Libreelec Audiophile Version

1st Official Post

    Good morning all!

    I discovered a version of libreelec mod special Audiophile for Raspberry pi 2/3, this one works impeccably with my DAC USB Mydac MICROMEGA.

    I no longer have a sound problem in the Netflix addon or on some FLACs.

    Here is the link of the translated page (Koreen origin):

    Google Traduction

    original:

    미노의 리눅스 소리 : 네이버 블로그

    Github:GitHub - parkmino/audiophile: Mino's Audiophile Tunings for Linux and Open Souce Software

    Very good Audio MOD

    I think that this is generally a very good idea but I am not a fan of this being a Raspberry Pi (as much as I love this device) exclusive.

    Sure, there are a lot and affordable Pi Hats available that give you a great sound but what about good PC/Mac Sound cards or even proper studio grade ones that you can get from your local music store like the ones from RME, Apogee, Halo, Focusrite and many more? And even without a fancy sound interface, what about using the surplus computing power that we nowadays take for granted for optimizing the sound with things like Secret Rabbit Code (libresample) and/or SoX and maybe put something like freesurround on top of that?

    My approach would be to reinstate the development and implementation of the DSP section in Kodi and do the same for the MPD Addon which has been around years ago. Then add support for more Sound Interfaces that go beyond the usual suspects and make better use of SRC (Secret Rabbit Code, also known as libresample) and SoX which are already part of LibreELEC. Then take apart something like Volumio (already available for X86) or Runeaudio and intergrate it in a sensible way into LibreELEC in order to make LibreELEC the only media OS that you will ever need, including the so called Audiophiles. You would be surprised how great even some stock on board HD Audio codec or Intel/NVidia HD Audio over HDMI can sound if set up right and given that you have some decent speakers and/or headphones connected to it.

    One of the great advantages of LibreELEC is that it supports so many different hardware platforms and I would be strongly in favour of keeping it that way. I don't mind forks but would it not be nicer to have one project where everyone can participate in his own way instead of having a million different niche versions to choose from? What I would suggest tho is to split LibreELEC into a pure player and a pure server edition within the main LibreELEC project.

    • Official Post

    Kodi DSP development stopped because it was a one-man effort (nothing unusual in Kodi land) and that individual took a break due to research and work things in real-life. However, they surfaced again recently and said they would be resuming where they left off. I didn't see anything yet, but DSP may yet be revived. Removing it was still the right decision as it's was incomplete and it's been ~two years.

    • Official Post

    Not a good idea to build an audiophile LE version for RPi's. Not just what chewitt mentioned is a problem.

    Two more problems:

    People often want HD audio on RPi's HDMI, but it looks like this hardware (or software implementation of audio pass-through) is too slow for native (non-PCM pass-through) HD audio (and other high speed) formats.

    When trying to do the same thing with an USB DAC, then you need a real-time Linux kernel to deliver high speed audio data in time to USB. That's probably what the LE mod guys did, but it slows other tasks down.

    Probably the situation could be better now with RPi 4. No matter what, I am not able to bypass internal resampling in LE on RPi4. No matter if I use HDMI or USB to SPDIF. I can get multichannel FLAC output that my receiver recognizes as Dolby Digital multichannel, yet I am sure it has been transcoded in KODI, because I can change its volume in KODI.

    Just reviving an old thread as I dug out the old Bose Companion 5 for the kid’s bedroom. Working perfectly and was immediately recognised on the RPI3+ as per expectation. Problem is and was noted elsewhere on the forum it just stops working for no reason.

    A little digging outside the forum unearthed “quirks”. If I’m reading this right Linux is identifying the vendor ID incorrectly and as a result is using the incorrect driver. https://forums.raspberrypi.com/viewtopic.php?t=15872

    Would this solution be a major task to implement in LE11

    Quote from petediscrete

    Would this solution be a major task to implement in LE11

    It is your decision with which additional parameters you boot your kernel . ;)

    With snd-usb-audio being a kernel module in LE you even can put the parameter into a file in /storage/.config/modprobe.d

    Quote from mglae

    It is your decision with which additional parameters you boot your kernel . ;)

    With snd-usb-audio being a kernel module in LE you even can put the parameter into a file in /storage/.config/modprobe.d

    Ok so by editing the /storage/.config/modprobe.d and adding

    snd-usb-audio.quirk_alias=05a71020:047f02f7

    to the file this should resolve the issue.

