Re: [fluid-dev] FluidSynth on Raspberry Pi with Wolfson Pi card

[Maciej - filologia angielska]

Hello,

Thank you for your response.

1. Actually, I did not intend to say that ALSA and JACKD were giving me the same error in FluidSynth. The "fluidsynth: error: The audio device error: Input/output error" would appear when selecting ALSA, a few seconds after the initialization of FluidSynth (and the ">" prompt appearing). I simply wanted to say that the use of Jackd was not helpful, either (producing other error messages in the terminal window running jackd).

2. Today I noticed that the problem must be due to Raspberry Pi's limitations in terms of its computing power. I took your advice and started changing the frequency rates. With the following setting I was actually capable to play an entire MID file (of medium complexity):

fluidsynth -C0 -R0 -r22050 -l -a alsa -o audio.alsa.device=plughw:0

I used the following soundfont:

/usr/share/sounds/sf2/FluidR3_GM.sf2

Then I increased the -r to 44100 and subsequently to 48000. With each increase, the Rpi would encounter "funny noises/drop-outs" (I do not know how to call them) and eventually the machine would crash during some of the more complex parts of the MID song.

Disabling some of the system services (the desktop environment had been disabled by me before), and overclocking the RPi to 950MHz did not produce much of a change. At 1000MHz, I actually managed to play 2 minutes of a relatively complex MID file for 2 minutes until the machine crashed at a more complex part of the song featuring various instruments/chords on several channels.

It seems like processing power is the culprit (now I understand that before adjusting the parameters the "noise" I could hear for 1-2 seconds was just the beginning of the MID file followed by an immediate crash of the RPi). I really do not wish to cut the sampling frequency below 44100, and I can live with a low polyphony (I intend the RPi to work as an addition connected as a slave to my main synth/sequencer), but any advice on further optimizing the playback quality (buffer size?) would be greatly appreciated.

Once again, thank you for your advice and helpful suggestions.


Dnia 22 kwietnia 2016 0:52 Element Green <address@hidden> napisał(a):

Hello,

 

I find it interesting that you get the same error with jackd.  In that case does FluidSynth quit with the same error or does jackd quit?

 

Sometimes there are limitations with audio drivers in regards to sample rate, buffer sizes, etc.  You may want to try 48KHz or 44.1KHz (depending on which one you are using at the moment) for the sample rate.  What other applications have you tried that have been successful?  For example, aplay would be a simple way to test ALSA.

 

Element

On Thu, Apr 21, 2016 at 10:12 AM, Maciej - filologia angielska <address@hidden> wrote:

Hello,

First of all, I would like to welcome all members and subscribers of the mailing group.

I have been trying to make FluidSynth work with Wolfson Pi card for Raspberri Pi 1 (model B). While I can play MID files through the standard line-out of the Pi without any problems, I cannot get the line-out on the Wolfson to work (using either ALSA or JACKD).

Here is the error message I get:

"fluidsynth: error: The audio device error: Input/output error"

I have tested the line-out of the Wolfson Pi card and it is working properly. I also tried different Linux kernels, but to no avail.

Thank you in advance for any ideas/suggestions/comments.

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