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Output bit lower than source
#1
Hi,

I have the newest version of MoodeAudio running on a RPI4B and I notice that the output bit length is always 16 bit no matters if the source is at a bit higher or not.

[*]Encoded at: 24 bit, 44.1 kHz, Stereo FLAC
[*]Decoded to: 24 bit, 44.1 kHz, Stereo, 1.236 Mbps
[*]Destination: Local
[*]Output rate: 16 bit, 44.1 kHz, Stereo, 1.411 Mbps


Sometimes also at higher frequencies the sound is not clear.

I have the SOX disabled and I'm using HDMI as output port.

DSP OPERATIONS
[*]Resample rate: off
[*]Selective rate: off
[*]Resample quality: off
[*]Volume mixer: Disabled (0dB output)
AUDIO DEVICE
[*]Device: Pi HDMI 1
[*]Mixer name: HDMI
[*]Chip: Broadcom SoC


And I've connected the RPI to a Pioneer Receiver VSX 2021K.

Could you help to understand what are the missing configurations? Of course if I turned on the SOX Resampling the Output Rate will be the same that I configured.

Cheers.
Pedro
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#2
Stop playback and run the command below. It will list the sample rates and formats that are available for the integrated HDMI and Headphone ports and also for any connected I2S or USB audio devices.

Code:
alsacap
Enjoy the Music!
moodeaudio.org | Twitter Feed | Git Repo
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#3
(01-22-2021, 01:06 AM)Tim Curtis Wrote: Stop playback and run the command below. It will list the sample rates and formats that are available for the integrated HDMI and Headphone ports and also for any connected I2S or USB audio devices.

Code:
alsacap
Hi Tim, thank you for you feedback.
I ran this command and the output was
Card 0, ID `b1', name `bcm2835 HDMI 1'
  Device 0, ID `bcm2835 HDMI 1', name `bcm2835 HDMI 1', 4 subdevices (4 available)
    1..8 channels, sampling rate 8000..192000 Hz
    Sample formats: U8, S16_LE
    Buffer size range from 80 to 131072
    Period size range from 80 to 131072

The sample format S16_LE indicates the maximum 16 bit, it is correct? So this is the higher sample rate supported by the Pioneer Receiver, correct?
Thank you in advance.
Pedro
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#4
Yes, S16_LE is 16-bit. It's the max bit depth supported by the Pi HDMI port.
Enjoy the Music!
moodeaudio.org | Twitter Feed | Git Repo
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#5
Thank you again Smile

There's any way to improve, by software, the bit depth when using the RPI? In terms of hardware, I suspect that this this a behaviour for all RPI, so the solution is upgrade the RPI adding a DAC? This is correct? I'm using a receiver that have an internal DAC and the connection between RPI and the receiver is made by the HDMI port.

By the way, my receiver supports DSD through HDMI, but I can't activate this feature.

Best regards,
Pedro
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#6
You could try asking about the HDMI bit depth on the Raspberry Pi forum.
https://www.raspberrypi.org/forums/

What receiver are u using?
Enjoy the Music!
moodeaudio.org | Twitter Feed | Git Repo
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#7
(01-22-2021, 02:40 PM)Tim Curtis Wrote: You could try asking about the HDMI bit depth on the Raspberry Pi forum.
https://www.raspberrypi.org/forums/

What receiver are u using?

I'm using a Pioneer VSX 2021k (USA) or VSX LX 55 (EUROPE)

It has an internal DAC that supports 24bit/192khz
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#8
I would just check the manual to see what bit depths and sample rates the S/PDIF (optical, coaxial) or USB inputs support and try one of those.

A good S/PDIF coaxial board for the Pi is Allo DigiOne https://www.allo.com/sparky/digione.html
Enjoy the Music!
moodeaudio.org | Twitter Feed | Git Repo
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#9
(01-22-2021, 03:08 PM)Tim Curtis Wrote: I would just check the manual to see what bit depths and sample rates the S/PDIF (optical, coaxial) or USB inputs support and try one of those.

A good S/PDIF coaxial board for the Pi is Allo DigiOne https://www.allo.com/sparky/digione.html

Thank you, I will check for this coaxial board.

Please let me know if you know something more about my receiver.

Meanwhile I will post on the RPI forum a thread about the bit length.

Many thanks, Tim
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