[ST2094-50] Fix at decode scaling of component mix when not equal to 1.0

Quantization can result in sum of quantized value not equal to 50000 (1.0). Scaling by the sum of all custom coefficient.
Also fixed wrong common flag set at encode.

Author: Ronan Boitard

IsoLib/t35_tool/sources/SMPTE_ST2094_50.cpp

@@ -648,10 +648,10 @@ void SMPTE_ST2094_50::convertMetadataItemsToSyntaxElements(){
                   }
                   sumCoefficients = sumCoefficients + elm.component_mixing_coefficient[iAlt][iCmf];
               }
-              if (sumCoefficients != 60000) { logMsg(LOGLEVEL_ERROR, "sum component mixing coefficient for alternate %d is not equal to 1.0", iAlt); }
+              if (sumCoefficients != Q_COMPONENT_MIXING_COEFFICIENT) { logMsg(LOGLEVEL_WARNING, "Sum component mixing coefficient for alternate %d is not equal to 1.0, they will be scaled to 1.0 at decoding", iAlt); }
           }
           if (elm.component_mixing_type[0] != elm.component_mixing_type[iAlt]) {
-            elm.has_common_curve_params_flag = false;
+            elm.component_mixing_type = false;
           }
 
           // Create syntax elements for the gain curve function
@@ -1034,10 +1034,18 @@ void SMPTE_ST2094_50::convertSyntaxElementsToMetadataItems(){
             cgf.cm.componentMixGreen = 1.0f / 6.0f; 
             cgf.cm.componentMixBlue = 1.0f / 6.0f;}
           else if (elm.component_mixing_type[iAlt] == 3) {
+              // Compute sum of component
+              float sumComponent = 0.0f;
+              for (int k = 0; k < MAX_NB_COMPONENT_MIXING_COEFFICIENT; k++) {
+                sumComponent = float(elm.component_mixing_coefficient[iAlt][k]);
+              }
+              if (sumComponent != Q_COMPONENT_MIXING_COEFFICIENT){
+                logMsg(LOGLEVEL_WARNING, "Sum component mixing coefficient for alternate %d is not equal to 1.0, they will be scaled to 1.0.", iAlt); }
+              }
               for (int k = 0; k < MAX_NB_COMPONENT_MIXING_COEFFICIENT; k++) {
                   float value = 0.0f;
                   if (elm.has_component_mixing_coefficient_flag[iAlt][k]) {
-                      value = float(elm.component_mixing_coefficient[iAlt][k]) / Q_COMPONENT_MIXING_COEFFICIENT;
+                      value = float(elm.component_mixing_coefficient[iAlt][k]) / sumComponent;
                   }
                   switch (k) {
                       case 0: cgf.cm.componentMixRed = value; break;