Issue #252: YVYU support

man/ustreamer.1

@@ -52,7 +52,7 @@ Initial image resolution. Default: 640x480.
 .TP
 .BR \-m\ \fIfmt ", " \-\-format\ \fIfmt
 Image format.
-Available: YUYV, UYVY, RGB565, RGB24, JPEG; default: YUYV.
+Available: YUYV, YVYU, UYVY, RGB565, RGB24, JPEG; default: YUYV.
 .TP
 .BR \-a\ \fIstd ", " \-\-tv\-standard\ \fIstd
 Force TV standard.

src/libs/frame.c

@@ -73,6 +73,7 @@ unsigned us_frame_get_padding(const us_frame_s *frame) {
 	unsigned bytes_per_pixel = 0;
 	switch (frame->format) {
 		case V4L2_PIX_FMT_YUYV:
+		case V4L2_PIX_FMT_YVYU:
 		case V4L2_PIX_FMT_UYVY:
 		case V4L2_PIX_FMT_RGB565: bytes_per_pixel = 2; break;
 		case V4L2_PIX_FMT_BGR24:

src/ustreamer/device.c

@@ -38,6 +38,7 @@ static const struct {
 	const unsigned format; // cppcheck-suppress unusedStructMember
 } _FORMATS[] = {
 	{"YUYV",	V4L2_PIX_FMT_YUYV},
+	{"YVYU",	V4L2_PIX_FMT_YVYU},
 	{"UYVY",	V4L2_PIX_FMT_UYVY},
 	{"RGB565",	V4L2_PIX_FMT_RGB565},
 	{"RGB24",	V4L2_PIX_FMT_RGB24},

src/ustreamer/device.h

@@ -61,7 +61,7 @@
 #define US_STANDARDS_STR		"PAL, NTSC, SECAM"
 
 #define US_FORMAT_UNKNOWN		-1
-#define US_FORMATS_STR			"YUYV, UYVY, RGB565, RGB24, BGR24, MJPEG, JPEG"
+#define US_FORMATS_STR			"YUYV, YVYU, UYVY, RGB565, RGB24, BGR24, MJPEG, JPEG"
 
 #define US_IO_METHOD_UNKNOWN	-1
 #define US_IO_METHODS_STR		"MMAP, USERPTR"

src/ustreamer/encoders/cpu/encoder.c

@@ -38,6 +38,7 @@ typedef struct {
 static void _jpeg_set_dest_frame(j_compress_ptr jpeg, us_frame_s *frame);
 
 static void _jpeg_write_scanlines_yuyv(struct jpeg_compress_struct *jpeg, const us_frame_s *frame);
+static void _jpeg_write_scanlines_yvyu(struct jpeg_compress_struct *jpeg, const us_frame_s *frame);
 static void _jpeg_write_scanlines_uyvy(struct jpeg_compress_struct *jpeg, const us_frame_s *frame);
 static void _jpeg_write_scanlines_rgb565(struct jpeg_compress_struct *jpeg, const us_frame_s *frame);
 static void _jpeg_write_scanlines_rgb24(struct jpeg_compress_struct *jpeg, const us_frame_s *frame);
@@ -77,6 +78,7 @@ void us_cpu_encoder_compress(const us_frame_s *src, us_frame_s *dest, unsigned q
 	switch (src->format) {
 		// https://www.fourcc.org/yuv.php
 		WRITE_SCANLINES(V4L2_PIX_FMT_YUYV, _jpeg_write_scanlines_yuyv);
+		WRITE_SCANLINES(V4L2_PIX_FMT_YVYU, _jpeg_write_scanlines_yvyu);
 		WRITE_SCANLINES(V4L2_PIX_FMT_UYVY, _jpeg_write_scanlines_uyvy);
 		WRITE_SCANLINES(V4L2_PIX_FMT_RGB565, _jpeg_write_scanlines_rgb565);
 		WRITE_SCANLINES(V4L2_PIX_FMT_RGB24, _jpeg_write_scanlines_rgb24);
@@ -141,6 +143,39 @@ static void _jpeg_write_scanlines_yuyv(struct jpeg_compress_struct *jpeg, const
 	free(line_buf);
 }
 
+static void _jpeg_write_scanlines_yvyu(struct jpeg_compress_struct *jpeg, const us_frame_s *frame) {
+	uint8_t *line_buf;
+	US_CALLOC(line_buf, frame->width * 3);
+
+	const unsigned padding = us_frame_get_padding(frame);
+	const uint8_t *data = frame->data;
+
+	while (jpeg->next_scanline < frame->height) {
+		uint8_t *ptr = line_buf;
+
+		for (unsigned x = 0; x < frame->width; ++x) {
+			// See also: https://www.kernel.org/doc/html/v4.8/media/uapi/v4l/pixfmt-yuyv.html
+			const bool is_odd_pixel = x & 1;
+			const uint8_t y = data[is_odd_pixel ? 2 : 0];
+			const uint8_t u = data[3];
+			const uint8_t v = data[1];
+
+			ptr[0] = y;
+			ptr[1] = u;
+			ptr[2] = v;
+			ptr += 3;
+
+			data += (is_odd_pixel ? 4 : 0);
+		}
+		data += padding;
+
+		JSAMPROW scanlines[1] = {line_buf};
+		jpeg_write_scanlines(jpeg, scanlines, 1);
+	}
+
+	free(line_buf);
+}
+
 static void _jpeg_write_scanlines_uyvy(struct jpeg_compress_struct *jpeg, const us_frame_s *frame) {
 	uint8_t *line_buf;
 	US_CALLOC(line_buf, frame->width * 3);