I pass the savings on to you!

bin/main.c

@@ -85,6 +85,54 @@ error_malloc_png:
     return -1;
 }
 
+static uint8_t *read_png_file(const char *file,
+                              size_t *width,
+                              size_t *height,
+                              int *depth) {
+    png_t *png;
+    uint8_t *buf;
+
+    png_init(malloc, free);
+
+    if ((png = malloc(sizeof(*png))) == NULL) {
+        goto error_malloc_png;
+    }
+
+    if (png_open_file_read(png, file) < 0) {
+        goto error_png_open_file_read;
+    }
+
+    *width  = png->width;
+    *height = png->height;
+    *depth  = png->bpp;
+
+    if ((buf = malloc(*width * *height * *depth)) == NULL) {
+        goto error_malloc_buf;
+    }
+
+    if (png_get_data(png, buf) < 0) {
+        goto error_png_get_data;
+    }
+
+    png_close_file(png);
+
+    free(png);
+
+    return buf;
+
+error_png_get_data:
+    free(buf);
+
+error_malloc_buf:
+    png_close_file(png);
+
+error_png_open_file_read:
+    free(png);
+
+error_malloc_png:
+    return NULL;
+}
+
 static int import(int argc, char **argv) {
     cammy_sram *sram;
     png_t *png;
@@ -239,10 +287,9 @@ error_sram_open:
 }
 
 static int dither(int argc, char **argv) {
-    png_t *in;
     uint8_t *bufin, *bufout;
-
-    int error;
+    size_t width, height;
+    int depth;
 
     if (argc < 3) {
         usage(argc, argv, "No PNG input file provided");
@@ -250,75 +297,46 @@ static int dither(int argc, char **argv) {
         usage(argc, argv, "No PNG output filename provided");
     }
 
-    png_init(malloc, free);
-
-    if ((in = malloc(sizeof(*in))) == NULL) {
-        goto error_malloc_in;
-    }
-
-    if ((error = png_open_file_read(in, argv[2])) < 0) {
-        fprintf(stderr, "%s: %s: %s: %s\n",
-            argv[0], "png_open_file_read()", argv[2], png_error_string(error));
-
-        goto error_png_open_file_read;
-    }
-
-    if ((bufin = malloc(in->width * in->height * in->bpp)) == NULL) {
+    if ((bufin = read_png_file(argv[2], &width,
+                                        &height,
+                                        &depth)) == NULL) {
         fprintf(stderr, "%s: %s: %s\n",
-            argv[0], "malloc()", strerror(errno));
+            argv[0], "read_png_file()", strerror(errno));
 
-        goto error_malloc_bufin;
+        goto error_read_png_file;
     }
 
-    if ((bufout = malloc(in->width * in->height * 3)) == NULL) {
+    if ((bufout = malloc(width * height * 3)) == NULL) {
         fprintf(stderr, "%s: %s: %s\n",
             argv[0], "malloc()", strerror(errno));
 
         goto error_malloc_bufout;
     }
 
-    if ((error = png_get_data(in, bufin)) < 0) {
-        fprintf(stderr, "%s: %s: %s: %s\n",
-            argv[0], "png_get_data()", argv[2], png_error_string(error));
-
-        goto error_png_get_data;
-    }
-
-    cammy_image_dither(bufout, bufin, in->width, in->height, in->bpp, &palette);
+    cammy_image_dither(bufout, bufin, width, height, depth, &palette);
 
     if (save_buf_to_png_file(argv[3], bufout,
-                             in->width,
-                             in->height, 8, PNG_TRUECOLOR) < 0) {
+                             width,
+                             height, 8, PNG_TRUECOLOR) < 0) {
         fprintf(stderr, "%s: %s: %s: %s\n",
             argv[0], "save_buf_to_png_file()", argv[3], strerror(errno));
 
         goto error_save_buf_to_png_file;
     }
 
-    png_close_file(in);
-
     free(bufout);
 
     free(bufin);
 
-    free(in);
-
     return 0;
 
 error_save_buf_to_png_file:
-error_png_get_data:
     free(bufout);
 
 error_malloc_bufout:
     free(bufin);
 
-error_malloc_bufin:
-    png_close_file(in);
-
-error_png_open_file_read:
-    free(in);
-
-error_malloc_in:
+error_read_png_file:
     return 1;
 }