Remove average accumulated decay
The variable |av_decay_accumulator| restricts the boost of the key
frame. But its logic is not crystal clear.
Removing it makes the logic easier to understand.
And at the same time, removing it provides gains.
The potential downside is now key frame gets more boost.
Not a good news for rate control.
Test on 150 frames, spd1:
VBR Avg_psnr ovr_psnr ssim
Lowres 0.14 0.22 -0.02
Midres -0.31 -0.35 -0.87
Hdres -0.38 -0.33 -0.61
Q Avg_psnr ovr_psnr ssim
Lowres 0.03 0.05 -0.17
Midres -0.22 -0.19 -0.61
Hdres -0.32 -0.30 -0.46
STATS_CHANGED
Change-Id: I264dcd3da9987591f565f1a8eb8c18e2d160b47a
diff --git a/av1/encoder/pass2_strategy.c b/av1/encoder/pass2_strategy.c
index b3ffeb7..0ef696f 100644
--- a/av1/encoder/pass2_strategy.c
+++ b/av1/encoder/pass2_strategy.c
@@ -1440,9 +1440,7 @@
int i, j;
const FIRSTPASS_STATS *const start_position = twopass->stats_in;
int kf_bits = 0;
- int loop_decay_counter = 0;
double decay_accumulator = 1.0;
- double av_decay_accumulator = 0.0;
double zero_motion_accumulator = 1.0;
double boost_score = 0.0;
double kf_mod_err = 0.0;
@@ -1600,14 +1598,10 @@
get_prediction_decay_rate(cpi, &next_frame);
decay_accumulator *= loop_decay_rate;
decay_accumulator = AOMMAX(decay_accumulator, MIN_DECAY_FACTOR);
- av_decay_accumulator += decay_accumulator;
- ++loop_decay_counter;
}
boost_score += (decay_accumulator * frame_boost);
}
}
- if (loop_decay_counter > 0)
- av_decay_accumulator /= (double)loop_decay_counter;
reset_fpf_position(twopass, start_position);
@@ -1618,7 +1612,7 @@
twopass->section_intra_rating = calculate_section_intra_ratio(
start_position, twopass->stats_in_end, rc->frames_to_key);
- rc->kf_boost = (int)(av_decay_accumulator * boost_score);
+ rc->kf_boost = (int)boost_score;
// Special case for static / slide show content but don't apply
// if the kf group is very short.