    I've no idea if it solves your issue.

    To add the parameter create

    Code: /storage/.config/modprobe.d/bose.conf
    options snd-usb-audio quirk_alias=05a71020:047f02f7

    Thanks guys.

    No joy. The quirk was corrtectly applied as can be seen below, reboot but still no sound via Bose USB audio.

    This guy seemed confident he had the issue resolved but didn't mention what model RPI he was using. Both the RPI3b+ and the Bose Companion 5 are USB2.00 devices. This really is a curious one. https://forums.raspberrypi.com/viewtopic.php?t=15872

    Quote from petediscrete

    This guy seemed confident he had the issue resolved but didn't mention what model RPI he was using. Both the RPI3b+ and the Bose Companion 5 are USB2.00 devices. This really is a curious one. https://forums.raspberrypi.com/viewtopic.php?t=15872

    The guy mentioned a quirks file for the kernel. If that file is missing, your quirk alias has no effect.

    I suggest to try the same on Raspberry Pi OS. Maybe LE doesn't have that quirks file.

    I reversed out that quirks change as it appeared to do nothing.

    I remember getting it to work many moons ago in Ubuntu (9 or 10 not sure which) long before the RPI arrived on the scene. Just looking back at some of the so called solutions, or workarounds which would be a better description and very few of them look credible looking back now.

    I've had the Bose Companion 5 running all evening and just managed to loose sound once. What I did to fix that was power down the RPI and remove power from the Bose unit. Once I plugged back in the Bose unit and powered up the RPI everything was fine. Another workaround you could say but an acceptable one.

    I'm convinced the problem lies with the fact that when the Bose is not playing sound it automatically goes into mute mode and is not being woken up by LE. Even toggling the sound on the Bose controller does not change that. Maybe the author of the original driver never took that into account when writing the driver, who knows. I don't see anyone in any rush to revisit the Bose driver for a piece of equipment 17 years old now although quite a few of those units were sold at the time.

    Once again guys. thanks for having a look. It's kinda working now via USB and there's always the analogue route to fall back on if needed.

    Quote from Da Flex

    I'm using a Behringer UMC22 with my RPi3B+. Works out-of-the-box.

    And I’m using a Cambridge Audio Dac Magic 100 which in fact works better out of the box in LE than it does in most other Linux distros as it recognises both USB modes, USB 1 (48khz) and USB2 (192khz).

    Again these different modes are selectable via a switch on the DAC but other distros seem to ignore this and default to USB 1 no matter what you try.

    Appears to be a Pulse Audio issue in most cases although I haven’t as of yet tried its supposed successor PipeWire in Ubuntu to see if anything has changed on that front.

    I’m happy enough that the Bose Companion 5 is now working albeit a little unpredictable with LE11. I always thought that the USB feature as supplied by Bose was an afterthought at the time.

    Of course Bose always suggested at the time that you connect analog via the Bose controller if you were experiencing difficulties with USB.

    Yep, the Magic 100 is one of the best DAC's you can get, and it's known to work with LE. I mentioned the UMC22 in case you want to connect the Bose speakers to a cheaper DAC that just works.

    Quote from Da Flex

    Yep, the Magic 100 is one of the best DAC's you can get, and it's known to work with LE. I mentioned the UMC22 in case you want to connect the Bose speakers to a cheaper DAC that just works.

    You don’t mess with Bose equipment. Proprietary connectors. Nightmare. Reminds me of Apple equipment. Doesn’t play well with others.

    I’ve nearly worked out how to bypass the Bose controller and let LE do all the lifting. This hopefully will kill off that undocumented Bose Mute feature that appears to be causing all the trouble.

    Have to say, an old but still very capable Sony KDL 32inch (expensive in 2006 and HD Ready 🤩) teamed up with the Bose Companion 5 (2004 vintage ) and a humble RPI3b+ sprinkled with the LE fairy dust and you’ve got quite an impressive setup. In fact I’m thinking of bringing it back downstairs 😂

    Quote from petediscrete

    In fact I’m thinking of bringing it back downstairs 😂

    Because of the Windows driver it's a tinker project. I would solder connectors onto the speaker contacts to avoid that driver.

    With a frequency switch you could also use the subwoofer. If you don't want to invest the time, bring it back downstairs.