[libcamera-devel] [PATCH v3 13/13] android: camera_device: Support MJPEG stream construction

Jacopo Mondi jacopo at jmondi.org
Wed Aug 5 10:03:06 CEST 2020


Hi Kieran,

On Tue, Aug 04, 2020 at 10:47:11PM +0100, Kieran Bingham wrote:
> MJPEG streams must be created referencing a libcamera stream.
> This stream may already be provided by the request configuration,
> in which case the existing stream is utilised.
>
> If no compatible stream is available to encode, a new stream is requested
> from the libcamera configuration.
>
> Signed-off-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
>
> ---
>
> v3
>  - Add max jpeg size todo
>  - Fix metadata allocations
>  - Use a class member to store the max jpeg buffer size
>  - Remove the scoping level for jpeg blob header
>  - Don't rely on the compressor pointer as a flag
>  - Fix camera metadata size allocations
> ---
>  src/android/camera_device.cpp | 226 ++++++++++++++++++++++++++++++++--
>  src/android/camera_device.h   |  12 ++
>  2 files changed, 229 insertions(+), 9 deletions(-)
>
> diff --git a/src/android/camera_device.cpp b/src/android/camera_device.cpp
> index c529246e115c..433243c3bc56 100644
> --- a/src/android/camera_device.cpp
> +++ b/src/android/camera_device.cpp
> @@ -8,6 +8,7 @@
>  #include "camera_device.h"
>  #include "camera_ops.h"
>
> +#include <sys/mman.h>
>  #include <tuple>
>  #include <vector>
>
> @@ -22,6 +23,8 @@
>  #include "camera_metadata.h"
>  #include "system/graphics.h"
>
> +#include "jpeg/compressor_jpeg.h"
> +
>  using namespace libcamera;
>
>  namespace {
> @@ -129,6 +132,54 @@ const std::map<int, const Camera3Format> camera3FormatsMap = {
>
>  LOG_DECLARE_CATEGORY(HAL);
>
> +class MappedCamera3Buffer : public MappedBuffer
> +{
> +public:
> +	MappedCamera3Buffer(const buffer_handle_t camera3buffer, int flags);
> +};
> +
> +MappedCamera3Buffer::MappedCamera3Buffer(const buffer_handle_t camera3buffer,
> +					 int flags)
> +{
> +	maps_.reserve(camera3buffer->numFds);
> +	error_ = 0;
> +
> +	for (int i = 0; i < camera3buffer->numFds; i++) {
> +		if (camera3buffer->data[i] == -1)
> +			continue;
> +
> +		off_t length = lseek(camera3buffer->data[i], 0, SEEK_END);
> +		if (length < 0) {
> +			error_ = errno;
> +			LOG(HAL, Error) << "Failed to query plane length";
> +			break;
> +		}
> +
> +		void *address = mmap(nullptr, length, flags, MAP_SHARED,
> +				     camera3buffer->data[i], 0);
> +		if (address == MAP_FAILED) {
> +			error_ = errno;
> +			LOG(HAL, Error) << "Failed to mmap plane";
> +			break;
> +		}
> +
> +		maps_.emplace_back(static_cast<uint8_t *>(address),
> +				   static_cast<size_t>(length));
> +	}
> +
> +	valid_ = error_ == 0;
> +}
> +
> +CameraStream::CameraStream(PixelFormat f, Size s)
> +	: index(-1), format(f), size(s), jpeg(nullptr)
> +{
> +}
> +
> +CameraStream::~CameraStream()
> +{
> +	delete jpeg;
> +};
> +
>  /*
>   * \struct Camera3RequestDescriptor
>   *
> @@ -167,6 +218,12 @@ CameraDevice::CameraDevice(unsigned int id, const std::shared_ptr<Camera> &camer
>  	  facing_(CAMERA_FACING_FRONT), orientation_(0)
>  {
>  	camera_->requestCompleted.connect(this, &CameraDevice::requestComplete);
> +
> +	/*
> +	 * \todo Determine a more accurate value for this during
> +	 *  streamConfiguration.
