libcamera: Use stream roles directly instead of StreamUsage

In order to prepare for an API overhall of the camera configuration
generation, remove the StreamUsage class and replace its uses by stream
roles. The size hints can't be specified anymore, and will be replaced
with an API on the StreamConfiguration to negotiate configuration
parameters with cameras.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>

16 files changed, 69 insertions, 173 deletions

diff --git a/include/libcamera/camera.h b/include/libcamera/camera.h
index 306739b7..42ba5201 100644
--- a/include/libcamera/camera.h
+++ b/include/libcamera/camera.h
@@ -14,16 +14,13 @@
 
 #include <libcamera/request.h>
 #include <libcamera/signal.h>
+#include <libcamera/stream.h>
 
 namespace libcamera {
 
 class Buffer;
 class PipelineHandler;
 class Request;
-class Stream;
-class StreamUsage;
-
-struct StreamConfiguration;
 
 class CameraConfiguration
 {
@@ -74,8 +71,7 @@ public:
 	int release();
 
 	const std::set<Stream *> &streams() const;
-	CameraConfiguration
-	generateConfiguration(const std::vector<StreamUsage> &usage);
+	CameraConfiguration generateConfiguration(const StreamRoles &roles);
 	int configure(const CameraConfiguration &config);
 
 	int allocateBuffers();
diff --git a/include/libcamera/stream.h b/include/libcamera/stream.h
index 0c986310..59bdf217 100644
--- a/include/libcamera/stream.h
+++ b/include/libcamera/stream.h
@@ -8,6 +8,7 @@
 #define __LIBCAMERA_STREAM_H__
 
 #include <string>
+#include <vector>
 
 #include <libcamera/buffer.h>
 #include <libcamera/geometry.h>
@@ -25,48 +26,17 @@ struct StreamConfiguration {
 	std::string toString() const;
 };
 
-class StreamUsage
-{
-public:
-	enum Role {
-		StillCapture,
-		VideoRecording,
-		Viewfinder,
-	};
-
-	Role role() const { return role_; }
-	const Size &size() const { return size_; }
-
-protected:
-	explicit StreamUsage(Role role);
-	StreamUsage(Role role, const Size &size);
-
-private:
-	Role role_;
-	Size size_;
+enum StreamRole {
+	StillCapture,
+	VideoRecording,
+	Viewfinder,
 };
 
+using StreamRoles = std::vector<StreamRole>;
+
 class Stream
 {
 public:
-	class StillCapture : public StreamUsage
-	{
-	public:
-		StillCapture();
-	};
-
-	class VideoRecording : public StreamUsage
-	{
-	public:
-		VideoRecording();
-	};
-
-	class Viewfinder : public StreamUsage
-	{
-	public:
-		Viewfinder(int width, int height);
-	};
-
 	Stream();
 	BufferPool &bufferPool() { return bufferPool_; }
 	const StreamConfiguration &configuration() const { return configuration_; }
diff --git a/src/cam/main.cpp b/src/cam/main.cpp
index 6a2508dd..d603228c 100644
--- a/src/cam/main.cpp
+++ b/src/cam/main.cpp
@@ -87,13 +87,13 @@ static int parseOptions(int argc, char *argv[])
 
 static int prepareCameraConfig(CameraConfiguration *config)
 {
-	std::vector<StreamUsage> roles;
+	StreamRoles roles;
 
 	streamInfo.clear();
 
 	/* If no configuration is provided assume a single video stream. */
 	if (!options.isSet(OptStream)) {
-		*config = camera->generateConfiguration({ Stream::VideoRecording() });
+		*config = camera->generateConfiguration({ StreamRole::VideoRecording });
 		streamInfo[config->front()] = "stream0";
 		return 0;
 	}
@@ -106,14 +106,13 @@ static int prepareCameraConfig(CameraConfiguration *config)
 		KeyValueParser::Options conf = value.toKeyValues();
 
 		if (!conf.isSet("role")) {
-			roles.push_back(Stream::VideoRecording());
+			roles.push_back(StreamRole::VideoRecording);
 		} else if (conf["role"].toString() == "viewfinder") {
-			roles.push_back(Stream::Viewfinder(conf["width"],
-							   conf["height"]));
+			roles.push_back(StreamRole::Viewfinder);
 		} else if (conf["role"].toString() == "video") {
-			roles.push_back(Stream::VideoRecording());
+			roles.push_back(StreamRole::VideoRecording);
 		} else if (conf["role"].toString() == "still") {
-			roles.push_back(Stream::StillCapture());
+			roles.push_back(StreamRole::StillCapture);
 		} else {
 			std::cerr << "Unknown stream role "
 				  << conf["role"].toString() << std::endl;
diff --git a/src/libcamera/camera.cpp b/src/libcamera/camera.cpp
index 359174a4..a3921f91 100644
--- a/src/libcamera/camera.cpp
+++ b/src/libcamera/camera.cpp
@@ -542,23 +542,23 @@ const std::set<Stream *> &Camera::streams() const
 }
 
