megapixels: Implement quick-debayering all Bayer 8-bits pixel formats

This application was supporting only debayering of BGGR8 streams:
this is an issue on cameras that are outputting a different format.

Implement quick-debayering of all Bayer 8-bits pixfmts in order to
solve wrong tint issues on many, many camera sensors.

This was tested on a Sony Exmor-RS IMX300 sensor.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>

main.c

@@ -610,7 +610,9 @@ process_image(const int *p, int size)
 		}
 		pixbuf = gdk_pixbuf_new(GDK_COLORSPACE_RGB, FALSE, 8, current.width / (skip*2), current.height / (skip*2));
 		pixels = gdk_pixbuf_get_pixels(pixbuf);
-		quick_debayer_bggr8((const uint8_t *)p, pixels, current.width, current.height, skip, current.blacklevel);
+		quick_debayer((const uint8_t *)p, pixels, current.fmt,
+			       current.width, current.height, skip,
+			       current.blacklevel);
 
 		if (current.rotate == 0) {
 			pixbufrot = pixbuf;
@@ -765,7 +767,9 @@ process_image(const int *p, int size)
 			// Update the thumbnail if this is the last frame
 			pixbuf = gdk_pixbuf_new(GDK_COLORSPACE_RGB, FALSE, 8, current.width / (skip*2), current.height / (skip*2));
 			pixels = gdk_pixbuf_get_pixels(pixbuf);
-			quick_debayer_bggr8((const uint8_t *)p, pixels, current.width, current.height, skip, current.blacklevel);
+			quick_debayer((const uint8_t *)p, pixels, current.fmt,
+				      current.width, current.height, skip,
+				      current.blacklevel);
 
 			if (current.rotate == 0) {
 				pixbufrot = pixbuf;

quickdebayer.c

@@ -1,43 +1,77 @@
+/*
+ * Fast but bad debayer method that scales and rotates by skipping source
+ * pixels and doesn't interpolate any values at all
+ */
+
+#include <linux/videodev2.h>
 #include "quickdebayer.h"
 
-// Fast but bad debayer method that scales and rotates by skipping source pixels and
-// doesn't interpolate any values at all
+/* Linear -> sRGB lookup table */
+static const int srgb[] = {
+	0, 12, 21, 28, 33, 38, 42, 46, 49, 52, 55, 58, 61, 63, 66, 68, 70,
+	73, 75, 77, 79, 81, 82, 84, 86, 88, 89, 91, 93, 94, 96, 97, 99, 100,
+	102, 103, 104, 106, 107, 109, 110, 111, 112, 114, 115, 116, 117, 118,
+	120, 121, 122, 123, 124, 125, 126, 127, 129, 130, 131, 132, 133, 134,
+	135, 136, 137, 138, 139, 140, 141, 142, 142, 143, 144, 145, 146, 147,
+	148, 149, 150, 151, 151, 152, 153, 154, 155, 156, 157, 157, 158, 159,
+	160, 161, 161, 162, 163, 164, 165, 165, 166, 167, 168, 168, 169, 170,
+	171, 171, 172, 173, 174, 174, 175, 176, 176, 177, 178, 179, 179, 180,
+	181, 181, 182, 183, 183, 184, 185, 185, 186, 187, 187, 188, 189, 189,
+	190, 191, 191, 192, 193, 193, 194, 194, 195, 196, 196, 197, 197, 198,
+	199, 199, 200, 201, 201, 202, 202, 203, 204, 204, 205, 205, 206, 206,
+	207, 208, 208, 209, 209, 210, 210, 211, 212, 212, 213, 213, 214, 214,
+	215, 215, 216, 217, 217, 218, 218, 219, 219, 220, 220, 221, 221, 222,
+	222, 223, 223, 224, 224, 225, 226, 226, 227, 227, 228, 228, 229, 229,
+	230, 230, 231, 231, 232, 232, 233, 233, 234, 234, 235, 235, 236, 236,
+	237, 237, 237, 238, 238, 239, 239, 240, 240, 241, 241, 242, 242, 243,
+	243, 244, 244, 245, 245, 245, 246, 246, 247, 247, 248, 248, 249, 249,
+	250, 250, 251, 251, 251, 252, 252, 253, 253, 254, 254, 255
+};
+
+static void quick_debayer_set_dst(uint8_t *dst, uint8_t p0, uint8_t p1,
+				  uint8_t p2)
+{
+	dst[0] = p0;
+	dst[1] = p1;
+	dst[2] = p2;
+}
 
