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SPDIF Input on Hifiberry Digi+ I/O

Sergio Prado

August 11, 2017 13:55

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I'm trying to test SPDIF Input on Hifiberry Digi+ I/O.

I'm using the latest headless raspbian installed from NOOBS.

$ cat /etc/issue
Raspbian GNU/Linux 8 \n \l

$ uname -a
Linux raspberrypi 4.9.35-v7+ #1014 SMP Fri Jun 30 14:47:43 BST 2017 armv7l GNU/Linux

Playback seems to work fine:

$ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: sndrpihifiberry [snd_rpi_hifiberry_digi], device 0: HifiBerry Digi HiFi wm8804-spdif-0 []
Subdevices: 1/1
Subdevice #0: subdevice #0

pi@raspberrypi:~ $ speaker-test -c 2 -f 1000 -t sine

speaker-test 1.0.28

Playback device is default
Stream parameters are 48000Hz, S16_LE, 2 channels
Sine wave rate is 1000.0000Hz
Rate set to 48000Hz (requested 48000Hz)
Buffer size range from 128 to 131072
Period size range from 64 to 65536
Using max buffer size 131072
Periods = 4
was set period_size = 32768
was set buffer_size = 131072
0 - Front Left
1 - Front Right
^CTime per period = 1.522844

But capture is not working.

I can list the capture device:

$ arecord -l
**** List of CAPTURE Hardware Devices ****
card 0: sndrpihifiberry [snd_rpi_hifiberry_digi], device 0: HifiBerry Digi HiFi wm8804-spdif-0 []
Subdevices: 1/1
Subdevice #0: subdevice #0

But arecord is freezing when trying to start a capture:

$ arecord -d 5 /tmp/speaker-test.wav
Recording WAVE '/tmp/speaker-test.wav' : Unsigned 8 bit, Rate 8000 Hz, Mono

When canceling the arecord execution, I can see a DMA error message in dmesg:

[  787.405484] bcm2835-dma 3f007000.dma: DMA transfer could not be terminated

Should the capture work? Is it support supported by the machine/codec driver?

Thanks,

Sergio Prado

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22 comments

• 0
  
  HiFiBerry team August 12, 2017 05:44

  Hi,

  you need to select the correct sample rate of the incoming bitstream and the correct channel number (2). The Digi+ can't convert between sample rates. Therefore if you're using the wrong sample rate, recording won't work. Check the arecord command line options.

  Best regards,
  Daniel

• 0
  
  Sergio Prado August 12, 2017 12:09

  Hi Daniel,

  Thanks for the answer.

  I'm outputing a signal from my PC using speaker-test:

  $ speaker-test -t wav -c 2 -r 48000

  And then running arecord on Hifiberry:

  $ arecord -d 3 -r 48000 -c 2 /tmp/speaker-test.wav

  I got the same results, arecord is freezing and I get this error in the kernel log:

  [  655.131632] bcm2835-dma 3f007000.dma: DMA transfer could not be terminated

  I'm inspecting the I2S signals with an osciloscope. I can see the signals when I try a playback in the board, but nothing happens at the I2S bus when trying a capture using arecord.

  I've take a brief look at the machine driver (sound/soc/bcm/hifiberry_digi.c) and I did not find the code that enables the reception (only the transmission). That's why I asked if it is supported by the driver.

  Should it work? Do you have any suggestion on what can be done to test the capture?

  Thanks,

  Sergio Prado

   

   

   

   

  Edited by Sergio Prado August 12, 2017 12:11
• 0
  
  HiFiBerry team August 12, 2017 15:27

  Yes, recording is supported. If you don't see anything with the oscilloscope, the receiver does not seem to lock onto the input signal. Are you using the coaxial or the TOSLink input?

  Best regards,
  Daniel

• 0
  
  Sergio Prado August 13, 2017 17:50

  Hi Daniel,

  Thanks. Now it is working.

