libcamera: ipu3: Adjust and assign streams in validate()

Remove the adjustStream() and assignStream() methods, and perform stream
adjustment and assignment while iterating the StreamConfiguration
items.

The adjustStream() implementation had some arbitrary assumption, like
the main output having to be as large as the sensor resolution, and did
not take into account the different alignment requirements between the
main output and the viewfinder output.

The assignStream() implementation also assumes only full-size streams
can be produced by the main output, and having it as a separate function
prevents adjusting streams according to which output they are assigned.

Blend the two implementation in a single loop and perform the required
stream adjustment and assignment in one go.

As streams are now assigned at validate() time, remove the same
operation from the configure() function.

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

1 files changed, 112 insertions, 139 deletions

diff --git a/src/libcamera/pipeline/ipu3/ipu3.cpp b/src/libcamera/pipeline/ipu3/ipu3.cpp
index 22baacf9..0701fa55 100644
--- a/src/libcamera/pipeline/ipu3/ipu3.cpp
+++ b/src/libcamera/pipeline/ipu3/ipu3.cpp
@@ -70,9 +70,6 @@ public:
 	const std::vector<const Stream *> &streams() { return streams_; }
 
 private:
-	void assignStreams();
-	void adjustStream(StreamConfiguration &cfg, bool scale);
-
 	/*
 	 * The IPU3CameraData instance is guaranteed to be valid as long as the
 	 * corresponding Camera instance is valid. In order to borrow a
@@ -137,96 +134,6 @@ 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 Stream *> 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 Stream *stream;
-
-		if (info.colourEncoding == PixelFormatInfo::ColourEncodingRAW)
-			stream = &data_->rawStream_;
-		else if (cfg.size == cio2Configuration_.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. */
-	cfg.pixelFormat = formats::NV12;
-
-	if (scale) {
-		/*
-		 * Provide a suitable default that matches the sensor aspect
-		 * ratio.
-		 */
-		if (cfg.size.isNull()) {
-			cfg.size.width = 1280;
-			cfg.size.height = 1280 * cio2Configuration_.size.height
-					/ cio2Configuration_.size.width;
-		}
-
-		/*
-		 * \todo: Clamp the size to the hardware bounds when we will
-		 * figure them out.
-		 *
-		 * \todo: Handle the scaler (BDS) restrictions. The BDS can
-		 * only scale with the same factor in both directions, and the
-		 * scaling factor is limited to a multiple of 1/32. At the
-		 * moment the ImgU driver hides these constraints by applying
-		 * additional cropping, this should be fixed on the driver
-		 * side, and cropping should be exposed to us.
-		 */
-	} else {
-		/*
-		 * \todo: Properly support cropping when the ImgU driver
-		 * interface will be cleaned up.
-		 */
-		cfg.size = cio2Configuration_.size;
-	}
-
-	/*
-	 * Clamp the size to match the ImgU alignment constraints. The width
-	 * shall be a multiple of 8 pixels and the height a multiple of 4
-	 * pixels.
-	 */
-	if (cfg.size.width % 8 || cfg.size.height % 4) {
-		cfg.size.width &= ~7;
-		cfg.size.height &= ~3;
-	}
-}
-
 CameraConfiguration::Status IPU3CameraConfiguration::validate()
 {
 	Status status = Valid;
@@ -242,27 +149,27 @@ CameraConfiguration::Status IPU3CameraConfiguration::validate()
 
 	/*
 	 * Validate the requested stream configuration and select the sensor
-	 * format by collecting the maximum width and height and picking the
-	 * closest larger match, as the IPU3 can downscale only. If no
-	 * resolution is requested for any stream, or if no sensor resolution is
-	 * large enough, pick the largest one.
+	 * format by collecting the maximum RAW stream width and height and
+	 * picking the closest larger match, as the IPU3 can downscale only. If
+	 * no resolution is requested for the RAW stream, use the one from the
+	 * largest YUV stream, plus margins pixels for the IF and BDS to scale.
+	 * If no resolution is requested for any stream, pick the largest one.
 	 */
 	unsigned int rawCount = 0;
 	unsigned int yuvCount = 0;
-	Size size;
+	Size maxYuvSize;
+	Size maxRawSize;
 
 	for (const StreamConfiguration &cfg : config_) {
 		const PixelFormatInfo &info = PixelFormatInfo::info(cfg.pixelFormat);
 
