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pacemaker1000 · (This post was last modified: 2013-10-28, 14:34 by pacemaker1000.)

Every 2-5 minutes I get a gap in the audio for a mili second that is not only audible but is visible on my Amp

I am using a RPi with Openelec but have had no response to this on their forum so thought I would try here

I have eliminated the RPI and software by trying a new system and swapping the SD cards around in both
that leads me to believe it is either an Openelec fault (trying Rasbmc tonight) or a RPI one that is down to HDMI handshake issues?

Is there a firmware upgrade or does the RPi get upgraded along with Openelec?

Thanks this is driving me crazy

Ps also think this is only when streaming online stuff and not files off my server.

**h.udo** · 2013-10-28, 14:38

http://wiki.xbmc.org/index.php?title=Log_file/Easy

pacemaker1000 · 2013-10-28, 14:48

(2013-10-28, 14:38)hudo Wrote: http://wiki.xbmc.org/index.php?title=Log_file/Easy

Thanks will do

Marcel1982 · 2013-10-28, 14:54

I've got the same problem. I think it has something to do with refreshrate sync.

It started when i turned it on to have more fluent movie but resulted in audio that skips sometimes.
It's also visible on my receiver (passthrough), it blinks like if it looses the signal.

I did not have had any time to test this but maybe you can try it.

**popcornmix** · 2013-10-28, 15:26

The "Adjust display refresh rate to match video" option does adjust the HDMI clock to maintain sync.
The adjustments are minor and should be within spec (0.1%), but could theoretically upset a fussy receiver.

If turning off that option fixes the audio sync, you could try adding the to config.txt:

Code:
hdmi_clock_change_limit=50

The default value is 175. Smaller values mean smaller HDMI clock changes, so may be less likely to drop out.

pacemaker1000 · (This post was last modified: 2013-10-28, 15:43 by pacemaker1000.)

Interesting will check later but pretty sure I never enable that option, just the change refresh rate at start one

**popcornmix** · 2013-10-28, 16:09

(2013-10-28, 15:43)pacemaker1000 Wrote: Interesting will check later but pretty sure I never enable that option, just the change refresh rate at start one

If your TV changes to match refresh rate of video, then you do have the option I mentioned enabled (there is only one option that affects the refresh rate of TV).

Marcel1982 · 2013-10-28, 18:41

OK will try this hdmi_clock_change_limit=50 out this week.

pacemaker1000 · 2013-10-28, 21:36

(2013-10-28, 15:26)popcornmix Wrote: The "Adjust display refresh rate to match video" option does adjust the HDMI clock to maintain sync.
The adjustments are minor and should be within spec (0.1%), but could theoretically upset a fussy receiver.

If turning off that option fixes the audio sync, you could try adding the to config.txt:

Code:
hdmi_clock_change_limit=50

The default value is 175. Smaller values mean smaller HDMI clock changes, so may be less likely to drop out.

so i just copy and paste:

hdmi_clock_change_limit=50

to anywhere in the config file on the SD card when in my pc reader?

**h.udo** · 2013-10-28, 21:54

Yeap.

**popcornmix** · 2013-10-28, 21:55

(2013-10-28, 21:36)pacemaker1000 Wrote: so i just copy and paste:

hdmi_clock_change_limit=50

to anywhere in the config file on the SD card when in my pc reader?

First I'd disable "Adjust display refresh rate to match video" and see if that fixes it.
If not, then this won't help.

If it does fix it, then doing what you describe might allow you to enable "Adjust display refresh rate to match video" again.

kire1980 · 2013-10-28, 22:39

I am seeing similar issues with different video types. Usually, when powering up or rebooting xmbc the first file plays without gaps or hickups, but when pausing or stopping and restarting the video (or selecting another one to play), the hickups start occuring.

Disabling "Adjust display refresh rate to match video" seemed to help at first but also noticed hickups as well (but they seem to occur less). Adding hdmi_clock_change_limit=50 made no difference in any case.

What does the Adjust display rate option actually do?

I'm running OE 3.2.3 (I'm not sure if this issue was also the case with previous versions).

**popcornmix** · 2013-10-28, 23:05

(2013-10-28, 22:39)kire1980 Wrote: What does the Adjust display rate option actually do?

It first chooses the HDMI mode with best refresh rate compared to video (e.g. 24Hz).
Then it monitors where the frames are being presented compared to the display's vsync, and makes small adjustments to the hdmi clock to keep the video frames synchronised with the display updates.

There is a possibility that the clock adjustment may be causing the audio dropouts, although this scheme has been in place for a year, and there's very little evidence there's a connection.

pacemaker1000 · 2013-10-28, 23:07

Just tried a raspbmc build and audio drops massively reduced. Only two in an hour

Marcel1982 · (This post was last modified: 2013-10-28, 23:19 by Marcel1982.)

Just tried the hdmi_clock_change_limit=50 and this might solve the problem for me. Just watched a movie and had no dropouts.

Will test some more later this week.

Btw I am now using latest rjeb frodo back port build (26-10).

I did not had the dropouts with official openelec 3.1.6. It started at the 3.2.0 releases for me. 3.2.1 fixed it and it came back in 3.2.2 and 3.2.3. After that I switched to the custom builds.