Add option 'zero-coeff-rdo'

README.md

@@ -173,6 +173,8 @@ Compression tools:
                                         chroma mode search.
       --(no-)mv-rdo          : Rate-distortion optimized motion vector costs
                                [disabled]
+      --(no-)zero-coeff-rdo  : If a CU is set inter, check if forcing zero
+                               residual improves the RD cost. [enabled]
       --(no-)full-intra-search : Try all intra modes during rough search.
                                [disabled]
       --(no-)transform-skip  : Try transform skip [disabled]

configure.ac

@@ -23,7 +23,7 @@ AC_CONFIG_SRCDIR([src/encmain.c])
 #
 # Here is a somewhat sane guide to lib versioning: http://apr.apache.org/versioning.html
 ver_major=4
-ver_minor=2
+ver_minor=3
 ver_release=0
 
 # Prevents configure from adding a lot of defines to the CFLAGS

doc/kvazaar.1

@@ -1,4 +1,4 @@
-.TH KVAZAAR "1" "January 2020" "kvazaar v1.3.0" "User Commands"
+.TH KVAZAAR "1" "February 2020" "kvazaar v1.3.0" "User Commands"
 .SH NAME
 kvazaar \- open source HEVC encoder
 .SH SYNOPSIS
@@ -217,6 +217,10 @@ Intra mode search complexity [0]
 Rate\-distortion optimized motion vector costs
 [disabled]
 .TP
+\fB\-\-(no\-)zero\-coeff\-rdo 
+If a CU is set inter, check if forcing zero
+residual improves the RD cost. [enabled]
+.TP
 \fB\-\-(no\-)full\-intra\-search
 Try all intra modes during rough search.
 [disabled]

src/cfg.c

@@ -147,6 +147,8 @@ int kvz_config_init(kvz_config *cfg)
   cfg->partial_coding.startCTU_y = 0;
   cfg->partial_coding.fullWidth = 0;
   cfg->partial_coding.fullHeight = 0;
+
+  cfg->zero_coeff_rdo = true;
   return 1;
 }
 
@@ -1284,6 +1286,9 @@ int kvz_config_parse(kvz_config *cfg, const char *name, const char *value)
     cfg->partial_coding.fullWidth = fullWidth;
     cfg->partial_coding.fullHeight = fullHeight;
   }
+  else if OPT("zero-coeff-rdo") {
+  cfg->zero_coeff_rdo = (bool)atobool(value);
+  }
   else {
     return 0;
   }

src/cli.c

@@ -139,6 +139,8 @@ static const struct option long_options[] = {
   { "no-early-skip",            no_argument, NULL, 0 },
   { "ml-pu-depth-intra",        no_argument, NULL, 0 },
   { "partial-coding",     required_argument, NULL, 0 },
+  { "zero-coeff-rdo",           no_argument, NULL, 0 },
+  { "no-zero-coeff-rdo",        no_argument, NULL, 0 },
   {0, 0, 0, 0}
 };
 
@@ -459,6 +461,8 @@ void print_help(void)
     "                                        chroma mode search.\n"
     "      --(no-)mv-rdo          : Rate-distortion optimized motion vector costs\n"
     "                               [disabled]\n"
+    "      --(no-)zero-coeff-rdo  : If a CU is set inter, check if forcing zero\n"
+    "                               residual is improves the RD cost. [enabled]\n"
     "      --(no-)full-intra-search : Try all intra modes during rough search.\n"
     "                               [disabled]\n"
     "      --(no-)transform-skip  : Try transform skip [disabled]\n"

src/kvazaar.h

@@ -401,6 +401,9 @@ typedef struct kvz_config
     uint16_t fullHeight;
   } partial_coding;
 
+  /** \brief Always consider CU without any quantized residual */
+  uint8_t zero_coeff_rdo;
+
 } kvz_config;
 
 /**

src/search.c

@@ -625,7 +625,7 @@ static double search_cu(encoder_state_t * const state, int x, int y, int depth,
         const bool has_chroma = state->encoder_control->chroma_format != KVZ_CSP_400;
         kvz_inter_recon_cu(state, lcu, x, y, cu_width, true, has_chroma);
 
-        if (!ctrl->cfg.lossless && !ctrl->cfg.rdoq_enable) {
+        if (ctrl->cfg.zero_coeff_rdo && !ctrl->cfg.lossless && !ctrl->cfg.rdoq_enable) {
           //Calculate cost for zero coeffs
           inter_zero_coeff_cost = cu_zero_coeff_cost(state, work_tree, x, y, depth) + inter_bitcost * state->lambda;
 
@@ -668,7 +668,7 @@ static double search_cu(encoder_state_t * const state, int x, int y, int depth,
 
     cost += mode_bits * state->lambda;
 
-    if (inter_zero_coeff_cost <= cost) {
+    if (ctrl->cfg.zero_coeff_rdo && inter_zero_coeff_cost <= cost) {
       cost = inter_zero_coeff_cost;
 
       // Restore saved pixels from lower level of the working tree.