 /**
- * \brief Generate a default camera configuration according to stream usages
- * \param[in] usages A list of stream usages
+ * \brief Generate a default camera configuration according to stream roles
+ * \param[in] roles A list of stream roles
  *
- * Generate a camera configuration for a set of desired usages. The caller
- * specifies a list of stream usages and the camera returns a configuration
+ * Generate a camera configuration for a set of desired stream roles. The caller
+ * specifies a list of stream roles and the camera returns a configuration
  * containing suitable streams and their suggested default configurations.
  *
- * \return A valid CameraConfiguration if the requested usages can be satisfied,
+ * \return A valid CameraConfiguration if the requested roles can be satisfied,
  * or a invalid one otherwise
  */
 CameraConfiguration
-Camera::generateConfiguration(const std::vector<StreamUsage> &usages)
+Camera::generateConfiguration(const StreamRoles &roles)
 {
-	if (disconnected_ || !usages.size() || usages.size() > streams_.size())
+	if (disconnected_ || !roles.size() || roles.size() > streams_.size())
 		return CameraConfiguration();
 
-	CameraConfiguration config = pipe_->generateConfiguration(this, usages);
+	CameraConfiguration config = pipe_->generateConfiguration(this, roles);
 
 	std::ostringstream msg("streams configuration:", std::ios_base::ate);
 	unsigned int index = 0;
diff --git a/src/libcamera/include/pipeline_handler.h b/src/libcamera/include/pipeline_handler.h
index 9cc11a8e..3352cb0e 100644
--- a/src/libcamera/include/pipeline_handler.h
+++ b/src/libcamera/include/pipeline_handler.h
@@ -14,6 +14,8 @@
 #include <string>
 #include <vector>
 
+#include <libcamera/stream.h>
+
 namespace libcamera {
 
 class Buffer;
@@ -26,8 +28,6 @@ class DeviceMatch;
 class MediaDevice;
 class PipelineHandler;
 class Request;
-class Stream;
-class StreamUsage;
 
 class CameraData
 {
@@ -61,7 +61,7 @@ public:
 	void unlock();
 
 	virtual CameraConfiguration
-	generateConfiguration(Camera *camera, const std::vector<StreamUsage> &usages) = 0;
+	generateConfiguration(Camera *camera, const StreamRoles &roles) = 0;
 	virtual int configure(Camera *camera, const CameraConfiguration &config) = 0;
 
 	virtual int allocateBuffers(Camera *camera,
diff --git a/src/libcamera/pipeline/ipu3/ipu3.cpp b/src/libcamera/pipeline/ipu3/ipu3.cpp
index ba0c708f..d234a8ac 100644
--- a/src/libcamera/pipeline/ipu3/ipu3.cpp
+++ b/src/libcamera/pipeline/ipu3/ipu3.cpp
@@ -151,8 +151,7 @@ public:
 	PipelineHandlerIPU3(CameraManager *manager);
 
 	CameraConfiguration
-	generateConfiguration(Camera *camera,
-			      const std::vector<StreamUsage> &usages) override;
+	generateConfiguration(Camera *camera, const StreamRoles &roles) override;
 	int configure(Camera *camera,
 		      const CameraConfiguration &config) override;
 
@@ -211,7 +210,7 @@ PipelineHandlerIPU3::PipelineHandlerIPU3(CameraManager *manager)
 
 CameraConfiguration
 PipelineHandlerIPU3::generateConfiguration(Camera *camera,
-					   const std::vector<StreamUsage> &usages)
+					   const StreamRoles &roles)
 {
 	IPU3CameraData *data = cameraData(camera);
 	CameraConfiguration config = {};
@@ -220,13 +219,12 @@ PipelineHandlerIPU3::generateConfiguration(Camera *camera,
 		&data->vfStream_,
 	};
 
