Roonifying NDX - supporting 192kHz playback

Thanks to the many good posts on installing the LMS UPnPBridge, I was able to get Roon working with my NDX. Unfortunately, as some forum members noted, playback was limited to 96kHz files and I had to configured the Roon DSP sample rate conversion to down-sample higher frequency files.

I was able to resolve this limitation today. The fix was to significantly boost the size of the bridge’s buffers. I am sure these settings can be optimized, but the following are the buffer sizes in config.xml that get 192kHz music working without down-sampling for me.

<streambuf_size>2048576</streambuf_size>
<output_size>41943040</output_size>

Hope this is helpful,

David

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David,

Yes I had a problem with 24bit files for a while intermittent audio glitches…I have my buffers set exactly the same and it has all been working fine for some time.

May I just confirm the size of the output size is 41943040?
Mine was set as 4194304.

Hi @Camphuw ,
That is correct. Increasing the size of the output size buffer by a factor of 10 enabled streaming of 192kHz files. I am sure the memory efficiency can be improved, but I have plenty of memory on my Synology NAS where I run Roon so I didn’t take the time to optimize this value.

David

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Good spot, actually mine is set to 4194304 and seems to work well. Having said that I don’t have many 192kHZ files.

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Thanks for posting this.

Before you changed these settings would you get a static noise when starting playback f the high res format files?

I’ve been using on the default values with LMS-to-upnp running within LMS in a container on my QNAP and have been able to playback 24/192 files without issue.

When I say without issue the only occasions when I have had a problem is when rapidly changing tracks of various formats, i.e. excessive track skipping in a mixed playlist. I’d then find that playing theses files would be broken until I played a 16/44 file which seems to ‘reset’ things.

I did try using a Raspberry Pi instead of the container solution and found this much more unreliable so will give these settings a go on that.

Thanks for posting. I’ve applied the settings to my current ‘production’ version and all seems well.

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@trickydickie, before I applied these changes, 192kHz files failed to play silently. I had turned on verbose debug logging for the LMS UPNP Bridge and when UPNP data was being sent to the NDX, the connection was being dropped on these hi-resolution files.

Incidentally, I heard static noise when the L24_format was not set to 1.

David

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Useful - thanks