Reducing the latency in live music transmission with the BeagleBoard xM through resampling

In previous works, a widespread embedded platform, the BeagleBoard xM, was shown to provide sufficient through-put and acceptable latency for live music control and audio signals transmission on standard LAN and WLAN protocols. Although the preliminary work opened the way for further investigations, the software stack did not prove efficient enough to deliver stable audio performance below the perceptual latency threshold for good ensemble playing. This work reports on a custom Debian Linux image, called WeMUST-OS for the BeagleBoard xM, configured for the task at hand by careful low-level ALSA driver configuration with the DM3730 SoC and the TPS65950 audio codec to improve local audio input/output latency. Furthermore Jacktrip, an application for music audio transmission, has been modified with added support to resampling enabling seamless connection with other devices running audio at different sample rate and period size. Leveraging these two achievements, latency is shown to keep under perceptual threshold for ensemble music performance including transmission of the monitoring signal.