Real-time multi-level wavelet lifting scheme on a fixed-point DSP for JPEG 2000 and scalable video coding
In this paper, we discuss the design and real-time implementation of a multi-level two-dimensional Discrete Wavelet Transform (2D-DWT). The wavelet transform uses the well-known 5/3 filter coefficients and is implemented using the lifting framework. However, the transform allows complexity-scalable solutions with different latencies for scalable video coding. We have extensively utilized SIMD (Single Instruction Multiple Data) and DMA (Direct Memory Access) techniques, where the proposed process of background DMA transfers is so effective, that the ALUs are almost never starved for data input. The obtained execution performs a 4-level transform at CCIR-601 broadcast resolution in 3.65 Mcycles, including memory stalls, on a DM642 DSP. At a clock rate of 600MHz this translates to more than 160 transforms per second, satisfying the performance requirements for a real-time image/video encoding system for e.g. surveillance applications.