  For some reason my PC was not outputing the audio to the SPDIF port. Now it is, and I could successfully test the recording running speaker-test from my PC and capturing with arecord on the Hifiberry.

  The catch was to select in both commands (arecord and speaker-test) the correct sample rate and channel number (2).

  Best regards,

  Sergio Prado

• 0
  
  David January 14, 2018 07:38

  Hi Sergio,

   

  Can you provide some insight into how you setup your I/O? I can't get any devices to list with arecord so spdif input is a no go.

   

  Thanks!

• 0
  
  HiFiBerry team January 14, 2018 07:48

  Hi David,

  does "aplay -l" list the card? If not, I guess, you did not configure the card.
  Check out this document:

  https://www.hifiberry.com/build/documentation/configuring-linux-3-18-x/

  Best regards,
  Daniel

• 0
  
  David January 14, 2018 08:22

  Hi Daniel,

  Thanks for the quick reply and the link. That worked and I now have it listed in arecord.

  It's strange as setting the dtoverlay with openelec didn't work.

  Then I tried raspbian and enabled and loaded the modules via menuconfig with no luck.

  Wish I saw this sooner! 

  Thanks agian!

   

• 0
  
  Waldemar Gumowski November 10, 2019 16:39

  Hello Guys

  I'm having trouble recording from the spdif coax and optic input.

  
  My set consists of Raspberry Pi 3B + and Hifiberry Digi + I / O.
  I have the latest Rasbian Buster installed with all updates.
  The /boot/config.txt configuration includes:
  dtparam=i2c_arm = on
  dtparam=I2S = on
  dtoverlay = hifiberry-digi
  dtparam=audio = on
  enable_uart = 0
  gpu_mem = 124
  dtdebug = 1
  dtparam = spi = on

  
  The system recognizes the cards correctly:

  pi @ raspberrypi: ~ $ aplay -l
  **** List of PLAYBACK Hardware Devices ****
  card 0: ALSA [bcm2835 ALSA], device 0: bcm2835 ALSA [bcm2835 ALSA]
    Subdevices: 7/7
    Subdevice # 0: subdevice # 0
    Subdevice # 1: subdevice # 1
    Subdevice # 2: subdevice # 2
    Subdevice # 3: subdevice # 3
    Subdevice # 4: subdevice # 4
    Subdevice # 5: subdevice # 5
    Subdevice # 6: subdevice # 6
  card 0: ALSA [bcm2835 ALSA], device 1: bcm2835 IEC958 / HDMI [bcm2835 IEC958 / HDMI]
    Subdevices: 1/1
    Subdevice # 0: subdevice # 0
  card 0: ALSA [bcm2835 ALSA], device 2: bcm2835 IEC958 / HDMI1 [bcm2835 IEC958 / HDMI1]
    Subdevices: 1/1
    Subdevice # 0: subdevice # 0
  card 1: sndrpihifiberry [snd_rpi_hifiberry_digi], device 0: HifiBerry Digi HiFi wm8804-spdif-0 []
    Subdevices: 1/1
    Subdevice # 0: subdevice # 0

  pi @ raspberrypi: ~ $ arecord -l
  **** List of CAPTURE Hardware Devices ****
  card 1: sndrpihifiberry [snd_rpi_hifiberry_digi], device 0: HifiBerry Digi HiFi wm8804-spdif-0 []
    Subdevices: 1/1
    Subdevice # 0: subdevice # 0