> +	 */
> +	max_jpeg_buffer_size_ = 13 << 20; /* 13631488 from USB HAL */
>  }
>
>  CameraDevice::~CameraDevice()
> @@ -417,10 +474,10 @@ std::tuple<uint32_t, uint32_t> CameraDevice::calculateStaticMetadataSize()
>  {
>  	/*
>  	 * \todo Keep this in sync with the actual number of entries.
> -	 * Currently: 50 entries, 647 bytes of static metadata
> +	 * Currently: 51 entries, 667 bytes of static metadata
>  	 */
> -	uint32_t numEntries = 50;
> -	uint32_t byteSize = 651;
> +	uint32_t numEntries = 51;
> +	uint32_t byteSize = 667;
>
>  	/*
>  	 * Calculate space occupation in bytes for dynamically built metadata
> @@ -576,6 +633,12 @@ const camera_metadata_t *CameraDevice::getStaticMetadata()
>  				  availableThumbnailSizes.data(),
>  				  availableThumbnailSizes.size());
>
> +	/*
> +	 * \todo Calculate the maximum JPEG buffer size by asking the compressor
> +	 * giving the maximum frame size required.
> +	 */
> +	staticMetadata_->addEntry(ANDROID_JPEG_MAX_SIZE, &max_jpeg_buffer_size_, 1);
> +
>  	/* Sensor static metadata. */
>  	int32_t pixelArraySize[] = {
>  		2592, 1944,
> @@ -789,6 +852,7 @@ const camera_metadata_t *CameraDevice::getStaticMetadata()
>  		ANDROID_CONTROL_AWB_LOCK_AVAILABLE,
>  		ANDROID_CONTROL_AVAILABLE_MODES,
>  		ANDROID_JPEG_AVAILABLE_THUMBNAIL_SIZES,
> +		ANDROID_JPEG_MAX_SIZE,
>  		ANDROID_SENSOR_INFO_PIXEL_ARRAY_SIZE,
>  		ANDROID_SENSOR_INFO_ACTIVE_ARRAY_SIZE,
>  		ANDROID_SENSOR_INFO_SENSITIVITY_RANGE,
> @@ -855,6 +919,9 @@ const camera_metadata_t *CameraDevice::getStaticMetadata()
>  		ANDROID_SENSOR_EXPOSURE_TIME,
>  		ANDROID_STATISTICS_LENS_SHADING_MAP_MODE,
>  		ANDROID_STATISTICS_SCENE_FLICKER,
> +		ANDROID_JPEG_SIZE,
> +		ANDROID_JPEG_QUALITY,
> +		ANDROID_JPEG_ORIENTATION,
>  	};
>  	staticMetadata_->addEntry(ANDROID_REQUEST_AVAILABLE_RESULT_KEYS,
>  				  availableResultKeys.data(),
> @@ -1016,8 +1083,10 @@ int CameraDevice::configureStreams(camera3_stream_configuration_t *stream_list)
>  	 */
>  	unsigned int streamIndex = 0;
>
> +	/* First handle all non-MJPEG streams. */
>  	for (unsigned int i = 0; i < stream_list->num_streams; ++i) {
>  		camera3_stream_t *stream = stream_list->streams[i];
> +		Size size(stream->width, stream->height);
>
>  		PixelFormat format = toPixelFormat(stream->format);
>
> @@ -1031,16 +1100,71 @@ int CameraDevice::configureStreams(camera3_stream_configuration_t *stream_list)
>  		if (!format.isValid())
>  			return -EINVAL;
>
> +		streams_.emplace_back(format, size);
> +		stream->priv = static_cast<void *>(&streams_[i]);
> +
> +		/* Defer handling of MJPEG streams until all others are known. */
> +		if (format == formats::MJPEG)
> +			continue;
> +
>  		StreamConfiguration streamConfiguration;
>
> -		streamConfiguration.size.width = stream->width;
> -		streamConfiguration.size.height = stream->height;
> +		streamConfiguration.size = size;
>  		streamConfiguration.pixelFormat = format;
>
>  		config_->addConfiguration(streamConfiguration);
>
>  		streams_[i].index = streamIndex++;
> -		stream->priv = static_cast<void *>(&streams_[i]);
> +	}
> +
> +	/* Now handle MJPEG streams, adding a new stream if required. */
> +	for (unsigned int i = 0; i < stream_list->num_streams; ++i) {
> +		camera3_stream_t *stream = stream_list->streams[i];
