[libcamera-devel] [PATCH v6 5/7] android: Track and notify post processing of streams

Laurent Pinchart laurent.pinchart at ideasonboard.com
Mon Oct 25 15:25:09 CEST 2021


Hi Umang,

On Mon, Oct 25, 2021 at 06:46:39PM +0530, Umang Jain wrote:
> On 10/25/21 11:33 AM, Laurent Pinchart wrote:
> > On Sat, Oct 23, 2021 at 04:03:00PM +0530, Umang Jain wrote:
> >> Notify that the post processing for a request has been completed,
> >> via a signal. The signal emit with a context pointer along with status
> > s/emit/is emitted/ ?
> >
> >> 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 then as the sequential order of post-processing completion
> >> of various requests won't be guaranteed then.
> >>
> >> A streamProcessMutex_ has been introduced here as well, which will be
> >
> > s/streamProcessMutex_/streamsProcessMutex_/
> >
> >> 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 at ideasonboard.com>
> >> ---
> >>   src/android/camera_device.cpp            | 95 ++++++++++++++++++------
> >>   src/android/camera_device.h              |  4 +
> >>   src/android/camera_request.h             |  6 ++
> >>   src/android/camera_stream.cpp            | 15 ++++
> >>   src/android/jpeg/post_processor_jpeg.cpp |  2 +
> >>   src/android/post_processor.h             |  9 +++
> >>   src/android/yuv/post_processor_yuv.cpp   |  8 +-
> >>   7 files changed, 114 insertions(+), 25 deletions(-)
> >>
> >> diff --git a/src/android/camera_device.cpp b/src/android/camera_device.cpp
> >> index 2a98a2e6..3114def0 100644
> >> --- a/src/android/camera_device.cpp
> >> +++ b/src/android/camera_device.cpp
> >> @@ -926,6 +926,8 @@ int CameraDevice::processCaptureRequest(camera3_capture_request_t *camera3Reques
> >>   			 * Request.
> >>   			 */
> >>   			LOG(HAL, Debug) << ss.str() << " (mapped)";
> > Blank line here, or no blank line below.
> >
> >> +			descriptor->pendingStreamsToProcess_.insert(
> >> +				{ cameraStream, &buffer });
> >>   			continue;
> >>   
> >>   		case CameraStream::Type::Direct:
> >> @@ -955,6 +957,9 @@ 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;
> >>   		}
> >>   
> >> @@ -1118,43 +1123,46 @@ void CameraDevice::requestComplete(Request *request)
> >>   	}
> >>   
> >>   	/* Handle post-processing. */
> >> -	bool hasPostProcessingErrors = false;
> >> -	for (auto &buffer : descriptor->buffers_) {
> >> -		CameraStream *stream = buffer.stream;
> >> -
> >> -		if (stream->type() == CameraStream::Type::Direct)
> >> -			continue;
> >> +	bool needPostProcessing = false;
> >> +	/*
> >> +	 * \todo Protect the loop below with streamProcessMutex_ when post
> >> +	 * processor runs asynchronously.
> >> +	 */
> >> +	auto iter = descriptor->pendingStreamsToProcess_.begin();
> >> +	while (descriptor->pendingStreamsToProcess_.size() > 0) {
> > 	while (!descriptor->pendingStreamsToProcess_.empty()) {
> >
> > But it's not correct. The fix is in 7/7:
> >
> > 	while (iter != descriptor->pendingStreamsToProcess_.end()) {
> 
> Yes, it was a tricky to handle the loop for async and sync variations
> 
> For the async one, iter == end() was the only choice I  believe (Without 
> introducing a counter)
> 
> >> +		CameraStream *stream = iter->first;
> >> +		Camera3RequestDescriptor::StreamBuffer *buffer = iter->second;
> >> +		needPostProcessing = true;
> >>   
> >>   		FrameBuffer *src = request->findBuffer(stream->stream());
> >>   		if (!src) {
> >>   			LOG(HAL, Error) << "Failed to find a source stream buffer";
> >> -			buffer.status = Camera3RequestDescriptor::Status::Error;
> >> -			notifyError(descriptor->frameNumber_, stream->camera3Stream(),
> >> -				    CAMERA3_MSG_ERROR_BUFFER);
> >> -			hasPostProcessingErrors = true;
> >> +			setBufferStatus(*buffer, Camera3RequestDescriptor::Status::Error);
> >> +			iter = descriptor->pendingStreamsToProcess_.erase(iter);
> >>   			continue;
> >>   		}
> >>   
> >> -		int ret = stream->process(*src, buffer);
> >> +		++iter;
> >> +		int ret = stream->process(*src, *buffer);
> >> +		if (ret) {
> >> +			setBufferStatus(*buffer, Camera3RequestDescriptor::Status::Error);
> >> +			descriptor->pendingStreamsToProcess_.erase(stream);
> >> +		}
> >> +	}
> >>   
> >> +	if (needPostProcessing) {
> >>   		/*
> >> -		 * If the framebuffer is internal to CameraStream return it back
> >> -		 * now that we're done processing it.
> >> +		 * \todo We will require to check if we failed to queue
> >> +		 * post-processing requests when we migrate to post-processor
> >> +		 * running asynchronously.
> >> +		 *
> >> +		 * if (descriptor->pendingStreamsToProcess_.size() == 0)
> >> +		 *	completeDescriptor(descriptor);
> >
> > Can't we do this already here ? I think you can actually drop the
> > needPostProcessing variable and just write
> >
> > 	if (descriptor->pendingStreamsToProcess_.empty())
> > 		completeDescriptor(descriptor);
> >
> > as needPostProcessing can only be false if pendingStreamsToProcess_ was
> > empty before the while loop above, and it will thus be empty after the
> > loop as well in that case.
> 
> True, but we need needPostProcessing variable for async.

