Add more bayer formats, fix padding/width mode bytes functions for some formats

src/mode.c

@@ -113,6 +113,38 @@ static struct libmegapixels_modename mode_lut[] = {
 		.bpp = 10,
 		.cfa = LIBMEGAPIXELS_CFA_RGGB,
 	},
+	{
+		.name = "BGGR12",
+		.v4l_pixel_format = V4L2_PIX_FMT_SBGGR12,
+		.media_bus_format = MEDIA_BUS_FMT_SBGGR12_1X12,
+		.bpc = 12,
+		.bpp = 12,
+		.cfa = LIBMEGAPIXELS_CFA_BGGR,
+	},
+	{
+		.name = "GBRG12",
+		.v4l_pixel_format = V4L2_PIX_FMT_SGBRG12,
+		.media_bus_format = MEDIA_BUS_FMT_SGBRG12_1X12,
+		.bpc = 12,
+		.bpp = 12,
+		.cfa = LIBMEGAPIXELS_CFA_GBRG,
+	},
+	{
+		.name = "GRBG12",
+		.v4l_pixel_format = V4L2_PIX_FMT_SGRBG12,
+		.media_bus_format = MEDIA_BUS_FMT_SGRBG12_1X12,
+		.bpc = 12,
+		.bpp = 12,
+		.cfa = LIBMEGAPIXELS_CFA_GRBG,
+	},
+	{
+		.name = "RGGB12",
+		.v4l_pixel_format = V4L2_PIX_FMT_SRGGB12,
+		.media_bus_format = MEDIA_BUS_FMT_SRGGB12_1X12,
+		.bpc = 12,
+		.bpp = 12,
+		.cfa = LIBMEGAPIXELS_CFA_RGGB,
+	},
 	{
 		.name = "BGGR16",
 		.v4l_pixel_format = V4L2_PIX_FMT_SBGGR16,
@@ -274,31 +306,33 @@ libmegapixels_format_cfa_pattern(int format)
 	}
 }
 
-// mp_pixel_format_width_to_bytes
+/* Calculates the number of bytes required to store a row of pixels for a given mode and width. */
 uint32_t
 libmegapixels_mode_width_to_bytes(int index, uint32_t width)
 {
 	uint32_t bits_per_pixel = mode_lut[index].bpp;
 	uint64_t bits_per_width = width * (uint64_t) bits_per_pixel;
 	uint64_t remainder = bits_per_width % 8;
+	uint32_t result = 0;
 	if (remainder == 0)
-		return bits_per_width / 8;
+		result = bits_per_width / 8;
+	else
+		result = (bits_per_width + 8 - remainder) / 8;
 
-	return (bits_per_width + 8 - remainder) / 8;
+	return result;
 }
 
+/* Calculates the padding (in bytes) required at the end of each row for a given mode and width. */
 uint32_t
 libmegapixels_mode_width_to_padding(int index, uint32_t width)
 {
-	if (mode_lut[index].bpp == 8) {
-		return 0;
-	}
-	uint64_t bytes_per_width = libmegapixels_mode_width_to_bytes(index, width);
-	uint64_t remainder = bytes_per_width % 8;
+	int remainder = mode_lut[index].bpp % 8;
 	if (remainder == 0)
-		return remainder;
+		return 0;
+
+	uint32_t padding = ((uint64_t) (8 - remainder) * width) / 8;
 
-	return 8 - remainder;
+	return padding;
 }
 
 uint32_t

src/mode.h

@@ -7,8 +7,8 @@ struct libmegapixels_modename {
 		char *name;
 		uint32_t v4l_pixel_format;
 		uint32_t media_bus_format;
-		int bpp;
-		int bpc;
+		int bpp; /* Bits per pixel */
+		int bpc; /* Bits per color - not currently used */
 		int cfa;
 };