Single-loop re-quantizer for FGS encoding

This work presents a high-performance single-loop RE-Quantization (REQ) design for Fine Grain Scalable (FGS) video encoders. Due to the necessity of re-quantizing residual data for each enhancement layer in the FGS encoder, either time multiplexing method or parallel computing method is adopted in conventional works. The time multiplexing method and the parallel computing method respectively result in low data throughput rate and high hardware cost. Hence, this work can reduce the multiple loops, required in the conventional requantization, to only single loop through fundamental algorithmic optimization. In the case of a three-layer FGS encoder, the proposed REQ coding scheme dramatically reduces the computation complexity to only 33.3% of the conventional re-quantization block, and still keeps approximately equivalent rate-distortion performance. Thus, we not only can significantly accelerate the computation speed but also reduce the hardware cost. Abundant experiments show that the proposed scheme holds almost equivalent video quality when compared with the conventional scheme in terms of both objective and subjective tests. After being implemented by using a 0.18-¿m technology, this work can achieve real-time performance of 4 K × 2 K @ 30 frames per second when operated at 90 MHz at the cost of 13 K gates.