Bit Perfect Audio from Linux
May 3, 2014 at 7:32 PM Post #271 of 544
Deadbeef is probably using a included mixer, most music players offer a way to turn off volume control in settings, if they ever don't just remember to leave then at 100%. The best way to test that deadbeef has exclusivity is just to try to play a file in something else / YouTube. Only music should be audible.
 
May 4, 2014 at 8:00 AM Post #272 of 544
Tried playing something else whilst listening to audio.
 
There is just one audio device that is built into the mobo, so card 0 outputs to HDMI and card 1 outputs to PCH, which contains the SPDIF out. When I play something on soundcloud while listening to music on deadbeef, it plays via HDMI but nothing goes through the SPDIF. So I guess that's fine.
 
Me being paranoid here but if the file is being passed through a software mixer before being output digitally through SPDIF - could this potentially be flawed and not 'bit perfect' ?
 
Tried it with clementine also and when set up to output with ALSA, I am able to use the built in equaliser and mess around with the L/R balance.
 
:/
 
May 4, 2014 at 8:12 AM Post #273 of 544
  Thanks, that seems to be the case.
 
Me being paranoid here but if the file is being passed through a software mixer before being output digitally through SPDIF - could this potentially be flawed and not 'bit perfect' ?
 
Tried it with clementine also and when set up to output with ALSA, I am able to use the built in equaliser and mess around with the L/R balance.
 
:/

 
"bit perfect" = the bit stream from the music file is passed as-is and excusively to the spdif output, without any kind of processing.
means: no volume/balance adjustment, no eq/bass boost/treble boost, no mixing with other bit streams, no resampling, no crossfading, no anything else.
 
so yes, you are correct. as soon as there's any kind of software mixer in between it's technically not bit perfect.
 
May 4, 2014 at 8:54 AM Post #274 of 544
how do I fix this?
 
I tried Audacious and it seems that it allows you to 'set' a bit-depth and not let the bit-depth be determined by the audio file. The good thing about Audacious is that it allows you to disable all software volume control, so essentially the output is perfect as far as I am concerned
 
cat /proc/asound/card1/pcm1p/sub0/hw_params

 
shows me that the bit depth does change when I try to tinker with preferences in Audacious to set a bit depth.
 
Using DeadbeeF or Clementine PUSHES all tracks to a bit-depth of 32 and I don't know the significance of that on bit perfectness.
 
Please advise!
 
May 4, 2014 at 9:40 AM Post #275 of 544
Originally Posted by mofonyx /img/forum/go_quote.gif
 
Using DeadbeeF or Clementine PUSHES all tracks to a bit-depth of 32 and I don't know the significance of that on bit perfectness.

 
don't worry. the "increase" in bit depth does nothing but stuff zeros to the lesser significant bits, where the additional info would supposed to be.
 
May 4, 2014 at 10:21 AM Post #276 of 544
Oh, right. Great.
 
I found that MPD with GMPC works best (and adjusts bit-depth according to files - although you've mentioned that this bears little significance). Audacious comes close with working very well too. These two programs disable software control altogether.
 
DeadbeeF and Clementine seem to allow software volume control, which is a slight annoyance.
 
Jun 15, 2014 at 8:08 PM Post #277 of 544
Oh lord... I updated to fedora 20 with KDE 4.12.5 a few days ago, and it's killing me.
 
They broke EVERYTHING!
 
3 days of messing around and I still cant get Amarok to output bit perfect trough my SPDIF like it was on fedora 18. Ugh. 
 
They totally broke Phonon in the name of "improved user experience". There is no way to select specific ALSA channels in the "Device Preference" tab, and they created a new tab which uses "profiles" to setup your channels. And just to help things, there's no profile that uses both my laptop's speakers while allowing some apps to use direct devices.
 
Worst is the new "PulseAudio Integration" of Kmix. It took me a while to figure out how to turn it off, but now the mute button on my laptop is broken. Hitting it once mutes both the Master and Speaker channels, but hitting it again only unmutes one of those channel, the one you selected as master channel. Re Ugh.
 