Why is that ? Won't

 	if (descriptor->pendingStreamsToProcess_.empty())
 		completeDescriptor(descriptor);

work in async mode too ?

> I pre-empted 
> its introduction deliberately to set the design beforehand andthen,  I 
> can introduce async bits with minimal diff for 
> CamreraDevice::requestComplete()
> 
> >>   		 */
> >> -		if (buffer.internalBuffer)
> >> -			stream->putBuffer(buffer.internalBuffer);
> >>   
> >> -		if (ret) {
> >> -			buffer.status = Camera3RequestDescriptor::Status::Error;
> >> -			hasPostProcessingErrors = true;
> >> -			notifyError(descriptor->frameNumber_, stream->camera3Stream(),
> >> -				    CAMERA3_MSG_ERROR_BUFFER);
> >> -		}
> >> +		return;
> >>   	}
> >>   
> >> -	if (hasPostProcessingErrors)
> >> -		descriptor->status_ = Camera3RequestDescriptor::Status::Error;
> >> -
> >>   	completeDescriptor(descriptor);
> >>   }
> >>   
> >> @@ -1210,6 +1218,45 @@ void CameraDevice::sendCaptureResults()
> >>   	}
> >>   }
> >>   
> >> +void CameraDevice::setBufferStatus(Camera3RequestDescriptor::StreamBuffer &streamBuffer,
> >> +				   Camera3RequestDescriptor::Status 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);
> > I'd move this to the caller, as it's not about the buffer 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)
> >> +{
> >> +	Camera3RequestDescriptor *request = streamBuffer->request;
> >> +	MutexLocker locker(request->streamsProcessMutex_);
> >> +
> >> +	setBufferStatus(*streamBuffer, status);
> > Do we need to protect the setBufferStatus() call with
> > streamsProcessMutex_ ? I thought it only protects
> > pendingStreamsToProcess_.
> 
> 
> Ah, I don't see why we need to lock it. This is a good catch.
> 
> For the async version, the main thread isn't expected to call 
> setBufferStatus() on the same descriptor (because we are already 
> handling synchronous errors beforehand), so I don't expect to race. So I 
> should remove setBufferStatus() from the lock section.
> 
> >
> >> +	request->pendingStreamsToProcess_.erase(streamBuffer->stream);
> >> +
> >> +	if (request->pendingStreamsToProcess_.size() > 0)
> > 	if (!request->pendingStreamsToProcess_.empty())
> >
> >> +		return;
> >> +
> >> +	locker.unlock();
> >> +
> >> +	completeDescriptor(streamBuffer->request);
> >> +}
> >> +
> >>   std::string CameraDevice::logPrefix() const
> >>   {
> >>   	return "'" + camera_->id() + "'";
> >> diff --git a/src/android/camera_device.h b/src/android/camera_device.h
> >> index e544f2bd..2a414020 100644
> >> --- a/src/android/camera_device.h
> >> +++ b/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;
> >>   
> >> diff --git a/src/android/camera_request.h b/src/android/camera_request.h
> >> index c4bc5d6e..cc2b7035 100644
> >> --- a/src/android/camera_request.h
> >> +++ b/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();
> >> diff --git a/src/android/camera_stream.cpp b/src/android/camera_stream.cpp
> >> index 0e268cdf..4e275cde 100644
> >> --- a/src/android/camera_stream.cpp
> >> +++ b/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) {
> >> diff --git a/src/android/jpeg/post_processor_jpeg.cpp b/src/android/jpeg/post_processor_jpeg.cpp
> >> index da71f113..cbbe7128 100644
> >> --- a/src/android/jpeg/post_processor_jpeg.cpp
> >> +++ b/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;
> >>   }
> >> diff --git a/src/android/post_processor.h b/src/android/post_processor.h
> >> index 128161c8..4ac74fcf 100644
> >> --- a/src/android/post_processor.h
> >> +++ b/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__ */
> >> diff --git a/src/android/yuv/post_processor_yuv.cpp b/src/android/yuv/post_processor_yuv.cpp
> >> index eeb8f1f4..8e77bf57 100644
> >> --- a/src/android/yuv/post_processor_yuv.cpp
> >> +++ b/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->destBuffer.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;
> >>   }
> >>   

-- 
Regards,

Laurent Pinchart


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