Hi Deb,
Some comment below:
On 25/04/2021 07:46, Deborah Brouwer wrote:
> If the controlling device simply stops sending audio rate messages, give
> the cec-follower the ability to detect that it has not received an audio
> rate message within 2 seconds as required. The cec-follower will quit the
> audio rate controlled mode. Eliminate the need to measure an interval
> between two audio rate messages.
>
> Signed-off-by: Deborah Brouwer <deborahbrouwer3563@xxxxxxxxx>
> ---
> utils/cec-follower/cec-processing.cpp | 17 ++++++++++-------
> 1 file changed, 10 insertions(+), 7 deletions(-)
>
> diff --git a/utils/cec-follower/cec-processing.cpp b/utils/cec-follower/cec-processing.cpp
> index 93db4059..111b3604 100644
> --- a/utils/cec-follower/cec-processing.cpp
> +++ b/utils/cec-follower/cec-processing.cpp
> @@ -233,18 +233,20 @@ static __u8 current_power_state(struct node *node)
> return CEC_OP_POWER_STATUS_TO_STANDBY;
> }
>
> -static void aud_rate_msg_interval_check(__u64 ts_new, __u64 ts_old)
> +static void aud_rate_msg_interval_check(__u64 ts_new, struct node *node)
Swap the arguments: node is typically the first argument.
> {
> /*
> - * The interval between messages is not relevant if this is the
> - * first audio rate control message or if the previous message
> - * turned off the audio rate control.
> + * The interval since the last audio rate message is not relevant
> + * unless the Source is currently in audio rate controlled mode.
> */
> + __u64 ts_old = node->state.last_aud_rate_rx_ts;
Add a newline here.
> if (ts_old) {
> unsigned interval = (ts_new - ts_old) / 1000000000;
Ditto.
Also, I just realized that the test below is actually wrong: by dividing the
interval above by 1000000000 you reduce the precision to one second intervals.
> if (interval > MAX_AUD_RATE_MSG_INTERVAL) {
Instead multiple MAX_AUD_RATE_MSG_INTERVAL by 1000000000, that way the
check is much more precise.
> - warn("The interval between Audio Rate Control messages was greater\n");
> + warn("The interval since the last Audio Rate Control message was greater\n");
> warn("than the Maxiumum Audio Rate Message Interval (2s).\n");
> + warn("Turning off audio rate control.\n");
> + node->state.last_aud_rate_rx_ts = 0;
> }
> }
> }
> @@ -802,7 +804,6 @@ static void processMsg(struct node *node, struct cec_msg &msg, unsigned me)
>
> switch (msg.msg[2]) {
> case CEC_OP_AUD_RATE_OFF:
> - aud_rate_msg_interval_check(msg.rx_ts, node->state.last_aud_rate_rx_ts);
You want to keep this check...
> node->state.last_aud_rate_rx_ts = 0;
> return;
> case CEC_OP_AUD_RATE_WIDE_STD:
> @@ -811,7 +812,6 @@ static void processMsg(struct node *node, struct cec_msg &msg, unsigned me)
> case CEC_OP_AUD_RATE_NARROW_STD:
> case CEC_OP_AUD_RATE_NARROW_FAST:
> case CEC_OP_AUD_RATE_NARROW_SLOW:
> - aud_rate_msg_interval_check(msg.rx_ts, node->state.last_aud_rate_rx_ts);
...and this check, because...
> node->state.last_aud_rate_rx_ts = msg.rx_ts;
> return;
> default:
> @@ -1033,6 +1033,9 @@ void testProcessing(struct node *node, bool wallclock)
> node->state.rc_state = NOPRESS;
> }
> }
> +
> + if (node->has_aud_rate)
> + aud_rate_msg_interval_check(ts_now, node);
...this periodic check only happens once a second, so is less precise. I.e., it might not
catch the case where the audio rate message arrived 2.1 seconds too late if this check was
performed e.g. 2.2 seconds later.
Regards,
Hans
> }
> mode = CEC_MODE_INITIATOR;
> doioctl(node, CEC_S_MODE, &mode);
>
