HDMI glitches on Pi2 and Denon Receiver

As you can guess, I have issues with the configuration in the title on Alpha 4.

At frequent, but somewhat irregular (if you understand what I mean) intervals the sound momentarily cuts out and audibly “clicks”. I’ve done my best to eliminate other causes: Switched cables, Hooked PC up to receiver (same content, same source, same cable), Hooked RPI1 up to receiver (same content, same source, same cable), etc. Moreover I played with numerous settings to do with the video mode/framerates/audio settings/etc. Only the Pi2 running OSMC has a problem, and nothing I do seems to help mitigate it.

Moreover, at very infrequent intervals the picture goes away entirely, but the sound continues as per normal.

I would suspect this is either an HDMI driver issue, or an actual issue with the hardware, interacting with my receiver (Denon AVR-X2000 btw) in a non-great way.

So, anyone with tips? Is someone somewhere working away at fixing issues like these and all I have to do is wait for a new release? Can I help with a debugging effort in any way I haven’t mentioned above?

Could you try ‘hdmi_clock_change_limit=40’ in your /boot/config.txt ?
It solved most my problems :smile:

No beans, worth a try though. :slight_smile:

However, I think I will tinker now with those settings a bit…

Try disabling omxplayer in “video/acceleration” settings.
Try config_hdmi_boost=7 in config settings.

After playing with the settings I’ve found config_hdmi_boost does mitigate the problem to a huge degree. I still get the odd glitch, but I only turned it up to 4. Sure 7 should do the trick “all the way”. Thanks very much guys for the input.

What is the length and quality of the HDMI cable ?

What is the power supply that you’re running the Pi 2 off like ?

In my experience needing to use config_hdmi_boost > 4 is either an HDMI cable that is too long, or marginal power to the Pi.

As the Pi 2 seems to need quite a bit more power than the Pi 1 it stands to reason that you may see the issue only on the Pi 2 even if you are testing both with the same power supply or model of power supply.

As @DBMandrake has mentioned I’d agree the issue is with the power supply, do you ever get a rainbow square in the top right corner indicating low voltage / current?

I use a 5m HDMI cable and used to have issues, I tried increasing the hdmi boost and it worked but got the rainbow square.

Now I use a dedicated 2 amp power supply and don’t need hdmi boost and get no rainbow square.

Valid concerns here…

I use a fair quality (not a cheapo) 2m cable. The rainbow icon… Yeah I think I saw it once a long time ago. Not recently though. I had to go check, my power comes from a 700mA wall wart: Probably time to invest in something with a bit more oomph… I recall 700mA being the upper limit for the Pi1, if the Pi2 is more thirsty then this is (part of) my problem.


After investing in a Raspberry pi branded 2A power supply and increasing hmdi boost to 6, and trying hdmi_safe, and updating the software as much as could… I still have audio glitching on the Pi2. I think I’ve satisfied myself it’s not power related.

I do note though, running ‘deluged’ in the background (which I wasn’t doing before and it still happens without, fyi) seems to increase the frequency of audio glitching… which points me now towards processing power/threading/buffering issues. This seems strange to me, since nobody else seems to be having the same issue. But there you have it nonetheless.

Can you bypass the AVR and connect the pi directly to the TV and replicate the same issue?

I noticed some very small audio skips while watching movies sometimes. Did not have that on Raspbmc iirc.
That is with hdmi audio passthrough though.

@ActionA: Yes, it is, I’ll give it a go once I get home.

@mcobit: I get it on all audio/video settings, fwiw.

Update: I got this to go away by turning the hmdi boost up to maximum. I know that’s not recommended, but, the power supply made no difference, cables made no difference, etc…

I still get the occasional audio glitch but it’s now infrequent enough not to enrage and a lot less harsh (the duration of the rogue click is significantly reduced, and so it’s not as jarring). I don’t recall seeing a total video drop-out glitch as I was seeing before in quite a while, that seems to be resolved.

In other words, I’m for the time-being blaming this on problematic hardware and I’ve found a non-optimal but workable partial solution for now.

Update2: Eventually I changed one of the cables one day to a different device and sure enough, that device struggled… Huh?! I’d checked my cables over and over… OK, a whole new set of cables then… I replaced every cable in my setup and the problem was completely sorted. Sigh, well, there you have it.

But I have a new problem that I’ll create a new topic for…

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