[libcamera-devel] [PATCH/RFC 05/11] libcamera: Define constants for pixel formats in the public API

[Laurent Pinchart]

libcamera uses pixel format FourCC and modifier values from DRM. This
requires inclusion of drm_fourcc.h, creating a dependency on a header
that is packaged differently between distributions, and causing possible
issues with third-party applications.

Define constants for the supported pixel formats in the public API, in
order to remove the dependency on drm_fourcc.h. The numerical values are
still identical to the DRM pixel formats, keeping the direct
interoperability.

Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
---
 include/libcamera/formats.h    | 94 ++++++++++++++++++++++++++++++++++
 include/libcamera/meson.build  |  1 +
 src/libcamera/formats.cpp      |  2 +-
 src/libcamera/pixel_format.cpp |  1 +
 4 files changed, 97 insertions(+), 1 deletion(-)
 create mode 100644 include/libcamera/formats.h

diff --git a/include/libcamera/formats.h b/include/libcamera/formats.h
new file mode 100644
index 000000000000..bd164226d712
--- /dev/null
+++ b/include/libcamera/formats.h
@@ -0,0 +1,94 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2020, Google Inc.
+ *
+ * formats.h - Formats
+ */
+#ifndef __LIBCAMERA_FORMATS_H__
+#define __LIBCAMERA_FORMATS_H__
+
+#include <stdint.h>
+
+#include <libcamera/pixel_format.h>
+
+namespace libcamera {
+
+namespace formats {
+
+namespace {
+
+constexpr uint32_t __fourcc(char a, char b, char c, char d)
+{
+	return (static_cast<uint32_t>(a) <<  0) |
+	       (static_cast<uint32_t>(b) <<  8) |
+	       (static_cast<uint32_t>(c) << 16) |
+	       (static_cast<uint32_t>(d) << 24);
+}
+
+constexpr uint64_t __mod(unsigned int vendor, unsigned int mod)
+{
+	return (static_cast<uint64_t>(vendor) << 56) |
+	       (static_cast<uint64_t>(mod) << 0);
+}
+
+} /* namespace */
+
+constexpr PixelFormat R8{ __fourcc('R', '8', ' ', ' ') };
+
+constexpr PixelFormat RGB888{ __fourcc('R', 'G', '2', '4') };
+constexpr PixelFormat BGR888{ __fourcc('B', 'G', '2', '4') };
+
+constexpr PixelFormat XRGB8888{ __fourcc('X', 'R', '2', '4') };
+constexpr PixelFormat XBGR8888{ __fourcc('X', 'B', '2', '4') };
+constexpr PixelFormat RGBX8888{ __fourcc('R', 'X', '2', '4') };
+constexpr PixelFormat BGRX8888{ __fourcc('B', 'X', '2', '4') };
+
+constexpr PixelFormat ARGB8888{ __fourcc('A', 'R', '2', '4') };
+constexpr PixelFormat ABGR8888{ __fourcc('A', 'B', '2', '4') };
+constexpr PixelFormat RGBA8888{ __fourcc('R', 'A', '2', '4') };
+constexpr PixelFormat BGRA8888{ __fourcc('B', 'A', '2', '4') };
+
+constexpr PixelFormat YUYV{ __fourcc('Y', 'U', 'Y', 'V') };
+constexpr PixelFormat YVYU{ __fourcc('Y', 'V', 'Y', 'U') };
+constexpr PixelFormat UYVY{ __fourcc('U', 'Y', 'V', 'Y') };
+constexpr PixelFormat VYUY{ __fourcc('V', 'Y', 'U', 'Y') };
+
+constexpr PixelFormat NV12{ __fourcc('N', 'V', '1', '2') };
+constexpr PixelFormat NV21{ __fourcc('N', 'V', '2', '1') };
