fldigi stops after a few seconds while receiving audio from airspy-fmradion via snd-aloop

[EricFROL]

Running on dietpi. Starts fine, and without printing any error stops the output of audio, as fldigi stops receiving data.

Log:

airspy-fmradion -t airspyhf -q -m usb -c freq=13881000,hf_att=0 -P -
airspy-fmradion 20231216-0
Software FM/AM radio for Airspy R2, Airspy HF+, and RTL-SDR
VOLK_VERSION = 020502
ALSA lib pcm.c:2666:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.front
ALSA lib pcm.c:2666:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.rear
ALSA lib pcm.c:2666:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.center_lfe
ALSA lib pcm.c:2666:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.side
ALSA lib pcm.c:2666:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.surround21
ALSA lib pcm.c:2666:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.surround21
ALSA lib pcm.c:2666:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.surround40
ALSA lib pcm.c:2666:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.surround41
ALSA lib pcm.c:2666:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.surround50
ALSA lib pcm.c:2666:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.surround51
ALSA lib pcm.c:2666:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.surround71
ALSA lib pcm.c:2666:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.iec958
ALSA lib pcm.c:2666:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.iec958
ALSA lib pcm.c:2666:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.iec958
ALSA lib confmisc.c:1369:(snd_func_refer) Unable to find definition 'cards.0.pcm.hdmi.0:CARD=0,AES0=4,AES1=130,AES2=0,AES3=2'
ALSA lib conf.c:5180:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
ALSA lib conf.c:5703:(snd_config_expand) Evaluate error: No such file or directory
ALSA lib pcm.c:2666:(snd_pcm_open_noupdate) Unknown PCM hdmi
ALSA lib confmisc.c:1369:(snd_func_refer) Unable to find definition 'cards.0.pcm.hdmi.0:CARD=0,AES0=4,AES1=130,AES2=0,AES3=2'
ALSA lib conf.c:5180:(_snd_config_evaluate) function snd_func_refer returned error: No such file or directory
ALSA lib conf.c:5703:(snd_config_expand) Evaluate error: No such file or directory
ALSA lib pcm.c:2666:(snd_pcm_open_noupdate) Unknown PCM hdmi
ALSA lib pcm.c:2666:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.modem
ALSA lib pcm.c:2666:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.modem
ALSA lib pcm.c:2666:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.phoneline
ALSA lib pcm.c:2666:(snd_pcm_open_noupdate) Unknown PCM cards.pcm.phoneline
Cannot connect to server socket err = No such file or directory
Cannot connect to server request channel
jack server is not running or cannot be started
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock
Cannot connect to server socket err = No such file or directory
Cannot connect to server request channel
jack server is not running or cannot be started
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock
ALSA lib pcm_oss.c:397:(_snd_pcm_oss_open) Cannot open device /dev/dsp
ALSA lib pcm_oss.c:397:(_snd_pcm_oss_open) Cannot open device /dev/dsp
ALSA lib pcm_a52.c:1001:(_snd_pcm_a52_open) a52 is only for playback
ALSA lib conf.c:5670:(snd_config_expand) Unknown parameters {AES0 0x6 AES1 0x82 AES2 0x0 AES3 0x2 CARD 0}
ALSA lib pcm.c:2666:(snd_pcm_open_noupdate) Unknown PCM iec958:{AES0 0x6 AES1 0x82 AES2 0x0 AES3 0x2 CARD 0}
ALSA lib confmisc.c:160:(snd_config_get_card) Invalid field card
ALSA lib pcm_usb_stream.c:482:(_snd_pcm_usb_stream_open) Invalid card 'card'
ALSA lib confmisc.c:160:(snd_config_get_card) Invalid field card
ALSA lib pcm_usb_stream.c:482:(_snd_pcm_usb_stream_open) Invalid card 'card'
ALSA lib pcm_dmix.c:999:(snd_pcm_dmix_open) unable to open slave
Cannot connect to server socket err = No such file or directory
Cannot connect to server request channel
jack server is not running or cannot be started
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock
playing audio to PortAudio default device: name 'default'
using device 0: Serial 2f528d8095444ad5
tuned for 13.881 [MHz]
Decoding modulation type: usb
IF sample rate: 384000 [Hz], IF decimation: / 8
Demodulator rate: 48000 [Hz], audio decimation: / 1
AM demodulator deemphasis: 100 [µs]
Filter type: default

[jj1bdx]

You must use a loopback device (snd_aloop or snd-aloop) between airspy-fmradion and fldigi. The whole setup must be on ALSA level because airspy-fmradion does not use PulseAudio at all. You can find the PortAudio device number by system_info.py of PyAudio.

