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The Java programming language manages memory automatically through the use of a garbage collector (GC). The Java Virtual Machine provides several GCs tuned for different usage scenarios. One such GC is ZGC. Both ZGC and other GCs utilize bump-pointer allocation, which allocates objects compactly but leads to the creation of unusable memory gaps over time, known as fragmentation. ZGC handles fragmentation through relocation, a process which is costly. This thesis proposes an alternative memory allocation method leveraging free-lists to reduce the need for relocation to manage fragmentation.We design and develop a new allocator tailored for ZGC, based on the TLSF allocator by Masmano et al. Previous research on the customization of allocators shows varying results and does not fully investigate usage in complex environments like a GC.Opportunities for enhancements in performance and memory efficiency are identified and implemented through the exploration of ZGC's operational boundaries. The most significant adaptation is the introduction of a 0-byte header, which leverages information within ZGC to significantly reduce internal fragmentation of the allocator. We evaluate the performance of our adapted allocator and compare it to a reference implementation of TLSF. Results show that the adapted allocator performs on par with the reference implementation for single allocations but is slightly slower for single frees and when applying allocation patterns from real-world programs. The findings of this work suggest that customizing allocators for garbage collection is worth considering and may be useful for future integration.

The demand for streaming high-quality video increases each year and the energy used by consumers is estimated to increase by 23% from 2020 to 2030. The largest contributor to this is increased data transmission. To minimise data transmission, a video encoding method called per-shot encoding can be used, which splits and processes a video into smaller segments called shots. By utilising this method, the bitrate for a video can be reduced without compromising quality. This leads to less data that needs to be transmitted, which reduces energy consumption. In this project, a website that interfaces with a per-shot encoder is implemented. To evaluate the per-shot encoder, both visual quality and bitrate are quantitatively measured. From evaluation, the bitrate is reduced by up to 2.5% for a selection of videos, without compromising the viewing experience. This is a substantial decrease compared to alternative methods., Efterfrågan av högkvalitativ videoströmning ökar varje år och konsumenters energianvändning uppskattas att ha ökat med 23% år 2030 jämfört med år 2020. Den största orsaken till detta är ökad dataöverföring. För att minska mängden data som behöver skickas kan per-shot-kodning användas, vilket är en videokodningsmetod som delar upp och bearbetar en video i ett flertal mindre delar som kallas shots. Bithastigheten för en video kan minskas med hjälp av per-shot-kodning utan att påverka kvaliteten. Detta leder till att mindre data behöver skickas, vilket innebär minskad energiförbrukning. I detta projekt har en per-shot-kodare tillsammans med en hemsida utvecklats. För att utvärdera per-shot-kodaren kommer skillnad i kvalitet och bithastighet att mätas kvantitativt. Utvärderingen har visat att per-shot-kodaren kan minska bithastigheten med upp till 2.5% för ett urval av videor, utan att påverka tittarupplevelsen. Detta är en avsevärd minskning jämfört med alternativa metoder.