  I can receive a stream from the internet and output it on spdif out:

  pi @ raspberrypi: ~ $ ffmpeg -i http://94.23.36.117:5064 -f alsa -ar 44100 -acodec pcm_s16le hw: 1
  ffmpeg version 4.1.4-1 + rpt1 ~ deb10u1 Copyright (c) 2000-2019 the FFmpeg developers
    built with gcc 8 (Raspbian 8.3.0-6 + rpi1)
    configuration: --prefix = / usr --extra-version = '1 + rpt1 ~ deb10u1' --toolchain = hardened --libdir = / usr / lib / arm-linux-gnueabihf --incdir = / usr / include / arm -linux-gnueabihf --arch = arm --enable-gpl --disable-stripping --enable-avresample --disable-filter = resample --enable-avisynth --enable-gnutls --enable-ladspa --enable- libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libflite --enable-libfontconfig --enable-libfreetype --enable- libfribidi --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable- librsvg --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvidstab --enable- libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --en able-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opengl --enable-sdl2 --enable-omx-rpi --enable-mmal --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libx264 --enable-shared
    libavutil 56. 22.100 / 56. 22.100
    libavcodec 58. 35.100 / 58. 35.100
    libavformat 58. 20.100 / 58. 20.100
    libavdevice 58. 5.100 / 58. 5.100
    libavfilter 7. 40.101 / 7. 40.101
    libavresample 4. 0. 0 / 4. 0. 0
    libswscale 5. 3.100 / 5. 3.100
    libswresample 3. 3.100 / 3. 3.100
    libpostproc 55. 3.100 / 55. 3.100
  Input # 0, mp3, from 'http://94.23.36.117:5064':
    metadata:
      icy-notice1: <BR> This stream requires <a href="http://www.winamp.com"> Winamp </a> <BR>
      icy-notice2: SHOUTcast DNAS / posix (linux x86) v2.5.5.733 <BR>
      icy-name: R. Family
      icy-genre: Christian
      icy-br: 96
      icy-sr: 48,000
      icy-url: www.radiorodzina.kalisz.pl
      icy-pub: 1
    Duration: N / A, start: 0.000000, bitrate: 96 kbps
      Stream # 0: 0: Audio: mp3, 48000 Hz, stereo, fltp, 96 kbps
  Stream mapping:
    Stream # 0: 0 -> # 0: 0 (mp3 (mp3float) -> pcm_s16le (native))
  Press [q] to stop, [?] For help
  Output # 0, alsa, to 'hw: 1':
    metadata:
      icy-notice1: <BR> This stream requires <a href="http://www.winamp.com"> Winamp </a> <BR>
      icy-notice2: SHOUTcast DNAS / posix (linux x86) v2.5.5.733 <BR>
      icy-name: R. Family
      icy-genre: Christian
      icy-br: 96
      icy-sr: 48,000
      icy-url: www.radiorodzina.kalisz.pl
      icy-pub: 1
      encoder: Lavf58.20.100
      Stream # 0: 0: Audio: pcm_s16le, 44100 Hz, stereo, s16, 1411 kbps
      metadata:
        encoder: Lavc58.35.100 pcm_s16le
      
  size = N / A time = 00: 07: 26.88 bitrate = N / A speed = 1.01x

  I am sure that I have the correct digital signal on the spdif coax and optic output because I measure it with a TCelectronic meter - I attach a photo.

   

• 0
  
  HiFiBerry team November 10, 2019 16:41

  What do you do to record something? You logs show only playback.

  Best regards,
  Daniel

• 0
  
  Waldemar Gumowski November 10, 2019 16:44

  

• 0
  
  Waldemar Gumowski November 10, 2019 16:48

  The problem occurs when I want to record an audio stream from the spdif input. This applies to both coax and optical inputs.

  pi @ raspberrypi: ~ $ arecord -v -V stereo -D hw: 1 -c 2 -d 10 -t wav -r 44100 -f S16_LE test-ar.wav
  Recording WAVE 'test-ar.wav': Signed 16 bit Little Endian, Rate 44100 Hz, Stereo
  Hardware PCM card 1 'snd_rpi_hifiberry_digi' device 0 subdevice 0
  Its setup is:
    stream: CAPTURE
    access: RW_INTERLEAVED
    format: S16_LE
    subformat: STD
    channels: 2
    rate: 44100
    exact rate: 44100 (44100/1)
    msbits: 16
    buffer_size: 22052
    period_size: 5513
    period_time: 125011
    tstamp_mode: NONE
    tstamp_type: MONOTONIC
    period_step: 1
    avail_min: 5513
    period_event: 0
    start_threshold: 1
    stop_threshold: 22052
    silence_threshold: 0
    silence_size: 0
    boundary: 1445199872
    appl_ptr: 0
    hw_ptr: 0
  arecord: pcm_read: 2145: read error: input / output error