-	for (const StreamUsage &usage : usages) {
+	for (const StreamRole role : roles) {
 		StreamConfiguration cfg = {};
-		StreamUsage::Role role = usage.role();
 		IPU3Stream *stream = nullptr;
 
 		switch (role) {
-		case StreamUsage::Role::StillCapture:
+		case StreamRole::StillCapture:
 			/*
 			 * Pick the output stream by default as the Viewfinder
 			 * and VideoRecording roles are not allowed on
@@ -256,11 +254,11 @@ PipelineHandlerIPU3::generateConfiguration(Camera *camera,
 
 			break;
 
-		case StreamUsage::Role::Viewfinder:
-		case StreamUsage::Role::VideoRecording: {
+		case StreamRole::Viewfinder:
+		case StreamRole::VideoRecording: {
 			/*
 			 * We can't use the 'output' stream for viewfinder or
-			 * video capture usages.
+			 * video capture roles.
 			 *
 			 * \todo This is an artificial limitation until we
 			 * figure out the exact capabilities of the hardware.
@@ -275,15 +273,13 @@ PipelineHandlerIPU3::generateConfiguration(Camera *camera,
 			stream = &data->vfStream_;
 
 			/*
-			 * Align the requested viewfinder size to the
-			 * maximum available sensor resolution and to the
-			 * IPU3 alignment constraints.
+			 * Align the default viewfinder size to the maximum
+			 * available sensor resolution and to the IPU3
+			 * alignment constraints.
 			 */
 			const Size &res = data->cio2_.sensor_->resolution();
-			unsigned int width = std::min(usage.size().width,
-						      res.width);
-			unsigned int height = std::min(usage.size().height,
-						       res.height);
+			unsigned int width = std::min(1280U, res.width);
+			unsigned int height = std::min(720U, res.height);
 			cfg.size = { width & ~7, height & ~3 };
 
 			break;
diff --git a/src/libcamera/pipeline/rkisp1/rkisp1.cpp b/src/libcamera/pipeline/rkisp1/rkisp1.cpp
index 4d02f960..4bd8c510 100644
--- a/src/libcamera/pipeline/rkisp1/rkisp1.cpp
+++ b/src/libcamera/pipeline/rkisp1/rkisp1.cpp
@@ -35,7 +35,7 @@ public:
 	~PipelineHandlerRkISP1();
 
 	CameraConfiguration generateConfiguration(Camera *camera,
-		const std::vector<StreamUsage> &usages) override;
+		const StreamRoles &roles) override;
 	int configure(Camera *camera,
 		const CameraConfiguration &config) override;
 
@@ -107,7 +107,7 @@ PipelineHandlerRkISP1::~PipelineHandlerRkISP1()
  */
 
 CameraConfiguration PipelineHandlerRkISP1::generateConfiguration(Camera *camera,
-	const std::vector<StreamUsage> &usages)
+	const StreamRoles &roles)
 {
 	RkISP1CameraData *data = cameraData(camera);
 	CameraConfiguration config;
diff --git a/src/libcamera/pipeline/uvcvideo.cpp b/src/libcamera/pipeline/uvcvideo.cpp
index 118b9745..d2e1f7d4 100644
--- a/src/libcamera/pipeline/uvcvideo.cpp
+++ b/src/libcamera/pipeline/uvcvideo.cpp
@@ -26,8 +26,7 @@ public:
 	PipelineHandlerUVC(CameraManager *manager);
 
 	CameraConfiguration
-	generateConfiguration(Camera *camera,
-			      const std::vector<StreamUsage> &usages) override;
+	generateConfiguration(Camera *camera, const StreamRoles &roles) override;
 	int configure(Camera *camera,
 		      const CameraConfiguration &config) override;
 
@@ -77,7 +76,7 @@ PipelineHandlerUVC::PipelineHandlerUVC(CameraManager *manager)
 
 CameraConfiguration
 PipelineHandlerUVC::generateConfiguration(Camera *camera,
-					  const std::vector<StreamUsage> &usages)
+					  const StreamRoles &roles)
 {
 	UVCCameraData *data = cameraData(camera);
 	CameraConfiguration config;
diff --git a/src/libcamera/pipeline/vimc.cpp b/src/libcamera/pipeline/vimc.cpp
index 74959581..17e2491e 100644
--- a/src/libcamera/pipeline/vimc.cpp
+++ b/src/libcamera/pipeline/vimc.cpp
@@ -26,8 +26,7 @@ public:
 	PipelineHandlerVimc(CameraManager *manager);
 
