How I got Pianoteq to work on a Chromebook

Hello:

A new Pianoteq user here. After some tinkering, I got it to work on a Chromebook. I am sharing some info about the process, as it seems it may be useful to others.

So I was considering Pianoteq, and I had an idle Acer Chromebook with a Celeron N3160 cpu. As a Linux user, I decided to try it to put it to good use.

My initial attempt was with the "native" Linux provided by Google. However, it quickly became apparent that this works like a container that does not support direct hardware access as required. For example, I did not get a response from cpufreq-info and apparently was not able to set the real-time priority and performance settings as indicated in the Linux README. So this was a dead end.

Therefore, I went back to the "old" approach with crouton. I was happy to read in its documentation that this does provide direct hardware access in contrast to the native approach. So I followed the instructions to install it - a smooth process. And indeed, now I was able to set the required settings and notice their effect.

The remaining issue was to avoid PulseAudio, the default sound control layer, and the corresponding latency. One has to select direct soundcard access under Devices. However, avoiding PulseAudio is not that straightforward, and as soon as one uses it, for example to control headphone volume, it blocks soundcard access. So then one has to kill its processes - all a bit messy. To avoid this I used alsamixer instead for sound control, but that is not very user-friendly.

To avoid these issues, I decided to purchase an external soundcard - Focusrite 2i2 (and a usb hub to have more inputs). After hooking everything up, it worked like a charm.

Voilà :-)

Jan

Roland FP-30X -> usb -> Chromebook / crouton Pianoteq 7.5 <-> usb <-> Focusrite 2i2 -> AKG k240 headphone

I was inspired by your post to get Pianoteq running my Toshiba Chromebook 2 (2014 version, with the Celeron N2840), with success.

The impetus was that Google had stopped providing updates to the ChromeOS, and I like tinkering. 
I chose GalliumOS (a derivative of Xubuntu because it is lightweight and optimized for ChromeOS devices, and because I found detailed instructions for exactly what I need to to do make this work (https://roytanck.com/2021/03/13/upgradi...-run-linux).

The biggest hurdle was needing to replace the stock firmware, which was an absolute requirement for performing a full linux installed.  I choose "Full Firmware [UEFI]" which completely replaces the ChromeOS (no dual-boot).  Replacing the firmware required removing the back and disabling the write-protect jumper, which was surprisingly easy. 

I had zero expectations of success with the built-in sound, so I used a USB audio interface, and JACK.

Pianoteq works like a charm.  I am able to get very low latency (2.9 msec) and no audible dropouts at 48 note polyphony.  The performance index is between 14 and 20.  For comparison:
- I saw a performance index of around 17 using a Raspberry Pi 4B without overclocking and with the 32-bit Raspberry Pi OS.
- This improved to about 20 with overclocking to 2 GHz
- This improved to about 30 with the 64-bit Operating system
- I saw about 75 on a 2015 MacBook Pro

But these all "feel" about the same in terms of performance - which is to say that performance is not an issue.  I'm frankly amazed. 

I know, this feels like a stunt. But I will actually use this, at least for rehearsals and travel. 

jandecaluwe wrote:

Hello:

A new Pianoteq user here. After some tinkering, I got it to work on a Chromebook. I am sharing some info about the process, as it seems it may be useful to others.

So I was considering Pianoteq, and I had an idle Acer Chromebook with a Celeron N3160 cpu. As a Linux user, I decided to try it to put it to good use.

My initial attempt was with the "native" Linux provided by Google. However, it quickly became apparent that this works like a container that does not support direct hardware access as required. For example, I did not get a response from cpufreq-info and apparently was not able to set the real-time priority and performance settings as indicated in the Linux README. So this was a dead end.

Therefore, I went back to the "old" approach with crouton. I was happy to read in its documentation that this does provide direct hardware access in contrast to the native approach. So I followed the instructions to install it - a smooth process. And indeed, now I was able to set the required settings and notice their effect.

The remaining issue was to avoid PulseAudio, the default sound control layer, and the corresponding latency. One has to select direct soundcard access under Devices. However, avoiding PulseAudio is not that straightforward, and as soon as one uses it, for example to control headphone volume, it blocks soundcard access. So then one has to kill its processes - all a bit messy. To avoid this I used alsamixer instead for sound control, but that is not very user-friendly.

To avoid these issues, I decided to purchase an external soundcard - Focusrite 2i2 (and a usb hub to have more inputs). After hooking everything up, it worked like a charm.

Voilà :-)

Jan

Roland FP-30X -> usb -> Chromebook / crouton Pianoteq 7.5 <-> usb <-> Focusrite 2i2 -> AKG k240 headphone