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.

       -v, --verbose
              Turn 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.

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

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

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 1.14.2                                   August 2016                                   CEC-FOLLOWER(1)