+constexpr PixelFormat NV16{ __fourcc('N', 'V', '1', '6') };
+constexpr PixelFormat NV61{ __fourcc('N', 'V', '6', '1') };
+constexpr PixelFormat NV24{ __fourcc('N', 'V', '2', '4') };
+constexpr PixelFormat NV42{ __fourcc('N', 'V', '4', '2') };
+
+constexpr PixelFormat MJPEG{ __fourcc('M', 'J', 'P', 'G') };
+
+constexpr PixelFormat SRGGB8{ __fourcc('R', 'G', 'G', 'B') };
+constexpr PixelFormat SGRBG8{ __fourcc('G', 'R', 'B', 'G') };
+constexpr PixelFormat SGBRG8{ __fourcc('G', 'B', 'R', 'G') };
+constexpr PixelFormat SBGGR8{ __fourcc('B', 'A', '8', '1') };
+
+constexpr PixelFormat SRGGB10{ __fourcc('R', 'G', '1', '0') };
+constexpr PixelFormat SGRBG10{ __fourcc('B', 'A', '1', '0') };
+constexpr PixelFormat SGBRG10{ __fourcc('G', 'B', '1', '0') };
+constexpr PixelFormat SBGGR10{ __fourcc('B', 'G', '1', '0') };
+
+constexpr PixelFormat SRGGB12{ __fourcc('R', 'G', '1', '2') };
+constexpr PixelFormat SGRBG12{ __fourcc('B', 'A', '1', '2') };
+constexpr PixelFormat SGBRG12{ __fourcc('G', 'B', '1', '2') };
+constexpr PixelFormat SBGGR12{ __fourcc('B', 'G', '1', '2') };
+
+constexpr PixelFormat SRGGB10_CSI2P{ __fourcc('R', 'G', '1', '0'), __mod(10, 1) };
+constexpr PixelFormat SGRBG10_CSI2P{ __fourcc('B', 'A', '1', '0'), __mod(10, 1) };
+constexpr PixelFormat SGBRG10_CSI2P{ __fourcc('G', 'B', '1', '0'), __mod(10, 1) };
+constexpr PixelFormat SBGGR10_CSI2P{ __fourcc('B', 'G', '1', '0'), __mod(10, 1) };
+
+constexpr PixelFormat SRGGB12_CSI2P{ __fourcc('R', 'G', '1', '2'), __mod(10, 1) };
+constexpr PixelFormat SGRBG12_CSI2P{ __fourcc('B', 'A', '1', '2'), __mod(10, 1) };
+constexpr PixelFormat SGBRG12_CSI2P{ __fourcc('G', 'B', '1', '2'), __mod(10, 1) };
+constexpr PixelFormat SBGGR12_CSI2P{ __fourcc('B', 'G', '1', '2'), __mod(10, 1) };
+
+} /* namespace formats */
+
+} /* namespace libcamera */
+
+#endif /* __LIBCAMERA_FORMATS_H__ */
diff --git a/include/libcamera/meson.build b/include/libcamera/meson.build
index 73c5b999acf4..170744d0fbbc 100644
--- a/include/libcamera/meson.build
+++ b/include/libcamera/meson.build
@@ -9,6 +9,7 @@ libcamera_public_headers = files([
     'event_dispatcher.h',
     'event_notifier.h',
     'file_descriptor.h',
+    'formats.h',
     'framebuffer_allocator.h',
     'geometry.h',
     'logging.h',
diff --git a/src/libcamera/formats.cpp b/src/libcamera/formats.cpp
index 2ac3b412ecdb..74c239a5e710 100644
--- a/src/libcamera/formats.cpp
+++ b/src/libcamera/formats.cpp
@@ -12,7 +12,7 @@
 #include "libcamera/internal/log.h"
 
 /**
- * \file formats.h
+ * \file internal/formats.h
  * \brief Types and helper methods to handle libcamera image formats
  */
 
diff --git a/src/libcamera/pixel_format.cpp b/src/libcamera/pixel_format.cpp
index d501c5f09c6b..0709d1526b82 100644
--- a/src/libcamera/pixel_format.cpp
+++ b/src/libcamera/pixel_format.cpp
@@ -5,6 +5,7 @@
  * pixel_format.cpp - libcamera Pixel Format
  */
 
+#include <libcamera/formats.h>
 #include <libcamera/pixel_format.h>
 
 /**
-- 
Regards,

Laurent Pinchart