libcamera: imx8-isi: Split Bayer/YUV config generation

At generateConfiguration() a YUV/RGB pixel format is preferred for the
StillCapture/VideoRecording/Viewfinder roles, but currently there are no
guarantees in place that the sensor provides a non-Bayer bus format from
which YUV/RGB can be generated.

This makes the default configuration generated for those roles not to
work if the sensor is a RAW-only one.

To improve the situation split the configuration generation in two,
one for YUV modes and one for Raw Bayer mode.

StreamRoles assigned to a YUV mode will try to first generate a YUV
configuration and then fallback to RAW if that's what the sensor can
provide.

As an additional requirement, for YUV streams, the generated mode has to
be validated with the sensor to confirm the desired sizes can be
generated. In order to test a format on the sensor introduce
CameraSensor::tryFormat().

Reported-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>

3 files changed, 173 insertions, 76 deletions

diff --git a/include/libcamera/internal/camera_sensor.h b/include/libcamera/internal/camera_sensor.h
index b9f4d786..ce3a790f 100644
--- a/include/libcamera/internal/camera_sensor.h
+++ b/include/libcamera/internal/camera_sensor.h
@@ -54,6 +54,7 @@ public:
 	V4L2SubdeviceFormat getFormat(const std::vector<unsigned int> &mbusCodes,
 				      const Size &size) const;
 	int setFormat(V4L2SubdeviceFormat *format);
+	int tryFormat(V4L2SubdeviceFormat *format) const;
 
 	const ControlInfoMap &controls() const;
 	ControlList getControls(const std::vector<uint32_t> &ids);
diff --git a/src/libcamera/camera_sensor.cpp b/src/libcamera/camera_sensor.cpp
index a210aa4f..dfe59303 100644
--- a/src/libcamera/camera_sensor.cpp
+++ b/src/libcamera/camera_sensor.cpp
@@ -758,6 +758,20 @@ int CameraSensor::setFormat(V4L2SubdeviceFormat *format)
 }
 
 /**
+ * \brief Try the sensor output format
+ * \param[in] format The desired sensor output format
+ *
+ * The ranges of any controls associated with the sensor are not updated.
+ *
+ * \return 0 on success or a negative error code otherwise
+ */
+int CameraSensor::tryFormat(V4L2SubdeviceFormat *format) const
+{
+	return subdev_->setFormat(pad_, format,
+				  V4L2Subdevice::Whence::TryFormat);
+}
+
+/**
  * \brief Retrieve the supported V4L2 controls and their information
  *
  * Control information is updated automatically to reflect the current sensor
diff --git a/src/libcamera/pipeline/imx8-isi/imx8-isi.cpp b/src/libcamera/pipeline/imx8-isi/imx8-isi.cpp
index 764e2121..7a888310 100644
--- a/src/libcamera/pipeline/imx8-isi/imx8-isi.cpp
+++ b/src/libcamera/pipeline/imx8-isi/imx8-isi.cpp
@@ -145,6 +145,10 @@ private:
 
 	Pipe *pipeFromStream(Camera *camera, const Stream *stream);
 
+	StreamConfiguration generateYUVConfiguration(Camera *camera,
+						     const Size &size);
+	StreamConfiguration generateRawConfiguration(Camera *camera);
+
 	void bufferReady(FrameBuffer *buffer);
 
 	MediaDevice *isiDev_;
@@ -697,6 +701,132 @@ PipelineHandlerISI::PipelineHandlerISI(CameraManager *manager)
 {
 }
 
