ref: 238cf66eb5e376062ee13198ef537e848866b8aa
parent: 3ac2b57015000dde5731ceb9fc824e86747c5945
author: Hui Su <huisu@google.com>
date: Tue Jun 12 07:56:09 EDT 2018
Improve the partition search breakout speed feature
Use a linear model to make partition search breakout decisions.
Currently the model is tuned for large quantizers and small resolutions.
So it is only used when q-index is larger than 200 and frame
width/height is smaller than 720. Also it's not yet supported for high
bit depth.
Tested speed 1 and 2 on lowres and midres. Compression performance is
neutral. At low bitrates, encoding speedup is up to 50% for speed 1;
up to 30% for speed 2.
Some sample numbers:
into_tree_480p, speed 1
QP=60 before: 35.228 dB, 3488b/f, 7.78 fps
now: 35.217 dB, 3475b/f, 11.57 fps
QP=50 before: 37.492 dB, 7983b/f, 6.24 fps
now: 37.491 dB, 7974b/f, 7.55 fps
PartyScene_832x480_50, speed 1
QP=60 before: 30.104 dB, 22426b/f, 3.28 fps
now: 30.109 dB, 22410b/f, 4.43 fps
QP=50 before: 33.016 dB, 46984b/f, 2.78 fps
now: 33.018 dB, 46998b/f, 3.35 fps
into_tree_480p, speed 2
QP=60 before: 35.175 dB, 3506b/f, 10.96 fps
now: 35.185 dB, 3510b/f, 13.47 fps
QP=50 before: 37.448 dB, 8016b/f, 9.04 fps
now: 37.459 dB, 8048b/f, 9.81 fps
PartyScene_832x480_50, speed 2
QP=60 before: 30.060 dB, 22537b/f, 4.42 fps
now: 30.061 dB, 22541b/f, 5.38 fps
QP=50 before: 32.923 dB, 47134b/f, 3.85 fps
now: 32.920 dB, 47073b/f, 4.31 fps
Change-Id: I674cba4f027c4c65f7837d5ec9179d6201e6ba86
--- a/vp9/encoder/vp9_encodeframe.c
+++ b/vp9/encoder/vp9_encodeframe.c
@@ -3314,6 +3314,79 @@
return 0;
}
+#define FEATURES 4
+static const float partition_breakout_weights_64[FEATURES + 1] = {+ -0.016673f, -0.001025f, -0.000032f, 0.000833f, 1.94261885f - 2.1f,
+};
+
+static const float partition_breakout_weights_32[FEATURES + 1] = {+ -0.010554f, -0.003081f, -0.000134f, 0.004491f, 1.68445992f - 3.5f,
+};
+
+static const float partition_breakout_weights_16[FEATURES + 1] = {+ -0.013154f, -0.002404f, -0.000977f, 0.008450f, 2.57404566f - 5.5f,
+};
+
+static const float partition_breakout_weights_8[FEATURES + 1] = {+ -0.011807f, -0.009873f, -0.000931f, 0.034768f, 1.32254851f - 2.0f,
+};
+
+// ML-based partition search breakout.
+static int ml_predict_breakout(const VP9_COMP *const cpi, BLOCK_SIZE bsize,
+ const MACROBLOCK *const x,
+ const RD_COST *const rd_cost) {+ DECLARE_ALIGNED(16, static const uint8_t, vp9_64_zeros[64]) = { 0 };+ float features[FEATURES];
+ const float *linear_weights = NULL; // Linear model weights.
