Re: [fluid-dev] Distorted sound from fluidsynth

[Janne Kivijarvi]

Hi again,

I replaced all '/dev/dsp':s with '/dev/dsp1' in fluid_oss.c, recompiled,
and the distortion was long gone (i.e. the other sound card works a whole
lot better). Now, how do I make fluidsynth use ALSA's card1?

>Probably not the problem. I assume you are using the ALSA driver since
>you are using the ALSA sequencer as well? Perhaps try different buffer

Options -a oss and -a alsa produce the same kind of output.

>sizes and counts -z and -c (maybe -z 1024 -c 3, -z 512 -c 3, etc). Or
>perhaps even a different audio driver (-a oss).

With -z 1024 -c 3 I get the same distortion in the sound, plus a notable
delay between keypress and sound. With -z 512 -c 3 the delay is smaller,
but the sound is same. Some combinations of size and count for example
-z 256 -c 2 create clicks and pops in addition to the distortion.

>What sound card do you have? Do other apps work fine with this card?

The sound 'card' is a VIA 8235 on the motherboard (via82xx driver in
ALSA), which does work on other apps altough not quite well enough:
it distorts on highest volumes and picks up a lot of noise (the audio
cabling inside the computer is insane for one).

The card the works is an Ensoniq AudioPCI (ENS1371).

------------------------------------------------------
$ fluidsynth -m alsa_seq -a alsa /mnt/m1/Classic.sf2

$ /proc/asound/card0/pcm0p/sub1> cat hw_params
access: RW_INTERLEAVED
format: S16_LE
subformat: STD
channels: 2
rate: 44100 (44100/1)
period_size: 64
buffer_size: 1024
tick_time: 10000

$ /proc/asound/card0/pcm0p/sub1> cat sw_params
tstamp_mode: NONE
period_step: 1
sleep_min: 0
avail_min: 32
xfer_align: 64
start_threshold: 64
stop_threshold: 4294967295
silence_threshold: 0
silence_size: 0
boundary: 1073741824

------------------------------------------------------
for reference, the parameters from the subdevice in use by artsd:

$ /proc/asound/card0/pcm0p/sub0> cat hw_params
access: RW_INTERLEAVED
format: S16_LE
subformat: STD
channels: 2
rate: 44100 (44100/1)
period_size: 1024
buffer_size: 10240
tick_time: 10000
OSS format: S16_LE
OSS channels: 2
OSS rate: 44100
OSS period bytes: 4096
OSS periods: 10

$ /proc/asound/card0/pcm0p/sub0> cat sw_params
tstamp_mode: NONE
period_step: 1
sleep_min: 0
avail_min: 1024
xfer_align: 1
start_threshold: 1
stop_threshold: 10240
silence_threshold: 0
silence_size: 0
boundary: 1342177280
------------------------------------------------------

Janne

-- 
Moving parts shall not be able to crush, cut or pierce parts of the body
of an OPERATOR likely to contact them, nor severely pinch the OPERATOR's
skin. (Compliance is checked by inspection.)                - IEC 1010-1