libvpx: Pull from upstream

source/libvpx/vp9/encoder/vp9_picklpf.c

Index: source/libvpx/vp9/encoder/vp9_picklpf.c
===================================================================
--- source/libvpx/vp9/encoder/vp9_picklpf.c	(revision 247498)
+++ source/libvpx/vp9/encoder/vp9_picklpf.c	(working copy)
@@ -14,158 +14,95 @@
 #include "vp9/encoder/vp9_onyx_int.h"
 #include "vp9/encoder/vp9_picklpf.h"
 #include "vp9/encoder/vp9_quantize.h"
+#include "vp9/common/vp9_quant_common.h"
 #include "vpx_mem/vpx_mem.h"
 #include "vpx_scale/vpx_scale.h"
 #include "vp9/common/vp9_alloccommon.h"
 #include "vp9/common/vp9_loopfilter.h"
 #include "./vpx_scale_rtcd.h"
 
-void vp9_yv12_copy_partial_frame_c(YV12_BUFFER_CONFIG *src_ybc,
-                                   YV12_BUFFER_CONFIG *dst_ybc, int fraction) {
-  const int height = src_ybc->y_height;
-  const int stride = src_ybc->y_stride;
-  const int offset = stride * ((height >> 5) * 16 - 8);
-  const int lines_to_copy = MAX(height >> (fraction + 4), 1) << 4;
-
-  assert(src_ybc->y_stride == dst_ybc->y_stride);
-  vpx_memcpy(dst_ybc->y_buffer + offset, src_ybc->y_buffer + offset,
-             stride * (lines_to_copy + 16));
+static int get_min_filter_level(VP9_COMP *cpi, int base_qindex) {
+  return 0;
 }
 
-static int calc_partial_ssl_err(YV12_BUFFER_CONFIG *source,
-                                YV12_BUFFER_CONFIG *dest, int Fraction) {
-  int i, j;
-  int Total = 0;
-  int srcoffset, dstoffset;
-  uint8_t *src = source->y_buffer;
-  uint8_t *dst = dest->y_buffer;
-
-  int linestocopy = (source->y_height >> (Fraction + 4));
-
-  if (linestocopy < 1)
-    linestocopy = 1;
-
-  linestocopy <<= 4;
-
-
-  srcoffset = source->y_stride   * (dest->y_height >> 5) * 16;
-  dstoffset = dest->y_stride     * (dest->y_height >> 5) * 16;
-
-  src += srcoffset;
-  dst += dstoffset;
-
-  // Loop through the raw Y plane and reconstruction data summing the square
-  // differences.
-  for (i = 0; i < linestocopy; i += 16) {
-    for (j = 0; j < source->y_width; j += 16) {
-      unsigned int sse;
-      Total += vp9_mse16x16(src + j, source->y_stride, dst + j, dest->y_stride,
-                            &sse);
-    }
-
-    src += 16 * source->y_stride;
-    dst += 16 * dest->y_stride;
-  }
-
-  return Total;
+static int get_max_filter_level(VP9_COMP *cpi, int base_qindex) {
+  return cpi->twopass.section_intra_rating > 8 ? MAX_LOOP_FILTER * 3 / 4
+                                               : MAX_LOOP_FILTER;
 }
 
-// Enforce a minimum filter level based upon baseline Q
-static int get_min_filter_level(VP9_COMP *cpi, int base_qindex) {
-  int min_filter_level;
-  min_filter_level = 0;
-
-  return min_filter_level;
+// Stub function for now Alt LF not used
+void vp9_set_alt_lf_level(VP9_COMP *cpi, int filt_val) {
 }
 
-// Enforce a maximum filter level based upon baseline Q
-static int get_max_filter_level(VP9_COMP *cpi, int base_qindex) {
-  int max_filter_level = MAX_LOOP_FILTER;
-  (void)base_qindex;
+static int try_filter_frame(const YV12_BUFFER_CONFIG *sd, VP9_COMP *const cpi,
+                            MACROBLOCKD *const xd, VP9_COMMON *const cm,
+                            int filt_level, int partial) {
+  int filt_err;
 
