System architectures for just-in-time video transcoding mode decision on heterogeneous high performance computers

doctoral thesis

• Title (croatian): Arhitekture sustava za odlučivanje o načinu pravovremenoga videotranskodiranja na reznorodnim računalima visokih performaci
• Author: Leon Dragić
• Mentor: Mario Kovač (mentor)
• Committee member: Mario Kovač (član povjerenstva)
• Granter: University of Zagreb; Faculty of Electrical Engineering and Computing; (Department of Control and Computer Engineering); Zagreb
• Defense date and country: 2019, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Computing; Architecture of Computer Systems
• Universal decimal classification (UDC): 621.3 - Electrical engineering

Abstract

Today, Internet traffic is dominated by video content and projections show that this trend will continue to increase. The performance growth of the technology also allowed the introduction of High Definition (HD) and Ultra-High Definition (UHD) videos. These are some of the facts that point out that efficiency in storing and streaming video content is a necessity. Current methods and paradigms for storing and streaming multimedia are not sustainable. To provide optimal efficiency of storing and streaming video, it is necessary to have the possibility to encode the video with occasion-specific parameters. This can be achieved using just-in-time transcoding. Efficient video transcoding requires significant work on modeling, mapping and optimizing parts of the algorithms to different underlying architectural elements. Software optimizations are required but not sufficient, and the use of the hardware accelerator kernels for critical parts of the algorithm is mandatory to enable efficient processing from the performance, power and QoE perspective. Balancing between these three characteristics in real-time presents a great challenge and is often considered as a critical point called mode decision. Mode decision algorithms can be efficiently co-designed with hardware-based accelerator kernels to provide greater performance, while maintaining the quality and compression efficiency.In this thesis, two original scientific contributions were achieved:1. Design of performance-optimized just-in-time video transcoding mode decision algorithms and hardware-based accelerator kernels for heterogeneous high performance computers 2. Performance-efficient integration of system architectures composed of implemented just-in-time video transcoding mode decision algorithms and hardware-based accelerator kernels on heterogeneous high performance computers

Abstract (croatian)

U današnje vrijeme, 80% ukupnog Internet prometa čini video sadržaj, a predviđanja pokazuju da će taj udio nastaviti rasti tokom idućih godina. Ova iznimna količina video sadržaja, glavni je pokretač razvoja novih normi za enkodiranje odnosno kompresiju videa kojima se omogućuje njegova učinkovita pohrana i prijenos. Trenutne metode i paradigme pohrane i prijenosa video sadržaja nisu održive. Umjesto da se video sadržaj transkodira u različite formate prilikom pohrane na poslužitelj, moguće je pohraniti samo sadržaj najviše kvalitete te ga kasnije pravovremeno transkodirati na zahtjev korisnika. Ovaj proces naziva se pravovremeno videotranskodiranje. Pravovremeno videotranskodiranje iznimno je računalno zahtjevan proces koji rješava problem višestruke pohrane istog sadržaja na poslužitelj, ali i omogućuje dinamičku prilagodbu svojstava video sadržaja korisničkom uređaju i okolini čime se ostvaruje ušteda u energiji te povećava učinkovitost i korisnički doživljaj.Učinkovit sustav video transkodiranja zahtijeva modeliranje, mapiranje i optimiziranje algoritama različitim arhitekturama za izvođenje. Programske optimizacije su potrebne, ali ne i dovoljne te je nužno koristiti jezgre za ubrzanje za kritične dijelove algoritma kako bi se ostvarila učinkovitost iz 3 perspektive: učinkovitost obzirom na performance, učinkovitost potrošnje energije i osiguravanje kvalitete usluge. Balansiranje između ove 3 karakteristike u stvarnom vremenu predstavlja veliki izazov i smatra se kritičnim dijelom sustava koji se još naziva algoritmom odlučivanja.Unutar ovog doktorskog rada ostvareni su sljedeći doprinosi:Dizajn algoritama odlučivanja o načinu pravovremenoga videotranskodiranja i sklopovskih jezgara za ubrzanje, optimiranih za učinkovito izvođenje na raznorodnim računalima visokih performanci.Integracija arhitektura sustava, učinkovita s obzirom na performance, sačinjena od izvedenih algoritama odlučivanja o načinu pravovremenoga videotranskodiranja i sklopovskih jezgara za ubrzanje na raznorodnim računalima visokih performanci.

• Keywords: video transcoding; mode decision; just-in-time; HEVC; hw/sw co-design; video encoding; accelerator cores
• Keywords (croatian): videotranskodiranje; algoritmi odlučivanja; pravovremeno videotranskodiranje; HEVC; video enkodiranje; jezgra za ubrzanje
• Language: english
• URN:NBN: urn:nbn:hr:168:198242
• Study programme: Title: Electrical Engineering and Computing; Study programme type: university; Study level: postgraduate; Academic / professional title: Doktor znanosti elektrotehnike i računarstva (Doktor znanosti elektrotehnike i računarstva)
• Type of resource: Text
• Extent: 131 str. ; 30 cm
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2020-01-21 12:30:20