From fe9e31ef5ee9d0f6daeae1ce04e3e13563281f62 Mon Sep 17 00:00:00 2001
From: Pascal Massimino <pascal.massimino@gmail.com>
Date: Wed, 8 Jun 2016 13:36:04 +0200
Subject: [PATCH] clarify variable names in HistogramRemap()

also simplify the loop by removing the initial special case

Change-Id: I4fc1b9eb14a42381a815354599137703c21ed9e6
---
 src/enc/histogram.c | 37 ++++++++++++++++++-------------------
 1 file changed, 18 insertions(+), 19 deletions(-)

diff --git a/src/enc/histogram.c b/src/enc/histogram.c
index 869882de..47270dce 100644
--- a/src/enc/histogram.c
+++ b/src/enc/histogram.c
@@ -808,24 +808,23 @@ static VP8LHistogram* HistogramCombineStochastic(
 
 // Find the best 'out' histogram for each of the 'in' histograms.
 // Note: we assume that out[]->bit_cost_ is already up-to-date.
-static void HistogramRemap(const VP8LHistogramSet* const orig_histo,
-                           const VP8LHistogramSet* const image_histo,
+static void HistogramRemap(const VP8LHistogramSet* const in,
+                           const VP8LHistogramSet* const out,
                            uint16_t* const symbols) {
   int i;
-  VP8LHistogram** const orig_histograms = orig_histo->histograms;
-  VP8LHistogram** const histograms = image_histo->histograms;
-  const int orig_histo_size = orig_histo->size;
-  const int image_histo_size = image_histo->size;
-  if (image_histo_size > 1) {
-    for (i = 0; i < orig_histo_size; ++i) {
+  VP8LHistogram** const in_histo = in->histograms;
+  VP8LHistogram** const out_histo = out->histograms;
+  const int in_size = in->size;
+  const int out_size = out->size;
+  if (out_size > 1) {
+    for (i = 0; i < in_size; ++i) {
       int best_out = 0;
-      double best_bits =
-          HistogramAddThresh(histograms[0], orig_histograms[i], MAX_COST);
+      double best_bits = MAX_COST;
       int k;
-      for (k = 1; k < image_histo_size; ++k) {
+      for (k = 0; k < out_size; ++k) {
         const double cur_bits =
-            HistogramAddThresh(histograms[k], orig_histograms[i], best_bits);
-        if (cur_bits < best_bits) {
+            HistogramAddThresh(out_histo[k], in_histo[i], best_bits);
+        if (k == 0 || cur_bits < best_bits) {
           best_bits = cur_bits;
           best_out = k;
         }
@@ -833,20 +832,20 @@ static void HistogramRemap(const VP8LHistogramSet* const orig_histo,
       symbols[i] = best_out;
     }
   } else {
-    assert(image_histo_size == 1);
-    for (i = 0; i < orig_histo_size; ++i) {
+    assert(out_size == 1);
+    for (i = 0; i < in_size; ++i) {
       symbols[i] = 0;
     }
   }
 
   // Recompute each out based on raw and symbols.
-  for (i = 0; i < image_histo_size; ++i) {
-    HistogramClear(histograms[i]);
+  for (i = 0; i < out_size; ++i) {
+    HistogramClear(out_histo[i]);
   }
 
-  for (i = 0; i < orig_histo_size; ++i) {
+  for (i = 0; i < in_size; ++i) {
     const int idx = symbols[i];
-    VP8LHistogramAdd(orig_histograms[i], histograms[idx], histograms[idx]);
+    VP8LHistogramAdd(in_histo[i], out_histo[idx], out_histo[idx]);
   }
 }