> +		bool match = false;
> +
> +		if (streams_[i].format != formats::MJPEG)
> +			continue;
> +
> +		/* Search for a compatible stream */
> +		for (unsigned int j = 0; j < config_->size(); j++) {
> +			StreamConfiguration &cfg = config_->at(j);
> +
> +			/*
> +			 * \todo The PixelFormat must also be compatible with
> +			 * the encoder.
> +			 */
> +			if (cfg.size == streams_[i].size) {
> +				LOG(HAL, Info) << "Stream " << i
> +					       << " using libcamera stream " << j;
> +
> +				match = true;
> +				streams_[i].index = j;
> +			}
> +		}
> +
> +		/*
> +		 * Without a compatible match for JPEG encoding we must
> +		 * introduce a new stream to satisfy the request requirements.
> +		 */
> +		if (!match) {
> +			StreamConfiguration streamConfiguration;
> +
> +			/*
> +			 * \todo: The pixelFormat should be a 'best-fit' choice
> +			 * and may require a validation cycle. This is not yet
> +			 * handled, and should be considered as part of any
> +			 * stream configuration reworks.
> +			 */
> +			streamConfiguration.size.width = stream->width;
> +			streamConfiguration.size.height = stream->height;
> +			streamConfiguration.pixelFormat = formats::NV12;
> +
> +			LOG(HAL, Info) << "Adding " << streamConfiguration.toString()
> +				       << " for MJPEG support";
> +
> +			config_->addConfiguration(streamConfiguration);
> +			streams_[i].index = streamIndex++;
> +		}
>  	}
>
>  	switch (config_->validate()) {
> @@ -1067,6 +1191,18 @@ int CameraDevice::configureStreams(camera3_stream_configuration_t *stream_list)
>
>  		/* Use the bufferCount confirmed by the validation process. */
>  		stream->max_buffers = cfg.bufferCount;
> +
> +		/*
> +		 * Construct a software compressor for MJPEG streams from the
> +		 * chosen libcamera source stream.
> +		 */
> +		if (cameraStream->format == formats::MJPEG) {
> +			cameraStream->jpeg = new CompressorJPEG();
> +			cameraStream->jpeg->configure(cfg);
> +		} else {
> +			/* Either construct this correctly, or use a better interface */
> +			cameraStream->jpeg = nullptr;
> +		}
>  	}
>
>  	/*
> @@ -1161,6 +1297,10 @@ int CameraDevice::processCaptureRequest(camera3_capture_request_t *camera3Reques
>  		descriptor->buffers[i].stream = camera3Buffers[i].stream;
>  		descriptor->buffers[i].buffer = camera3Buffers[i].buffer;
>
> +		/* Software streams are handled after hardware streams complete. */
> +		if (cameraStream->format == formats::MJPEG)
> +			continue;
> +
>  		/*
>  		 * Create a libcamera buffer using the dmabuf descriptors of
>  		 * the camera3Buffer for each stream. The FrameBuffer is
> @@ -1217,8 +1357,76 @@ void CameraDevice::requestComplete(Request *request)
>  	resultMetadata = getResultMetadata(descriptor->frameNumber,
>  					   buffer->metadata().timestamp);
>
> -	/* Prepare to call back the Android camera stack. */
> +	/* Handle any JPEG compression */
> +	for (unsigned int i = 0; i < descriptor->numBuffers; ++i) {
> +		CameraStream *cameraStream =
> +			static_cast<CameraStream *>(descriptor->buffers[i].stream->priv);
> +
> +		if (cameraStream->format != formats::MJPEG)
> +			continue;
> +
> +		Compressor *compressor = cameraStream->jpeg;
> +		/* Only handle streams with compression enabled. */
> +		if (!compressor)
> +			continue;

