Runeaudio downsampling via USB output?

[hondagx35]

Hi,

please read my post again.
You have to determine your card number with "aplay -l".

Frank

[fongalv]

edit:
ok got it!

[fongalv]

[fongalv]

[hondagx35]

[fongalv]

Oh dear...my bad...missed that point, but even if I didn't, I probably wouldn't have known it converts 24/32bit to 16bits


Btw, is there any recommended buffer size for the Rpi2 to get optimal performance? I'm getting some random drops(suspect wifi).


Been picking up quite some Linux knowledge, cheers!

[hondagx35]

[fongalv]

Hi Frank,

I removed the second part of the question because after fiddling around around even more, I discovered the DSD128 files actually played fine after a while.

I thus tried playing the file via USB flash drive(as opposed to network mount from desktop), and the file played smoothly, and so I attributed the inconsistent playback to the wifi signal strength.

My DAC supports DSD, but I'm not sure why the Rpi2 CPU was so strained when I played the file yesterday. It know it wasn't re-sampling because the DAC shows that it was receiving a DSD signal. I even took a video of the CPU load while playing the DSD128 file here(normal 16/24bit music barely loaded the CPU).

I find this really strange because if it playback was affected due to WIFI signal strength, why was the CPU strained?

[bertie]

May I ask a question, please be gentle coz I am so far out of my depth (but enjoying the ride).

I have started using Rune, using a Raspberry Pi3 to USB 2.0 Cambridge DacMagicPlus with a powered USB 2.0/3.0 hard drive as the USB music source. I downloaded the Rune image only 2 weeks ago.

Everything works just as I hoped and it sounds really good!

However, the output (at least according to the user interface) is locked to 16bit 44.1kHZ, even if I am playing higher rez files (either FLAC or WAV).

Working through the forum thread above I used the command :
cat /proc/asound/card1/pcm0p/sub0/hw_params

The SSH showed the 'format' (presumably bit size) is correct at 32 (shown as 'S32_LE') but the SSH showed the rate only '44100 44100/1'. I think it should be more like 384000? I have read the docs that I am aware off (I've disabled pretty much everything that can be disabled, volume control, normalisation etc).

Not sure if it relevant but the same command above shows the 'buffer size' as only 22050 (which is nothing like the 2048 kB default shown in the user interface).

I am interested to know I can increase the 'rate' (and 'buffer size', if relevant)

Sorry if this is stupid question! Thanks

[bertie]

...well yes it was a stupid question!
Still, the following might be of interest to other novices like me. I can now see the (probably obvious) point that you have to run the command on the params file while the track of interest is actually playing (I did it while the device was dormant, doh!).
When you run the command on a track that is playing, the 'format' always seems to be returned as 32 regardless, however, the rate shown is the actual rate of the current track file. By bad luck, something was wrong with computer files I was testing (I really don't know what, the DAC didn't show any the rate at all for them and I was blaming the Pi). Anyway, when I play a verified hirez track I can confirm that the rate is now displaying correctly in both the user interface and the DAC.

Edit
I still do wonder what is wrong my FLAC/WAV files which has affected many more tracks than I realised. When playing, these display in the Rune user interface as 16 bit 44.1kHz but, interesting the kbps is displayed as 0 (wtf?!). My DAC cant detect the rate at all.

Close Out
I since found elsewhere on this forum that the kbps is measured 'on the fly' typically at the start of each track and is largely meaningless. If the track starts with a pause then the instantaneous rate might well be measured as 0kbps. Finally, even though I feel too lazy to test it more formally, I am prepared to take a punt that my 44.1kHz LED light has blown on the DAC since all confirmed 96 and 192 sample rates are detected fine.
Conclusion is that Runeaudio works perfectly.

Unrelated (actual) insight
Since I occasionally turn on the livingroom projector to view the (otherwise headless) pi 3, the default display powerdown has been most annoying and the various 'xset' solutions suggested on this forum Do Not Work for Pi3. What DOES work is editing the /boot/cmdline.txt by adding consoleblank=0 at the end.
See, I made a contribution after all!