 	CameraConfiguration
-	generateConfiguration(Camera *camera,
-			      const std::vector<StreamUsage> &usages) override;
+	generateConfiguration(Camera *camera, const StreamRoles &roles) override;
 	int configure(Camera *camera,
 		      const CameraConfiguration &config) override;
 
@@ -77,7 +76,7 @@ PipelineHandlerVimc::PipelineHandlerVimc(CameraManager *manager)
 
 CameraConfiguration
 PipelineHandlerVimc::generateConfiguration(Camera *camera,
-					   const std::vector<StreamUsage> &usages)
+					   const StreamRoles &roles)
 {
 	VimcCameraData *data = cameraData(camera);
 	CameraConfiguration config;
diff --git a/src/libcamera/pipeline_handler.cpp b/src/libcamera/pipeline_handler.cpp
index b9ac6432..81c11149 100644
--- a/src/libcamera/pipeline_handler.cpp
+++ b/src/libcamera/pipeline_handler.cpp
@@ -221,18 +221,18 @@ void PipelineHandler::unlock()
  * \fn PipelineHandler::generateConfiguration()
  * \brief Generate a camera configuration for a specified camera
  * \param[in] camera The camera to generate a default configuration for
- * \param[in] usages A list of stream usages
+ * \param[in] roles A list of stream roles
  *
- * Generate a default configuration for the \a camera for a specified group of
- * use-cases. The caller shall populate the \a usages array with the use-cases
- * it wishes to fetch the default configuration for. The returned configuration
+ * Generate a default configuration for the \a camera for a specified list of
+ * stream roles. The caller shall populate the \a roles with the use-cases it
+ * wishes to fetch the default configuration for. The returned configuration
  * can then be examined by the caller to learn about the selected streams and
  * their default parameters.
  *
  * The intended companion to this is \a configure() which can be used to change
  * the group of streams parameters.
  *
- * \return A valid CameraConfiguration if the requested usages can be satisfied,
+ * \return A valid CameraConfiguration if the requested roles can be satisfied,
  * or a invalid configuration otherwise
  */
 
diff --git a/src/libcamera/stream.cpp b/src/libcamera/stream.cpp
index af259510..fe4c4ecf 100644
--- a/src/libcamera/stream.cpp
+++ b/src/libcamera/stream.cpp
@@ -75,62 +75,32 @@ std::string StreamConfiguration::toString() const
 }
 
 /**
- * \class StreamUsage
- * \brief Stream usage information
- *
- * The StreamUsage class describes how an application intends to use a stream.
- * Usages are specified by applications and passed to cameras, that then select
- * the most appropriate streams and their default configurations.
- */
-
-/**
- * \enum StreamUsage::Role
+ * \enum StreamRole
  * \brief Identify the role a stream is intended to play
- * \var StreamUsage::StillCapture
+ *
+ * The StreamRole describes how an application intends to use a stream. Roles
+ * are specified by applications and passed to cameras, that then select the
+ * most appropriate streams and their default configurations.
+ *
+ * \var StillCapture
  * The stream is intended to capture high-resolution, high-quality still images
  * with low frame rate. The captured frames may be exposed with flash.
- * \var StreamUsage::VideoRecording
+ * \var VideoRecording
  * The stream is intended to capture video for the purpose of recording or
  * streaming. The video stream may produce a high frame rate and may be
  * enhanced with video stabilization.
- * \var StreamUsage::Viewfinder
+ * \var Viewfinder
  * The stream is intended to capture video for the purpose of display on the
- * local screen. The StreamUsage includes the desired resolution. Trade-offs
- * between quality and usage of system resources are acceptable.
+ * local screen. Trade-offs between quality and usage of system resources are
+ * acceptable.
  */
 
 /**
- * \fn StreamUsage::role()
- * \brief Retrieve the stream role
- * \return The stream role
+ * \typedef StreamRoles
+ * \brief A vector of StreamRole
  */
 
 /**
- * \fn StreamUsage::size()
- * \brief Retrieve desired size
- * \return The desired size
- */
-
-/**
- * \brief Create a stream usage
- * \param[in] role Stream role
- */
-StreamUsage::StreamUsage(Role role)
-	: role_(role)
-{
-}
-
-/**
- * \brief Create a stream usage with a desired size
- * \param[in] role Stream role
- * \param[in] size The desired size
- */
-StreamUsage::StreamUsage(Role role, const Size &size)
-	: role_(role), size_(size)
-{
-}
-
-/**
  * \class Stream
  * \brief Video stream for a camera
  *
@@ -149,39 +119,6 @@ StreamUsage::StreamUsage(Role role, const Size &size)
  */
 