+/*
+ * Generate a StreamConfiguration for YUV/RGB use case.
+ *
+ * Verify it the sensor can produce a YUV/RGB media bus format and ollect
+ * all the processed pixel formats the ISI can generate as supported stream
+ * configurations.
+ */
+StreamConfiguration PipelineHandlerISI::generateYUVConfiguration(Camera *camera,
+								 const Size &size)
+{
+	ISICameraData *data = cameraData(camera);
+	PixelFormat pixelFormat = formats::YUYV;
+	unsigned int mbusCode;
+
+	mbusCode = data->getYuvMediaBusFormat(&pixelFormat);
+	if (!mbusCode)
+		return {};
+
+	/* Adjust the requested size to the sensor's capabilities. */
+	const CameraSensor *sensor = data->sensor_.get();
+
+	V4L2SubdeviceFormat sensorFmt;
+	sensorFmt.mbus_code = mbusCode;
+	sensorFmt.size = size;
+
+	int ret = sensor->tryFormat(&sensorFmt);
+	if (ret) {
+		LOG(ISI, Error) << "Failed to try sensor format.";
+		return {};
+	}
+
+	Size sensorSize = sensorFmt.size;
+
+	/*
+	 * Populate the StreamConfiguration.
+	 *
+	 * As the sensor supports at least one YUV/RGB media bus format all the
+	 * processed ones in formatsMap_ can be generated from it.
+	 */
+	std::map<PixelFormat, std::vector<SizeRange>> streamFormats;
+
+	for (const auto &[pixFmt, pipeFmt] : ISICameraConfiguration::formatsMap_) {
+		const PixelFormatInfo &info = PixelFormatInfo::info(pixFmt);
+		if (info.colourEncoding == PixelFormatInfo::ColourEncodingRAW)
+			continue;
+
+		streamFormats[pixFmt] = { { kMinISISize, sensorSize } };
+	}
+
+	StreamFormats formats(streamFormats);
+
+	StreamConfiguration cfg(formats);
+	cfg.pixelFormat = pixelFormat;
+	cfg.size = sensorSize;
+	cfg.bufferCount = 4;
+
+	return cfg;
+}
+
+/*
+ * Generate a StreamConfiguration for Raw Bayer use case.
+ *
+ * Verify if the sensor can produce a RAW bayer format
+ * The Raw Bayer format with the largest bit depth is selected as default and
+ * one stream configuration is collected for each Raw Bayer format the sensor
+ * can produce.
+ */
+StreamConfiguration PipelineHandlerISI::generateRawConfiguration(Camera *camera)
+{
+	const std::map<unsigned int, PixelFormat> rawFormats = {
+		{ MEDIA_BUS_FMT_SBGGR8_1X8, formats::SBGGR8 },
+		{ MEDIA_BUS_FMT_SGBRG8_1X8, formats::SGBRG8 },
+		{ MEDIA_BUS_FMT_SGRBG8_1X8, formats::SGRBG8 },
+		{ MEDIA_BUS_FMT_SRGGB8_1X8, formats::SRGGB8 },
+		{ MEDIA_BUS_FMT_SBGGR10_1X10, formats::SBGGR10 },
+		{ MEDIA_BUS_FMT_SGBRG10_1X10, formats::SGBRG10 },
+		{ MEDIA_BUS_FMT_SGRBG10_1X10, formats::SGRBG10 },
+		{ MEDIA_BUS_FMT_SRGGB10_1X10, formats::SRGGB10 },
+		{ MEDIA_BUS_FMT_SBGGR12_1X12, formats::SBGGR12 },
+		{ MEDIA_BUS_FMT_SGBRG12_1X12, formats::SGBRG12 },
+		{ MEDIA_BUS_FMT_SGRBG12_1X12, formats::SGRBG12 },
+		{ MEDIA_BUS_FMT_SRGGB12_1X12, formats::SRGGB12 },
+	};
+
+	ISICameraData *data = cameraData(camera);
+	PixelFormat pixelFormat = formats::SBGGR10;
+	unsigned int mbusCode;
+
+	/* pixelFormat will be adjusted, if the sensor can produce RAW. */
+	mbusCode = data->getRawMediaBusFormat(&pixelFormat);
+	if (!mbusCode)
+		return {};
+
+	/*
+	 * Populate the StreamConfiguration with all the supported Bayer
+	 * formats the sensor can produce.
+	 */
+	std::map<PixelFormat, std::vector<SizeRange>> streamFormats;
+	const CameraSensor *sensor = data->sensor_.get();
+
+	for (unsigned int code : sensor->mbusCodes()) {
+		/* Find a Bayer media bus code from the sensor. */
+		const BayerFormat &bayerFormat = BayerFormat::fromMbusCode(code);
+		if (!bayerFormat.isValid())
+			continue;
+
+		auto it = rawFormats.find(code);
+		if (it == rawFormats.end()) {
+			LOG(ISI, Warning) << bayerFormat
+					  << " not supported in ISI formats map.";
+			continue;
+		}
+
+		streamFormats[it->second] = { { kMinISISize, sensor->resolution() } };
+	}
+
+	StreamFormats formats(streamFormats);
+
+	StreamConfiguration cfg(formats);
+	cfg.size = sensor->resolution();
+	cfg.pixelFormat = pixelFormat;
+	cfg.bufferCount = 4;
+
+	return cfg;
+}
+
 std::unique_ptr<CameraConfiguration>
 PipelineHandlerISI::generateConfiguration(Camera *camera,
 					  const StreamRoles &roles)
@@ -714,79 +844,45 @@ PipelineHandlerISI::generateConfiguration(Camera *camera,
 		return nullptr;
 	}
 
