Add support for discrete animation including strings.

[mlt] / src / framework / mlt_property.c

diff --git a/src/framework/mlt_property.c b/src/framework/mlt_property.c
index 4d5f57c7c53ed84c1c7acadc77e90e6c0beaf796..21c6e08c7cd4f81c6e48ab47bbbdac5d64d7530d 100644 (file)
--- a/src/framework/mlt_property.c
+++ b/src/framework/mlt_property.c
@@ -924,3 +924,50 @@ char *mlt_property_get_time( mlt_property self, mlt_time_format format, double f
        // Return the string (may be NULL)
        return self->prop_string;
 }
+
+static int is_property_numeric( mlt_property self, locale_t locale )
+{
+       int result = ( self->types & mlt_prop_int ) ||
+                       ( self->types & mlt_prop_int64 ) ||
+                       ( self->types & mlt_prop_double ) ||
+                       ( self->types & mlt_prop_position );
+
+       // If not already numeric but string is numeric.
+       if ( ( !result && self->types & mlt_prop_string ) && self->prop_string )
+       {
+               double temp;
+               char *p = NULL;
+#if defined(__GLIBC__) || defined(__DARWIN__)
+               if ( locale )
+                       temp = strtod_l( self->prop_string, &p, locale );
+               else
+#endif
+               temp = strtod( self->prop_string, &p );
+               result = ( p != self->prop_string );
+       }
+       return result;
+}
+
+static inline double linearstep( double start, double end, double position, int length )
+{
+       double o = ( end - start ) / length;
+       return start + position * o;
+}
+
+int mlt_property_interpolate(mlt_property self, mlt_property previous, mlt_property next,
+       double position, int length, double fps, locale_t locale )
+{
+       int error = 0;
+       if ( fps > 0 && is_property_numeric( previous, locale ) && is_property_numeric( next, locale ) )
+       {
+               double start = previous? mlt_property_get_double( previous, fps, locale ) : 0;
+               double end = next? mlt_property_get_double( next, fps, locale ) : 0;
+               double value = next? linearstep( start, end, position, length ) : start;
+               error = mlt_property_set_double( self, value );
+       }
+       else
+       {
+               mlt_property_pass( self, previous );
+       }
+       return error;
+}