[libcamera-devel] [PATCH 04/10] libcamera: ipu3: Breakout stream assignment to new function

[Niklas Söderlund]

Picking which stream that is 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 where added, break it out into a separate
function.

Signed-off-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
---
 src/libcamera/pipeline/ipu3/ipu3.cpp | 87 +++++++++++++++++-----------
 1 file changed, 53 insertions(+), 34 deletions(-)

diff --git a/src/libcamera/pipeline/ipu3/ipu3.cpp b/src/libcamera/pipeline/ipu3/ipu3.cpp
index f7363244e1d2d0ff..0e7555c716b36749 100644
--- a/src/libcamera/pipeline/ipu3/ipu3.cpp
+++ b/src/libcamera/pipeline/ipu3/ipu3.cpp
@@ -190,6 +190,7 @@ private:
 	static constexpr unsigned int IPU3_BUFFER_COUNT = 4;
 	static constexpr unsigned int IPU3_MAX_STREAMS = 3;
 
+	int updateStreams();
 	void adjustStream(StreamConfiguration &cfg, bool scale);
 
 	/*
@@ -256,6 +257,51 @@ IPU3CameraConfiguration::IPU3CameraConfiguration(Camera *camera,
 	data_ = data;
 }
 
+int IPU3CameraConfiguration::updateStreams()
+{
+	std::set<const IPU3Stream *> availableStreams = {
+		&data_->outStream_,
+		&data_->vfStream_,
+		&data_->rawStream_,
+	};
+
+	/* Pick the stream most suitable for the requested configuration. */
+	std::vector<const IPU3Stream *> streams;
+	for (unsigned int i = 0; i < config_.size(); ++i) {
+		const StreamConfiguration &cfg = config_[i];
+		const IPU3Stream *stream;
+
+		/*
+		 * Only the raw stream can support Bayer formats.
+		 */
+		if (cfg.pixelFormat.modifier() == IPU3_FORMAT_MOD_PACKED)
+			stream = &data_->rawStream_;
+		/*
+		 * Output stream can't scale so can only be used if the size
+		 * matches the size of the sensor.
+		 *
+		 * NOTE: It can crop but is not supported.
+		 */
+		else if (cfg.size == sensorFormat_.size)
+			stream = &data_->outStream_;
+		/*
+		 * Pick the view finder stream last as it may scale.
+		 */
+		else
+			stream = &data_->vfStream_;
+
+		if (availableStreams.find(stream) == availableStreams.end())
+			return -EINVAL;
+
+		streams.push_back(stream);
+		availableStreams.erase(stream);
+	}
+
+	streams_ = streams;
+
+	return 0;
+}
+
 void IPU3CameraConfiguration::adjustStream(StreamConfiguration &cfg, bool scale)
 {
 	/* The only pixel format the driver supports is NV12. */
@@ -342,40 +388,16 @@ 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. */
+	if (updateStreams())
+		return Invalid;
 
+	/* 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 Size size = cfg.size;
-		const IPU3Stream *stream;
-
-		if (cfg.pixelFormat.modifier() == IPU3_FORMAT_MOD_PACKED)
-			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 org = cfg;
+		const IPU3Stream *stream = streams_[i];
 
 		if (stream->raw_) {
 			const auto &itFormat =
@@ -392,15 +414,12 @@ CameraConfiguration::Status IPU3CameraConfiguration::validate()
 
 		cfg.bufferCount = IPU3_BUFFER_COUNT;
 
-		if (cfg.pixelFormat != pixelFormat || cfg.size != size) {
+		if (cfg.pixelFormat != org.pixelFormat || cfg.size != org.size) {
 			LOG(IPU3, Debug)
 				<< "Stream " << i << " configuration adjusted to "
 				<< cfg.toString();
 			status = Adjusted;
 		}
-
-		streams_.push_back(stream);
-		availableStreams.erase(stream);
 	}
 
 	return status;
-- 
2.26.2