Raw image input

Add the ability to open 8bit PNG's instead of audio files, this is useful for things like playing around with false color paramaters due to reduced processing time
Also reduce some buffer sizes to more sane values

main.c

@@ -223,7 +223,6 @@ static void distrib(char *filename, float **prow, int nrow) {
 		for(int y = 0; y < 256; y++)
 			distrib[y][x] = distrib[y][x] / max * 255;
 
-
 	ImageOut(filename, "Brightness distribution", distrib, 256, 256, 0, NULL, 0);
 }
 
@@ -258,10 +257,68 @@ static void usage(void) {
    	exit(1);
 }
 
+int readRawImage(char *filename, float **prow, int *nrow) {
+	png_bytep *PNGrows = NULL;
+	FILE *fp = fopen(filename, "r");
+
+	// Create read struct
+	png_structp png = png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+	if(!png) return 0;
+
+	// Create info struct
+	png_infop info = png_create_info_struct(png);
+	if(!info) return 0;
+
+	// Init I/O
+	png_init_io(png, fp);
+
+	// Read info from header
+	png_read_info(png, info);
+	int width = png_get_image_width(png, info);
+	int height = png_get_image_height(png, info);
+	png_byte color_type = png_get_color_type(png, info);
+	png_byte bit_depth  = png_get_bit_depth(png, info);
+
+	// Check the image
+	if(width != 2080){
+		fprintf(stderr, "Expected a 2080px wide PNG, got a %ipx wide PNG", width);
+		return 0;
+	}
+	if(bit_depth != 8){
+		fprintf(stderr, "Expected an 8 bit PNG, got an %i bit PNG", bit_depth);
+		return 0;
+	}
+	if(color_type != PNG_COLOR_TYPE_GRAY){
+		fprintf(stderr, "Expected a grayscale PNG");
+		return 0;
+	}
+
+	// Create row buffers
+	PNGrows = (png_bytep *) malloc(sizeof(png_bytep) * height);
+	for(int y = 0; y < height; y++) PNGrows[y] = (png_byte *) malloc(png_get_rowbytes(png, info));
+
+	png_read_image(png, PNGrows);
+
+	// Tidy up	
+	fclose(fp);
+	png_destroy_read_struct(&png, &info, NULL);
+
+	// Put into prow
+	*nrow = height;
+	for(int y = 0; y < height; y++) {
+		prow[y] = (float *) malloc(sizeof(float) * width);
+		for(int x = 0; x < width; x++)
+			prow[y][x] = (float)PNGrows[y][x];
+	}
+
+	return 1;
+}
+
 int main(int argc, char **argv) {
     char pngfilename[1024];
-    char name[500];
-    char pngdirname[500] = "";
+    char name[128];
+    char pngdirname[128] = "";
+	char *extension;
 
 	// Default to a raw image, with equalization and cropped telemetry
     char imgopt[20] = "r";
@@ -323,7 +380,7 @@ int main(int argc, char **argv) {
 		}
     }
 	if(optind == argc){
-		printf("No audio files provided.\n");
+		printf("No input files provided.\n");
 		usage();
 	}
 
@@ -335,29 +392,35 @@ int main(int argc, char **argv) {
 		strcpy(pngfilename, argv[optind]);
 		strcpy(name, basename(pngfilename));
 		strtok(name, ".");
+		extension = strtok(NULL, ".");
 
 		if (pngdirname[0] == '\0')
 			strcpy(pngdirname, dirname(pngfilename));
 
-		// Open sound file, exit if that fails
-		if (initsnd(argv[optind]) == 0)
-			exit(1);
-
-		// Main image building loop
-		for (nrow = 0; nrow < 3000; nrow++) {
-			// Allocate 2150 floats worth of memory for every line of the image
-			prow[nrow] = (float *) malloc(sizeof(float) * 2150);
-			
-			// Read into prow and break the loop once we reach the end of the image
-			if (getpixelrow(prow[nrow]) == 0)
-				break;
+		if(strcmp(extension, "png") == 0){
+			printf("Reading %s", argv[optind]);
+			readRawImage(argv[optind], prow, &nrow);
+		}else{
+			// Open sound file, exit if that fails
+			if (initsnd(argv[optind]) == 0) exit(1);
+
+			// Main image building loop
+			for (nrow = 0; nrow < 3000; nrow++) {
+				// Allocate 2150 floats worth of memory for every line of the image
+				prow[nrow] = (float *) malloc(sizeof(float) * 2150);
+				
+				// Read into prow and break the loop once we reach the end of the image
+				if (getpixelrow(prow[nrow]) == 0) break;
+
+				printf("Row: %d\r", nrow);
+				fflush(stdout);
+			}
 
-			printf("Row: %d\r", nrow);
-			fflush(stdout);
+			// Close sound file
+			sf_close(inwav);
 		}
-		printf("\nTotal rows: %d\n", nrow);
 
-		sf_close(inwav);
+		printf("\nTotal rows: %d\n", nrow);
 
 		chA = calibrate(prow, nrow, CHA_OFFSET, CH_WIDTH, 0);
 		chB = calibrate(prow, nrow, CHB_OFFSET, CH_WIDTH, 0);