Sound Quality

[vbor]

Hi

I'm about to build a media centre for hifi sound output and watching movies. I plan to connect the Pi 2 to an amplifier and then the speakers.

Will the Pi be able to deliver hifi sound to the amplifier given the sound file is good?

Will I have to use the HDMI output to get the best sound quality or doesn't it matter if I use USB or the 3.5mm audio jack?

Thanks for your answer.

[drgeoff]

The analogue audio from the RPi is not up to full CD quality. Whether it satisfies your ears depends on you.

A good USB sound card should give comparable quality to that from HDMI.

[eriktheitalian]

Rpi's analog output SNR ratio is poor. But u can get perfect SNR ratios with wolfson/cirrus or same type cards. ( U cant find this snr quality on pc sound cards with this price ) Only problem last kernel or pi2 breaks compatibility. I'm not know details.

Easy choice is c-media cm108 based usb adapters. Enough quality. U can find cheap usb cards with spdif output with analog 2/4/5.1 output. But high quality 5.1 output's mean is high load on usb....

[vbor]

The analogue audio from the RPi is not up to full CD quality. Whether it satisfies your ears depends on you.

A good USB sound card should give comparable quality to that from HDMI.

Then I assume I will get more or less perfect sound quality if I use the HDMI output on the PI? If that's the case then I'll use HDMI between the Pi and the receiver. With the receiver set to passthrough I can forward the picture to the TV.

[gkreidl]

Yes, that is the best solution (USB sound cards are not supported by omxplayer!).

[PeterO]

Dont forget I2S !
http://iqaudio.com/
PeterO

[vbor]

Dont forget I2S !
http://iqaudio.com/
PeterO

But this shouldn't be needed if I use HDMI and already have a receiver.

[gkreidl]

Dont forget I2S !
http://iqaudio.com/
PeterO

Not supported by omxplayer also, AFAIK.

[eriktheitalian]

Dont forget I2S !
http://iqaudio.com/
PeterO

Not supported by omxplayer also, AFAIK.

Because omxplayer coded for directly analog audio output or hdmi output. Not alsa not pulseaudio no other api ? Is it true ?

[PeterO]

Dont forget I2S !
http://iqaudio.com/
PeterO

Not supported by omxplayer also, AFAIK.

Hmmm seems some work was done to get ALSA supported, but I can't find evidence of it ever becomming part of released builds
I've not actually tried omxplayer with my IQaudIO DAC.
PeterO

[dom]

Because omxplayer coded for directly analog audio output or hdmi output. Not alsa not pulseaudio no other api ? Is it true ?

omxplayer is a media player whose playback engine runs on the GPU. That means it only knows about the GPU side audio devices (hdmi/analogue) and not about ALSA drivers.
So, no omxplayer will never support ALSA.

kodi does have an alternative media player (dvdplayer) which runs the playback engine on the arm and does support ALSA.

[Gswg]

Dom, is then a non starter for I2S devices? Anything I can look at?

[email protected]

[eriktheitalian]

Because omxplayer coded for directly analog audio output or hdmi output. Not alsa not pulseaudio no other api ? Is it true ?

omxplayer is a media player whose playback engine runs on the GPU. That means it only knows about the GPU side audio devices (hdmi/analogue) and not about ALSA drivers.
So, no omxplayer will never support ALSA.

kodi does have an alternative media player (dvdplayer) which runs the playback engine on the arm and does support ALSA.

I understand omxplayer is gpu cell focused player. Ok.
Omxplayer is good for me but i'm not care lot.

Kodi is very good software i'm used at lots of scenario. Its not limited with x11. Always smoth gui with full screen opengl/opengles/directx api.

[gkreidl]

ote]

I understand omxplayer is gpu cell focused player. Ok.
Omxplayer is good for me but i'm not care lot.

Kodi is very good software i'm used at lots of scenario. Its not limited with x11. Always smoth gui with full screen opengl/opengles/directx api.

Kodi uses also omxplayer and it's the only one that can play full HD video.

[dom]

Kodi uses also omxplayer and it's the only one that can play full HD video.

It also supports dvdplayer, which gets enabled when ALSA audio is used, so Kodi does support ALSA.

[dom]

Dom, is then a non starter for I2S devices? Anything I can look at?

Command line omxplayer doesn't support alsa, and there is no simple way of adding support (the audio scheduling and rendering is handled by GPU).

Alternatives that support ALSA are Kodi, and VLC.
Note: vlc in apt-get repo is too old, but building from source gets a version with hardware acceleration for Pi.