[libcamera-devel] [PATCH 09/14] libcamera: converter: Introduce dw100 converter

[Xavier Roumegue]

Add converter support for the Vivante DW100 Dewarp Processor IP core
found on i.MX8MP SoC.

The processor core applies a programmable geometrical transformation on
input images to correct distorsion introduced by lenses.
The transformation function is exposed as a grid map with 16x16 pixel
macroblocks indexed using X, Y vertex coordinates.

A set of input/output vertices mapping can be loaded at runtime through
a configuration file. If no mapping is loaded, the vertices mapping
fallbacks to an identity transformation. Scaling and pixel format
conversion can be used independently of the vertices remapping.

Signed-off-by: Xavier Roumegue <xavier.roumegue at oss.nxp.com>
---
 include/libcamera/internal/converter_dw100.h | 25 +++++++++++++++
 include/libcamera/internal/meson.build       |  1 +
 src/libcamera/converter_dw100.cpp            | 32 ++++++++++++++++++++
 src/libcamera/meson.build                    |  1 +
 4 files changed, 59 insertions(+)
 create mode 100644 include/libcamera/internal/converter_dw100.h
 create mode 100644 src/libcamera/converter_dw100.cpp

diff --git a/include/libcamera/internal/converter_dw100.h b/include/libcamera/internal/converter_dw100.h
new file mode 100644
index 00000000..1972d6a2
--- /dev/null
+++ b/include/libcamera/internal/converter_dw100.h
@@ -0,0 +1,25 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright 2022 NXP
+ *
+ * converter_dw100.h - V4l2 M2M dw100 format converter interface
+ */
+
+#pragma once
+
+#include <linux/dw100.h>
+
+#include "libcamera/internal/converter_v4l2_m2m.h"
+#include "libcamera/internal/media_device.h"
+
+namespace libcamera {
+
+class DW100Converter : public V4L2M2MConverter
+{
+public:
+	DW100Converter(MediaDevice *media)
+		: V4L2M2MConverter(media){};
+	virtual int applyMapping(Stream *stream, Mapping &mapping) override;
+};
+
+} /* namespace libcamera */
diff --git a/include/libcamera/internal/meson.build b/include/libcamera/internal/meson.build
index 132de5ef..c2dd094f 100644
--- a/include/libcamera/internal/meson.build
+++ b/include/libcamera/internal/meson.build
@@ -20,6 +20,7 @@ libcamera_internal_headers = files([
     'control_serializer.h',
     'control_validator.h',
     'converter.h',
+    'converter_dw100.h',
     'converter_v4l2_m2m.h',
     'delayed_controls.h',
     'device_enumerator.h',
diff --git a/src/libcamera/converter_dw100.cpp b/src/libcamera/converter_dw100.cpp
new file mode 100644
index 00000000..b079fb37
--- /dev/null
+++ b/src/libcamera/converter_dw100.cpp
@@ -0,0 +1,32 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright 2022 NXP
+ *
+ * converter_dw100.cpp - V4L2 M2M dw100 format converter
+ */
+
+#include "libcamera/internal/converter_dw100.h"
+
+#include <libcamera/base/log.h>
+
+#include <libcamera/controls.h>
+
+#include "libcamera/internal/v4l2_videodevice.h"
+
+namespace libcamera {
+
+LOG_DECLARE_CATEGORY(Converter)
+
+int DW100Converter::applyMapping(Stream *stream, Mapping &mapping)
+{
+	ControlList ctrls;
+	auto value = Span<const int32_t>(reinterpret_cast<const int32_t *>(mapping.getMapping()), mapping.getLength());
+	ControlValue c(value);
+	ctrls.set(V4L2_CID_DW100_DEWARPING_16x16_VERTEX_MAP, c);
+	stream->m2m_->capture()->setControls(&ctrls);
+	return 0;
+}
+
+REGISTER_CONVERTER("dw100", DW100Converter)
+
+} /* namespace libcamera */
diff --git a/src/libcamera/meson.build b/src/libcamera/meson.build
index b12c8401..83da3e5f 100644
--- a/src/libcamera/meson.build
+++ b/src/libcamera/meson.build
@@ -14,6 +14,7 @@ libcamera_sources = files([
     'control_serializer.cpp',
     'control_validator.cpp',
     'converter.cpp',
+    'converter_dw100.cpp',
     'converter_v4l2_m2m.cpp',
     'delayed_controls.cpp',
     'device_enumerator.cpp',
-- 
2.37.3