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| author | sdeng <sdeng@google.com> | 2019-11-18 11:33:22 -0800 |
|---|---|---|
| committer | sdeng <sdeng@google.com> | 2019-11-18 16:57:22 -0800 |
| commit | e6bfdce30df73cd2f86c16d010b5430ed14ed090 (patch) | |
| tree | a1ceb6dd00eb04a7ce79001ac6a5bf3d3140886d /vp9/encoder/vp9_encoder.c | |
| parent | 76d9afc349fec0d1edc4d674daaca89b6c8c9c90 (diff) | |
| download | libvpx-e6bfdce30df73cd2f86c16d010b5430ed14ed090.tar libvpx-e6bfdce30df73cd2f86c16d010b5430ed14ed090.tar.gz libvpx-e6bfdce30df73cd2f86c16d010b5430ed14ed090.tar.bz2 libvpx-e6bfdce30df73cd2f86c16d010b5430ed14ed090.zip | |
Use a better model for tune=ssim
Comparing to the baseline tune=ssim, the average gains are
PSNR -0.55, SSIM -0.30, MS-SSIM -0.98, VMAF -1.26
Details: (150f VBR)
PSNR SSIM MS-SSIM VMAF
Lowres -1.347 0.291 -0.307 -1.291
Midres -0.628 -0.329 -1.011 -2.173
Hdres 0.781 -0.656 -1.319 0.210
Ugc360p -2.695 -0.972 -1.503 -4.055
Lowres_bd10 0.074 0.196 -0.623 -0.835
Midres_bd10 0.517 -0.327 -1.124 0.566
Change-Id: Ie034eaedf20e1fe843921cafbb3b7ad9a2bc89d1
Diffstat (limited to 'vp9/encoder/vp9_encoder.c')
| -rw-r--r-- | vp9/encoder/vp9_encoder.c | 18 |
1 files changed, 4 insertions, 14 deletions
diff --git a/vp9/encoder/vp9_encoder.c b/vp9/encoder/vp9_encoder.c index 1a894d53c..e52fc3247 100644 --- a/vp9/encoder/vp9_encoder.c +++ b/vp9/encoder/vp9_encoder.c @@ -4863,17 +4863,6 @@ static void set_frame_index(VP9_COMP *cpi, VP9_COMMON *cm) { } } -// Implementation and modifications of C. Yeo, H. L. Tan, and Y. H. Tan, "On -// rate distortion optimization using SSIM," Circuits and Systems for Video -// Technology, IEEE Transactions on, vol. 23, no. 7, pp. 1170-1181, 2013. -// SSIM_VAR_SCALE defines the strength of the bias towards SSIM in RDO. -// Some sample values are: -// (for midres test set) -// SSIM_VAR_SCALE avg_psnr ssim ms_ssim -// 8.0 9.421 -5.537 -6.898 -// 16.0 4.703 -5.378 -6.238 -// 32.0 1.929 -4.308 -4.807 -#define SSIM_VAR_SCALE 16.0 static void set_mb_ssim_rdmult_scaling(VP9_COMP *cpi) { VP9_COMMON *cm = &cpi->common; ThreadData *td = &cpi->td; @@ -4890,8 +4879,6 @@ static void set_mb_ssim_rdmult_scaling(VP9_COMP *cpi) { double log_sum = 0.0; int row, col; - const double c2 = 58.5225 * SSIM_VAR_SCALE; // 58.5225 = (.03*255)^2 - // Loop through each 64x64 block. for (row = 0; row < num_rows; ++row) { for (col = 0; col < num_cols; ++col) { @@ -4925,7 +4912,10 @@ static void set_mb_ssim_rdmult_scaling(VP9_COMP *cpi) { } } var = var / num_of_var / 64.0; - var = 2.0 * var + c2; + + // Curve fitting with an exponential model on all 16x16 blocks from the + // Midres dataset. + var = 67.035434 * (1 - exp(-0.0021489 * var)) + 17.492222; cpi->mi_ssim_rdmult_scaling_factors[index] = var; log_sum += log(var); } |