[Jack-Devel] Capture problems with jack2 on Axia-Alsa device

[Christian Affolter]

Hi Thomas,

thanks for your reply.

On 30.01.2018 13:09, Thomas Brand wrote:
> 
> Hi Chris,
> 
> this sounds like a SR mismatch but it's not obvious.

Yes, most likely.


> before you debug more, can you try to record with
> https://github.com/kmatheussen/jack_capture ?

This results in the same issue. I've started jack_capture with the
following parameters:

jack_capture -b 32 -c 2 -d 10 -fn /tmp/test-jack_capture.wav \
             -p system:capture_1 \
             -p system:capture_2

The resulting file:
https://filebin.ca/3pykjU8lo2jO/test-jack_capture.wav


> A simple test is to connect system:capture to system:playback and see if
> you get what's expected on your headphone/speakers.

Yes, but unfortunately it's a virtual device running on a headless
server without any speakers attached. The playout would go into the
Livewire+ network where I would have to re-capture it from another system.

> You can then go on to
> see if jack_capture solves the issue for you.
> 
> Greetings
> Thomas

Thanks,
Chris

> 
> On Tue, January 30, 2018 12:35, Christian Affolter wrote:
>> Hi everyone,
>>
>>
>> capturing from ALSA capture devices via the Jack2 sound server (1.9.12),
>> results in too high pitched wav files (they are playing "too fast" and
>> sound like the "chipmunks"). If I run the same capture directly from the
>> ALSA devices (without Jack involved), everything sounds as expected
>> without any problems.
>>
>> Audio examples:
>> Capture via jackrec: https://filebin.ca/3pyMxBw8cexQ/test-jackrec.wav
>> Capture via arecord: https://filebin.ca/3pyOPjcKGym5/test-arecord.wav
>>
>>
>> The device in question is a "virtual" Axia-ALSA (Livewire+) audio device
>> on CentOS 7 which operates at a sample rate of 48kHz and a bit depth of
>> either 16 or 32. As far as I can see, the sample rate and format detection
>> on the Jack side looks correct. I'm therefore looking for some guidance on
>> how to further debug this, I most certainly missed something obvious.
>>
>> I've also tried to play an mp3 file via mpg123 over jack (without the
>> involvement of the Alsa device) and record it again with jackrec. This
>> works and sounds correct.
>>
>> Here is what I've tried and what the environment looks like:
>>
>>
>> # Capabilities of the Axia-ALSA device
>> arecord -D hw:0 --dump-hw-params
>>
>> Recording WAVE 'stdin' : Unsigned 8 bit, Rate 8000 Hz, Mono
>> HW Params of device "hw:0":
>> --------------------
>> ACCESS:  MMAP_INTERLEAVED RW_INTERLEAVED
>> FORMAT:  S16_LE S32_LE
>> SUBFORMAT:  STD
>> SAMPLE_BITS: [16 32]
>> FRAME_BITS: [16 256]
>> CHANNELS: [1 8]
>> RATE: 48000
>> PERIOD_TIME: (41 1365334)
>> PERIOD_SIZE: [2 65536]
>> PERIOD_BYTES: [64 131072]
>> PERIODS: [1 1024]
>> BUFFER_TIME: (41 1365334)
>> BUFFER_SIZE: [2 65536]
>> BUFFER_BYTES: [64 131072]
>> TICK_TIME: ALL
>> --------------------
>> arecord: set_params:1299: Sample format non available
>> Available formats:
>> - S16_LE
>> - S32_LE
>>
>>
>>
>> # Capture via arecord directly from the ALSA device (without jackd)
>> # This works as expected and the WAV file sounds fine
>> arecord -D hw:0 -c 2 -d 10 -r 48000 -f S32_LE -v /tmp/test-arecord.wav
>>
>> Recording WAVE '/tmp/test-arecord.wav' : Signed 32 bit Little Endian,
>> Rate 48000 Hz, Stereo
>> Hardware PCM card 0 'Axia' device 0 subdevice 0
>> Its setup is:
>> stream       : CAPTURE access       : RW_INTERLEAVED format       : S32_LE
>> subformat    : STD channels     : 2 rate         : 48000 exact rate   :
>> 48000 (48000/1)
>> msbits       : 32 buffer_size  : 16384 period_size  : 4096 period_time  :
>> 85333
>> tstamp_mode  : NONE tstamp_type  : MONOTONIC period_step  : 1 avail_min 
>   :
>> 4096
>> period_event : 0 start_threshold  : 1 stop_threshold   : 16384
>> silence_threshold: 0
>> silence_size : 0 boundary     : 4611686018427387904 appl_ptr     : 0 hw_ptr
>> : 0
>>
>>
>>
>> # playing arecord wav (via my local notebook's HDA Intel PCH
>> # device), sounds correct
>> aplay test-arecord.wav
>>
>> Playing WAVE 'test-arecord.wav' : Signed 32 bit Little Endian, Rate
>> 48000 Hz, Stereo
>>
>>
>>
>>
>> # Starting jackd
>> # Verbose output at: https://pastebin.com/YzHEGSnR
>> jackd -d alsa -d hw:0
>>
>> jackdmp 1.9.12 Copyright 2001-2005 Paul Davis and others.
>> Copyright 2004-2016 Grame.
>> Copyright 2016-2017 Filipe Coelho.
>> jackdmp comes with ABSOLUTELY NO WARRANTY This is free software, and you
>> are welcome to redistribute it under certain conditions; see the file
>> COPYING for details
>> no message buffer overruns no message buffer overruns no message buffer
>> overruns JACK server starting in realtime mode with priority 20
>> self-connect-mode is "Don't restrict self connect requests"
>> audio_reservation_init Acquire audio card Audio0
>> creating alsa driver ... hw:0|hw:0|1024|2|48000|0|0|nomon|swmeter|-|32bit
>> configuring for 48000Hz, period = 1024 frames (21.3 ms), buffer = 2
>> periods ALSA: final selected sample format for capture: 32bit integer
>> little-endian ALSA: use 2 periods for capture
>> ALSA: final selected sample format for playback: 32bit integer
>> little-endian ALSA: use 2 periods for playback
>>
>>
>>
>> # Capture via jackrec
>> # This results in a too high pitched WAV file
>> # Verbose output at: https://pastebin.com/PCnymKLA
>> jackrec -f /tmp/test-jackrec.wav -d 10 -b 32 system:capture_1
>> system:capture_2
>>
>>
>> # playing jackrec wav (via my local notebook's HDA Intel PCH
>> # device), sounds incorrect
>> aplay test-jackrec.wav
>>
>> Playing WAVE 'test-jackrec.wav' : Signed 32 bit Little Endian, Rate
>> 48000 Hz, Stereo
>>
>>
>>
>> System environment:
>> Distribution: CentOS 7.4.1708
>> Kernel:       3.10.0-693.17.1.el7.x86_64
>> ALSA Utils:   1.1.3
>> Jackd:        1.9.12
>>
>>
>> The jackd was rebuilt from Fedora source RPM to be able to test with the
>> latest version:
>> https://build.opensuse.org/package/show/home:radiorabe:audio/jack-audio-c
>> onnection-kit
>>
>>
>> Many thanks and best regards
>> Chris
>> _______________________________________________
>> Jack-Devel mailing list
>> Jack-Devel at lists.jackaudio.org
>> http://lists.jackaudio.org/listinfo.cgi/jack-devel-jackaudio.org
>>
>>
> 
>