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

       cec-follower - An application to emulate CEC followers

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

       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

       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

       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

       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.

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

       -v, --verbose
              Turn on verbose reporting.

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

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

       -h, --help
              Prints the help message.

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

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

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

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

       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.

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

v4l-utils 1.16.5                  August 2016                  CEC-FOLLOWER(1)