-		if (info.colourEncoding == PixelFormatInfo::ColourEncodingRAW)
+		if (info.colourEncoding == PixelFormatInfo::ColourEncodingRAW) {
 			rawCount++;
-		else
+			maxRawSize.expandTo(cfg.size);
+		} else {
 			yuvCount++;
-
-		if (cfg.size.width > size.width)
-			size.width = cfg.size.width;
-		if (cfg.size.height > size.height)
-			size.height = cfg.size.height;
+			maxYuvSize.expandTo(cfg.size);
+		}
 	}
 
 	if (rawCount > 1 || yuvCount > 2) {
@@ -270,43 +177,114 @@ CameraConfiguration::Status IPU3CameraConfiguration::validate()
 		return Invalid;
 	}
 
-	/* Generate raw configuration from CIO2. */
-	cio2Configuration_ = data_->cio2_.generateConfiguration(size);
+	if (maxRawSize.isNull())
+		maxRawSize = maxYuvSize.alignedUpTo(IMGU_OUTPUT_WIDTH_MARGIN,
+						    IMGU_OUTPUT_HEIGHT_MARGIN)
+				       .boundedTo(data_->cio2_.sensor()->resolution());
+
+	/*
+	 * Generate raw configuration from CIO2.
+	 *
+	 * The output YUV streams will be limited in size to the maximum
+	 * frame size requested for the RAW stream.
+	 */
+	cio2Configuration_ = data_->cio2_.generateConfiguration(maxRawSize);
 	if (!cio2Configuration_.pixelFormat.isValid())
 		return Invalid;
 
-	/* Assign streams to each configuration entry. */
-	assignStreams();
+	LOG(IPU3, Debug) << "CIO2 configuration: " << cio2Configuration_.toString();
 
-	/* Verify and adjust configuration if needed. */
+	/*
+	 * Adjust the configurations if needed and assign streams while
+	 * iterating them.
+	 */
+	bool mainOutputAvailable = true;
 	for (unsigned int i = 0; i < config_.size(); ++i) {
-		StreamConfiguration &cfg = config_[i];
-		const StreamConfiguration oldCfg = cfg;
-		const Stream *stream = streams_[i];
-
-		if (stream == &data_->rawStream_) {
-			cfg.size = cio2Configuration_.size;
-			cfg.pixelFormat = cio2Configuration_.pixelFormat;
-			cfg.bufferCount = cio2Configuration_.bufferCount;
+		const PixelFormatInfo &info = PixelFormatInfo::info(config_[i].pixelFormat);
+		const StreamConfiguration originalCfg = config_[i];
+		StreamConfiguration *cfg = &config_[i];
+
+		LOG(IPU3, Debug) << "Validating stream: " << config_[i].toString();
+
+		if (info.colourEncoding == PixelFormatInfo::ColourEncodingRAW) {
+			/* Initialize the RAW stream with the CIO2 configuration. */
+			cfg->size = cio2Configuration_.size;
+			cfg->pixelFormat = cio2Configuration_.pixelFormat;
+			cfg->bufferCount = cio2Configuration_.bufferCount;
+			cfg->stride = info.stride(cfg->size.width, 0, 64);
+			cfg->frameSize = info.frameSize(cfg->size, 64);
+			cfg->setStream(const_cast<Stream *>(&data_->rawStream_));
+
+			LOG(IPU3, Debug) << "Assigned " << cfg->toString()
+					 << " to the raw stream";
 		} else {
-			bool scale = stream == &data_->vfStream_;
-			adjustStream(config_[i], scale);
-			cfg.bufferCount = IPU3_BUFFER_COUNT;
+			/* Assign and configure the main and viewfinder outputs. */
+
+			/*
+			 * Clamp the size to match the ImgU size limits and the
+			 * margins from the CIO2 output frame size.
+			 *
+			 * The ImgU outputs needs to be strictly smaller than
+			 * the CIO2 output frame and rounded down to 64 pixels
+			 * in width and 32 pixels in height. This assumption
+			 * comes from inspecting the pipe configuration script
+			 * results and the available suggested configurations in
+			 * the ChromeOS BSP .xml camera tuning files and shall
+			 * be validated.
+			 *
+			 * \todo Clarify what are the hardware constraints
+			 * that require this alignements, if any. It might
+			 * depend on the BDS scaling factor of 1/32, as the main
+			 * output has no YUV scaler as the viewfinder output has.
+			 */
+			unsigned int limit;
+			limit = utils::alignDown(cio2Configuration_.size.width - 1,
+						 IMGU_OUTPUT_WIDTH_MARGIN);
+			cfg->size.width = utils::clamp(cfg->size.width,
+						       IMGU_OUTPUT_MIN_SIZE.width,
+						       limit);
+
+			limit = utils::alignDown(cio2Configuration_.size.height - 1,
+						 IMGU_OUTPUT_HEIGHT_MARGIN);
+			cfg->size.height = utils::clamp(cfg->size.height,
+							IMGU_OUTPUT_MIN_SIZE.height,
+							limit);
+
+			cfg->size.alignDownTo(IMGU_OUTPUT_WIDTH_ALIGN,
+					      IMGU_OUTPUT_HEIGHT_ALIGN);
+
+			cfg->pixelFormat = formats::NV12;
+			cfg->bufferCount = IPU3_BUFFER_COUNT;
+			cfg->stride = info.stride(cfg->size.width, 0, 1);
+			cfg->frameSize = info.frameSize(cfg->size, 1);
+
+			/*
+			 * Use the main output stream in case only one stream is
+			 * requested or if the current configuration is the one
+			 * with the maximum YUV output size.
+			 */
+			if (mainOutputAvailable &&
+			    (originalCfg.size == maxYuvSize || yuvCount == 1)) {
+				cfg->setStream(const_cast<Stream *>(&data_->outStream_));
+				mainOutputAvailable = false;
+
+				LOG(IPU3, Debug) << "Assigned " << cfg->toString()
+						 << " to the main output";
+			} else {
+				cfg->setStream(const_cast<Stream *>(&data_->vfStream_));
+
+				LOG(IPU3, Debug) << "Assigned " << cfg->toString()
+						 << " to the viewfinder output";
+			}
 		}
 
