android: jpeg: Support multi-planar buffers

The JPEG post-processor uses MappedFrameBuffer to access pixel data, but
only uses data from the first plane. Pass the vector of planes to the
encode() function to correctly handle multi-planar formats (currently
limited to NV12).

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

src/android/jpeg/encoder_libjpeg.cpp

@@ -103,9 +103,9 @@ int EncoderLibJpeg::configure(const StreamConfiguration &cfg)
 	return 0;
 }
 
-void EncoderLibJpeg::compressRGB(Span<const uint8_t> frame)
+void EncoderLibJpeg::compressRGB(const std::vector<Span<uint8_t>> &planes)
 {
-	unsigned char *src = const_cast<unsigned char *>(frame.data());
+	unsigned char *src = const_cast<unsigned char *>(planes[0].data());
 	/* \todo Stride information should come from buffer configuration. */
 	unsigned int stride = pixelFormatInfo_->stride(compress_.image_width, 0);
 
@@ -121,7 +121,7 @@ void EncoderLibJpeg::compressRGB(Span<const uint8_t> frame)
  * Compress the incoming buffer from a supported NV format.
  * This naively unpacks the semi-planar NV12 to a YUV888 format for libjpeg.
  */
-void EncoderLibJpeg::compressNV(Span<const uint8_t> frame)
+void EncoderLibJpeg::compressNV(const std::vector<Span<uint8_t>> &planes)
 {
 	uint8_t tmprowbuf[compress_.image_width * 3];
 
@@ -143,8 +143,8 @@ void EncoderLibJpeg::compressNV(Span<const uint8_t> frame)
 	unsigned int cb_pos = nvSwap_ ? 1 : 0;
 	unsigned int cr_pos = nvSwap_ ? 0 : 1;
 
-	const unsigned char *src = frame.data();
+	const unsigned char *src = planes[0].data();
-	const unsigned char *src_c = src + y_stride * compress_.image_height;
+	const unsigned char *src_c = planes[1].data();
 
 	JSAMPROW row_pointer[1];
 	row_pointer[0] = &tmprowbuf[0];
@@ -188,11 +188,12 @@ int EncoderLibJpeg::encode(const FrameBuffer &source, Span<uint8_t> dest,
 		return frame.error();
 	}
 
-	return encode(frame.planes()[0], dest, exifData, quality);
+	return encode(frame.planes(), dest, exifData, quality);
 }
 
-int EncoderLibJpeg::encode(Span<const uint8_t> src, Span<uint8_t> dest,
+int EncoderLibJpeg::encode(const std::vector<Span<uint8_t>> &src,
-			   Span<const uint8_t> exifData, unsigned int quality)
+			   Span<uint8_t> dest, Span<const uint8_t> exifData,
+			   unsigned int quality)
 {
 	unsigned char *destination = dest.data();
 	unsigned long size = dest.size();
@@ -220,6 +221,8 @@ int EncoderLibJpeg::encode(Span<const uint8_t> src, Span<uint8_t> dest,
 	LOG(JPEG, Debug) << "JPEG Encode Starting:" << compress_.image_width
 			 << "x" << compress_.image_height;
 
+	ASSERT(src.size() == pixelFormatInfo_->numPlanes());
+
 	if (nv_)
 		compressNV(src);
 	else

src/android/jpeg/encoder_libjpeg.h

@@ -9,6 +9,8 @@
 
 #include "encoder.h"
 
+#include <vector>
+
 #include "libcamera/internal/formats.h"
 
 #include <jpeglib.h>
@@ -24,14 +26,14 @@ public:
 		   libcamera::Span<uint8_t> destination,
 		   libcamera::Span<const uint8_t> exifData,
 		   unsigned int quality) override;
-	int encode(libcamera::Span<const uint8_t> source,
+	int encode(const std::vector<libcamera::Span<uint8_t>> &planes,
 		   libcamera::Span<uint8_t> destination,
 		   libcamera::Span<const uint8_t> exifData,
 		   unsigned int quality);
 
 private:
-	void compressRGB(libcamera::Span<const uint8_t> frame);
+	void compressRGB(const std::vector<libcamera::Span<uint8_t>> &planes);
-	void compressNV(libcamera::Span<const uint8_t> frame);
+	void compressNV(const std::vector<libcamera::Span<uint8_t>> &planes);
 
 	struct jpeg_compress_struct compress_;
 	struct jpeg_error_mgr jerr_;

src/android/jpeg/post_processor_jpeg.cpp

@@ -72,7 +72,7 @@ void PostProcessorJpeg::generateThumbnail(const FrameBuffer &source,
 		 */
 		thumbnail->resize(rawThumbnail.size());
 
-		int jpeg_size = thumbnailEncoder_.encode(rawThumbnail,
+		int jpeg_size = thumbnailEncoder_.encode({ rawThumbnail },
 							 *thumbnail, {}, quality);
 		thumbnail->resize(jpeg_size);
 

src/android/jpeg/thumbnailer.cpp

@@ -59,11 +59,12 @@ void Thumbnailer::createThumbnail(const FrameBuffer &source,
 	const unsigned int tw = targetSize.width;
 	const unsigned int th = targetSize.height;
 
+	ASSERT(frame.planes().size() == 2);
 	ASSERT(tw % 2 == 0 && th % 2 == 0);
 
 	/* Image scaling block implementing nearest-neighbour algorithm. */
-	unsigned char *src = static_cast<unsigned char *>(frame.planes()[0].data());
+	unsigned char *src = frame.planes()[0].data();
-	unsigned char *srcC = src + sh * sw;
+	unsigned char *srcC = frame.planes()[1].data();
 	unsigned char *srcCb, *srcCr;
 	unsigned char *dstY, *srcY;