Audio Stream Format Not Supported - Resolved (20bit not supported) [Ticket in]

I have had no problem getting Roon to recognize files I have uploaded to my Nucleus Plus. But I started using FLAC files and now I get the message, Audio Stream Format Not Supported. The FLAC files are 24 bit, 48K. According to the documentation, FLAC files should be supported. They all have the file extension “.flac” as specified. So why does Roon not recognize them? I have attached a OneDrive link to my latest files as retrieved from the Nucleus Plus: . [Link removed by support]

  • Mike Harkins

Do you mean that they show up in Skipped Files with reason “Audio Stream Format Not Supported”?
At least, that’s the case on my setup. I haven’t got a message.

MPC-HC reports your files to be only 20 bits, 48kHz.


MPC-HC as well as VLC can play the files.

From Skipped Files:

Audio Stream Format Not Supported - The file is may be valid, but Roon doesn’t support this format. It might use an unsupported codec (for example, an MPEG4 file with a .m4a extension where we couldn’t locate an AAC or ALAC track), use an unsupported sample rate or bit depth, be a video file, or otherwise be a type of media that Roon is not prepared to handle right now.

So maybe the bit depth (20 bits) is the culprit here.

Blackjack: Yes, I mean they show up in Skipped Files with the message you stated. I recorded these using Vinyl Studio and they claim to have 24 bits, not 20. I’ll re-check that. - Mike H.

Correction: The files are indeed 20 bit as I checked the settings in Vinyl Studio. Will Roon not play that format? I can set to 24 bit, 48 KHz. However, I will have wasted a lot of time making recordings that won’t play on Roon. - Mike Harkins

I don’t know for sure as I’m only a Roon user like you, but the current state with your files seems to indicate that.

This sounds like a good way to test if it’s indeed the bit depth that causes the problem.

Most likely there are converters out there that can automatically convert your files to another bit depth. As I never had the need to do so, I have no recommendation for you. Maybe other users can help here (if this is really the solution for your problem).

google is your friend here

Dear Wizard: Google my be my friend, but I don’t know what question to ask. Are you referring to converting from 20 bit to 24 bit?

That would be the matter at hand…as we have no idea what you used on what platform for suggestions

OK. I tried recording one track (a single) in 24 bit 48 kHz FLAC using Vinyl Studio. I stored that track on the Nucleus+ and it immediately was recognized by Roon. Eureka! Apparently, 20-bit FLAC is not recognized by Roon but 24 bit is. I tried playing it back and the sound was superb!!! Instead of converting to 24 bit, I decided to re-record the albums I had already saved to FLAC files. I only have a few so it won’t take that long. I only wish Roon had told me that 20-bit was a no-go. - Mike Harkins

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I’m curious as to how you ended ups at 20bit in the first place…is this a default value in Vinyl Studio (MAC then I assume) or did you do it for size?

Dear Wizard: I decided on 20-bit originally because I wanted something better than CD quality (16-bit). That was the next step higher than 16-bit as an option in Vinyl Studio for FLAC files. I don’t really need 24 bit because S/N with 20 bit must be around 120 dB since 16 bit is 96 dB. Anyway, 24 bit is even higher and will take up more storage space, but it works. I’m using a PC with Creative Labs Zx sound card as my means of gathering music from records and digitizing them with Vinyl Studio. - Mike Harkins

Well Mike I guess we live an learn something new every day…Didnt know VS had a PC version, or that 20bit was an issue for Roon either so there we have it.

Lucky you only had a small number of LP’s to go back over…I’m dreading doing mine but will still opt for the better 24/96 Flac I think even tho I could go up to DSD using a PSAudio NPC I got a few years ago.

I’m moving this to #roon area as its not a support nor nucleus issue and changing the topic for others to perhaps be aware.

I also own Vinyl Studio. Fabulous program! Under Batch->More there is an option to ‘Convert File Format of Selected Albums…’
This would spare you re-recording the albums if you have not done it already.

Just to add to Ogs comment. Especially if all you want to do is go from 20 to 24 bit, as that is just filling it up with zeros. However, if you really want to re-rip, go for it. I’d try one re-ripped compared to just 20 to 24 bit converted and see if you hear a sonic difference.

I didn’t know that. But it is good to know since I might have some albums I want to convert. Thanks. - Mike Harkins

Dear Wizard, I only put this question in the Nucleus area since I didn’t know where the problem was coming from. If the 20-bit FLAC option doesn’t work for Roon, then it’s not a Nucleus problem for sure and should move to the #roon area as you mentioned. I’m also thanking Og for his insight regarding the Vinyl Studio software and its ability to convert the format. It is a very nice program. It’s ability to remove pops and clicks (or ticks) from vinyl is impressive. But be careful, because it can remove some high frequency content. I used it on Huey Lewis’s recording of “I want a new drug” and the synthesizer lost a lot of its edge!!! - Mike Harkins

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From FAQ: What audio file formats does Roon support?:

The documentation does not indicate that 20-bit is not supported.

Maybe @support is able to confirm if the observed behavior is working as intended (and eventually update the documentation to reflect the actually supported bit-depths) or a bug.

BlackJack: I read the exact same thing. They don’t say anything about bit-depth, so my natural assumption was that 20-bit was fine. Unfortunately, that may not be true. A comment from Roon on this would be helpful. I moved to 24-bit though, since I know that works. - Mike Harkins

Hi @Michael_Harkins,

I discussed this with the team. It looks like, even though 20 bit is not common, this appears to be a valid FLAC file. We have opened up a ticket with our team to investigate this further. I can’t make any guarantees or provide timelines here, but we’ll be sure to reach out when we have more information available.