[libcamera-devel] [PATCH] libcamera: add support for planar YUV422 and YUV420 formats

[David Plowman]

These formats can be helpful when downstream applications or libraries
support them natively (avoiding a costly conversion).

Signed-off-by: David Plowman <david.plowman at raspberrypi.com>
---
 src/libcamera/formats.cpp          | 14 ++++++++++++++
 src/libcamera/v4l2_pixelformat.cpp |  2 ++
 src/v4l2/v4l2_camera_proxy.cpp     |  2 ++
 3 files changed, 18 insertions(+)

diff --git a/src/libcamera/formats.cpp b/src/libcamera/formats.cpp
index 2ac3b41..dcd1dcf 100644
--- a/src/libcamera/formats.cpp
+++ b/src/libcamera/formats.cpp
@@ -268,6 +268,20 @@ const std::map<PixelFormat, PixelFormatInfo> pixelFormatInfo{
 		.colourEncoding = PixelFormatInfo::ColourEncodingYUV,
 		.packed = false,
 	} },
+	{ PixelFormat(DRM_FORMAT_YUV422), {
+		.format = PixelFormat(DRM_FORMAT_YUV422),
+		.v4l2Format = V4L2PixelFormat(V4L2_PIX_FMT_YUV422P),
+		.bitsPerPixel = 16,
+		.colourEncoding = PixelFormatInfo::ColourEncodingYUV,
+		.packed = false,
+	} },
+	{ PixelFormat(DRM_FORMAT_YUV420), {
+		.format = PixelFormat(DRM_FORMAT_YUV420),
+		.v4l2Format = V4L2PixelFormat(V4L2_PIX_FMT_YUV420),
+		.bitsPerPixel = 12,
+		.colourEncoding = PixelFormatInfo::ColourEncodingYUV,
+		.packed = false,
+	} },
 
 	/* Greyscale formats. */
 	{ PixelFormat(DRM_FORMAT_R8), {
diff --git a/src/libcamera/v4l2_pixelformat.cpp b/src/libcamera/v4l2_pixelformat.cpp
index 94fae47..01778c0 100644
--- a/src/libcamera/v4l2_pixelformat.cpp
+++ b/src/libcamera/v4l2_pixelformat.cpp
@@ -64,6 +64,8 @@ const std::map<V4L2PixelFormat, PixelFormat> vpf2pf{
 	{ V4L2PixelFormat(V4L2_PIX_FMT_NV61), PixelFormat(DRM_FORMAT_NV61) },
 	{ V4L2PixelFormat(V4L2_PIX_FMT_NV12), PixelFormat(DRM_FORMAT_NV12) },
 	{ V4L2PixelFormat(V4L2_PIX_FMT_NV21), PixelFormat(DRM_FORMAT_NV21) },
+	{ V4L2PixelFormat(V4L2_PIX_FMT_YUV422P), PixelFormat(DRM_FORMAT_YUV422) },
+	{ V4L2PixelFormat(V4L2_PIX_FMT_YUV420), PixelFormat(DRM_FORMAT_YUV420) },
 
 	/* Greyscale formats. */
 	{ V4L2PixelFormat(V4L2_PIX_FMT_GREY), PixelFormat(DRM_FORMAT_R8) },
diff --git a/src/v4l2/v4l2_camera_proxy.cpp b/src/v4l2/v4l2_camera_proxy.cpp
index d7f14e6..a54d47e 100644
--- a/src/v4l2/v4l2_camera_proxy.cpp
+++ b/src/v4l2/v4l2_camera_proxy.cpp
@@ -576,6 +576,8 @@ static const std::array<PixelFormatInfo, 14> pixelFormatInfo = {{
 	{ PixelFormat(DRM_FORMAT_NV61),		V4L2_PIX_FMT_NV61,	2, {{ {  8, 1, 1 }, { 16, 2, 1 }, {  0, 0, 0 } }} },
 	{ PixelFormat(DRM_FORMAT_NV24),		V4L2_PIX_FMT_NV24,	2, {{ {  8, 1, 1 }, { 16, 1, 1 }, {  0, 0, 0 } }} },
 	{ PixelFormat(DRM_FORMAT_NV42),		V4L2_PIX_FMT_NV42,	2, {{ {  8, 1, 1 }, { 16, 1, 1 }, {  0, 0, 0 } }} },
+	{ PixelFormat(DRM_FORMAT_YUV422),	V4L2_PIX_FMT_YUV422P,	2, {{ {  8, 1, 1 }, { 8, 2, 1 }, {  8, 2, 1 } }} },
+	{ PixelFormat(DRM_FORMAT_YUV420),	V4L2_PIX_FMT_YUV420,	2, {{ {  8, 1, 1 }, { 8, 2, 2 }, {  8, 2, 2 } }} },
 	/* Compressed formats. */
 	/*
 	 * \todo Get a better image size estimate for MJPEG, via
-- 
2.20.1