-  if (cpi->twopass.section_intra_rating > 8)
-    max_filter_level = MAX_LOOP_FILTER * 3 / 4;
+  vp9_set_alt_lf_level(cpi, filt_level);
+  vp9_loop_filter_frame(cm, xd, filt_level, 1, partial);
 
-  return max_filter_level;
-}
+  filt_err = vp9_calc_ss_err(sd, cm->frame_to_show);
 
+  // Re-instate the unfiltered frame
+  vpx_yv12_copy_y(&cpi->last_frame_uf, cm->frame_to_show);
 
-// Stub function for now Alt LF not used
-void vp9_set_alt_lf_level(VP9_COMP *cpi, int filt_val) {
+  return filt_err;
 }
 
-void vp9_pick_filter_level(YV12_BUFFER_CONFIG *sd, VP9_COMP *cpi, int partial) {
+static void search_filter_level(const YV12_BUFFER_CONFIG *sd, VP9_COMP *cpi,
+                                int partial) {
+  MACROBLOCKD *const xd = &cpi->mb.e_mbd;
   VP9_COMMON *const cm = &cpi->common;
   struct loopfilter *const lf = &cm->lf;
-
-  int best_err = 0;
-  int filt_err = 0;
   const int min_filter_level = get_min_filter_level(cpi, cm->base_qindex);
   const int max_filter_level = get_max_filter_level(cpi, cm->base_qindex);
-
-  int filter_step;
-  int filt_high = 0;
-  // Start search at previous frame filter level
-  int filt_mid = lf->filter_level;
-  int filt_low = 0;
+  int best_err;
   int filt_best;
   int filt_direction = 0;
+  // Start the search at the previous frame filter level unless it is now out of
+  // range.
+  int filt_mid = clamp(lf->filter_level, min_filter_level, max_filter_level);
+  int filter_step = filt_mid < 16 ? 4 : filt_mid / 4;
+  // Sum squared error at each filter level
+  int ss_err[MAX_LOOP_FILTER + 1];
 
-  int Bias = 0;  // Bias against raising loop filter in favor of lowering it.
+  // Set each entry to -1
+  vpx_memset(ss_err, 0xFF, sizeof(ss_err));
 
   //  Make a copy of the unfiltered / processed recon buffer
   vpx_yv12_copy_y(cm->frame_to_show, &cpi->last_frame_uf);
 
-  lf->sharpness_level = cm->frame_type == KEY_FRAME ? 0
-                                                    : cpi->oxcf.Sharpness;
-
-  // Start the search at the previous frame filter level unless it is now out of
-  // range.
-  filt_mid = clamp(lf->filter_level, min_filter_level, max_filter_level);
-
-  // Define the initial step size
-  filter_step = filt_mid < 16 ? 4 : filt_mid / 4;
-
-  // Get baseline error score
-  vp9_set_alt_lf_level(cpi, filt_mid);
-  vp9_loop_filter_frame(cm, &cpi->mb.e_mbd, filt_mid, 1, partial);
-
-  best_err = vp9_calc_ss_err(sd, cm->frame_to_show);
+  best_err = try_filter_frame(sd, cpi, xd, cm, filt_mid, partial);
   filt_best = filt_mid;
+  ss_err[filt_mid] = best_err;
 
-  //  Re-instate the unfiltered frame
-  vpx_yv12_copy_y(&cpi->last_frame_uf, cm->frame_to_show);
-
   while (filter_step > 0) {
-    Bias = (best_err >> (15 - (filt_mid / 8))) * filter_step;
+    const int filt_high = MIN(filt_mid + filter_step, max_filter_level);
+    const int filt_low = MAX(filt_mid - filter_step, min_filter_level);
+    int filt_err;
 
+    // Bias against raising loop filter in favor of lowering it.
+    int bias = (best_err >> (15 - (filt_mid / 8))) * filter_step;
+
     if (cpi->twopass.section_intra_rating < 20)
-      Bias = Bias * cpi->twopass.section_intra_rating / 20;
+      bias = bias * cpi->twopass.section_intra_rating / 20;
 
