android: post_processor: Consolidate contextual information

Save and provide the context for post-processor of a camera stream
via Camera3RequestDescriptor::StreamBuffer. We extend the structure
to include source and destination buffers for the post processor, along
with CameraStream::Type::Internal buffer pointer (if any). In addition
to that, a back pointer to Camera3RequestDescriptor is convenient to
get access to overall descriptor (status, metadata settings etc.).

Also, migrate CameraStream::process() and PostProcessor::process()
signature to use Camera3RequestDescriptor::StreamBuffer only. This
will be helpful when we move to async post-processing 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/jpeg/post_processor_jpeg.cpp

@@ -98,15 +98,17 @@ void PostProcessorJpeg::generateThumbnail(const FrameBuffer &source,
 	}
 }
 
-int PostProcessorJpeg::process(const FrameBuffer &source,
-			       CameraBuffer *destination,
-			       Camera3RequestDescriptor *request)
+int PostProcessorJpeg::process(Camera3RequestDescriptor::StreamBuffer *streamBuffer)
 {
 	ASSERT(encoder_);
+
+	const FrameBuffer &source = *streamBuffer->srcBuffer;
+	CameraBuffer *destination = streamBuffer->dstBuffer.get();
+
 	ASSERT(destination->numPlanes() == 1);
 
-	const CameraMetadata &requestMetadata = request->settings_;
-	CameraMetadata *resultMetadata = request->resultMetadata_.get();
+	const CameraMetadata &requestMetadata = streamBuffer->request->settings_;
+	CameraMetadata *resultMetadata = streamBuffer->request->resultMetadata_.get();
 	camera_metadata_ro_entry_t entry;
 	int ret;
 

src/android/jpeg/post_processor_jpeg.h

@@ -22,9 +22,7 @@ public:
 
 	int configure(const libcamera::StreamConfiguration &incfg,
 		      const libcamera::StreamConfiguration &outcfg) override;
-	int process(const libcamera::FrameBuffer &source,
-		    CameraBuffer *destination,
-		    Camera3RequestDescriptor *request) override;
+	int process(Camera3RequestDescriptor::StreamBuffer *streamBuffer) override;
 
 private:
 	void generateThumbnail(const libcamera::FrameBuffer &source,