  I made an oscilloscope measurement at the input of the wm8804 (pin 20) - there is the correct signal. At the DOUT (pin 12) output, the oscilloscope unfortunately detects nothing.
  What am I doing wrong? Where is the problem.

  I tried various configuration options:
  1. 44100 u16le
  2. 44100 u24le
  3. 44100 u24-3le (3 bait)
  4. 48,000 u16le
  5. 48000 u24le
  6. 48000 u24-3le
  None of them work!

  Please help me....Thanks

  Waldemar

• 0
  
  Waldemar Gumowski November 10, 2019 18:38

  Sorry, I submit before I finished...

• 0
  
  Waldemar Gumowski November 10, 2019 21:10

  Next test I made

  1. 44100 s16le
  2. 44100 s24le
  3. 44100 s24-3le (3 bait)
  4. 48000 s16le
  5. 48000 s24le
  6. 48000 s24-3le

  still nothing...

• 0
  
  HiFiBerry team November 11, 2019 07:09

  Do you have any application running that uses the output? 

• 0
  
  Waldemar Gumowski November 11, 2019 08:10

  Hi, no I haven't.

  

  I have a second RaspberryPi with ... Digi output on which I start playback. I also have TASCAM recorder to convert and listen to SPDIF Coax / Optic

  

  This is not the latest equipment but has inputs and outputs:AS / EBU, SPDIF, Analog - so it works as a monitor and tester.

  I also conducted a test on one RaspberryPi from output to input (ffmpeg out to arecord in) - no luck...

  Waldemar

   

   

• 0
  
  Waldemar Gumowski November 13, 2019 20:19

  Hi.

  Any suggestions...? Any ideas...?
  I have no changes.

  I ordered the HiFiBerry Digi I / O sticky art.
  When it comes I will let you know if the problem is still there.

  Regards

   

• 0
  
  Waldemar Gumowski November 13, 2019 20:20

  Hi.

  Any suggestions...? Any ideas...?
  I have no changes.

  I ordered the HiFiBerry Digi I / O sticky art.
  When it comes I will let you know if the problem is still there.

  Regards

   

• 0
  
  HiFiBerry team November 13, 2019 20:22

  The cables you are using there do not look like 75 Ohm SPDIF cables, but low frequency audio cables. First things I would recommend is to use correct 75 Ohm coax cables.
  BTW: What are these cables connected to?

  Edited by HiFiBerry team November 13, 2019 20:23
• 0
  
  Waldemar Gumowski November 13, 2019 20:32

  This is not an argument ... It is the same with an optical cable

• 0
  
  Waldemar Gumowski November 13, 2019 20:37

  by the way ... with cable lengths of several centimeters, resistance should not be so important

• 0
  
  Waldemar Gumowski November 28, 2019 17:57

  Hi again after some days...

  I have good and bad news at one time!

  The good news is that I was able to finally start recording via the SPDIF and Optic interface. But the bad thing is that this was done on the new (second) DIGI + I / O module. I was almost sure on November 13, 2019 when I conducted all possible trials and tests that that module has a problem.
  I bought this current and previous DIGI + I / O module on the "Reichelt Elektronik" website - they suggest that the manufacturer replace the defective product for me! What do you say about that?

  Greetings!

  Waldemar

• 0
  
  HiFiBerry team November 28, 2019 19:15

  I'll open a ticket for this.