Android - Send Hdmi Cec Commands To Tv - Minix - Libcec

October 04, 2023 Post a Comment

i'm working on a Minix NEO X8-H (Android media center, 4.4.2) and i need to send HDMI-CEC command to TV: when my App receives a call i want to change automatically the TV Source to

Solution 1:

First of all, very impressive reverse engineering work!

Secondly, I'm facing a similar issue (but with a non Minix product). Have you tried upgrading to a newer firmware, such as this one:

http://minixforum.com/threads/x8-x8-plus-x8-h-official-firmware-004a-not-for-x8-h-plus.5567/

I am suggesting this as a possible solution, because one of the issues it fixes is this:

Fixed HDMI-CEC multi devices issues

This means the device is not only a "slave", but also a "master" (i.e. can send commands to other hdmi devices).

Please note that as stated in the link, it is not intended for the plus version.

Good luck!

Solution 2:

My two cents on the issue:

Baca Juga

Chapter I: Compassion

I went through all the trouble you went, too, especially with libCEC, so I'd like to describe the only way I got any interaction going between an Android TV box and the TV connected to it with HDMI cable.

Chapter II: Cooking low and slow

Send a request for connected device's power status echo 0x40 0x8F > /sys/class/cec/cmd

To get the response, you can:

read the "registry" cat /sys/class/cec/dump_reg
wait and look for the response in logcat

//Example:02-06 16:33:10.568  4012  4105 D CEC     : [cec_rx_loop]msg:04900002-06 16:33:10.570  4012  4105 D HdmiCecExtend:onCecMessageRx02-06 16:33:10.657  4012  4012 W HDMI    : [1]:Unhandledceccommand:<ReportPowerStatus>src:0,dst:4,params:0002-06 16:33:10.762  4012  4104 D CEC     : [cec_send_message][4->0]len:3,body:009000,result:success

Magic numbers (codes) explanation:

40 - Playback device #104 - TV device #1
On - 9000
Off - 0000// in registry or no response at all in logcat

Other available codes can be constructed or read on Cec-O-Matic or amlogic.

Chapter III: New hope

I still have to try and get to Android's HdmiControlService but I still don't know how, probably through Java reflection. You can see HdmiCecExtend: onCecMessageRx so the API is available on the device, but you cannot use it in Android Studio, as far as I know, it's only available to Android TV vendors.

Will update if anything comes along.

Android Coder