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ALSABAT(1)		    General Commands Manual		    ALSABAT(1)

       alsabat - command-line sound tester for ALSA sound card driver

       alsabat [flags]

       ALSABAT(ALSA  Basic  Audio Tester) is a simple command-line utility in-
       tended to help automate audio driver and	sound server testing with lit-
       tle  human  interaction.	 ALSABAT  can  be  used	to test	audio quality,
       stress test features and	test audio before and after PM state changes.

       ALSABAT's design	is relatively simple. ALSABAT plays  an	 audio	stream
       and  captures  the same stream in either	a digital or analog loop back.
       It then compares	the captured stream using a FFT	to the original	to de-
       termine if the test case	passes or fails.

       ALSABAT	can  either  run  wholly  on  the  target machine being	tested
       (standalone mode) or can	run as a client/server mode where  by  alsabat
       client runs on the target and runs as a server on a separate tester ma-
       chine. The client/server	mode still requires  some  manual  interaction
       for  synchronization,  but  this	is actively being developed for	future

       The hardware testing configuration may require the use of an analog ca-
       ble connecting target to	tester machines	or a cable to create an	analog
       loopback	if no loopback mode is not available  on  the  sound  hardware
       that  is	being tested.  An analog loopback cable	can be used to connect
       the "line in" to	"line out" jacks to create a loopback. If  only	 head-
       phone  and  mic	jacks (or combo	jack) are available then the following
       simple circuit can be used to create an analog loopback :-

       If tinyalsa is installed	in system, user	can choose tinyalsa as backend
       lib of alsabat, with configure option "--enable-alsabat-backend-tiny".

       -h, --help
	      Help: show syntax.

       -D     Select sound card	to be tested by	name.

       -P     Select the playback PCM device.

       -C     Select the capture PCM device.

       -f     Sample format
	      Recognized sample	formats	are: U8	S16_LE S24_3LE S32_LE
	      Some of these may	not be available on selected hardware
	      The available format shortcuts are:
	      -f cd (16	bit little endian, 44100, stereo) [-f S16_LE -c2 -r44100]
	      -f dat (16 bit little endian, 48000, stereo) [-f S16_LE -c2 -r48000]
	      If no format is given S16_LE is used.

       -c     The  number of channels. The default is one channel.  Valid val-
	      ues at the moment	are 1 or 2.

       -r     Sampling rate in Hertz. The default rate is 44100	Hertz.	 Valid
	      values depends on	hardware support.

       -n     Duration	of generated signal.  The value	could be either	of the
	      two forms:
	      1. Decimal integer, means	number of frames;
	      2. Floating point	with suffix 's', means number of seconds.
	      The default is 2 seconds.

       -k     Sigma k value for	analysis.
	      The analysis function reads data from WAV	file, run FFT  against
	      the  data	to get magnitude of frequency vectors, and then	calcu-
	      lates the	average	value and standard deviation of	frequency vec-
	      tors. After that,	we define a threshold:
	      threshold	= k * standard_deviation + mean_value
	      Frequencies  with	amplitude larger than threshold	will be	recog-
	      nized as a peak, and the frequency with largest peak value  will
	      be recognized as a detected frequency.
	      ALSABAT  then  compares  the  detected  frequency	to target fre-
	      quency, to decide	if the detecting passes	or fails.
	      The default value	is 3.0.

       -F     Target frequency for signal generation and analysis,  in	Hertz.
	      The default is 997.0 Hertz.  Valid range is (DC_THRESHOLD, 40% *
	      Sampling rate).

       -p     Total number of periods to play or capture.

	      Write stderr and stdout output to	this log file.

	      Input WAV	file for playback.

	      Target WAV file to save capture test content.

	      Internal loopback	mode.  Playback, capture and analysis internal
	      to  ALSABAT  only.  This	is intended for	developers to test new
	      ALSABAT features as no audio is routed outside of	ALSABAT.

	      Add support for standalone mode where ALSABAT will run on	a dif-
	      ferent machine to	the one	being tested.  In standalone mode, the
	      sound data can be	generated, playback and	captured just like  in
	      normal  mode, but	will not be analyzed.  The ALSABAT being built
	      without libfftw3 support is  always  in  standalone  mode.   The
	      ALSABAT  in  normal mode can also	bypass data analysis using op-
	      tion "--standalone".

	      Round trip latency test.	Audio latency is the time delay	as  an
	      audio  signal  passes through a system.  There are many kinds of
	      audio latency metrics. One useful	metric is the round  trip  la-
	      tency, which is the sum of output	latency	and input latency.

	      Noise  detection	threshold in SNR (dB). 26dB indicates 5% noise
	      in amplitude.  ALSABAT  will  return  error  if  signal  SNR  is
	      smaller than the threshold.

	      Noise  detection threshold in percentage of noise	amplitude (%).
	      ALSABAT will return error	if the noise amplitude is larger  than
	      the threshold.

       alsabat -P plughw:0,0 -C	plughw:0,0 -c 2	-f S32_LE -F 250
	      Generate	and  play  a sine wave of 250 Hertz with 2 channel and
	      S32_LE format, and then capture and analyze.

       alsabat -P plughw:0,0 -C	plughw:0,0 --file 500Hz.wav
	      Play the RIFF WAV	file  "500Hz.wav"  which  contains  500	 Hertz
	      waveform LPCM data, and then capture and analyze.

       On success, returns 0.
       If no peak be detected, returns -1001;
       If only DC be detected, returns -1002;
       If  peak	 frequency  does  not match with the target frequency, returns


       Currently only support RIFF WAV format with PCM data. Please report any
       bugs to the alsa-devel mailing list.

       alsabat	is by Liam Girdwood <>, Bernard
       Gautier	<>  and  Han  Lu  <>.
       This document is	by Liam	Girdwood <> and
       Han Lu <>.

			       20th October 2015		    ALSABAT(1)


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