In some cases use a shorter GF interval.
We break early anytime after min_gf_interval in certain cases, based on
some motion vector stats.
This is based on similar logic in VP9, tweaked for AV1.
Significant PSNR improvement on some videos. For example:
midres/station2_480p25: -8.933%
lowres/tennis_sif: -3.813%
No regressions (over noise level).
STATS_CHANGED
Change-Id: I7682f9a4c08354b4a224a34fdb68ff688a2cee01
diff --git a/av1/encoder/firstpass.c b/av1/encoder/firstpass.c
index 6350875..e68e4fa 100644
--- a/av1/encoder/firstpass.c
+++ b/av1/encoder/firstpass.c
@@ -2379,6 +2379,10 @@
(kf_zero_motion >= STATIC_KF_GROUP_THRESH);
}
+#if CONFIG_FIX_GF_LENGTH
+#define ARF_ABS_ZOOM_THRESH 4.4
+#endif // CONFIG_FIX_GF_LENGTH
+
// Analyse and define a gf/arf group.
static void define_gf_group(AV1_COMP *cpi, FIRSTPASS_STATS *this_frame) {
AV1_COMMON *const cm = &cpi->common;
@@ -2392,10 +2396,9 @@
double boost_score = 0.0;
#if !CONFIG_FIX_GF_LENGTH
double old_boost_score = 0.0;
- double mv_ratio_accumulator_thresh;
int active_max_gf_interval;
+#endif // !CONFIG_FIX_GF_LENGTH
int active_min_gf_interval;
-#endif
double gf_group_err = 0.0;
#if GROUP_ADAPTIVE_MAXQ
double gf_group_raw_error = 0.0;
@@ -2455,10 +2458,14 @@
gf_group_skip_pct -= this_frame->intra_skip_pct;
gf_group_inactive_zone_rows -= this_frame->inactive_zone_rows;
}
-#if !CONFIG_FIX_GF_LENGTH
// Motion breakout threshold for loop below depends on image size.
- mv_ratio_accumulator_thresh =
+ const double mv_ratio_accumulator_thresh =
(cpi->initial_height + cpi->initial_width) / 4.0;
+
+#if CONFIG_FIX_GF_LENGTH
+ // TODO(urvang): Try the 'else' like logic to vary min and max interval.
+ active_min_gf_interval = rc->min_gf_interval;
+#else
// Set a maximum and minimum interval for the GF group.
// If the image appears almost completely static we can extend beyond this.
{
@@ -2483,7 +2490,8 @@
else if (active_max_gf_interval > rc->max_gf_interval)
active_max_gf_interval = rc->max_gf_interval;
}
-#endif // !CONFIG_FIX_GF_LENGTH
+#endif // CONFIG_FIX_GF_LENGTH
+
double avg_sr_coded_error = 0;
double avg_raw_err_stdev = 0;
int non_zero_stdev_count = 0;
@@ -2552,6 +2560,16 @@
twopass->kf_zeromotion_pct)) {
break;
}
+
+ // Some conditions to breakout after min interval.
+ if (i >= active_min_gf_interval &&
+ // If possible don't break very close to a kf
+ (rc->frames_to_key - i >= rc->min_gf_interval) && (i & 0x01) &&
+ !flash_detected &&
+ (mv_ratio_accumulator > mv_ratio_accumulator_thresh ||
+ abs_mv_in_out_accumulator > ARF_ABS_ZOOM_THRESH)) {
+ break;
+ }
#else
// Break out conditions.
// Break at maximum of active_max_gf_interval unless almost totally static.
