[atrocity2001]

I apologize up-front for not being 100% precise in my terminology, but I'm not at home right now with my equipment and somehow never seem to find (or make!) the time to post when I am.

As a longtime user of the Logitech Squeezebox system for plain stereo music, I've tried for years to find something that can work much the same way with multichannel FLAC.

Kodi on the Pi 2 (max2play distribution) gets me closer than anything else yet, but it's still not quite there for me. I've tried every conceivable combination of passthrough, sync, disable this, enable that, HDMI boost, etc. I believe I have a 3 amp power supply, so there shouldn't be an issue there.

The problem I consistently have is that attempting to play a 24bit/96kHz 5.1 FLAC through HDMI results in intermittent, inconsistent dropouts. There is no interesting level of CPU activity and it doesn't matter if the files are accessed via SMB, NFS, on the internal card or on a USB drive.

I've finally got it to where it consistently outputs uninterrupted audio by forcing a 48kHz sample rate. I'm not one of those people who's absolutely convinced that 96k really matters, so it's not the end of the world, but it just seems really odd to me. It appears that Kodi or the Pi or something has no trouble at all decompressing the FLAC and downconverting it, yet somehow it just can't keep up if it's not downconverting.

Is it possible that the HDMI output on the Pi is just not that great? I can play the same files with the same cable into the same Onkyo receiver(s) on a W*nd*ws box running Foobar2000 and it consistently works perfectly.

For that matter, do all the tiny little computers suffer from HDMI issues? One of the other attempts I've made involves OpenELEC on a Cubox-i4Pro. In that case, 24/96 results in random bursts of static on top of the music. Forcing 48kHz seems to eliminate the static, but I haven't listened for an extended period because it also consistently results in an audio dropout a few seconds before the end of the outgoing track.

While the reasons for my asking are obscure, I'm wondering if the HDMI output on either box is using mmap and, if so, if it's possible (and easy!) to turn that off. Google has not been my friend in that regard.

Thank you and I'm sorry if this has already been asked, but I haven't been able to find it.

[popcornmix]

Can you enabled buffermode=1 to start with. HOW-TO:Modify_the_video_cache (wiki)
I'm not sure that's your problem, but high samplerate multichannel FLACs tend to need that.

What distribution/version of kodi are you running? Some of the multichannel fixes require a recent build.

[atrocity2001]

Can you enabled buffermode=1 to start with. HOW-TO:Modify_the_video_cache (wiki)
I'm not sure that's your problem, but high samplerate multichannel FLACs tend to need that.

I don't believe I've done that, but I will certainly give it a try when I get home this evening.

What distribution/version of kodi are you running? Some of the multichannel fixes require a recent build.

On the Pi I'm running max2play but I'm not sure which version of Kodi that involves. On the Cubox-i4Pro it's OpenELEC but again, not sure how up to date.

Thank you for the very fast response!

[popcornmix]

No idea what max2play installs.
Would be useful if you could test OpenELEC 5.95.4 or latest OSMC which are known to have latest fixes in.

[atrocity2001]

No idea what max2play installs.

I'm not sure what the underlying system is, but it's an attempt to have Kodi and various Squeezebox-related things at the same time.

Would be useful if you could test OpenELEC 5.95.4 or latest OSMC which are known to have latest fixes in.

OK, I set up the latest OpenELEC on the Pi 2 this evening and changed very little beyond limiting output to HDMI and enabling passthrough. Played an entire 5.1 24/96 album with no trouble at all as well as a few assorted addtional tracks, but finally had a brief dropout on a 5.0 24/96 track. I have not yet changed the buffering, I'll try that tomorrow. Music is on an SMB share, I can switch to NFS easily but assume if the problem had been with SMB the experience would have been much worse.

Also tried the latest OpenELEC for the Cubox-i4Pro and didn't notice any issues but did not play with that one nearly as long.

Thank you for the suggestion to try the latest!

[atrocity2001]

Also tried the latest OpenELEC for the Cubox-i4Pro and didn't notice any issues but did not play with that one nearly as long.

Definitely still getting random static at 96kHz on the Cubox (and that was after setting the buffermode to 1). Played a 48kHz album without noticing any issues, though I fell asleep before it was over.

[atrocity2001]

Definitely still getting random static at 96kHz on the Cubox (and that was after setting the buffermode to 1).

And because of that, I've started a fresh thread in the "OS independent / Other" section.

As for the Pi I was also complaining about, I haven't had a dropout since going with

Code:

<advancedsettings>
  <network>
    <buffermode>1</buffermode>
    <cachemembuffersize>157286400</cachemembuffersize>
    <readbufferfactor>20</readbufferfactor>
  </network>
</advancedsettings>

but I only had one before making that change after updating to the latest OpenELEC beta. I can't tell yet if the problem is truly fixed or just much, much, much better.

Again, I appreciate the suggestion to upgrade.

[atrocity2001]

I can't tell yet if the problem is truly fixed or just much, much, much better.

The latter, unfortunately. I still get dropouts, but they're very rare, maybe once an hour or so. It's frustrating because it's so, so close to being perfect!

[popcornmix]

The latter, unfortunately. I still get dropouts, but they're very rare, maybe once an hour or so. It's frustrating because it's so, so close to being perfect!

Does adding hdmi_samples_limit=384000 to config.txt avoid the dropouts completely?

[atrocity2001]

The latter, unfortunately. I still get dropouts, but they're very rare, maybe once an hour or so. It's frustrating because it's so, so close to being perfect!

Does adding hdmi_samples_limit=384000 to config.txt avoid the dropouts completely?

I've just made the change and hope to be able to spend some serious listening time this afternoon. Thank you!

[atrocity2001]

I've just made the change and hope to be able to spend some serious listening time this afternoon. Thank you!

I was just able to get through an entire 24/96 4.0 album without a single dropout, so that's good news.

On the other hand, while the 4.0 consistently makes it to the receiver as 96k, I'm noticing that 5.1 96k material is consistently showing up as 48k. I'm definitely not telling it to resample.

Honestly, had I not gone out of my way to check the receiver's display, I can't imagine I'd ever have noticed, so as a purely practical matter it's probably not important as long as gaps or other weirdness don't get introduced.

I'll try a complete 96k 5.1 album now just to see what happens.

Thanks again!

[popcornmix]

On the other hand, while the 4.0 consistently makes it to the receiver as 96k, I'm noticing that 5.1 96k material is consistently showing up as 48k. I'm definitely not telling it to resample.

Honestly, had I not gone out of my way to check the receiver's display, I can't imagine I'd ever have noticed, so as a purely practical matter it's probably not important as long as gaps or other weirdness don't get introduced.

Yes, that setting will limit (channels * samplerate) to 384000, so you will get 48kHz for multichannel audio.
I'd like to know if that definitely cures the dropouts.

If we are sure it's good with that setting, there are some other tweaks that may get it dropout free without limiting sample rate (although as you say you won't hear the difference).

[atrocity2001]

If we are sure it's good with that setting, there are some other tweaks that may get it dropout free without limiting sample rate (although as you say you won't hear the difference).

I've just spent a few hours listening to 96k 4.0 and 5.1 files and didn't get a single dropout!

Thank you!

[atrocity2001]

I've just spent a few hours listening to 96k 4.0 and 5.1 files and didn't get a single dropout!

Unfortunately, it just dropped out again tonight. So it's rare, but not gone.

Even more unfortunately, I didn't have debug logging on, so there's nothing useful in the log.