• Hui Su's avatar
    ext-intra experiment · be3559ba
    Hui Su authored
    Currently there are two parts in this experiment: extra directional intra
    prediction modes and the filter intra modes migrated from the nextgen branch.
    Several macros are defined in "blockd.h" to provide controls of the experiment
    settings. Setting "DR_ONLY" as 1 (default is 0) means we only use directional
    modes, and skip the filter-intra modes; "EXT_INTRA_ANGLES" (default is 128)
    defines the number of different angles we want to support; setting
    "ANGLE_FAST_SEARCH" as 1 (default is 1) means we use fast sub-optimal search
    for the best prediction angle, instead of exhaustive search. The fast search
    is about 6 times faster than the exhaustive search, while preserving about
    60% of the coding gains.
    With extra directional prediction modes (fast search), we observe the following
    code gains (number in parentheses is for all-key-frame setting):
    derflr +0.42%  (+1.79%)
    hevclr +0.78%  (+2.19%)
    hevcmr +1.20%  (+3.49%)
    stdhd  +0.56%
    Speed-wise, about 110% slower for key frames, and 30% slower overall.
    The gains of filter intra modes mostly add up with the gains of directional
    modes. The overall coding gain of this experiment:
    derflr +0.94%
    hevclr +1.46%
    hevcmr +1.94%
    stdhd  +1.58%
    Change-Id: Ida9ad00cdb33aff422d06eb42b4f4e5f25df8a2a