[libcamera-devel] [PATCH v2 28/27] android: jpeg: Support multi-planar buffers

[Laurent Pinchart]

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 at ideasonboard.com>
---
 src/android/jpeg/encoder_libjpeg.cpp     | 18 +++++++++---------
 src/android/jpeg/encoder_libjpeg.h       |  8 +++++---
 src/android/jpeg/post_processor_jpeg.cpp |  2 +-
 src/android/jpeg/thumbnailer.cpp         |  4 ++--
 4 files changed, 17 insertions(+), 15 deletions(-)

diff --git a/src/android/jpeg/encoder_libjpeg.cpp b/src/android/jpeg/encoder_libjpeg.cpp
index b8b01e20a001..7f63f36e793e 100644
--- a/src/android/jpeg/encoder_libjpeg.cpp
+++ b/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];
 
@@ -133,7 +133,6 @@ void EncoderLibJpeg::compressNV(Span<const uint8_t> frame)
 	 * Possible hints at:
 	 * https://sourceforge.net/p/libjpeg/mailman/message/30815123/
 	 */
-	unsigned int y_stride = pixelFormatInfo_->stride(compress_.image_width, 0);
 	unsigned int c_stride = pixelFormatInfo_->stride(compress_.image_width, 1);
 
 	unsigned int horzSubSample = 2 * compress_.image_width / c_stride;
@@ -143,8 +142,8 @@ 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_c = src + y_stride * compress_.image_height;
+	const unsigned char *src = planes[0].data();
+	const unsigned char *src_c = planes[1].data();
 
 	JSAMPROW row_pointer[1];
 	row_pointer[0] = &tmprowbuf[0];
@@ -188,11 +187,12 @@ 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,
-			   Span<const uint8_t> exifData, unsigned int quality)
+int EncoderLibJpeg::encode(const std::vector<Span<uint8_t>> &src,
+			   Span<uint8_t> dest, Span<const uint8_t> exifData,
+			   unsigned int quality)
 {
 	unsigned char *destination = dest.data();
 	unsigned long size = dest.size();
diff --git a/src/android/jpeg/encoder_libjpeg.h b/src/android/jpeg/encoder_libjpeg.h
index 61fbd1a69278..45ffbd7fae5d 100644
--- a/src/android/jpeg/encoder_libjpeg.h
+++ b/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 compressNV(libcamera::Span<const uint8_t> frame);
+	void compressRGB(const std::vector<libcamera::Span<uint8_t>> &planes);
+	void compressNV(const std::vector<libcamera::Span<uint8_t>> &planes);
 
 	struct jpeg_compress_struct compress_;
 	struct jpeg_error_mgr jerr_;
diff --git a/src/android/jpeg/post_processor_jpeg.cpp b/src/android/jpeg/post_processor_jpeg.cpp
index 3160a784419c..68d74842925d 100644
--- a/src/android/jpeg/post_processor_jpeg.cpp
+++ b/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);
 
diff --git a/src/android/jpeg/thumbnailer.cpp b/src/android/jpeg/thumbnailer.cpp
index 043c7b33f06a..2c341535de9e 100644
--- a/src/android/jpeg/thumbnailer.cpp
+++ b/src/android/jpeg/thumbnailer.cpp
@@ -62,8 +62,8 @@ void Thumbnailer::createThumbnail(const FrameBuffer &source,
 	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 *srcC = src + sh * sw;
+	unsigned char *src = frame.planes()[0].data();
+	unsigned char *srcC = frame.planes()[1].data();
 	unsigned char *srcCb, *srcCr;
 	unsigned char *dstY, *srcY;
 
-- 
Regards,

Laurent Pinchart