Assessing Performance Portability of Hybrid Video Encoders
Maciej Okoń, Beata Bylina
DOI: http://dx.doi.org/10.15439/2026F3256
Citation: Maciej Okoń, Beata Bylina (2026). Assessing Performance Portability of Hybrid Video Encoders. In M. Bolanowski, M. Ganzha, M. Grzegorowski, L. Maciaszek, M. Paprzycki, A. Paszkiewicz, D. Ślęzak (eds), Proceedings of the 21st Conference on Computer Science and Intelligence Systems (FedCSIS). ACSIS, Vol. 47, pages 597–602.
Abstract. While the Java Virtual Machine ensures functional code portability, achieving consistent execution efficiency across hardware generations remains a significant challenge for compute-intensive multimedia applications. This paper evaluates performance portability in a hybrid video encoder, focusing on the interaction between algorithmic complexity and parallelization granularity. We contrast a legacy fine-grained model, utilizing macroblock-level task scheduling, with a coarse-grained architecture based on Group of Pictures (GOP) parallelism. The study quantifies how these two paradigms respond to increasing core density and generational shifts in server-grade hardware. The evaluation utilizes three configurations: an intra-frame baseline, a hybrid model with integer-pixel motion estimation, and a sub-pixel hybrid model. Stability is assessed across four server generations using a framework that combines harmonic portability metrics with arithmetic efficiency averages and cascade visualizations. This approach identifies the exact points where task synchronization and memory latency limit hardware utilization in managed execution environments. The results demonstrate that the GOP-parallel implementation significantly enhances performance portability, achieving architectural portability metrics between 0.83 and 0.87. In contrast, the legacy macroblock-level model exhibits severe efficiency degradation on modern high-density processors, with portability scores dropping as low as 0.41. Visualization through efficiency cascades and platform fingerprints confirms that the coarse-grained GOP model effectively mitigates synchronization overheads and latency sensitivities. The study demonstrates that fine-grained parallelization strategies are insufficient for maintaining performance portability on modern many-core architectures within managed environments, whereas a coarse-grained GOP-level approach provides a more robust alternative for achieving consistent execution efficiency.
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