From e4880aa4b7bcca9d3fa29adf4300316465b334cd Mon Sep 17 00:00:00 2001
From: Marko Viitanen <fador@iki.fi>
Date: Thu, 20 Feb 2014 17:22:33 +0200
Subject: [PATCH] Fixed SAO bitstream generation and band offset a bit

---
 src/encoder.c | 17 +++++++----------
 src/sao.c     |  6 ++++--
 2 files changed, 11 insertions(+), 12 deletions(-)

diff --git a/src/encoder.c b/src/encoder.c
index 74902359..dd81422e 100644
--- a/src/encoder.c
+++ b/src/encoder.c
@@ -1141,13 +1141,8 @@ void encode_sao_color(encoder_control *encoder, sao_info *sao, color_index color
   
   /// sao_offset_abs[][][][]: TR, cMax = (1 << (Min(bitDepth, 10) - 5)) - 1,
   ///                         cRiceParam = 0, bins = {bypass x N}
-  for (i = SAO_EO_CAT1; i <= SAO_EO_CAT2; ++i) {
-    assert(sao->offsets[i] >= 0);
-    cabac_write_unary_max_symbol_ep(&cabac, sao->offsets[i], SAO_ABS_OFFSET_MAX);
-  }
-  for (i = SAO_EO_CAT3; i <= SAO_EO_CAT4; ++i) {
-    assert(sao->offsets[i] <= 0);
-    cabac_write_unary_max_symbol_ep(&cabac, -sao->offsets[i], SAO_ABS_OFFSET_MAX);
+  for (i = SAO_EO_CAT1; i <= SAO_EO_CAT4; ++i) {
+    cabac_write_unary_max_symbol_ep(&cabac, abs(sao->offsets[i]), SAO_ABS_OFFSET_MAX);
   }
 
   /// sao_offset_sign[][][][]: FL, cMax = 1, bins = {bypass}
@@ -1157,11 +1152,13 @@ void encode_sao_color(encoder_control *encoder, sao_info *sao, color_index color
   if (sao->type == SAO_TYPE_BAND) {
     for (i = SAO_EO_CAT1; i <= SAO_EO_CAT4; ++i) {
       // Positive sign is coded as 0.
-      CABAC_BIN_EP(&cabac, sao->offsets[i] >= 0 ? 0 : 1, "sao_offset_sign");
+      if(sao->offsets[i] != 0) {
+        CABAC_BIN_EP(&cabac, sao->offsets[i] < 0 ? 1 : 0, "sao_offset_sign");
+      }
     }
     // TODO: sao_band_position
-    // FL cMax=31 (6 bits)
-    CABAC_BINS_EP(&cabac, sao->band_position, 6, "sao_band_position");
+    // FL cMax=31 (5 bits)
+    CABAC_BINS_EP(&cabac, sao->band_position, 5, "sao_band_position");
   } else if (color_i != COLOR_V) {
     CABAC_BINS_EP(&cabac, sao->eo_class, 2, "sao_eo_class");
   }
diff --git a/src/sao.c b/src/sao.c
index ea829566..32823919 100644
--- a/src/sao.c
+++ b/src/sao.c
@@ -73,9 +73,11 @@ int calc_sao_band_offsets(int sao_bands[2][32], int offsets[4], int *band_positi
   // Calculate distortion for each band using N*h^2 - 2*h*E
   for (band = 0; band < 32; band++) {
     best_dist = INT_MAX;
-    offset = sao_bands[1][band];
+    offset = sao_bands[1][band]?sao_bands[0][band]/sao_bands[1][band]:0;
+    dist[band] = offset==0?0:INT_MAX;
+    temp_offsets[band] = 0;    
     while(offset != 0) {
-      temp_dist = sao_bands[0][band]*offset*offset - 2*offset*sao_bands[0][band];
+      temp_dist = sao_bands[1][band]*offset*offset - 2*offset*sao_bands[0][band];
 
       // Store best distortion and offset
       if(temp_dist < best_dist) {