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Full Version: MinimServer w/Bubble UPnP Won't Play FLAC
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The only time that Bubble UPnP will not stream FLAC 44.1 to my Galaxy S5 phone is when I am on the T-Mobile 4G network.

When I am at home on Wi-Fi, I get FLAC 44.1 via Bubble UPnP running on top of Universal Media Server.

When I switch to a 4G mobile network, I can only get MP3/128kbps.

The metadata for any given track looks like this when on 4G:

This suggests to me that the FLAC was transcoded to a low bitrate MP3 long before it ever hit my phone.

Every setting on Bubble UPnP is set to avoid all needless transcoding and all settings that include a bitrate are set to "original". Experimenting with those settings (and others) made no difference; I always wind up with a low bitrate MP3.

Are there any user-configurable settings in MinimServer that I should be looking at?

Am I trying to do something that is currently technically impossible?
Much to my embarrassment, I discovered that Bubble had lost my network configuration and I wasn't even accessing my FLAC files through the internet from my home media server. Instead, Bubble was pulling MP3s from the SD card in my phone. BRILLIANT!

Now that I'm actually connected to the server, I managed to get two FLACs to start, stutter, and eventually stop altogether. Now I can't get any FLAC files to do anything. The only indication I get from the Bubble player is that as soon as I press the start button, it changes it right back to the stop button, and so naturally the song never starts.

What I can't tell is whether MinimServer is doing the FLAC-to-WAV transcoding before transmitting the data to me. Being that Android can play FLAC natively, I can only assume that FLAC files are not well-structured for streaming which might explain why they are transcoded to WAV either before they get to my phone or on my phone, although I'm not seeing any RAM or CPU spikes that would suggest that my phone is doing any transcoding.

Further adding confusion is that when my phone is connected to my LAN via Wi-Fi, the Bubble player clearly displays "FLAC | 44.1 kHz" and it works beautifully. Sounds great, too. Why can this not be accomplished via a 4G cellular WAN?

When my phone is connected via a 4G mobile network, the Bubble player displays "WAV | 44.1 kHz" apparently due to the FLAC-to-WAV transcoding, but no matter how many times I hit the play button (the white arrow head pointed to the right), it changes right back to the stop icon (a white square). If I assume the file is somehow being transcoded and perhaps "buffered up" somewhere upstream.....nothing ever happens- not even after 15-30 minutes.

I checked in with the author of Bubble and he let me know that the cache setting on Bubble is not used at all when it comes to lossless formats such as FLAC "due to the size requirement". It makes me wonder if the cache setting on Universal Media Server matters at all (a separate issue).

I'm starting to suspect this is the root cause- due to the structure of FLAC/WAV files, there may be no way to effectively or efficiently stream them since they might not be playable or have any seek functionality until the ENTIRE file is present on the rendering device.

The disappointing workaround is to go to Network Settings, change the Mobile Max Bitrate to anything other than "Original" (select 320, 256, 192, etc...) and then check the box for "Lossless only" which says "If enabled, only lossless audio is possibly transcoded for playback, using Max Bitrate settings".

Once you implement that workaround, all of a sudden Bubble starts caching the incoming data just like you would expect for ANY kind of data.

The final result being that by using Universal Media Server, Bubble UPnP, and MinimServer, I can only listen to my FLAC library from my home server over a 4G network on my phone as transcoded 320 kHz MP3 files which actually sound worse than the 192 kHz MP3 (VBR encoding) that I already have on the SD card in my phone which contains well over 10,000 songs.

In other words, I've wasted almost two days of experimentation only to discover that my objective was impossible from the beginning, even though every piece of software involved in the signal path clearly and loudly proclaims to allow you listen to your FLAC files in their native format without destructive, convoluted transcoding.

Somebody please tell me I'm wrong. I know I've structured my question poorly and much of it has nothing to do with MinimServer, but there are so many parts, pieces, configurations, and hardware elements involved that it's virtually impossible to know where to start troubleshooting.

Problem is, I don't think this is a problem. I think it's something the devs knew from the beginning and carefully worked around it with some relatively clever techno-marketing speak.
I've come to the embarrassing conclusion that the root cause of this problem is the 1Mbps upload speed on my home internet connection.

Sad but true, but they say confession is good for the soul.
They do.... and in this case, it may also be helpful to someone else who is experiencing a similar problem.
(07-09-2017 00:08)funkyblimp Wrote: [ -> ]I've come to the embarrassing conclusion that the root cause of this problem is the 1Mbps upload speed on my home internet connection.

Sad but true, but they say confession is good for the soul.

A few notes.

1) You say that MinimServer transcodes FLAC to WAV? Have you checked the settings in MinimWatch for this? If it is turned on then you uncompress your signal before you send it out to your phone. In other words, you go from around 900 kbits to 1411kbits. It would be better to leave FLAC as FLAC given that Android can natively decode FLAC. In fact, you may even choose to store your FLAC files with the highest compression (8) to limit bandwith as much as possible.

2) Internet speeds are typically advertised inclusive of any overheads to keep the connection going. Your 1mbps upload is therefore even less than that.

3) FLAC was actually designed with streaming in mind. Lossles streaming services like TIDAL, Qobuz and Deezer use FLAC to stream.
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