Reducing 3D wavelet transform execution time through the Streaming SIMD Extensions

Bernabé, Gregorio; García, José M.; González, José María Faci

doi:10.1109/empdp.2003.1183565

Cited by 5 publications

(4 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, the final proposed approach maintains both the high compression ratio and the excellent video quality of the original encoder [15]. This article is a major revision of two papers published in [18] and [19]. The rest of this article is organized as follows.…”

Section: Introductionmentioning

confidence: 99%

Reducing 3D Fast Wavelet Transform Execution Time Using Blocking and the Streaming SIMD Extensions

Bernabé

García

González

2005

J VLSI Sign Process Syst Sign Image Video Technol

View full text Add to dashboard Cite

The video compression algorithms based on the 3D wavelet transform obtain excellent compression rates at the expense of huge memory requirements, that drastically affects the execution time of such applications. Its objective is to allow the real-time video compression based on the 3D fast wavelet transform. We show the hardware and software interaction for this multimedia application on a general-purpose processor. First, we mitigate the memory problem by exploiting the memory hierarchy of the processor using several techniques. As for instance, we implement and evaluate the blocking technique. We present two blocking approaches in particular: cube and rectangular, both of which differ in the way the original working set is divided. We also put forward the reuse of previous computations in order to decrease the number of memory accesses and floating point operations. Afterwards, we present several optimizations that cannot be applied by the compiler due to the characteristics of the algorithm. On the one hand, the Streaming SIMD Extensions (SSE) are used for some of the dimensions of the sequence (y and time), to reduce the number of floating point instructions, exploiting Data Level Parallelism. Then, we apply loop unrolling and data prefetching to specific parts of the code. On the other hand, the algorithm is vectorized by columns, allowing the use of SIMD instructions for the y dimension. Results show speedups of 5x in the execution time over a version compiled with the maximum optimizations of the Intel C/C++ compiler, maintaining the compression ratio and the video quality (PSNR) of the original encoder based on the 3D wavelet transform. Our experiments also show that, allowing the compiler to perform some of these optimizations (i.e. automatic code vectorization), causes performance slowdown, demonstrating the effectiveness of our optimizations.

show abstract

Section: Introductionmentioning

confidence: 99%

Reducing 3D Fast Wavelet Transform Execution Time Using Blocking and the Streaming SIMD Extensions

Bernabé

García

González

2005

J VLSI Sign Process Syst Sign Image Video Technol

View full text Add to dashboard Cite

show abstract

“…Below we are going to present a number of techniques that we developed [6] [8] [9] to improve the execution time of our encoder.…”

Section: Optimizing the Sequential Algorithmmentioning

confidence: 99%

“…Column vectorization consists of interleaving the calculations of the transform in the Y dimension and the transform in the X dimension, exploiting the fact that the results from the X dimension are the values needed to perform the calculations in the Y dimension [6].…”

Section: Columns Vectorizationmentioning

confidence: 99%