CEC-FOLLOWER(1)			 User Commands		       CEC-FOLLOWER(1)

NAME
       cec-follower - An application to emulate CEC followers

SYNOPSIS
       cec-follower [-h] [-d <dev>] [other options]

DESCRIPTION
       The cec-follower tool is used to emulate CEC followers. Based on the
       configured logical address(es) of the CEC device it will emulate the
       CEC behavior accordingly.

       Configuring the CEC device is done using cec-ctl. Certain CEC
       functionalities are only emulated if the corresponding Device Features
       flag is set (these are set when configuring with cec-ctl). These are:

	   - Audio Return Channel (RX and TX)
	   - Audio Rate Control
	   - Deck Control
	   - Record TV screen

       cec-follower is basically a message loop, waiting for messages to
       arrive and taking the appropriate action for each message (incoming
       messages can be shown with the --show-msgs option). The follower
       maintains an internal state with appropriate parameters such as volume,
       current active source, power state and so on (state changes can be
       shown with the --show-state option).

       It also aims to be a reference implementation on how a follower should
       behave.

       cec-follower will keep track of incoming messages and look for
       violations of the CEC specification with regards to timings. For
       example, it will warn if it receives the same message again within
       200ms after it replied <Feature Abort> ["Unrecognized Opcode"] to that
       message, and it will check that press and hold behavior is done
       properly.

       cec-follower will periodically send out polling messages to discover
       when a remote device is removed or a new one has appeared. When a
       device is removed, the recorded information about it is cleared. Each
       logical address is polled about once every 15 seconds. In between
       polls, removing a remote device or replacing it with a new one is not
       detected.

       When running compliance tests with cec-compliance, cec-follower should
       be run on the same device to act on incoming messages that are not
       replies to messages sent by the compliance tool. Before each test-run
       cec-follower should be restarted if it is running, to initialize the
       emulated device with a clean and known initial state.

OPTIONS
       -d, --device <dev>
	      Use device <dev> as the CEC device. If <dev> is a number, then
	      /dev/cec<dev> is used.

       -D, --driver <drv>
	      Use a cec device that has driver name <drv>, as returned by the
	      CEC_ADAP_G_CAPS ioctl.  This option can be combined with -a to
	      uniquely identify a CEC device without having to rely on the
	      device node number.

       -a, --adapter <adap-name>
	      Use a cec device that has adapter name <adap-name>, as returned
	      by the CEC_ADAP_G_CAPS ioctl.  This option can be combined with
	      -D to uniquely identify a CEC device without having to rely on
	      the device node number.

       -v, --verbose
	      Turn on verbose reporting.

       --version
	      Show version information.

       -w, --wall-clock
	      Show timestamps as wall-clock time. This also turns on verbose
	      reporting.

       -T, --trace
	      Trace all called ioctls. Useful for debugging.

       -h, --help
	      Prints the help message.

       -n, --no-warnings
	      Turn off warning messages.

       -e, --exclusive
	      If specified, then the follower uses exclusive mode
	      (CEC_MODE_EXCL_FOLLOWER).

       -m, --show-msgs
	      Show received messages.

       -s, --show-state
	      Show state changes from the emulated device.

       --service-by-dig-id
	      Report digital services by digital ID instead of by channel.

       --standby
	      Start the follower in the Standby status.

       --toggle-power-status <secs>
	      Toggle the power status every <secs> seconds. Only supported if
	      the follower is emulating a TV.

       -i, --ignore <la>,<opcode>
	      Ignore messages from logical address <la> and opcode <opcode>.
	      'all' can be used for <la> or <opcode> to match all logical
	      addresses or opcodes.

       --ignore-standby <n>
	      Ignore every <n>th received Standby message.

       --ignore-view-on <n>
	      Ignore every <n>th received Image/Text View On message.


EXIT STATUS
       On success, it returns 0. Otherwise, it will return the error code.

BUGS
       This manual page is a work in progress.

       Bug reports or questions about this utility should be sent to the
       linux-media@vger.kernel.org mailinglist.

SEE ALSO
       cec-compliance(1), cec-ctl(1)

v4l-utils 1.30.1		  August 2016		       CEC-FOLLOWER(1)