android: Track and notify post processing of streams

Notify that the post processing for a request has been completed,
via a signal. The signal is emitted with a context pointer along with
status of the buffer. The function CameraDevice::streamProcessingComplete()
will finally set the status on the request descriptor and complete the
descriptor if all the streams requiring post processing are completed.
If buffer status obtained is in error state, notify the status to the
framework and set the overall error status on the descriptor via
setBufferStatus().

We need to track the number of streams requiring post-processing
per Camera3RequestDescriptor (i.e. per capture request). Introduce
a std::map to track the post-processing of streams. The nodes
are dropped from the map when a particular stream post processing
is completed (or on error paths). A std::map is selected for tracking
post-processing requests, since we will move post-processing to be
asynchronous in subsequent commits. A vector or queue will not be
suitable as the sequential order of post-processing completion
of various requests won't be guaranteed then.

A streamsProcessMutex_ has been introduced here as well, which will be
applicable to guard access to descriptor's pendingStreamsToProcess_ when
post-processing is moved to be asynchronous in subsequent commits.

Signed-off-by: Umang Jain <umang.jain@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Hirokazu Honda <hiroh@chromium.org>

src/android/camera_device.cpp

@@ -926,6 +926,9 @@ int CameraDevice::processCaptureRequest(camera3_capture_request_t *camera3Reques
 			 * Request.
 			 */
 			LOG(HAL, Debug) << ss.str() << " (mapped)";
+
+			descriptor->pendingStreamsToProcess_.insert(
+				{ cameraStream, &buffer });
 			continue;
 
 		case CameraStream::Type::Direct:
@@ -955,6 +958,9 @@ int CameraDevice::processCaptureRequest(camera3_capture_request_t *camera3Reques
 			frameBuffer = cameraStream->getBuffer();
 			buffer.internalBuffer = frameBuffer;
 			LOG(HAL, Debug) << ss.str() << " (internal)";
+
+			descriptor->pendingStreamsToProcess_.insert(
+				{ cameraStream, &buffer });
 			break;
 		}
 
@@ -1118,42 +1124,42 @@ void CameraDevice::requestComplete(Request *request)
 	}
 
 	/* Handle post-processing. */
-	for (auto &buffer : descriptor->buffers_) {
+	/*
-		CameraStream *stream = buffer.stream;
+	 * \todo Protect the loop below with streamsProcessMutex_ when post
-
+	 * processor runs asynchronously.
-		if (stream->type() == CameraStream::Type::Direct)
+	 */
-			continue;
+	auto iter = descriptor->pendingStreamsToProcess_.begin();
+	while (iter != descriptor->pendingStreamsToProcess_.end()) {
+		CameraStream *stream = iter->first;
+		Camera3RequestDescriptor::StreamBuffer *buffer = iter->second;
 
 		FrameBuffer *src = request->findBuffer(stream->stream());
 		if (!src) {
 			LOG(HAL, Error) << "Failed to find a source stream buffer";
-			buffer.status = Camera3RequestDescriptor::Status::Error;
+			setBufferStatus(*buffer, Camera3RequestDescriptor::Status::Error);
-			notifyError(descriptor->frameNumber_, stream->camera3Stream(),
+			iter = descriptor->pendingStreamsToProcess_.erase(iter);
-				    CAMERA3_MSG_ERROR_BUFFER);
-			descriptor->status_ = Camera3RequestDescriptor::Status::Error;
 			continue;
 		}
 
-		buffer.srcBuffer = src;
+		buffer->srcBuffer = src;
-
-		int ret = stream->process(&buffer);
-
-		/*
-		 * If the framebuffer is internal to CameraStream return it back
-		 * now that we're done processing it.
-		 */
-		if (buffer.internalBuffer)
-			stream->putBuffer(buffer.internalBuffer);
 
