Fix few nits

Add/remove few casts, fixed indentation.

Change-Id: Icd141694201843c04e476f09142ce4be6e502dff

src/dsp/lossless.c

@@ -541,26 +541,25 @@ static const PredictorFunc kPredictors[16] = {
   Predictor0, Predictor0    // <- padding security sentinels
 };
 
-static float PredictionCostSpatial(const int* const counts, int weight_0,
+static float PredictionCostSpatial(const int counts[256], int weight_0,
-                                   double exp_val, int n) {
+                                   double exp_val) {
-  const int significant_symbols = n >> 4;
+  const int significant_symbols = 256 >> 4;
   const double exp_decay_factor = 0.6;
   double bits = weight_0 * counts[0];
   int i;
   for (i = 1; i < significant_symbols; ++i) {
-    bits += exp_val * (counts[i] + counts[n - i]);
+    bits += exp_val * (counts[i] + counts[256 - i]);
     exp_val *= exp_decay_factor;
   }
   return (float)(-0.1 * bits);
 }
 
 // Compute the combined Shanon's entropy for distribution {X} and {X+Y}
-static float CombinedShannonEntropy(const int* const X,
+static float CombinedShannonEntropy(const int X[256], const int Y[256]) {
-                                    const int* const Y, int n) {
   int i;
   double retval = 0.;
   int sumX = 0, sumXY = 0;
-  for (i = 0; i < n; ++i) {
+  for (i = 0; i < 256; ++i) {
     const int x = X[i];
     const int xy = x + Y[i];
     if (x != 0) {
@@ -583,8 +582,8 @@ static float PredictionCostSpatialHistogram(const int accumulated[4][256],
   double retval = 0;
   for (i = 0; i < 4; ++i) {
     const double kExpValue = 0.94;
-    retval += PredictionCostSpatial(tile[i], 1, kExpValue, 256);
+    retval += PredictionCostSpatial(tile[i], 1, kExpValue);
-    retval += CombinedShannonEntropy(tile[i], accumulated[i], 256);
+    retval += CombinedShannonEntropy(tile[i], accumulated[i]);
   }
   return (float)retval;
 }
@@ -839,7 +838,7 @@ static WEBP_INLINE void ColorCodeToMultipliers(uint32_t color_code,
   m->red_to_blue_   = (color_code >> 16) & 0xff;
 }
 
-static WEBP_INLINE uint32_t MultipliersToColorCode(Multipliers* const m) {
+static WEBP_INLINE uint32_t MultipliersToColorCode(const Multipliers* const m) {
   return 0xff000000u |
          ((uint32_t)(m->red_to_blue_) << 16) |
          ((uint32_t)(m->green_to_blue_) << 8) |
@@ -917,8 +916,8 @@ static float PredictionCostCrossColor(const int accumulated[256],
   // Favor low entropy, locally and globally.
   // Favor small absolute values for PredictionCostSpatial
   static const double kExpValue = 2.4;
-  return CombinedShannonEntropy(counts, accumulated, 256) +
+  return CombinedShannonEntropy(counts, accumulated) +
-         PredictionCostSpatial(counts, 3, kExpValue, 256);
+         PredictionCostSpatial(counts, 3, kExpValue);
 }
 
 static float GetPredictionCostCrossColorRed(
@@ -1630,4 +1629,3 @@ void VP8LDspInit(void) {
 }
 
 //------------------------------------------------------------------------------
-

src/enc/histogram.c

@@ -455,7 +455,7 @@ static int GetHistoBinIndex(
   return bin_id;
 }
 
-// Construct the Histogram from backward references.
+// Construct the histograms from backward references.
 static void HistogramBuild(
     int xsize, int histo_bits, const VP8LBackwardRefs* const backward_refs,
     VP8LHistogramSet* const init_histo) {
@@ -499,7 +499,6 @@ static void HistogramAnalyzeBin(
   int i;
   const int histo_size = init_histo->size;
   VP8LHistogram** const histograms = init_histo->histograms;
-  if (bin_map != NULL) {
   const int bin_depth = init_histo->size + 1;
   DominantCostRange cost_range;
   DominantCostRangeInit(&cost_range);
@@ -525,11 +524,10 @@ static void HistogramAnalyzeBin(
     // Get and increment the num_histos in that bin.
     num_histos = ++bin_map[bin_offset];
     assert(bin_offset + num_histos < bin_depth * BIN_SIZE);
-      // Add Histogram i'th index at num_histos (last) position in the bin_map.
+    // Add histogram i'th index at num_histos (last) position in the bin_map.
     bin_map[bin_offset + num_histos] = i;
   }
 }
-}
 
 // Compact the histogram set by moving the valid one left in the set to the
 // head and moving the ones that have been merged to other histograms towards
@@ -565,7 +563,6 @@ static void HistogramCombineBin(VP8LHistogramSet* const histo_image,
                                 VP8LHistogram* const histos,
                                 int bin_depth,
                                 int16_t* const bin_map) {
-  int i;
   int bin_id;
   VP8LHistogram* cur_combo = histos;
 
@@ -573,8 +570,9 @@ static void HistogramCombineBin(VP8LHistogramSet* const histo_image,
     const int bin_offset = bin_id * bin_depth;
     const int num_histos = bin_map[bin_offset];
     const int idx1 = bin_map[bin_offset + 1];
-    for (i = 2; i <= num_histos; ++i) {
+    int n;
-      const int idx2 = bin_map[bin_offset + i];
+    for (n = 2; n <= num_histos; ++n) {
+      const int idx2 = bin_map[bin_offset + n];
       const double bit_cost_idx2 = histo_image->histograms[idx2]->bit_cost_;
       if (bit_cost_idx2 > 0.) {
         const double bit_cost_thresh = -bit_cost_idx2 * 0.1;
@@ -742,17 +740,13 @@ int VP8LGetHistoImageSymbols(int xsize, int ysize,
     if (bin_map == NULL) goto Error;
   }
 
-  // Construct the Histogram from backward references.
+  // Construct the histogram from backward references.
   HistogramBuild(xsize, histo_bits, refs, init_histo);
 
   if (bin_map != NULL) {
-    // Partition Histograms to different entropy bins for three dominant
-    // (literal red and blue) symbol costs and compute the histogram aggregate
-    // bit_cost.
     HistogramAnalyzeBin(init_histo, histo_image, bin_map);
     HistogramCombineBin(histo_image, histos, bin_depth, bin_map);
   } else {
-    // Compute the histogram aggregate bit_cost.
     HistogramAnalyze(init_histo, histo_image);
   }