• Jingning Han's avatar
    Use 8x8 DCT transform for I8X8 prediction mode · c7846ebc
    Jingning Han authored
    Apply 2D-DCT transform of dimension 8x8 to encode prediction
    residuals of I8X8 mode.
    Brought back block type 3 probability context model for 8x8 tokens,
    which is used for the coefficients of Y blocks in I8x8 modes. The
    coefficient costs estimate of I8X8 mode in rate-distortion is also
    changed appropriately.
    Performance results:
    derf:   0.246
    yt:     0.114
    std-hd: 0.730
    hd:     0.670
    Change-Id: If1d970eeb4e1827c9f0d2c5b27d33089b347ea27