diff --git a/source/ntsc/md_ntsc.h b/source/ntsc/md_ntsc.h
index e987d58..648fe74 100644
--- a/source/ntsc/md_ntsc.h
+++ b/source/ntsc/md_ntsc.h
@@ -137,11 +137,11 @@ struct md_ntsc_t {
 }
 
 /* x is always zero except in snes_ntsc library */
-#ifdef USE_15BPP_RENDERING
+#if MD_NTSC_OUT_DEPTH == 15
 #define MD_NTSC_RGB_OUT_( rgb_out, x ) {\
     rgb_out = (raw_>>(14-x)& 0x7C00)|(raw_>>(9-x)&0x03E0)|(raw_>>(4-x)&0x001F);\
    }
-#else
+#elif MD_NTSC_OUT_DEPTH == 16
 #define MD_NTSC_RGB_OUT_( rgb_out, x ) {\
     rgb_out = (raw_>>(13-x)& 0xF800)|(raw_>>(8-x)&0x07E0)|(raw_>>(4-x)&0x001F);\
    }
diff --git a/source/ntsc/md_ntsc_config.h b/source/ntsc/md_ntsc_config.h
index 0cd00f5..8864dde 100644
--- a/source/ntsc/md_ntsc_config.h
+++ b/source/ntsc/md_ntsc_config.h
@@ -3,18 +3,22 @@
 #ifndef MD_NTSC_CONFIG_H
 #define MD_NTSC_CONFIG_H
 
-/* Format of source pixels */
+/* Format of source & output pixels (RGB555 or RGB565 only)*/
 #ifdef USE_15BPP_RENDERING
 #define MD_NTSC_IN_FORMAT MD_NTSC_RGB15
+#define MD_NTSC_OUT_DEPTH 15
 #else
 #define MD_NTSC_IN_FORMAT MD_NTSC_RGB16
+#define MD_NTSC_OUT_DEPTH 16
 #endif
-#define MD_NTSC_IN_FORMAT MD_NTSC_RGB16
 
-/* Original CRAM format */
+/* Original CRAM format (not used) */
 /* #define MD_NTSC_IN_FORMAT MD_NTSC_BGR9 */
 
-/* Type of input pixel values */
+/* The following affect the built-in blitter only; a custom blitter can
+handle things however it wants. */
+
+/* Type of input pixel values (fixed to 16-bit) */
 #define MD_NTSC_IN_T unsigned short
 
 /* Each raw pixel input value is passed through this. You might want to mask
diff --git a/source/ntsc/sms_ntsc.h b/source/ntsc/sms_ntsc.h
index 9471d94..eba6228 100644
--- a/source/ntsc/sms_ntsc.h
+++ b/source/ntsc/sms_ntsc.h
@@ -137,11 +137,11 @@ struct sms_ntsc_t {
 }
 
 /* x is always zero except in snes_ntsc library */
-#ifdef USE_15BPP_RENDERING
+#if SMS_NTSC_OUT_DEPTH == 15
 #define SMS_NTSC_RGB_OUT_( rgb_out, x ) {\
     rgb_out = (raw_>>(14-x)& 0x7C00)|(raw_>>(9-x)&0x03E0)|(raw_>>(4-x)&0x001F);\
    }
-#else
+#elif SMS_NTSC_OUT_DEPTH == 16
 #define SMS_NTSC_RGB_OUT_( rgb_out, x) {\
     rgb_out = (raw_>>(13-x)& 0xF800)|(raw_>>(8-x)&0x07E0)|(raw_>>(4-x)&0x001F);\
    }
diff --git a/source/ntsc/sms_ntsc_config.h b/source/ntsc/sms_ntsc_config.h
index 7022448..6b9e0bf 100644
--- a/source/ntsc/sms_ntsc_config.h
+++ b/source/ntsc/sms_ntsc_config.h
@@ -3,20 +3,22 @@
 #ifndef SMS_NTSC_CONFIG_H
 #define SMS_NTSC_CONFIG_H
 
-/* Format of source pixels */
+/* Format of source & output pixels (RGB555 or RGB565 only) */
 #ifdef USE_15BPP_RENDERING
 #define SMS_NTSC_IN_FORMAT SMS_NTSC_RGB15
+#define SMS_NTSC_OUT_DEPTH 15
 #else
 #define SMS_NTSC_IN_FORMAT SMS_NTSC_RGB16
+#define SMS_NTSC_OUT_DEPTH 16
 #endif
 
-/* Original CRAM format */
+/* Original CRAM format (not used) */
 /* #define SMS_NTSC_IN_FORMAT SMS_NTSC_BGR12 */
 
 /* The following affect the built-in blitter only; a custom blitter can
 handle things however it wants. */
 
-/* Type of input pixel values */
+/* Type of input pixel values (fixed to 16-bit)*/
 #define SMS_NTSC_IN_T unsigned short
 
 /* Each raw pixel input value is passed through this. You might want to mask