Measuring Audio Processing Latency for Lip-Sync purposes in DSP-based Home Theatre Systems

Higher communication requirements introduced with advances in digital audio have also led to many connectivity and compatibility challenges in consumer electronics (CE). Systems composed of several audio-video, pre-and post-processing components such as Home Theatres (HT) often open up some major issues due to incompatibile processing times between included components. The main such issue is lip-sync error - one of the most disturbing flaws of HT and similar systems from consumers perspective. With announcement of HDMI feature known as Enhanced Audio Return Channel (eARC) utilization of full audio bandwidth and thus processing of HQ object-based audio technologies such as Dolby Atmos and DTS:X is finally possible. However, audio bandwidth magnified by several milions of bits has also increased audio processing latencies and has made even wider gap between audio-video processing times. In order to optmize high memory demands and compensate for delays in the HT system, audio engineers need to precisely measure digital audio processing latencies. This paper proposes a method for the most accurate measurement of digital processing times in DSP-based audio systems.