     // yx, bias less for large block size
-    if (cpi->common.tx_mode != ONLY_4X4)
-      Bias >>= 1;
+    if (cm->tx_mode != ONLY_4X4)
+      bias >>= 1;
 
-    filt_high = ((filt_mid + filter_step) > max_filter_level)
-                    ? max_filter_level
-                    : (filt_mid + filter_step);
-    filt_low = ((filt_mid - filter_step) < min_filter_level)
-                   ? min_filter_level
-                   : (filt_mid - filter_step);
-
-    if ((filt_direction <= 0) && (filt_low != filt_mid)) {
+    if (filt_direction <= 0 && filt_low != filt_mid) {
       // Get Low filter error score
-      vp9_set_alt_lf_level(cpi, filt_low);
-      vp9_loop_filter_frame(cm, &cpi->mb.e_mbd, filt_low, 1, partial);
-
-      filt_err = vp9_calc_ss_err(sd, cm->frame_to_show);
-
-      //  Re-instate the unfiltered frame
-      vpx_yv12_copy_y(&cpi->last_frame_uf, cm->frame_to_show);
-
+      if (ss_err[filt_low] < 0) {
+        filt_err = try_filter_frame(sd, cpi, xd, cm, filt_low, partial);
+        ss_err[filt_low] = filt_err;
+      } else {
+        filt_err = ss_err[filt_low];
+      }
       // If value is close to the best so far then bias towards a lower loop
       // filter value.
-      if ((filt_err - Bias) < best_err) {
+      if ((filt_err - bias) < best_err) {
         // Was it actually better than the previous best?
         if (filt_err < best_err)
           best_err = filt_err;
@@ -175,17 +112,15 @@
     }
 
     // Now look at filt_high
-    if ((filt_direction >= 0) && (filt_high != filt_mid)) {
-      vp9_set_alt_lf_level(cpi, filt_high);
-      vp9_loop_filter_frame(cm, &cpi->mb.e_mbd, filt_high, 1, partial);
-
-      filt_err = vp9_calc_ss_err(sd, cm->frame_to_show);
-
-      //  Re-instate the unfiltered frame
-      vpx_yv12_copy_y(&cpi->last_frame_uf, cm->frame_to_show);
-
+    if (filt_direction >= 0 && filt_high != filt_mid) {
+      if (ss_err[filt_high] < 0) {
+        filt_err = try_filter_frame(sd, cpi, xd, cm, filt_high, partial);
+        ss_err[filt_high] = filt_err;
+      } else {
+        filt_err = ss_err[filt_high];
+      }
       // Was it better than the previous best?
-      if (filt_err < (best_err - Bias)) {
+      if (filt_err < (best_err - bias)) {
         best_err = filt_err;
         filt_best = filt_high;
       }
@@ -203,3 +138,27 @@
 
   lf->filter_level = filt_best;
 }
+
+void vp9_pick_filter_level(const YV12_BUFFER_CONFIG *sd, VP9_COMP *cpi,
+                           int method) {
+  VP9_COMMON *const cm = &cpi->common;
+  struct loopfilter *const lf = &cm->lf;
+
+  lf->sharpness_level = cm->frame_type == KEY_FRAME ? 0
+                                                    : cpi->oxcf.sharpness;
+
+  if (method == 2) {
+    const int min_filter_level = get_min_filter_level(cpi, cm->base_qindex);
+    const int max_filter_level = get_max_filter_level(cpi, cm->base_qindex);
+    const int q = vp9_ac_quant(cm->base_qindex, 0);
+    // These values were determined by linear fitting the result of the
+    // searched level
+    // filt_guess = q * 0.316206 + 3.87252
+    int filt_guess = (q * 20723 + 1015158 + (1 << 17)) >> 18;
+    if (cm->frame_type == KEY_FRAME)
+      filt_guess -= 4;
+    lf->filter_level = clamp(filt_guess, min_filter_level, max_filter_level);
+  } else {
+    search_filter_level(sd, cpi, method == 1);
+  }
+}