This tool can be run on any Linux machine, not just a ChromeBook, providied the ALSA audio subsystem is available, and it usually will be. Scripts would be different for different laptop/chromebook devices as the configuration of audio inputs and outputs can be very different across different platforms. It is a command line tool which lends itself to being script driven. This could be handled by using a larger transform space and taking a little more time in processing. More than 7 tones can be used but peak discrimination of the convolved signal becomes more difficult. During that time up to 7 sinsusoidal tones are polyphonically played, captured, Fourier analyzed, a report given and an optional spectrogram created. This test is fast- usually running in 1/2 second per port combination tested. Any missing or unexpected tones are reported.
The incoming sound is convolved through a Fourier Transform and the resulting energy peaks are filtered, sorted and compared to the known expected tones. USB/audio dongles can also be tested and the audio output present in a HDMI port can likewise be tested with an appropriate dongle while looping back to an incoming microphone port. The external Mic/Headphone jack can easily be tested but the built-in speakers and microphone can also be tested by placing the ChromeBook/Laptop in a box and arranging for the built-in speaker sound to bounce off a surface and be directed to the built-in microphone. It performs polyphonic tone synthesis while simultaneously capturing the incoming sound in some form of external audio loopback. This package intends to be a fast and powerful automated audio test tool. 3224399 cyclic_bench_test: Add script to get cyclic test result.fe5a780 audiofuntest: Add an option to save played audio file by Cheng Yueh.a0a7ca5 audiofuntest: Add an option to save recorded audio file by Cheng Yueh.d38d1e4 audiofuntest: Allows for different input/output sample rates by Gene Chang.c4f3a48 loopback_latency: Add flag for pinning capture device by Li-Yu Yu.asoundrc or nf files put the following: pcm. You now have access to the hardware loopback device. Setting up the loopback deviceįirst load the loopback kernel module snd-aloop normally using modprobe or init scripts or whatever suits you: modprobe snd-aloop. This can be achieved using the ALSA loopback device. If you need the virtual machine for some audio applications, it would be hugely practical to be able to somehow mix guest audio with host audio. It requires exclusive access to the hardware ALSA device, which of course leaves the host system without audio. The problem is, KVM does not support virtual ALSA devices. The latter two being not so useful for practical audio on modern systems, ALSA is the only real option.
AUDIO LOOPBACK TEST DRIVERS
On the host end, available drivers include ALSA, OSS and WAV. Valid sound card names (comma separated):
As of version 2.3.0, the Kernel-based Virtual Machine (KVM) has the ability to emulate several audio devices: ~ $ qemu-system-x86_64 -soundhw help