[libcamera-devel,1/8] libcamera: stream: add basic Stream class

335 diff mbox series

diff --git a/include/libcamera/libcamera.h b/include/libcamera/libcamera.h
index c0511cf6d662b63f..272dfd5e4a67d5de 100644
--- a/include/libcamera/libcamera.h
+++ b/include/libcamera/libcamera.h
@@ -12,6 +12,7 @@ 
 #include <libcamera/event_dispatcher.h>
 #include <libcamera/event_notifier.h>
 #include <libcamera/signal.h>
+#include <libcamera/stream.h>
 #include <libcamera/timer.h>
 
 #endif /* __LIBCAMERA_LIBCAMERA_H__ */
diff --git a/include/libcamera/meson.build b/include/libcamera/meson.build
index d7cb55ba4a49e1e8..54a680787e5c17aa 100644
--- a/include/libcamera/meson.build
+++ b/include/libcamera/meson.build
@@ -5,6 +5,7 @@  libcamera_api = files([
     'event_notifier.h',
     'libcamera.h',
     'signal.h',
+    'stream.h',
     'timer.h',
 ])
 
diff --git a/include/libcamera/stream.h b/include/libcamera/stream.h
new file mode 100644
index 0000000000000000..415815ba12c65e47
--- /dev/null
+++ b/include/libcamera/stream.h
@@ -0,0 +1,25 @@ 
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2019, Google Inc.
+ *
+ * stream.h - Stream object interface
+ */
+#ifndef __LIBCAMERA_STREAM_H__
+#define __LIBCAMERA_STREAM_H__
+
+namespace libcamera {
+
+class Stream final
+{
+public:
+	Stream(unsigned int id);
+
+	unsigned int id() const { return id_; };
+
+private:
+	unsigned int id_;
+};
+
+} /* namespace libcamera */
+
+#endif /* __LIBCAMERA_STREAM_H__ */
diff --git a/src/libcamera/meson.build b/src/libcamera/meson.build
index f9f25c0ecf1564cc..9f6ff99eebe2f5bc 100644
--- a/src/libcamera/meson.build
+++ b/src/libcamera/meson.build
@@ -10,6 +10,7 @@  libcamera_sources = files([
     'media_object.cpp',
     'pipeline_handler.cpp',
     'signal.cpp',
+    'stream.cpp',
     'timer.cpp',
     'v4l2_device.cpp',
 ])
diff --git a/src/libcamera/stream.cpp b/src/libcamera/stream.cpp
new file mode 100644
index 0000000000000000..3b44e834ee02b35a
--- /dev/null
+++ b/src/libcamera/stream.cpp
@@ -0,0 +1,66 @@ 
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2019, Google Inc.
+ *
+ * stream.cpp - Stream information handeling
+ */
+
+#include <libcamera/stream.h>
+
+/**
+ * \file stream.h
+ * \brief Stream information
+ *
+ * A camera device can provide frames in different resolutions and formats
+ * concurrently from a single image source. The Stream class represents
+ * one of the multiple concurrent streams format.
+ *
+ * All streams exposed by a camera device share the same image source and are
+ * thus not fully independent. Parameters related to the image source, such as
+ * the exposure time or flash control, are common to all streams. Other
+ * parameters, such as format or resolution, may be specified per-stream,
+ * depending on the capabilities of the camera device.
+ *
+ * Camera devices expose at least one stream, and may expose additional streams
+ * based on the device capabilities. This can be used, for instance, to
+ * implement concurrent viewfinder and video capture, or concurrent viewfinder,
+ * video capture and still image capture.
+ */
+
+namespace libcamera {
+
+/**
+ * \class Stream
+ * \brief Stream information carrier
+ *
+ * The Stream class is a model of all static information which are associated
+ * with a single video stream. A application should acquire Stream objects from
+ * the camera.
+ *
+ * Some cameras are capable of supplying more then one stream from the same
+ * video source. In such cases a application will receive a array of streams to
+ * inspect and select from to best fit its use-case.
+ *
+ * \todo Add capabilities to the Stream API. Without this the Stream class
+ *	 only serves to reveal how many streams of unknown capabilities a camera
+ *	 supports. This in it self is productive as it allows applications to
+ *	 configure and capture from one or more streams even if it won't be able
+ *	 to select the optimal stream for the task.
+ */
+
+/**
+ * \brief Create a new stream with a ID
+ * \param[in] id Numerical ID which should be unique for the camera device the stream belongs to
+ */
+Stream::Stream(unsigned int id)
+	: id_(id)
+{
+}
+
+/**
+ * \fn Stream::id()
+ * \brief Retrieve the streams ID
+ * \return The stream ID
+ */
+
+} /* namespace libcamera */