+ float linear_score = 0.0f;
+
+ switch (bsize) {+ case BLOCK_64X64: linear_weights = partition_breakout_weights_64; break;
+ case BLOCK_32X32: linear_weights = partition_breakout_weights_32; break;
+ case BLOCK_16X16: linear_weights = partition_breakout_weights_16; break;
+ case BLOCK_8X8: linear_weights = partition_breakout_weights_8; break;
+ default: assert(0 && "Unexpected block size."); return 0;
+ }
+ if (!linear_weights) return 0;
+
+ { // Generate feature values.+ const VP9_COMMON *const cm = &cpi->common;
+ const int ac_q = vp9_ac_quant(cm->base_qindex, 0, cm->bit_depth);
+ const int num_pels_log2 = num_pels_log2_lookup[bsize];
+ int feature_index = 0;
+ unsigned int var, sse;
+ float rate_f, dist_f;
+
+ var = cpi->fn_ptr[bsize].vf(x->plane[0].src.buf, x->plane[0].src.stride,
+ vp9_64_zeros, 0, &sse);
+ var = var >> num_pels_log2;
+
+ vpx_clear_system_state();
+
+ rate_f = (float)VPXMIN(rd_cost->rate, INT_MAX);
+ dist_f = (float)(VPXMIN(rd_cost->dist, INT_MAX) >> num_pels_log2);
+ rate_f =
+ ((float)x->rdmult / 128.0f / 512.0f / (float)(1 << num_pels_log2)) *
+ rate_f;
+
+ features[feature_index++] = rate_f;
+ features[feature_index++] = dist_f;
+ features[feature_index++] = (float)var;
+ features[feature_index++] = (float)ac_q;
+ assert(feature_index == FEATURES);
+ }
+
+ { // Calculate the output score.+ int i;
+ linear_score = linear_weights[FEATURES];
+ for (i = 0; i < FEATURES; ++i)
+ linear_score += linear_weights[i] * features[i];
+ }
+
+ return linear_score >= 0;
+}
+#undef FEATURES
+
// TODO(jingning,jimbankoski,rbultje): properly skip partition types that are
// unlikely to be selected depending on previous rate-distortion optimization
// results, for encoding speed-up.
@@ -3499,12 +3572,27 @@
// If all y, u, v transform blocks in this partition are skippable,
// and the dist & rate are within the thresholds, the partition search
// is terminated for current branch of the partition search tree.
- if (!x->e_mbd.lossless && ctx->skippable &&
- ((best_rdc.dist < (dist_breakout_thr >> 2)) ||
- (best_rdc.dist < dist_breakout_thr &&
- best_rdc.rate < rate_breakout_thr))) {- do_split = 0;
- do_rect = 0;
+ if (!x->e_mbd.lossless && ctx->skippable) {+ int use_ml_based_breakout =
+ cpi->sf.use_ml_partition_search_breakout &&
+ cm->base_qindex >= 200;
+#if CONFIG_VP9_HIGHBITDEPTH
+ if (x->e_mbd.cur_buf->flags & YV12_FLAG_HIGHBITDEPTH)
+ use_ml_based_breakout = 0;
+#endif // CONFIG_VP9_HIGHBITDEPTH
+ if (use_ml_based_breakout) {+ if (ml_predict_breakout(cpi, bsize, x, &this_rdc)) {+ do_split = 0;
+ do_rect = 0;
+ }
+ } else {+ if ((best_rdc.dist < (dist_breakout_thr >> 2)) ||
+ (best_rdc.dist < dist_breakout_thr &&
+ best_rdc.rate < rate_breakout_thr)) {+ do_split = 0;
+ do_rect = 0;
+ }
+ }
}
} else {// Currently, the machine-learning based partition search early
--- a/vp9/encoder/vp9_speed_features.c
+++ b/vp9/encoder/vp9_speed_features.c
@@ -82,6 +82,7 @@
} else {sf->disable_split_mask = DISABLE_COMPOUND_SPLIT;
sf->partition_search_breakout_thr.dist = (1 << 21);
+ sf->use_ml_partition_search_breakout = 1;
}
}
@@ -112,6 +113,7 @@
}
if (speed >= 3) {+ sf->use_ml_partition_search_breakout = 0;
if (VPXMIN(cm->width, cm->height) >= 720) {sf->disable_split_mask = DISABLE_ALL_SPLIT;
sf->schedule_mode_search = cm->base_qindex < 220 ? 1 : 0;
@@ -712,6 +714,7 @@
sf->partition_search_breakout_thr.dist = (1 << 19);
sf->partition_search_breakout_thr.rate = 80;
sf->ml_partition_search_early_termination = 0;
+ sf->use_ml_partition_search_breakout = 0;
if (oxcf->mode == REALTIME) {set_rt_speed_feature_framesize_dependent(cpi, sf, oxcf->speed);
--- a/vp9/encoder/vp9_speed_features.h
+++ b/vp9/encoder/vp9_speed_features.h
@@ -467,6 +467,9 @@
// Partition search early breakout thresholds.
PARTITION_SEARCH_BREAKOUT_THR partition_search_breakout_thr;
+ // Use ML-based partition search early breakout.
+ int use_ml_partition_search_breakout;
+
// Machine-learning based partition search early termination
int ml_partition_search_early_termination;