Banners should use RGBA4444 color.

source/3ds/cbmd.cpp

@@ -31,7 +31,7 @@ u8* build_cbmd_data(CBMD cbmd, u32* size, bool bnr) {
 
     u32 pad = 0;
     if(bnr) {
-        pad = 16 - (offset % 16);
+        pad = 0x10 - (offset % 0x10);
         offset += pad;
     }
 

source/3ds/cwav.cpp

@@ -30,11 +30,6 @@ typedef struct {
     u32 totalChannels;
 } InfoHeader;
 
-typedef struct {
-    char magic[4] = {'D', 'A', 'T', 'A'};
-    u32 length;
-} DataHeader;
-
 typedef struct {
     u32 flags = 0x7100;
     u32 offset;
@@ -48,6 +43,11 @@ typedef struct {
     u32 padding = 0;
 } ChannelData;
 
+typedef struct {
+    char magic[4] = {'D', 'A', 'T', 'A'};
+    u32 length;
+} DataHeader;
+
 u8* build_cwav(WAV wav, u32* size) {
     Header header;
     u32 offset = sizeof(Header);

source/3ds/util.cpp

@@ -7,14 +7,23 @@ u8 TILE_ORDER[64] = { 0,  1,  8,  9,  2,  3,  10, 11, 16, 17, 24, 25, 18, 19, 26
         32, 33, 40, 41, 34, 35, 42, 43, 48, 49, 56, 57, 50, 51, 58, 59,
         36, 37, 44, 45, 38, 39, 46, 47, 52, 53, 60, 61, 54, 55, 62, 63 };
 
-u16 rgba_to_rgb565(u8 r, u8 g, u8 b, u8 a) {
-    r = (u8) (1.0f * r * a / 255.0f) >> 3;
-    g = (u8) (1.0f * g * a / 255.0f) >> 2;
-    b = (u8) (1.0f * b * a / 255.0f) >> 3;
-    return (r << 11) | (g << 5) | b;
+u16 pack_color(u8 r, u8 g, u8 b, u8 a, PixelFormat format) {
+    if(format == RGB565) {
+        float alpha = a / 255.0f;
+        r = (u8) (r * alpha) >> 3;
+        g = (u8) (g * alpha) >> 2;
+        b = (u8) (b * alpha) >> 3;
+        return (r << 11) | (g << 5) | b;
+    } else if(format == RGBA4444) {
+        r >>= 4;
+        g >>= 4;
+        b >>= 4;
+        a >>= 4;
+        return r << 12 | g << 8 | b << 4 | a;
+    }
 }
 
-u16* image_to_tiles(const char* image, u32 width, u32 height, u32* size) {
+u16* image_to_tiles(const char* image, u32 width, u32 height, PixelFormat format, u32* size) {
     unsigned char* img;
     unsigned int imgWidth, imgHeight;
     if(lodepng_decode32_file(&img, &imgWidth, &imgHeight, image)) {
@@ -44,7 +53,7 @@ u16* image_to_tiles(const char* image, u32 width, u32 height, u32* size) {
                 u32 yy = (u32) (TILE_ORDER[k] >> 3);
 
                 u8* pixel = img + (((y + yy) * width + (x + xx)) * 4);
-                converted[n++] = rgba_to_rgb565(pixel[0], pixel[1], pixel[2], pixel[3]);
+                converted[n++] = pack_color(pixel[0], pixel[1], pixel[2], pixel[3], format);
             }
         }
     }
@@ -57,11 +66,9 @@ u16* image_to_tiles(const char* image, u32 width, u32 height, u32* size) {
 }
 
 void utf8_to_utf16(u16* dst, const char* src, size_t max_len) {
-    u8* u8dst = (u8*) dst;
     size_t n = 0;
     while(src[n]) {
-        u8dst[n * 2] = (u8) src[n];
-        u8dst[n * 2 + 1] = 0;
+        dst[n] = (u16) src[n] << 8;
         if(n++ >= max_len) {
             return;
         }

source/3ds/util.h

@@ -3,8 +3,13 @@
 
 #include "../types.h"
 
-u16 rgba_to_rgb565(u8 r, u8 g, u8 b, u8 a);
-u16* image_to_tiles(const char* image, u32 width, u32 height, u32* size);
+typedef enum {
+    RGB565,
+    RGBA4444
+} PixelFormat;
+
+u16 pack_color(u8 r, u8 g, u8 b, u8 a, PixelFormat format);
+u16* image_to_tiles(const char* image, u32 width, u32 height, PixelFormat format, u32* size);
 void utf8_to_utf16(u16* dst, const char* src, size_t max_len);
 
 #endif

source/main.cpp

@@ -11,7 +11,7 @@
 
 u8* convert_to_cgfx(const char* image, u32 width, u32 height, u32* size) {
     u32 convertedSize = 0;
-    u16* converted = image_to_tiles(image, width, height, &convertedSize);
+    u16* converted = image_to_tiles(image, width, height, RGBA4444, &convertedSize);
     if(converted == NULL) {
         return NULL;
     }
@@ -110,7 +110,7 @@ int make_banner(const char* image, const char* audio, char* cgfxFile, char* cwav
 }
 
 int make_smdh(char* shortDescription, char* longDescription, char* publisher, char* icon, char* output) {
-    u16* icon48 = image_to_tiles(icon, 48, 48, NULL);
+    u16* icon48 = image_to_tiles(icon, 48, 48, RGB565, NULL);
     if(icon48 == NULL) {
         return 1;
     }