Fix default primaries and TRC for RGB colorspace

Author: bmatherly

src/framework/mlt_image.c

@@ -483,7 +483,7 @@ mlt_color_trc mlt_image_default_trc(mlt_colorspace colorspace)
 {
     switch (colorspace) {
     case mlt_colorspace_rgb:
-        return mlt_color_trc_smpte170m;
+        return mlt_color_trc_iec61966_2_1;
     case mlt_colorspace_bt709:
         return mlt_color_trc_bt709;
     case mlt_colorspace_bt470bg:
@@ -521,7 +521,6 @@ mlt_color_primaries mlt_image_default_primaries(mlt_colorspace colorspace, int h
 {
     switch (colorspace) {
     case mlt_colorspace_rgb:
-        return mlt_color_pri_smpte170m;
     case mlt_colorspace_bt709:
         return mlt_color_pri_bt709;
     case mlt_colorspace_bt470bg:

src/modules/core/producer_colour.c

@@ -245,8 +245,9 @@ static int producer_get_image(mlt_frame frame,
     mlt_properties_set_int(properties, "meta.media.height", *height);
 
     mlt_colorspace colorspace = mlt_colorspace_rgb;
-    mlt_color_trc color_trc = mlt_color_trc_smpte170m;
-    mlt_color_primaries primaries = mlt_color_pri_smpte170m;
+    mlt_color_trc color_trc = mlt_color_trc_iec61966_2_1;
+    mlt_color_primaries primaries = mlt_color_pri_bt709;
+
     int full_range = 1;
     switch (*format) {
     case mlt_image_yuv420p: