[libcamera-devel] [PATCH/RFC 11/12] libcamera: pipeline: uvcvideo: Validate format in UVCCameraConfiguration::validate()

[Laurent Pinchart]

From: Niklas Söderlund <niklas.soderlund at ragnatech.se>

Validate and potentially adjust the requested format with a list of
discrete formats retrieved from the video device.

Signed-off-by: Niklas Söderlund <niklas.soderlund at ragnatech.se>
---
 src/libcamera/pipeline/uvcvideo.cpp | 44 ++++++++++++++++++++++++-----
 1 file changed, 37 insertions(+), 7 deletions(-)

diff --git a/src/libcamera/pipeline/uvcvideo.cpp b/src/libcamera/pipeline/uvcvideo.cpp
index 286d19b0af01..e02d5b19e82a 100644
--- a/src/libcamera/pipeline/uvcvideo.cpp
+++ b/src/libcamera/pipeline/uvcvideo.cpp
@@ -37,6 +37,7 @@ public:
 
 	V4L2Device *video_;
 	Stream stream_;
+	StreamFormats formats_;
 };
 
 class UVCCameraConfiguration : public CameraConfiguration
@@ -45,6 +46,7 @@ public:
 	UVCCameraConfiguration();
 
 	Status validate() override;
+	StreamFormats formats;
 };
 
 class PipelineHandlerUVC : public PipelineHandler
@@ -96,21 +98,42 @@ CameraConfiguration::Status UVCCameraConfiguration::validate()
 
 	StreamConfiguration &cfg = config_[0];
 
-	/* \todo: Validate the configuration against the device capabilities. */
 	const unsigned int pixelFormat = cfg.pixelFormat;
 	const Size size = cfg.size;
+	const unsigned int bufferCount = cfg.bufferCount;
 
 	cfg.pixelFormat = V4L2_PIX_FMT_YUYV;
-	cfg.size = { 640, 480 };
+	if (cfg.pixelFormat != pixelFormat) {
+		LOG(UVC, Debug)
+			<< "Adjusting pixel format from " << pixelFormat
+			<< " to " << cfg.pixelFormat;
+		status = Adjusted;
+	}
 
-	if (cfg.pixelFormat != pixelFormat || cfg.size != size) {
+	const std::vector<Size> &formatSizes = formats.sizes(cfg.pixelFormat);
+	cfg.size = formatSizes.front();
+	for (const Size &formatsSize : formatSizes) {
+		if (formatsSize <= size)
+			cfg.size = formatsSize;
+
+		if (formatsSize == size)
+			break;
+	}
+
+	if (cfg.size != size) {
 		LOG(UVC, Debug)
-			<< "Adjusting configuration from " << cfg.toString()
-			<< " to " << cfg.size.toString() << "-YUYV";
+			<< "Adjusting size from " << size.toString()
+			<< " to " << cfg.size.toString();
 		status = Adjusted;
 	}
 
-	cfg.bufferCount = 4;
+	if (bufferCount < 4) {
+		cfg.bufferCount = 4;
+		LOG(UVC, Debug)
+			<< "Adjusting buffer count from " << bufferCount
+			<< " to " << cfg.bufferCount;
+		status = Adjusted;
+	}
 
 	return status;
 }
@@ -123,7 +146,10 @@ PipelineHandlerUVC::PipelineHandlerUVC(CameraManager *manager)
 CameraConfiguration *PipelineHandlerUVC::generateConfiguration(Camera *camera,
 	const StreamRoles &roles)
 {
-	CameraConfiguration *config = new UVCCameraConfiguration();
+	UVCCameraData *data = cameraData(camera);
+	UVCCameraConfiguration *config = new UVCCameraConfiguration();
+
+	config->formats = data->formats_;
 
 	if (!roles.empty()) {
 		StreamConfiguration cfg{};
@@ -242,6 +268,10 @@ bool PipelineHandlerUVC::match(DeviceEnumerator *enumerator)
 	if (data->video_->open())
 		return false;
 
+	data->formats_ = StreamFormats(data->video_->enumerateFrameSizes({ V4L2_PIX_FMT_YUYV }));
+	for (const Size &size : data->formats_.sizes(V4L2_PIX_FMT_YUYV))
+		LOG(UVC, Info) << size.toString();
+
 	data->video_->bufferReady.connect(data.get(), &UVCCameraData::bufferReady);
 
 	/* Create and register the camera. */
-- 
Regards,

Laurent Pinchart