• Alexander Bokov's avatar
    Improving the model for pruning the TX type search · 0c7eb10d
    Alexander Bokov authored
    Introduces two new TX type pruning modes that provide better
    speed-quality trade-off compared to the existing ones. A shallow
    neural network with one hidden layer trained separately for each
    block size is used as a prediction model. The new modes differ in
    thresholds applied to the output of the neural net, so that they
    prune different number of TX types on average.
    
    Owing to relatively low quality loss PRUNE_2D_ACCURATE is used
    by default, regardless of speed settings. Starting with speed
    setting of 3 we switch to PRUNE_2D_FAST mode to get better
    speed-up.
    
    Evaluation results:
    ----------------------------------------------------------
    Prune mode | Avg. speed-up | Quality loss | Quality loss
               |(high bitrates)|   (lowres)   |   (midres)
    ----------------------------------------------------------
    PRUNE_ONE  |     18.7%     |    0.396%    |    0.308%
    ----------------------------------------------------------
    PRUNE_TWO  |     27.2%     |    0.439%    |    0.389%
    ----------------------------------------------------------
    PRUNE_2D_  |     18.8%     |    0.032%    |    0.063%
    ACCURATE   |               |              |
    ----------------------------------------------------------
    PRUNE_2D_  |     33.3%     |    0.504%    |     ---
    FAST       |               |              |
    
    Change-Id: Ibd59f52eef493a499e529d824edad267daa65f9d
    0c7eb10d
speed_features.c 19.3 KB