-		if (cfg.pixelFormat != oldCfg.pixelFormat ||
-		    cfg.size != oldCfg.size) {
+		if (cfg->pixelFormat != originalCfg.pixelFormat ||
+		    cfg->size != originalCfg.size) {
 			LOG(IPU3, Debug)
 				<< "Stream " << i << " configuration adjusted to "
-				<< cfg.toString();
+				<< cfg->toString();
 			status = Adjusted;
 		}
-
-		const PixelFormatInfo &info = PixelFormatInfo::info(cfg.pixelFormat);
-		bool packedRaw = info.colourEncoding == PixelFormatInfo::ColourEncodingRAW;
-
-		cfg.stride = info.stride(cfg.size.width, 0, packedRaw ? 64 : 1);
-		cfg.frameSize = info.frameSize(cfg.size, packedRaw ? 64 : 1);
 	}
 
 	return status;
@@ -340,6 +318,9 @@ CameraConfiguration *PipelineHandlerIPU3::generateConfiguration(Camera *camera,
 			 * strictly smaller than the sensor resolution (limited
 			 * to the ImgU  maximum output size) and aligned down to
 			 * the required frame margin.
+			 *
+			 * \todo Clarify the alignment constraints as exaplained
+			 * in validate()
 			 */
 			size = sensorResolution.boundedTo(IMGU_OUTPUT_MAX_SIZE);
 			size.width = utils::alignDown(size.width - 1,
@@ -476,16 +457,8 @@ int PipelineHandlerIPU3::configure(Camera *camera, CameraConfiguration *c)
 	bool vfActive = false;
 
 	for (unsigned int i = 0; i < config->size(); ++i) {
-		/*
-		 * Use a const_cast<> here instead of storing a mutable stream
-		 * pointer in the configuration to let the compiler catch
-		 * unwanted modifications of camera data in the configuration
-		 * validate() implementation.
-		 */
-		Stream *stream = const_cast<Stream *>(config->streams()[i]);
 		StreamConfiguration &cfg = (*config)[i];
-
-		cfg.setStream(stream);
+		Stream *stream = cfg.stream();
 
 		if (stream == outStream) {
 			ret = imgu->configureOutput(cfg, &outputFormat);