Small nit: Can it happen that format == MJPEG and !compressor ? If it
happen, isn't it an error ?

Also the order of
                Compressor *compressor =
                /* A comment */
                if (!compressor)

is s abit weird


> +
> +		StreamConfiguration *streamConfiguration = &config_->at(cameraStream->index);
> +		Stream *stream = streamConfiguration->stream();
> +		FrameBuffer *buffer = request->findBuffer(stream);
> +		if (!buffer) {
> +			LOG(HAL, Error) << "Failed to find a source stream buffer";
> +			continue;
> +		}
> +
> +		MappedCamera3Buffer mapped(*descriptor->buffers[i].buffer, PROT_READ | PROT_WRITE);
> +		if (!mapped.isValid()) {
> +			LOG(HAL, Error) << "Failed to mmap android blob buffer";
> +			continue;
> +		}
> +
> +		CompressedImage output;
> +		output.data = static_cast<unsigned char *>(mapped.maps()[0].data());
> +		output.length = mapped.maps()[0].size();
> +
> +		int ret = compressor->compress(buffer, &output);
> +		if (ret) {
> +			LOG(HAL, Error) << "Failed to compress stream image";
> +			status = CAMERA3_BUFFER_STATUS_ERROR;
> +		}
>
> +		/*
> +		 * Fill in the JPEG blob header.
> +		 *
> +		 * The mapped size of the buffer is being returned as
> +		 * substantially larger than the requested JPEG_MAX_SIZE
> +		 * (which is referenced from max_jpeg_buffer_size_). Utilise
> +		 * this static size to ensure the correct offset of the blob is
> +		 * determined.
> +		 *
> +		 * \todo Investigate if the buffer size mismatch is an issue or
> +		 * expected behaviour.
> +		 */
> +		uint8_t *resultPtr = mapped.maps()[0].data() +
> +				     max_jpeg_buffer_size_ -
> +				     sizeof(struct camera3_jpeg_blob);
> +		auto *blob = reinterpret_cast<struct camera3_jpeg_blob *>(resultPtr);
> +		blob->jpeg_blob_id = CAMERA3_JPEG_BLOB_ID;
> +		blob->jpeg_size = output.length;
> +
> +		/* Update the JPEG result Metadata. */
> +		resultMetadata->addEntry(ANDROID_JPEG_SIZE,
> +					 &output.length, 1);
> +
> +		const uint32_t jpeg_quality = 95;
> +		resultMetadata->addEntry(ANDROID_JPEG_QUALITY,
> +					 &jpeg_quality, 1);
> +
> +		const uint32_t jpeg_orientation = 0;
> +		resultMetadata->addEntry(ANDROID_JPEG_ORIENTATION,
> +					 &jpeg_orientation, 1);
> +	}
> +
> +	/* Prepare to call back the Android camera stack. */
>  	camera3_capture_result_t captureResult = {};
>  	captureResult.frame_number = descriptor->frameNumber;
>  	captureResult.num_output_buffers = descriptor->numBuffers;
> @@ -1298,10 +1506,10 @@ std::unique_ptr<CameraMetadata> CameraDevice::getResultMetadata(int frame_number
>  {
>  	/*
>  	 * \todo Keep this in sync with the actual number of entries.
> -	 * Currently: 12 entries, 36 bytes
> +	 * Currently: 18 entries, 62 bytes
>  	 */
>  	std::unique_ptr<CameraMetadata> resultMetadata =
> -		std::make_unique<CameraMetadata>(15, 50);
> +		std::make_unique<CameraMetadata>(18, 62);
>  	if (!resultMetadata->isValid()) {
>  		LOG(HAL, Error) << "Failed to allocate static metadata";
>  		return nullptr;
> diff --git a/src/android/camera_device.h b/src/android/camera_device.h
> index 00472c219388..cfec5abeffa1 100644
> --- a/src/android/camera_device.h
> +++ b/src/android/camera_device.h
> @@ -23,15 +23,25 @@
>  #include "libcamera/internal/log.h"
>  #include "libcamera/internal/message.h"
>
> +#include "jpeg/compressor_jpeg.h"
> +
>  class CameraMetadata;
>
>  struct CameraStream {
> +	CameraStream(libcamera::PixelFormat, libcamera::Size);
> +	~CameraStream();
> +
>  	/*
>  	 * The index of the libcamera StreamConfiguration as added during
>  	 * configureStreams(). A single libcamera Stream may be used to deliver
>  	 * one or more streams to the Android framework.
>  	 */
>  	unsigned int index;
> +
> +	libcamera::PixelFormat format;
> +	libcamera::Size size;
> +
> +	CompressorJPEG *jpeg;
>  };
>
>  class CameraDevice : protected libcamera::Loggable
> @@ -104,6 +114,8 @@ private:
>
>  	int facing_;
>  	int orientation_;
> +
> +	unsigned int max_jpeg_buffer_size_;

This looks good! Thanks for sticking to all the pesky discussions on
v2!

Reviewed-by: Jacopo Mondi <jacopo at jmondi.org>

Thanks
  j

>  };
>
>  #endif /* __ANDROID_CAMERA_DEVICE_H__ */
> --
> 2.25.1
>
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