Enable tune=ssim in AV1
Got similar results in VP9:
Data Set AVG PSNR SSIM MS-SSIM
Lowres 4.9 -5.2 -4.2
Midres 4.0 -5.7 -5.9
HDres 4.3 -5.7 -6.1
Lowres_bd10 3.4 -5.1 -6.2
Midres_bd10 2.8 -5.4 -6.4
Tests on first 33 frames.
Change-Id: Ib9db1e628900af0de70234a94b7a31f15ff45153
diff --git a/av1/av1_cx_iface.c b/av1/av1_cx_iface.c
index 87cedcf..e9bc4c6 100644
--- a/av1/av1_cx_iface.c
+++ b/av1/av1_cx_iface.c
@@ -427,10 +427,6 @@
RANGE_CHECK(cfg, g_input_bit_depth, 8, 12);
RANGE_CHECK(extra_cfg, content, AOM_CONTENT_DEFAULT, AOM_CONTENT_INVALID - 1);
- // TODO(yaowu): remove this when ssim tuning is implemented for av1
- if (extra_cfg->tuning == AOM_TUNE_SSIM)
- ERROR("Option --tune=ssim is not currently supported in AV1.");
-
if (cfg->g_pass == AOM_RC_LAST_PASS) {
const size_t packet_sz = sizeof(FIRSTPASS_STATS);
const int n_packets = (int)(cfg->rc_twopass_stats_in.sz / packet_sz);
diff --git a/av1/encoder/encoder.c b/av1/encoder/encoder.c
index 035bc4f..deff0c0 100644
--- a/av1/encoder/encoder.c
+++ b/av1/encoder/encoder.c
@@ -4974,7 +4974,12 @@
// 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.
+// SSIM_VAR_SCALE defines the strength of the bias towards SSIM in RDO:
+// Test data set: mid_res (33 frames)
+// SSIM_VAR_SCALE avg_psnr ssim ms-ssim
+// 8 8.2 -6.0 -6.4
+// 16 4.0 -5.7 -5.9
+// 32 1.6 -4.4 -4.5
#define SSIM_VAR_SCALE 16.0
static void set_mb_ssim_rdmult_scaling(AV1_COMP *cpi) {
AV1_COMMON *cm = &cpi->common;
@@ -4993,14 +4998,9 @@
int row, col;
const int use_hbd = cpi->source->flags & YV12_FLAG_HIGHBITDEPTH;
- double c2;
- if (xd->bd == 10) {
- c2 = 941.8761; // (.03*1023)^2
- } else if (xd->bd == 12) {
- c2 = 15092.1225; // (.03*4095)^2
- } else {
- c2 = 58.5225; // (.03*255)^2
- }
+ // TODO(sdeng): tune this param for 12bit videos.
+ double c2 = 58.5225; // (.03*255)^2
+ c2 *= SSIM_VAR_SCALE;
// Loop through each 16x16 block.
for (row = 0; row < num_rows; ++row) {
@@ -5032,7 +5032,7 @@
num_of_var += 1.0;
}
}
- var = var / num_of_var / SSIM_VAR_SCALE;
+ var = var / num_of_var;
var = 2.0 * var + c2;
cpi->ssim_rdmult_scaling_factors[index] = var;
log_sum += log(var);
