GPU-based image method for room impulse response calculation
Zhonghua Fu, Jian-wei Li · Multimedia Tools and Applications · 2015
Room impulse response (RIR) simulation based on the image-source method is widely used in room acoustic research. The calculation of the RIR in computer has to digitalize sound propagation delay into discrete samples. To carefully consider the digitalization error greatly increases the massive computational load of the image-source method. Therefore many real-time audio applications simply round-off the propagation delay to its nearest sample. This approximation, however, especially when the sampling frequency is low, degrades the phase precision that is required by applications such as microphone array. In this paper, by involving a Hanning-windowed ideal low-pass filter to reduce the digitalization error, a more precise image-source model is studied. We analyze its parallel calculation procedure and propose to use Graphics Processing Unit (GPU) to accelerate the calculation speed. The calculation procedure is divided into many parallel threads and arranged according the GPU architecture and its optimization criteria. We evaluate the calculation speeds of different RIRs using a general 5-core CPU, an ordinary GPU (GTX750) and an advanced GPU (K20C). The results show that, with similar precise RIR results, the speedup ratios of GTX750 and K20C over the general CPU can achieve 20 and 120 respectively.