libcamera: pipeline: uvcvideo: Add format information and validation

Extend the uvcvideo pipeline with format information and validation. The
format information is gathered by enumerating the v4l2 device. This
enumeration approach is valid for UVC as it has a static and simple
media graph.

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

1 files changed, 31 insertions, 10 deletions

diff --git a/src/libcamera/pipeline/uvcvideo.cpp b/src/libcamera/pipeline/uvcvideo.cpp
index 45260f34..7ca9d0ee 100644
--- a/src/libcamera/pipeline/uvcvideo.cpp
+++ b/src/libcamera/pipeline/uvcvideo.cpp
@@ -5,6 +5,8 @@
  * uvcvideo.cpp - Pipeline handler for uvcvideo devices
  */
 
+#include <algorithm>
+
 #include <libcamera/camera.h>
 #include <libcamera/request.h>
 #include <libcamera/stream.h>
@@ -95,18 +97,33 @@ CameraConfiguration::Status UVCCameraConfiguration::validate()
 	}
 
 	StreamConfiguration &cfg = config_[0];
-
-	/* \todo: Validate the configuration against the device capabilities. */
+	const StreamFormats &formats = cfg.formats();
 	const unsigned int pixelFormat = cfg.pixelFormat;
 	const Size size = cfg.size;
 
-	cfg.pixelFormat = V4L2_PIX_FMT_YUYV;
-	cfg.size = { 640, 480 };
+	const std::vector<unsigned int> pixelFormats = formats.pixelformats();
+	auto iter = std::find(pixelFormats.begin(), pixelFormats.end(), pixelFormat);
+	if (iter == pixelFormats.end()) {
+		cfg.pixelFormat = pixelFormats.front();
+		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)
+			break;
+
+		cfg.size = formatsSize;
+	}
+
+	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;
 	}
 
@@ -123,14 +140,18 @@ PipelineHandlerUVC::PipelineHandlerUVC(CameraManager *manager)
 CameraConfiguration *PipelineHandlerUVC::generateConfiguration(Camera *camera,
 	const StreamRoles &roles)
 {
+	UVCCameraData *data = cameraData(camera);
 	CameraConfiguration *config = new UVCCameraConfiguration();
 
 	if (roles.empty())
 		return config;
 
-	StreamConfiguration cfg{};
-	cfg.pixelFormat = V4L2_PIX_FMT_YUYV;
-	cfg.size = { 640, 480 };
+	ImageFormats v4l2formats = data->video_->formats();
+	StreamFormats formats(v4l2formats.data());
+	StreamConfiguration cfg(formats);
+
+	cfg.pixelFormat = formats.pixelformats().front();
+	cfg.size = formats.sizes(cfg.pixelFormat).back();
 	cfg.bufferCount = 4;
 
 	config->addConfiguration(cfg);