I guess this is not an airspy-fmradion problem because your audio output is directed to PortAudio default device.

[EricFROL]

Any advice on how to make airspy-fmradion output to alsa instead of pulseaudio?

[EricFROL]

This is what I can select in fldigi

[EricFROL]

And these are my portaudio devices:

   0 bcm2835 Headphones: - (hw:0,0), ALSA (0 in, 8 out)
   1 Loopback: PCM (hw:2,0), ALSA (32 in, 32 out)
   2 Loopback: PCM (hw:2,1), ALSA (32 in, 2 out)
   3 sysdefault, ALSA (0 in, 128 out)
   4 lavrate, ALSA (0 in, 128 out)
   5 samplerate, ALSA (0 in, 128 out)
   6 speexrate, ALSA (0 in, 128 out)
   7 pulse, ALSA (32 in, 32 out)
   8 speex, ALSA (0 in, 1 out)
   9 upmix, ALSA (0 in, 8 out)
  10 vdownmix, ALSA (0 in, 6 out)
  11 dmix, ALSA (0 in, 2 out)
* 12 default, ALSA (32 in, 32 out)

[jj1bdx]

Use hw:2,0 for airspy-fmradion output (-P 2 in your setting), and use hw:2,1 for fldigi input. airspy-fmradion does not use PulseAudio at all.

[EricFROL]

Getting this when running with -P 2:

(...)
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for -1, skipping unlock
Expression 'paInvalidSampleRate' failed in 'src/hostapi/alsa/pa_linux_alsa.c', line: 2048
Expression 'PaAlsaStreamComponent_InitialConfigure( &self->playback, outParams, self->primeBuffers, hwParamsPlayback, &realSr )' failed in 'src/hostapi/alsa/pa_linux_alsa.c', line: 2721
Expression 'PaAlsaStream_Configure( stream, inputParameters, outputParameters, sampleRate, framesPerBuffer, &inputLatency, &outputLatency, &hostBufferSizeMode )' failed in 'src/hostapi/alsa/pa_linux_alsa.c', line: 2842
playing audio to PortAudio device 2: name 'Loopback: PCM (hw:2,1)'
ERROR: AudioOutput: Pa_OpenStream(): PortAudio error: (number: -9997 message: Invalid sample rate)

[jj1bdx]

fldigi

• open dialog box: Configure -> Config Dialog -> Soundcard -> Settings
• Set Sample rate to 48000Hz

Also:

• use hw:2,0 for airspy-fmradion -P 1 (that's my bad)

[EricFROL]

Now starts audio, but same issue as before, suddenly stops. Btw airspyfmradion command continues active. Getting this log: Expression 'ValidateParameters( inputParameters, hostApi, StreamDirection_In )' failed in 'src/hostapi/alsa/pa_linux_alsa.c', line: 1838

[jj1bdx]

In my case, running Ubuntu 22.04.3 x86_64, airspy-fmradion 20240107-0, and fldigi 4.2.03.10 worked OK (at least the audio didn't stop). I don't think this is airspy-fmradion's general issue but rather a configuration issue. Can you tell me your fldigi's version?

[jj1bdx]

I spent six hours trying to find out that this is a bug in the PortAudio of Raspberry Pi. I even tried to rebuild my own PortAudio and traced the issue, but I decided I wouldn't be able to go further. Here in my Raspberry Pi environment, the snd_aloop device is recognized by the alsa programs (such as "aplay -L"), but the snd_aloop devices are not recognized at all by PortAudio. Other than this, airspy-fmradion and fldigi (on Raspberry Pi) both worked fine.

Possible related issues:

• https://github.com/PortAudio/portaudio/issues/431
• https://github.com/PortAudio/portaudio/issues/860

[jj1bdx]

I installed a clean-slate Raspberry Pi OS 64bit (bookworm) to a Raspberry Pi 4B 2GB RAM, and necessary libraries with no private build other than airspy-fmradion, and found that everything went fine between the installed airspy-fmradion and fldigi. So I have to conclude there is something wrong with PortAudio on bullseye.

I conclude this is not an airspy-fmradion issue, so I will close this issue.

[jj1bdx]

Further discussion: #69

[EricFROL]

So what should I do?

[jj1bdx]

@EricFROL I'm sorry, I can't propose any viable solution right now because it's out of the scope of airspy-fmradion. The Debian bullseye problem of being unable to handle snd_aloop of PortAudio prevented me from debugging this case. As you told me privately, I hope your problem has been solved. I would consider terminating support for Raspberry Pi bullseye, due to older CMake and the whole issue I experienced yesterday (which I could not solve even by reinstalling PortAudio).