-	bool isRaw = false;
 	for (const auto &role : roles) {
 		/*
-		 * Prefer the following formats
+		 * Prefer the following formats:
 		 * - Still Capture: Full resolution YUYV
 		 * - ViewFinder/VideoRecording: 1080p YUYV
-		 * - RAW: sensor's native format and resolution
+		 * - RAW: Full resolution Bayer
 		 */
-		std::map<PixelFormat, std::vector<SizeRange>> streamFormats;
-		PixelFormat pixelFormat;
-		Size size;
+		StreamConfiguration cfg;
 
 		switch (role) {
 		case StreamRole::StillCapture:
-			/*
-			 * \todo Make sure the sensor can produce non-RAW formats
-			 * compatible with the ones supported by the pipeline.
-			 */
-			size = data->sensor_->resolution();
-			pixelFormat = formats::YUYV;
+			cfg = generateYUVConfiguration(camera,
+						       data->sensor_->resolution());
+			if (!cfg.pixelFormat.isValid()) {
+				/*
+				 * Fallback to use a Bayer format if that's what
+				 * the sensor supports.
+				 */
+				cfg = generateRawConfiguration(camera);
+			}
+
 			break;
 
 		case StreamRole::Viewfinder:
 		case StreamRole::VideoRecording:
-			/*
-			 * \todo Make sure the sensor can produce non-RAW formats
-			 * compatible with the ones supported by the pipeline.
-			 */
-			size = PipelineHandlerISI::kPreviewSize;
-			pixelFormat = formats::YUYV;
-			break;
-
-		case StreamRole::Raw: {
-			/*
-			 * Make sure the sensor can generate a RAW format and
-			 * prefer the ones with a larger bitdepth.
-			 */
-			const ISICameraConfiguration::FormatMap::value_type *rawPipeFormat = nullptr;
-			unsigned int maxDepth = 0;
-
-			for (unsigned int code : data->sensor_->mbusCodes()) {
-				const BayerFormat &bayerFormat = BayerFormat::fromMbusCode(code);
-				if (!bayerFormat.isValid())
-					continue;
-
-				/* Make sure the format is supported by the pipeline handler. */
-				auto it = std::find_if(ISICameraConfiguration::formatsMap_.begin(),
-						       ISICameraConfiguration::formatsMap_.end(),
-						       [code](auto &isiFormat) {
-							        auto &pipe = isiFormat.second;
-							        return pipe.sensorCode == code;
-						       });
-				if (it == ISICameraConfiguration::formatsMap_.end())
-					continue;
-
-				if (bayerFormat.bitDepth > maxDepth) {
-					maxDepth = bayerFormat.bitDepth;
-					rawPipeFormat = &(*it);
-				}
-			}
-
-			if (!rawPipeFormat) {
-				LOG(ISI, Error)
-					<< "Cannot generate a configuration for RAW stream";
-				return nullptr;
+			cfg = generateYUVConfiguration(camera,
+						       PipelineHandlerISI::kPreviewSize);
+			if (!cfg.pixelFormat.isValid()) {
+				/*
+				 * Fallback to use a Bayer format if that's what
+				 * the sensor supports.
+				 */
+				cfg = generateRawConfiguration(camera);
 			}
 
-			size = data->sensor_->resolution();
-			pixelFormat = rawPipeFormat->first;
-
-			streamFormats[pixelFormat] = { { kMinISISize, size } };
-			isRaw = true;
+			break;
 
+		case StreamRole::Raw: {
+			cfg = generateRawConfiguration(camera);
 			break;
 		}
 
@@ -795,26 +891,12 @@ PipelineHandlerISI::generateConfiguration(Camera *camera,
 			return nullptr;
 		}
 
-		/*
-		 * For non-RAW configurations the ISI can perform colorspace
-		 * conversion. List all the supported output formats here.
-		 */
-		if (!isRaw) {
-			for (const auto &[pixFmt, pipeFmt] : ISICameraConfiguration::formatsMap_) {
-				const PixelFormatInfo &info = PixelFormatInfo::info(pixFmt);
-				if (info.colourEncoding == PixelFormatInfo::ColourEncodingRAW)
-					continue;
-
-				streamFormats[pixFmt] = { { kMinISISize, size } };
-			}
+		if (!cfg.pixelFormat.isValid()) {
+			LOG(ISI, Error)
+				<< "Cannot generate configuration for role: " << role;
+			return nullptr;
 		}
 
-		StreamFormats formats(streamFormats);
-
-		StreamConfiguration cfg(formats);
-		cfg.pixelFormat = pixelFormat;
-		cfg.size = size;
-		cfg.bufferCount = 4;
 		config->addConfiguration(cfg);
 	}