Audio System
            4.0.0.0: Recording Device 1

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Using the CEC Adapter add-on (Pulse-Eight) I can successfully control the volume of the AVR when it is on, although it seems like the add-on is sending the underlying CEC volume control message directly to the AVR. At least there is no OSD shown on the TV and I can't control the TV's volume when the AVR is turned off.

This is the add-on's config:

Code

<settings>
    <setting id="activate_source" value="1"/>
    <setting id="button_release_delay_ms" value="0"/>
    <setting id="button_repeat_rate_ms" value="0"/>
    <setting id="cec_hdmi_port" value="1"/>
    <setting id="cec_standby_screensaver" value="0"/>
    <setting id="cec_wake_screensaver" value="0"/>
    <setting id="connected_device" value="36037"/>
    <setting id="device_name" value="Kodi"/>
    <setting id="device_type" value="36051"/>
    <setting id="double_tap_timeout_ms" value="300"/>
    <setting id="enabled" value="1"/>
    <setting id="pause_or_stop_playback_on_deactivate" value="36045"/>
    <setting id="pause_playback_on_deactivate" value="0"/>
    <setting id="physical_address" value="0"/>
    <setting id="power_avr_on_as" value="0"/>
    <setting id="send_inactive_source" value="1"/>
    <setting id="standby_devices" value="231"/>
    <setting id="standby_devices_advanced" value=""/>
    <setting id="standby_pc_on_tv_standby" value="36028"/>
    <setting id="standby_tv_on_pc_standby" value="0"/>
    <setting id="tv_vendor" value="0"/>
    <setting id="use_tv_menu_language" value="0"/>
    <setting id="wake_devices" value="36037"/>
    <setting id="wake_devices_advanced" value=""/>
</settings>

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So my question is:

Is it possible to have the CEC Adapter add-on send CEC volume control messages to the TV instead of the AVR?

HarryH · June 21, 2024 at 8:38 PM

Which remote control do you use?

Normally CEC is intended to use the remote control o the TV (or an universal one) to control the other downstream devices via TV. Because the TV (HDMI sink) is the boss. It seems to me, that your TV has an issue to switch back to TV speaker mode or you must somethere enable it. Maybe a firmware update of the TV/AVR is needed to correct this, if it's not only a setting issue.
The volume information up/down are send from TV to the AVR, not by the Pulse-Eight device. The Pulse-Eight device is in that case only a consumer.

This may differ if you try to control KODI directly with a separate remote control. I never tried CEC in this direction, if that supported, besides some debug sessions with cec-client.

MaxMustermann · June 21, 2024 at 8:49 PM

I am using an IR remote for the Pi and actually want it to be the boss

I might have found the culprit:

From xbmc/peripherals/devices/PeripheralCecAdapter.cpp [Omega], line 499ff:

Code

  switch (pendingVolumeChange)
  {
    case VOLUME_CHANGE_UP:
      m_cecAdapter->SendKeypress(CECDEVICE_AUDIOSYSTEM, CEC_USER_CONTROL_CODE_VOLUME_UP, false);
      break;
    case VOLUME_CHANGE_DOWN:
      m_cecAdapter->SendKeypress(CECDEVICE_AUDIOSYSTEM, CEC_USER_CONTROL_CODE_VOLUME_DOWN, false);
      break;
    case VOLUME_CHANGE_MUTE:
      m_cecAdapter->SendKeypress(CECDEVICE_AUDIOSYSTEM, CEC_USER_CONTROL_CODE_MUTE, false);
      {
        std::unique_lock<CCriticalSection> lock(m_critSection);
        m_bIsMuted = !m_bIsMuted;
      }
      break;
    case VOLUME_CHANGE_NONE:
      if (bSendRelease)
        m_cecAdapter->SendKeyRelease(CECDEVICE_AUDIOSYSTEM, false);
      break;
  }

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with CECDEVICE_AUDIOSYSTEM = 5 from libcec's include/cectypes.h.

So it is hardcoded in Kodi to always use the AVR as target, unfortunately. I wished the add-on used what is defined in <setting id="connected_device" value="36037"/>

Any idea how to override this`? Do we need a pull request of someone fully understanding the code?

HarryH · June 21, 2024 at 9:18 PM

Yes, I think we need a pull request. But you have made the first step in the right direction and pointing to the maybe problematic part. The most sources I found say "It will not work with a TV". Maybe they you use all KODI.

Can you please check if that work for you with the TV volume?

echo volup | cec-client -s -b 0 -d 1

echo voldown | cec-client -s -b 0 -d 1

If yes, the sources I found until now, were wrong.

MaxMustermann · June 21, 2024 at 9:26 PM

I am using cec-ctl for my scripts, so it would be

cec-ctl --to 0 --user-control-pressed ui-cmd=0x41 and

cec-ctl --to 0 --user-control-pressed ui-cmd=0x42

Further commands I use:

cec-ctl --to 5 --system-audio-mode-request phys-addr=0.0.0.0 to turn on the AVR and enable ARC

cec-ctl --to 5 --standby to turn the AVR off

cec-ctl --to 5 --give-audio-status to get the current volume of the AVR

So, yes, it works.

HarryH · June 21, 2024 at 9:55 PM

Quote from MaxMustermann

I wished the add-on used what is defined in <setting id="connected_device" value="36037"/>

As far as I know this setting in combination with cec_hdmi_port is to override the physical address. (But currently this also not persists, and is reset after a restart, because of libCECs auto-detection). It's not suitable for the volume device assigning.
Would have to be an additional switch or some kind of dependency on the standby states of the TV and/or AVR.

CEC volume control of TV and AVR

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