libvpx: Pull from upstream

source/libvpx/vp9/encoder/vp9_picklpf.c

 /*
  *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 36 matching lines @@
 
   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 Y plane raw and reconstruction data summing (square differences)
+  // 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;
 }
 
 // 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;
-  /*int q = (int) vp9_convert_qindex_to_q(base_qindex);
-
-  if (cpi->source_alt_ref_active && cpi->common.refresh_golden_frame && !cpi->common.refresh_alt_ref_frame)
-      min_filter_level = 0;
-  else
-  {
-      if (q <= 10)
-          min_filter_level = 0;
-      else if (q <= 64)
-          min_filter_level = 1;
-      else
-          min_filter_level = (q >> 6);
-  }
-  */
   min_filter_level = 0;
 
   return min_filter_level;
 }
 
 // Enforce a maximum filter level based upon baseline Q
 static int get_max_filter_level(VP9_COMP *cpi, int base_qindex) {
-  // PGW August 2006: Highest filter values almost always a bad idea
-
-  // jbb chg: 20100118 - not so any more with this overquant stuff allow high values
-  // with lots of intra coming in.
-  int max_filter_level = MAX_LOOP_FILTER;// * 3 / 4;
+  int max_filter_level = MAX_LOOP_FILTER;
   (void)base_qindex;
 
   if (cpi->twopass.section_intra_rating > 8)
     max_filter_level = MAX_LOOP_FILTER * 3 / 4;
 
   return max_filter_level;
 }
 
 
 // Stub function for now Alt LF not used
@@ skipping 10 matching lines @@
   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 filt_best;
   int filt_direction = 0;
 
-  int Bias = 0;                       // Bias against raising loop filter and in favour of lowering it
+  int Bias = 0;  // Bias against raising loop filter in favor of lowering it.
 
   //  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.
+  // 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);
   filt_best = filt_mid;
 
   //  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; // PGW change 12/12/06 for small images
+    Bias = (best_err >> (15 - (filt_mid / 8))) * filter_step;
 
-    // jbb chg: 20100118 - in sections with lots of new material coming in don't bias as much to a low filter value
     if (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;
 
-    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);
+    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)) {
       // 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 value is close to the best so far then bias towards a lower loop filter value.
+      // If value is close to the best so far then bias towards a lower loop
+      // filter value.
       if ((filt_err - Bias) < best_err) {
         // Was it actually better than the previous best?
         if (filt_err < best_err)
           best_err = filt_err;
 
         filt_best = filt_low;
       }
     }
 
     // Now look at filt_high
@@ skipping 18 matching lines @@
       filter_step = filter_step / 2;
       filt_direction = 0;
     } else {
       filt_direction = (filt_best < filt_mid) ? -1 : 1;
       filt_mid = filt_best;
     }
   }
 
   lf->filter_level = filt_best;
 }
-