+		++iter;
+		int ret = stream->process(buffer);
 		if (ret) {
-			buffer.status = Camera3RequestDescriptor::Status::Error;
+			setBufferStatus(*buffer, Camera3RequestDescriptor::Status::Error);
-			notifyError(descriptor->frameNumber_, stream->camera3Stream(),
+			descriptor->pendingStreamsToProcess_.erase(stream);
-				    CAMERA3_MSG_ERROR_BUFFER);
+
-			descriptor->status_ = Camera3RequestDescriptor::Status::Error;
+			/*
+			 * If the framebuffer is internal to CameraStream return
+			 * it back now that we're done processing it.
+			 */
+			if (buffer->internalBuffer)
+				stream->putBuffer(buffer->internalBuffer);
 		}
 	}
 
-	completeDescriptor(descriptor);
+	if (descriptor->pendingStreamsToProcess_.empty())
+		completeDescriptor(descriptor);
 }
 
 void CameraDevice::completeDescriptor(Camera3RequestDescriptor *descriptor)
@@ -1208,6 +1214,39 @@ void CameraDevice::sendCaptureResults()
 	}
 }
 
+void CameraDevice::setBufferStatus(Camera3RequestDescriptor::StreamBuffer &streamBuffer,
+				   Camera3RequestDescriptor::Status status)
+{
+	streamBuffer.status = status;
+	if (status != Camera3RequestDescriptor::Status::Success) {
+		notifyError(streamBuffer.request->frameNumber_,
+			    streamBuffer.stream->camera3Stream(),
+			    CAMERA3_MSG_ERROR_BUFFER);
+
+		/* Also set error status on entire request descriptor. */
+		streamBuffer.request->status_ =
+			Camera3RequestDescriptor::Status::Error;
+	}
+}
+
+void CameraDevice::streamProcessingComplete(Camera3RequestDescriptor::StreamBuffer *streamBuffer,
+					    Camera3RequestDescriptor::Status status)
+{
+	setBufferStatus(*streamBuffer, status);
+
+	/*
+	 * If the framebuffer is internal to CameraStream return it back now
+	 * that we're done processing it.
+	 */
+	if (streamBuffer->internalBuffer)
+		streamBuffer->stream->putBuffer(streamBuffer->internalBuffer);
+
+	Camera3RequestDescriptor *request = streamBuffer->request;
+	MutexLocker locker(request->streamsProcessMutex_);
+
+	request->pendingStreamsToProcess_.erase(streamBuffer->stream);
+}
+
 std::string CameraDevice::logPrefix() const
 {
 	return "'" + camera_->id() + "'";

src/android/camera_device.h

@@ -66,6 +66,8 @@ public:
 	int configureStreams(camera3_stream_configuration_t *stream_list);
 	int processCaptureRequest(camera3_capture_request_t *request);
 	void requestComplete(libcamera::Request *request);
+	void streamProcessingComplete(Camera3RequestDescriptor::StreamBuffer *bufferStream,
+				      Camera3RequestDescriptor::Status status);
 
 protected:
 	std::string logPrefix() const override;
@@ -95,6 +97,8 @@ private:
 	int processControls(Camera3RequestDescriptor *descriptor);
 	void completeDescriptor(Camera3RequestDescriptor *descriptor);
 	void sendCaptureResults();
+	void setBufferStatus(Camera3RequestDescriptor::StreamBuffer &buffer,
+			     Camera3RequestDescriptor::Status status);
 	std::unique_ptr<CameraMetadata> getResultMetadata(
 		const Camera3RequestDescriptor &descriptor) const;
 

src/android/camera_request.h

@@ -7,7 +7,9 @@
 #ifndef __ANDROID_CAMERA_REQUEST_H__
 #define __ANDROID_CAMERA_REQUEST_H__
 
+#include <map>
 #include <memory>
+#include <mutex>
 #include <vector>
 
 #include <libcamera/base/class.h>
@@ -43,6 +45,10 @@ public:
 		Camera3RequestDescriptor *request;
 	};
 
+	/* Keeps track of streams requiring post-processing. */
+	std::map<CameraStream *, StreamBuffer *> pendingStreamsToProcess_;
+	std::mutex streamsProcessMutex_;
+
 	Camera3RequestDescriptor(libcamera::Camera *camera,
 				 const camera3_capture_request_t *camera3Request);
 	~Camera3RequestDescriptor();

src/android/camera_stream.cpp

@@ -22,6 +22,7 @@
 #include "camera_capabilities.h"
 #include "camera_device.h"
 #include "camera_metadata.h"
+#include "post_processor.h"
 
 using namespace libcamera;
 