-void
-quick_debayer_bggr8(const uint8_t *source, uint8_t *destination, int width, int height, int skip, int blacklevel)
+void quick_debayer(const uint8_t *source, uint8_t *destination,
+		   uint32_t pix_fmt, int width, int height, int skip,
+		   int blacklevel)
 {
 	int byteskip = 2 * skip;
 	int input_size = width * height;
-	int output_size = (width/byteskip) * (height/byteskip);
-	int i;
-	int j=0;
+	int i = 0, j = 0;
 	int row_left = width;
 
-	// Linear -> sRGB lookup table
-	static int srgb[] = {
-		0, 12, 21, 28, 33, 38, 42, 46, 49, 52, 55, 58, 61, 63, 66, 68, 70, 73, 75, 77, 79, 
-		81, 82, 84, 86, 88, 89, 91, 93, 94, 96, 97, 99, 100, 102, 103, 104, 106, 107, 109,
-		110, 111, 112, 114, 115, 116, 117, 118, 120, 121, 122, 123, 124, 125, 126, 127, 129,
-		130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140, 141, 142, 142, 143, 144, 145,
-		146, 147, 148, 149, 150, 151, 151, 152, 153, 154, 155, 156, 157, 157, 158, 159, 160,
-		161, 161, 162, 163, 164, 165, 165, 166, 167, 168, 168, 169, 170, 171, 171, 172, 173,
-		174, 174, 175, 176, 176, 177, 178, 179, 179, 180, 181, 181, 182, 183, 183, 184, 185,
-		185, 186, 187, 187, 188, 189, 189, 190, 191, 191, 192, 193, 193, 194, 194, 195, 196,
-		196, 197, 197, 198, 199, 199, 200, 201, 201, 202, 202, 203, 204, 204, 205, 205, 206,
-		206, 207, 208, 208, 209, 209, 210, 210, 211, 212, 212, 213, 213, 214, 214, 215, 215,
-		216, 217, 217, 218, 218, 219, 219, 220, 220, 221, 221, 222, 222, 223, 223, 224, 224,
-		225, 226, 226, 227, 227, 228, 228, 229, 229, 230, 230, 231, 231, 232, 232, 233, 233,
-		234, 234, 235, 235, 236, 236, 237, 237, 237, 238, 238, 239, 239, 240, 240, 241, 241,
-		242, 242, 243, 243, 244, 244, 245, 245, 245, 246, 246, 247, 247, 248, 248, 249, 249,
-		250, 250, 251, 251, 251, 252, 252, 253, 253, 254, 254, 255
-	};
+	do {
+		uint8_t b0 = srgb[source[i] - blacklevel];
+		uint8_t b1 = srgb[source[i + 1] - blacklevel];
+		uint8_t b2 = srgb[source[i + width + 1] - blacklevel];
+
+		switch (pix_fmt) {
+			case V4L2_PIX_FMT_SBGGR8:
+				quick_debayer_set_dst(&destination[j],
+						      b2, b1, b0);
+				break;
+			case V4L2_PIX_FMT_SGBRG8:
+				quick_debayer_set_dst(&destination[j],
+						      b1, b2, b0);
+				break;
+			case V4L2_PIX_FMT_SGRBG8:
+				quick_debayer_set_dst(&destination[j],
+						      b1, b0, b2);
+				break;
+			case V4L2_PIX_FMT_SRGGB8:
+				/* fall through */
+			default:
+				quick_debayer_set_dst(&destination[j],
+						      b0, b1, b2);
+				break;
+		}
+		j += 3;
 
-	// B G
-	// G R
-	for(i=0;i<input_size;) {
-		destination[j++] = srgb[source[i+width+1] - blacklevel];
-		destination[j++] = srgb[source[i+1] - blacklevel];
-		destination[j++] = srgb[source[i] - blacklevel];
 		i = i + byteskip;
 		row_left = row_left - byteskip;
 		if(row_left < byteskip){
@@ -46,5 +80,5 @@ quick_debayer_bggr8(const uint8_t *source, uint8_t *destination, int width, int
 			i = i + width;
 			i = i + (width * 2 * (skip-1));
 		}
-	}
+	} while (i < input_size);
 }

quickdebayer.h

@@ -1,4 +1,5 @@
 #include <stdint.h>
 
-void quick_debayer_bggr8(const uint8_t *source, uint8_t *destination, int width, int height, int skip, int blacklevel);
-
+void quick_debayer(const uint8_t *source, uint8_t *destination,
+		   uint32_t pix_fmt, int width, int height, int skip,
+		   int blacklevel);