XVU Audio Utility

XVU (Xmos VU) is a host side utility written in Python that captures low-overhead xscope_int() instrumentation probes from your xcore app and turns the output into:

• A real time decibel meter with a peak hold function
• A wav file recorder
• An audio output from your host (Will be slightly glitchy due to rate mismatch)

The tool is tested with Xmos tools version 14.3.4.

Usage

You need to simultaneously run the firmware and the xvu script. They communicate via a port on the localhost:

xvu.py  -r 48000 -p 6231

and:

xrun --xscope-port localhost:6231 my_test_app.xe

The run command runs the binary and forwards the debug output over xscope to a port. The xvu.py script listens to the port and decodes the messages.

VU Meter example

Here is what the VU meter looks like to run:

xvu.py -r 48000 -p 6231 Please start target app: xrun --xscope-port localhost:6231 <binary.xe> Connected on localhost: 6231 Expecting xscope_int data: 32b @ 48000Hz

Raw mic -17.56dB -10.27dB *****************--@-- Processed -19.63dB -10.27dB ****************---@--

Wav file capture usage example

xvu.py -r 16000 -p 6231 -w ./micData.wav

xrun --xscope-port localhost:6231 app_voice_processing.xe

Performance

It copes OK with 2 channels at 48k on my 2014 i5 macbook, so should be able to do Multiple channels at 16k.

Enabling xscope

Please see the following for a simple example:

http://www.xcore.com/viewtopic.php?f=48&t=6939

Options

Here is the help output from the utility:

usage: xvu.py [-h] [-r SAMP_RATE] [-s SAMP_DEPTH] [-p PORT] [-w WAV_FILE]

[-m MONITOR] [-n]

XMOS Audio Probe Tool

optional arguments:

-h, --help	show this help message and exit
-r SAMP_RATE, --samp_rate SAMP_RATE
	Sample rate in Hz (default: 16000)
-s SAMP_DEPTH, --samp-depth SAMP_DEPTH
	Number of bits in audio samples from device xscope_int() output (default: 32)
-p PORT, --port PORT
	Port of localhost used to communicate with xrun (default: 6363)
-w WAV_FILE, --wav-file WAV_FILE
	Write wav file (default: None)
-m MONITOR, --monitor MONITOR
	Live monitor audio output of a probe. WARNING: May contain glitches (default: None)
-n, --no-vu	Disable VU (default: False)