@@ -97,6 +98,20 @@ int CameraStream::configure()
 		int ret = postProcessor_->configure(configuration(), output);
 		if (ret)
 			return ret;
+
+		postProcessor_->processComplete.connect(
+			this, [&](Camera3RequestDescriptor::StreamBuffer *streamBuffer,
+				  PostProcessor::Status status) {
+				Camera3RequestDescriptor::Status bufferStatus;
+
+				if (status == PostProcessor::Status::Success)
+					bufferStatus = Camera3RequestDescriptor::Status::Success;
+				else
+					bufferStatus = Camera3RequestDescriptor::Status::Error;
+
+				cameraDevice_->streamProcessingComplete(streamBuffer,
+									bufferStatus);
+			});
 	}
 
 	if (type_ == Type::Internal) {

src/android/jpeg/post_processor_jpeg.cpp

@@ -198,6 +198,7 @@ int PostProcessorJpeg::process(Camera3RequestDescriptor::StreamBuffer *streamBuf
 					 exif.data(), quality);
 	if (jpeg_size < 0) {
 		LOG(JPEG, Error) << "Failed to encode stream image";
+		processComplete.emit(streamBuffer, PostProcessor::Status::Error);
 		return jpeg_size;
 	}
 
@@ -211,6 +212,7 @@ int PostProcessorJpeg::process(Camera3RequestDescriptor::StreamBuffer *streamBuf
 
 	/* Update the JPEG result Metadata. */
 	resultMetadata->addEntry(ANDROID_JPEG_SIZE, jpeg_size);
+	processComplete.emit(streamBuffer, PostProcessor::Status::Success);
 
 	return 0;
 }

src/android/post_processor.h

@@ -7,6 +7,8 @@
 #ifndef __ANDROID_POST_PROCESSOR_H__
 #define __ANDROID_POST_PROCESSOR_H__
 
+#include <libcamera/base/signal.h>
+
 #include <libcamera/framebuffer.h>
 #include <libcamera/stream.h>
 
@@ -16,11 +18,18 @@
 class PostProcessor
 {
 public:
+	enum class Status {
+		Error,
+		Success
+	};
+
 	virtual ~PostProcessor() = default;
 
 	virtual int configure(const libcamera::StreamConfiguration &inCfg,
 			      const libcamera::StreamConfiguration &outCfg) = 0;
 	virtual int process(Camera3RequestDescriptor::StreamBuffer *streamBuffer) = 0;
+
+	libcamera::Signal<Camera3RequestDescriptor::StreamBuffer *, Status> processComplete;
 };
 
 #endif /* __ANDROID_POST_PROCESSOR_H__ */

src/android/yuv/post_processor_yuv.cpp

@@ -54,12 +54,15 @@ int PostProcessorYuv::process(Camera3RequestDescriptor::StreamBuffer *streamBuff
 	const FrameBuffer &source = *streamBuffer->srcBuffer;
 	CameraBuffer *destination = streamBuffer->dstBuffer.get();
 
-	if (!isValidBuffers(source, *destination))
+	if (!isValidBuffers(source, *destination)) {
+		processComplete.emit(streamBuffer, PostProcessor::Status::Error);
 		return -EINVAL;
+	}
 
 	const MappedFrameBuffer sourceMapped(&source, MappedFrameBuffer::MapFlag::Read);
 	if (!sourceMapped.isValid()) {
 		LOG(YUV, Error) << "Failed to mmap camera frame buffer";
+		processComplete.emit(streamBuffer, PostProcessor::Status::Error);
 		return -EINVAL;
 	}
 
@@ -77,9 +80,12 @@ int PostProcessorYuv::process(Camera3RequestDescriptor::StreamBuffer *streamBuff
 				    libyuv::FilterMode::kFilterBilinear);
 	if (ret) {
 		LOG(YUV, Error) << "Failed NV12 scaling: " << ret;
+		processComplete.emit(streamBuffer, PostProcessor::Status::Error);
 		return -EINVAL;
 	}
 
+	processComplete.emit(streamBuffer, PostProcessor::Status::Success);
+
 	return 0;
 }