 /**
- * \class Stream::StillCapture
- * \brief Describe a still capture usage
- */
-Stream::StillCapture::StillCapture()
-	: StreamUsage(Role::StillCapture)
-{
-}
-
-/**
- * \class Stream::VideoRecording
- * \brief Describe a video recording usage
- */
-Stream::VideoRecording::VideoRecording()
-	: StreamUsage(Role::VideoRecording)
-{
-}
-
-/**
- * \class Stream::Viewfinder
- * \brief Describe a viewfinder usage
- */
-
-/**
- * \brief Create a viewfinder usage with a desired dimension
- * \param[in] width The desired viewfinder width
- * \param[in] height The desired viewfinder height
- */
-Stream::Viewfinder::Viewfinder(int width, int height)
-	: StreamUsage(Role::Viewfinder, Size(width, height))
-{
-}
-
-/**
  * \brief Construct a stream with default parameters
  */
 Stream::Stream()
diff --git a/src/qcam/main_window.cpp b/src/qcam/main_window.cpp
index c91b8272..a984aaca 100644
--- a/src/qcam/main_window.cpp
+++ b/src/qcam/main_window.cpp
@@ -97,7 +97,7 @@ int MainWindow::startCapture()
 {
 	int ret;
 
-	config_ = camera_->generateConfiguration({ Stream::VideoRecording() });
+	config_ = camera_->generateConfiguration({ StreamRole::VideoRecording });
 	Stream *stream = config_.front();
 	ret = camera_->configure(config_);
 	if (ret < 0) {
diff --git a/test/camera/capture.cpp b/test/camera/capture.cpp
index bc3a4d6c..e7e64382 100644
--- a/test/camera/capture.cpp
+++ b/test/camera/capture.cpp
@@ -43,7 +43,7 @@ protected:
 	int run()
 	{
 		CameraConfiguration config =
-			camera_->generateConfiguration({ Stream::VideoRecording() });
+			camera_->generateConfiguration({ StreamRole::VideoRecording });
 		Stream *stream = config.front();
 		StreamConfiguration *cfg = &config[stream];
 
diff --git a/test/camera/configuration_default.cpp b/test/camera/configuration_default.cpp
index 340b5f58..8c4a03db 100644
--- a/test/camera/configuration_default.cpp
+++ b/test/camera/configuration_default.cpp
@@ -21,7 +21,7 @@ protected:
 		CameraConfiguration config;
 
 		/* Test asking for configuration for a video stream. */
-		config = camera_->generateConfiguration({ Stream::VideoRecording() });
+		config = camera_->generateConfiguration({ StreamRole::VideoRecording });
 		if (!config.isValid()) {
 			cout << "Default configuration invalid" << endl;
 			return TestFail;
@@ -29,11 +29,11 @@ protected:
 
 		/*
 		 * Test that asking for configuration for an empty array of
-		 * stream usages returns an empty list of configurations.
+		 * stream roles returns an empty list of configurations.
 		 */
 		config = camera_->generateConfiguration({});
 		if (config.isValid()) {
-			cout << "Failed to retrieve configuration for empty usage list"
+			cout << "Failed to retrieve configuration for empty roles list"
 			     << endl;
 			return TestFail;
 		}
diff --git a/test/camera/configuration_set.cpp b/test/camera/configuration_set.cpp
index 24d5ca66..76d8bc3e 100644
--- a/test/camera/configuration_set.cpp
+++ b/test/camera/configuration_set.cpp
@@ -19,7 +19,7 @@ protected:
 	int run()
 	{
 		CameraConfiguration config =
-			camera_->generateConfiguration({ Stream::VideoRecording() });
+			camera_->generateConfiguration({ StreamRole::VideoRecording });
 		StreamConfiguration *cfg = &config[config.front()];
 
 		if (!config.isValid()) {
diff --git a/test/camera/statemachine.cpp b/test/camera/statemachine.cpp
index bd2e61ff..7a74cd85 100644
--- a/test/camera/statemachine.cpp
+++ b/test/camera/statemachine.cpp
@@ -235,7 +235,7 @@ protected:
 
 	int run()
 	{
-		defconf_ = camera_->generateConfiguration({ Stream::VideoRecording() });
+		defconf_ = camera_->generateConfiguration({ StreamRole::VideoRecording });
 
 		if (testAvailable() != TestPass) {
 			cout << "State machine in Available state failed" << endl;