SqueezePlay Fix for 24 bit output on Linux

[linuxfox]

Hi
as noticed in other threads, squeezeplay outputs always in 16bit in linux.
I made a little change in squeezeplay/src/audio/decode/decode_alsa.c to make it output 24bit

I changed the line:
sample_size = luaL_optinteger(L, -1, 16);
with:
sample_size = luaL_optinteger(L, -1, 24);

And now the output is always S24_LE.

What happens to 16bit data? It sounds ok so I think that is padded to 24 bit by squeezeplay or portaudio, is that right?
Why the sample size is "fixed" to 16 bit?

Thank you
Fabio

[linuxfox]

I've done some listening tests and the 24bit files sound better in mplayer than in squeezeplay.
More test show that the previous fix didn't improve sound on 24bit files: they sound like 16bit files.
Alsa and squeezeplay debugging show that output is 24bit but it sounds like 16bit padded into 24bit. I think that squeezeplay converts the sound from 24bit to 16bit and (in the end, probably by jive_alsa) it is again converted to 24bit...
Any help from the developers?
Thank you in advance
Fabio

[kipeta]

in Linux you can choose the audio device and other parameters through setting file:
~/.squeezeplay/userpath/settings/DesktopJive.lua

I have following content in it:
settings = {mac="xx:xx:xx:xx:xx:xx",uuid="xxxxxxxxxxxxxxxxxxx x"",alsaSampleSize=24,alsaPlaybackDevice="plugh w:2 ,0",alsaEffectsDevice="plughw:0,0",alsaPlaybackB uf ferTime=50000,alsaPlaybackPeriodCount=3}

I have verified that above settings really give 24bit at least to my USB Audiophilleo1 device.

[linuxfox]

Great post. Now I do not have to patch the sources every time!
Interesting the alsaplaybackbuffertime option. Does a bigger buffer give better sound quality?

[wilbert-vb]

in Linux you can choose the audio device and other parameters through setting file:
~/.squeezeplay/userpath/settings/DesktopJive.lua

I have following content in it:
settings = {mac="xx:xx:xx:xx:xx:xx",uuid="xxxxxxxxxxxxxxxxxxx x"",alsaSampleSize=24,alsaPlaybackDevice="plugh w:2 ,0",alsaEffectsDevice="plughw:0,0",alsaPlaybackB uf ferTime=50000,alsaPlaybackPeriodCount=3}

I have verified that above settings really give 24bit at least to my USB Audiophilleo1 device.

Thank you very much for this gem of information, I do want to add that your line results in a high CPU load.
Top shows a load of 30%.

When I modify your line to this, I have a normal CPU load of 1%:
settings = {mac="xx:xx:xx:xx:xx:xx",uuid="yyy",alsaSampleSize =24,alsaPlaybackDevice="plughw:1,0",}

[kipeta]

Thank you very much for this gem of information, I do want to add that your line results in a high CPU load.
Top shows a load of 30%.

When I modify your line to this, I have a normal CPU load of 1%:
settings = {mac="xx:xx:xx:xx:xx:xx",uuid="yyy",alsaSampleSize =24,alsaPlaybackDevice="plughw:1,0",}

I don't personally have such a high load (jive and both jive_alsa's are showing 1-4% in Top). It's really difficult to guess the reason for your case. Which process of SqueezePlay is causing the load? jive or jive_alsa? jive_alsa of Effects or Playback device?