Anyone faced these new problems and came out with a solution? Any help would be welcome at this point...
 
edit: More technical details here http://fedoraproject.org/wiki/Features/KDE_PulseAudio_Integration
 
Jun 16, 2014 at 8:12 AM Post #279 of 544
you should give manjaro a try. i used to be a debian/*buntu/mint fan but finally got sick of using ppas to get the latest stuff. i've been using arch (manjaro's based on it) for more than a year and it's absolutely great.
 
i see debian's use in servers, not desktop though
 
 
ooh and KaOS is a new hype, looks good
 
Jun 16, 2014 at 9:14 AM Post #280 of 544
KimLaroux,
 
try deadbeef, it's pretty good player.
 
Jun 16, 2014 at 5:31 PM Post #281 of 544
Although it seems that KDE is still working on their Phonon, Qt5 marks the point where QtMultimedia replaces it instead. I'm not holding out on any hope of it getting much attention in the future.
frown.gif

 
To fix the problem with the mute you might have to think about disabling Pulse entirely, sticking with dmix for your day-to-day since KMix should work well enough for that, and using JACK for specific-apps-to-devices. A quick KDE install on an Arch box that was transplanted over a ALSA/JACK setup (make sure they both play nicely though), and moc plays through the FiiO while I have a youtube video playing on my speakers just fine. It's not as simple to use, but at least it works.
 
Jun 16, 2014 at 7:32 PM Post #282 of 544
  KimLaroux,
 
try deadbeef, it's pretty good player.

 
I do use deadbeef too, and it works flawlessly. But I still need Amarok to take care of my music library.
 
 
  Although it seems that KDE is still working on their Phonon, Qt5 marks the point where QtMultimedia replaces it instead. I'm not holding out on any hope of it getting much attention in the future.
frown.gif

 
To fix the problem with the mute you might have to think about disabling Pulse entirely, sticking with dmix for your day-to-day since KMix should work well enough for that, and using JACK for specific-apps-to-devices. A quick KDE install on an Arch box that was transplanted over a ALSA/JACK setup (make sure they both play nicely though), and moc plays through the FiiO while I have a youtube video playing on my speakers just fine. It's not as simple to use, but at least it works.

 
I have disabled pulse, but as you can see from the link I pasted, KDE modified both Phonon and KMix to work even closer to Pulse, so removing pulse is now far from enough.
 
The goal here is too remove layers so the audio stream is modified as little as possible. On fedora 18, phonon was able to output directly to a device, bypassing Dmix even. This meant Amarok streamed bit-perfect to my DAC. My goal for now is to gain this feature back. I'll go with jack as a last resort. I'm still hoping they didn't completely break things and I can still find the setup I used to have.
 
Jun 16, 2014 at 7:39 PM Post #283 of 544
I always used MPD and Sonata (or ncmpcpp) as the GUI front-end for it, running on Xubuntu or Arch Linux.  Whenever I did a cat of the hw_params or streams I was always in bit perfect play back through USB to my DAC.
 
I changed over recently because I got rid of that system and for my purposes, Jriver or similar was needed and the Linux version just ain't quite there yet.
 
Get rid of anything to do with Pulseaudio if at all possible, use ALSA with a basic configuration and everything from DeadBeef, Clementine, Sonata, ncmpcpp and others will run without an issue.  I never cared much for Amarok and others, as they seemed to clunky for my taste, unfortunately Jriver like in a way but it is what it is.
 
Jun 18, 2014 at 6:02 AM Post #284 of 544
Thanks to Rizlaw for the excellent instructions on getting bit perfect audio under Linux. I installed ALSA and totally removed pulseaudio.
 
My hardware is an Asus Xonar Essence STX and everything works fine, including the impedance selection and speaker/headphones switch. The onboard sound is disabled.
 
The OS is Linux Mint 16, running Gmusicbrowser as music player.
 
Just to make sure that the output is bit perfect, I connected my external DAC via coax to the Xonar and the sampling frequency corresponds with the source material.
 
Again thanks - this is a very helpful thread.
 

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