Opencl parallelization of the HEVC de-quantization and inverse transform for heterogeneous platforms

To tackle the growing demand for high efficient implementations of video decoders in a vast set of heterogeneous platforms, a high performance implementation of the HEVC de-quantization and inverse Discrete Cosine Transform (IDCT) modules is proposed. To efficiently take advantage of the several different GPU architectures that are currently available on these platforms, the proposed modules consist on unified OpenCL implementations, allowing their migration and acceleration in any of the available devices of current heterogeneous platforms. To achieve such objective, the memory accesses were highly optimized and no synchronization points were required, in order to attain the maximum performance. The presented experimental results evaluated the proposed implementation in three different GPUs, achieving processing times as low as 6.39 ms and 6.51 ms for Ultra HD 4K I-type and B-type frames, respectively, corresponding to speedup factors as high as 18.9× and 16.5× over the HEVC Test Model (HM) version 11.0.