[libcamera-devel] [PATCH v2] libcamera: add support for planar YUV422 and YUV420 formats

[Laurent Pinchart]

From: David Plowman <david.plowman at raspberrypi.com>

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>
Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
---
Changes since v1:

- Rebase on top of formats rework
- Fix number of planes in formats descriptions
---
 src/libcamera/formats.cpp          | 14 ++++++++++++++
 src/libcamera/formats.yaml         |  5 +++++
 src/libcamera/v4l2_pixelformat.cpp |  2 ++
 src/v4l2/v4l2_camera_proxy.cpp     |  4 +++-
 4 files changed, 24 insertions(+), 1 deletion(-)

David, could you please test this and provide a Tested-by tag (and
Reviewed-by too if possible) ?

diff --git a/src/libcamera/formats.cpp b/src/libcamera/formats.cpp
index 97e986786cc8..c0b53ce7cc97 100644
--- a/src/libcamera/formats.cpp
+++ b/src/libcamera/formats.cpp
@@ -270,6 +270,20 @@ const std::map<PixelFormat, PixelFormatInfo> pixelFormatInfo{
 		.colourEncoding = PixelFormatInfo::ColourEncodingYUV,
 		.packed = false,
 	} },
+	{ formats::YUV420, {
+		.format = PixelFormat(formats::YUV420),
+		.v4l2Format = V4L2PixelFormat(V4L2_PIX_FMT_YUV420),
+		.bitsPerPixel = 12,
+		.colourEncoding = PixelFormatInfo::ColourEncodingYUV,
+		.packed = false,
+	} },
+	{ formats::YUV422, {
+		.format = PixelFormat(formats::YUV422),
+		.v4l2Format = V4L2PixelFormat(V4L2_PIX_FMT_YUV422P),
+		.bitsPerPixel = 16,
+		.colourEncoding = PixelFormatInfo::ColourEncodingYUV,
+		.packed = false,
+	} },
 
 	/* Greyscale formats. */
 	{ formats::R8, {
diff --git a/src/libcamera/formats.yaml b/src/libcamera/formats.yaml
index a6841c618f93..ce06dbc41aa1 100644
--- a/src/libcamera/formats.yaml
+++ b/src/libcamera/formats.yaml
@@ -53,6 +53,11 @@ formats:
   - NV42:
       fourcc: DRM_FORMAT_NV42
 
+  - YUV420:
+      fourcc: DRM_FORMAT_YUV420
+  - YUV422:
+      fourcc: DRM_FORMAT_YUV422
+
   - MJPEG:
       fourcc: DRM_FORMAT_MJPEG
 
diff --git a/src/libcamera/v4l2_pixelformat.cpp b/src/libcamera/v4l2_pixelformat.cpp
index 741f6c2646bc..6745d17d4926 100644
--- a/src/libcamera/v4l2_pixelformat.cpp
+++ b/src/libcamera/v4l2_pixelformat.cpp
@@ -63,6 +63,8 @@ const std::map<V4L2PixelFormat, PixelFormat> vpf2pf{
 	{ V4L2PixelFormat(V4L2_PIX_FMT_NV61), formats::NV61 },
 	{ V4L2PixelFormat(V4L2_PIX_FMT_NV12), formats::NV12 },
 	{ V4L2PixelFormat(V4L2_PIX_FMT_NV21), formats::NV21 },
+	{ V4L2PixelFormat(V4L2_PIX_FMT_YUV420), formats::YUV420 },
+	{ V4L2PixelFormat(V4L2_PIX_FMT_YUV422P), formats::YUV422 },
 
 	/* Greyscale formats. */
 	{ V4L2PixelFormat(V4L2_PIX_FMT_GREY), formats::R8 },
diff --git a/src/v4l2/v4l2_camera_proxy.cpp b/src/v4l2/v4l2_camera_proxy.cpp
index bf47aa7ee633..86b87e379b98 100644
--- a/src/v4l2/v4l2_camera_proxy.cpp
+++ b/src/v4l2/v4l2_camera_proxy.cpp
@@ -560,7 +560,7 @@ struct PixelFormatInfo {
 
 namespace {
 
-static const std::array<PixelFormatInfo, 14> pixelFormatInfo = {{
+static const std::array<PixelFormatInfo, 16> pixelFormatInfo = {{
 	/* RGB formats. */
 	{ formats::RGB888,	V4L2_PIX_FMT_BGR24,	1, {{ { 24, 1, 1 }, {  0, 0, 0 }, {  0, 0, 0 } }} },
 	{ formats::BGR888,	V4L2_PIX_FMT_RGB24,	1, {{ { 24, 1, 1 }, {  0, 0, 0 }, {  0, 0, 0 } }} },
@@ -577,6 +577,8 @@ static const std::array<PixelFormatInfo, 14> pixelFormatInfo = {{
 	{ formats::NV61,	V4L2_PIX_FMT_NV61,	2, {{ {  8, 1, 1 }, { 16, 2, 1 }, {  0, 0, 0 } }} },
 	{ formats::NV24,	V4L2_PIX_FMT_NV24,	2, {{ {  8, 1, 1 }, { 16, 1, 1 }, {  0, 0, 0 } }} },
 	{ formats::NV42,	V4L2_PIX_FMT_NV42,	2, {{ {  8, 1, 1 }, { 16, 1, 1 }, {  0, 0, 0 } }} },
+	{ formats::YUV420,	V4L2_PIX_FMT_YUV420,	3, {{ {  8, 1, 1 }, {  8, 2, 2 }, {  8, 2, 2 } }} },
+	{ formats::YUV422,	V4L2_PIX_FMT_YUV422P,	3, {{ {  8, 1, 1 }, {  8, 2, 1 }, {  8, 2, 1 } }} },
 	/* Compressed formats. */
 	/*
 	 * \todo Get a better image size estimate for MJPEG, via
-- 
Regards,

Laurent Pinchart