libcamera: ipu3: Breakout stream assignment to new function

Selecting which stream is the most suitable for the requested
configuration is mixed with adjusting the requested format when
validating configurations. This is hard to read and got worse when
support for Bayer formats was added. Break it out to a separate
function.

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

1 files changed, 52 insertions, 36 deletions

diff --git a/src/libcamera/pipeline/ipu3/ipu3.cpp b/src/libcamera/pipeline/ipu3/ipu3.cpp
index 34403ebe..db52bff4 100644
--- a/src/libcamera/pipeline/ipu3/ipu3.cpp
+++ b/src/libcamera/pipeline/ipu3/ipu3.cpp
@@ -191,6 +191,7 @@ private:
 	static constexpr unsigned int IPU3_BUFFER_COUNT = 4;
 	static constexpr unsigned int IPU3_MAX_STREAMS = 3;
 
+	void assignStreams();
 	void adjustStream(StreamConfiguration &cfg, bool scale);
 
 	/*
@@ -257,6 +258,50 @@ IPU3CameraConfiguration::IPU3CameraConfiguration(Camera *camera,
 	data_ = data;
 }
 
+void IPU3CameraConfiguration::assignStreams()
+{
+	/*
+	 * Verify and update all configuration entries, and assign a stream to
+	 * each of them. The viewfinder stream can scale, while the output
+	 * stream can crop only, so select the output stream when the requested
+	 * resolution is equal to the sensor resolution, and the viewfinder
+	 * stream otherwise.
+	 */
+	std::set<const IPU3Stream *> availableStreams = {
+		&data_->outStream_,
+		&data_->vfStream_,
+		&data_->rawStream_,
+	};
+
+	/*
+	 * The caller is responsible to limit the number of requested streams
+	 * to a number supported by the pipeline before calling this function.
+	 */
+	ASSERT(availableStreams.size() >= config_.size());
+
+	streams_.clear();
+	streams_.reserve(config_.size());
+
+	for (const StreamConfiguration &cfg : config_) {
+		const PixelFormatInfo &info =
+			PixelFormatInfo::info(cfg.pixelFormat);
+		const IPU3Stream *stream;
+
+		if (info.colourEncoding == PixelFormatInfo::ColourEncodingRAW)
+			stream = &data_->rawStream_;
+		else if (cfg.size == sensorFormat_.size)
+			stream = &data_->outStream_;
+		else
+			stream = &data_->vfStream_;
+
+		if (availableStreams.find(stream) == availableStreams.end())
+			stream = *availableStreams.begin();
+
+		streams_.push_back(stream);
+		availableStreams.erase(stream);
+	}
+}
+
 void IPU3CameraConfiguration::adjustStream(StreamConfiguration &cfg, bool scale)
 {
 	/* The only pixel format the driver supports is NV12. */
@@ -343,41 +388,14 @@ CameraConfiguration::Status IPU3CameraConfiguration::validate()
 	if (!sensorFormat_.size.width || !sensorFormat_.size.height)
 		sensorFormat_.size = sensor->resolution();
 
-	/*
-	 * Verify and update all configuration entries, and assign a stream to
-	 * each of them. The viewfinder stream can scale, while the output
-	 * stream can crop only, so select the output stream when the requested
-	 * resolution is equal to the sensor resolution, and the viewfinder
-	 * stream otherwise.
-	 */
-	std::set<const IPU3Stream *> availableStreams = {
-		&data_->outStream_,
-		&data_->vfStream_,
-		&data_->rawStream_,
-	};
-
-	streams_.clear();
-	streams_.reserve(config_.size());
+	/* Assign streams to each configuration entry. */
+	assignStreams();
 
+	/* Verify and adjust configuration if needed. */
 	for (unsigned int i = 0; i < config_.size(); ++i) {
 		StreamConfiguration &cfg = config_[i];
-		const PixelFormat pixelFormat = cfg.pixelFormat;
-		const PixelFormatInfo &info = PixelFormatInfo::info(pixelFormat);
-		const Size size = cfg.size;
-		const IPU3Stream *stream;
-
-		if (info.colourEncoding == PixelFormatInfo::ColourEncodingRAW)
-			stream = &data_->rawStream_;
-		else if (cfg.size == sensorFormat_.size)
-			stream = &data_->outStream_;
-		else
-			stream = &data_->vfStream_;
-
-		if (availableStreams.find(stream) == availableStreams.end())
-			stream = *availableStreams.begin();
-
-		LOG(IPU3, Debug)
-			<< "Assigned '" << stream->name_ << "' to stream " << i;
+		const StreamConfiguration oldCfg = cfg;
+		const IPU3Stream *stream = streams_[i];
 
 		if (stream->raw_) {
 			const auto &itFormat =
@@ -394,15 +412,13 @@ CameraConfiguration::Status IPU3CameraConfiguration::validate()
 
 		cfg.bufferCount = IPU3_BUFFER_COUNT;
 
-		if (cfg.pixelFormat != pixelFormat || cfg.size != size) {
+		if (cfg.pixelFormat != oldCfg.pixelFormat ||
+		    cfg.size != oldCfg.size) {
 			LOG(IPU3, Debug)
 				<< "Stream " << i << " configuration adjusted to "
 				<< cfg.toString();
 			status = Adjusted;
 		}
-
-		streams_.push_back(stream);
-		availableStreams.erase(stream);
 	}
 
 	return status;