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/yuv/post_processor_yuv.cpp

@@ -49,10 +49,11 @@ int PostProcessorYuv::configure(const StreamConfiguration &inCfg,
 	return 0;
 }
 
-int PostProcessorYuv::process(const FrameBuffer &source,
-			      CameraBuffer *destination,
-			      [[maybe_unused]] Camera3RequestDescriptor *request)
+int PostProcessorYuv::process(Camera3RequestDescriptor::StreamBuffer *streamBuffer)
 {
+	const FrameBuffer &source = *streamBuffer->srcBuffer;
+	CameraBuffer *destination = streamBuffer->dstBuffer.get();
+
 	if (!isValidBuffers(source, *destination))
 		return -EINVAL;
 

src/android/yuv/post_processor_yuv.h

@@ -18,9 +18,7 @@ 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:
 	bool isValidBuffers(const libcamera::FrameBuffer &source,