Optimizing Off-Chip Memory Access Costs in Low Power MPEG-4 Decoder

Haitham Habli, Johan Ersfolk, Johan Lilius, T Westerlund, J Nurmi

    Research output: Chapter in Book/Conference proceedingConference contributionScientificpeer-review


    One of the main sources for energy consumption in modern video coding algorithms is caused by reading reference frames from main memory. Once a reference frame block is in the local memory, we need to predict in advance when the same reference frame block would be reread from the main memory. The prediction relies on the calculation of motion vectors according to their absolute addresses. The reduction of the number of read accesses can be attained by calculating which motion vectors point to a part of the reference frame that can be copied to a local memory. This increases data locality, and thus reduces energy consumption. The optimized memory access algorithm was integrated into low power MPEG-4 decoder architecture [1, 2] and modeled using SystemC. A cycle accurate model simulation with optimized algorithm showed an average of 10% increase on runtime performance compared to an unoptimized typical video decoding algorithm.
    Original languageUndefined/Unknown
    Title of host publication3rd International Conference on Information and Communication Systems
    PublisherACM Press
    Number of pages5
    ISBN (Print)978-1-4503-1327-8
    Publication statusPublished - 2012
    MoE publication typeA4 Article in a conference publication
    EventInternational Conference on Information and Communication Systems - International Conference on Information and Communication Systems
    Duration: 3 May 20125 May 2012


    ConferenceInternational Conference on Information and Communication Systems


    • Memory access
    • fine-grained
    • heterogeneous
    • low power
    • motion vector
    • reusable data
    • video decoder

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