From d48783eb7d26d40b383008710a1d2bb709c161cb Mon Sep 17 00:00:00 2001
From: gudvinr <gudvinr@gmail.com>
Date: Sat, 10 Sep 2022 07:40:32 +0300
Subject: [PATCH] Add GREY pixelformat

Fixes #170

Monochrome cameras send only Y component of YUV image
---
 src/libs/frame.c                     |  1 +
 src/ustreamer/device.c               |  1 +
 src/ustreamer/encoders/cpu/encoder.c | 31 ++++++++++++++++++++++++++++
 3 files changed, 33 insertions(+)

diff --git a/src/libs/frame.c b/src/libs/frame.c
index a5c58e25..1e172c52 100644
--- a/src/libs/frame.c
+++ b/src/libs/frame.c
@@ -72,6 +72,7 @@ bool us_frame_compare(const us_frame_s *a, const us_frame_s *b) {
 unsigned us_frame_get_padding(const us_frame_s *frame) {
 	unsigned bytes_per_pixel = 0;
 	switch (frame->format) {
+		case V4L2_PIX_FMT_GREY: bytes_per_pixel = 1; break;
 		case V4L2_PIX_FMT_YUYV:
 		case V4L2_PIX_FMT_UYVY:
 		case V4L2_PIX_FMT_RGB565: bytes_per_pixel = 2; break;
diff --git a/src/ustreamer/device.c b/src/ustreamer/device.c
index 427d9996..c42e6665 100644
--- a/src/ustreamer/device.c
+++ b/src/ustreamer/device.c
@@ -39,6 +39,7 @@ static const struct {
 } _FORMATS[] = {
 	{"YUYV",	V4L2_PIX_FMT_YUYV},
 	{"UYVY",	V4L2_PIX_FMT_UYVY},
+	{"GREY",	V4L2_PIX_FMT_GREY},
 	{"RGB565",	V4L2_PIX_FMT_RGB565},
 	{"RGB24",	V4L2_PIX_FMT_RGB24},
 	{"MJPEG",	V4L2_PIX_FMT_MJPEG},
diff --git a/src/ustreamer/encoders/cpu/encoder.c b/src/ustreamer/encoders/cpu/encoder.c
index 0eb5e2db..ffd56015 100644
--- a/src/ustreamer/encoders/cpu/encoder.c
+++ b/src/ustreamer/encoders/cpu/encoder.c
@@ -39,6 +39,7 @@ 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_uyvy(struct jpeg_compress_struct *jpeg, const us_frame_s *frame);
+static void _jpeg_write_scanlines_grey(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
 		// https://www.fourcc.org/yuv.php
 		WRITE_SCANLINES(V4L2_PIX_FMT_YUYV, _jpeg_write_scanlines_yuyv);
 		WRITE_SCANLINES(V4L2_PIX_FMT_UYVY, _jpeg_write_scanlines_uyvy);
+		WRITE_SCANLINES(V4L2_PIX_FMT_GREY, _jpeg_write_scanlines_grey);
 		WRITE_SCANLINES(V4L2_PIX_FMT_RGB565, _jpeg_write_scanlines_rgb565);
 		WRITE_SCANLINES(V4L2_PIX_FMT_RGB24, _jpeg_write_scanlines_rgb24);
 		default: assert(0 && "Unsupported input format for CPU encoder");
@@ -187,6 +189,35 @@ static void _jpeg_write_scanlines_uyvy(struct jpeg_compress_struct *jpeg, const
 	free(line_buf);
 }
 
+static void _jpeg_write_scanlines_grey(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;
+	unsigned z = 0;
+
+	while (jpeg->next_scanline < frame->height) {
+		uint8_t *ptr = line_buf;
+
+		for (unsigned x = 0; x < frame->width; ++x) {
+			const int y = data[0];
+
+			*(ptr++) = y;
+			*(ptr++) = y;
+			*(ptr++) = y;
+
+			data += 1;
+		}
+		data += padding;
+
+		JSAMPROW scanlines[1] = {line_buf};
+		jpeg_write_scanlines(jpeg, scanlines, 1);
+	}
+
+	free(line_buf);
+}
+
 #undef NORM_COMPONENT
 #undef YUV_B
 #undef YUV_G