android: Introduce JPEG encoding

Provide an encoder interface and implement a JPEG encoder using libjpeg.

Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

src/android/jpeg/encoder_libjpeg.h

@@ -0,0 +1,42 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2020, Google Inc.
+ *
+ * encoder_libjpeg.h - JPEG encoding using libjpeg
+ */
+#ifndef __ANDROID_JPEG_ENCODER_LIBJPEG_H__
+#define __ANDROID_JPEG_ENCODER_LIBJPEG_H__
+
+#include "encoder.h"
+
+#include "libcamera/internal/buffer.h"
+#include "libcamera/internal/formats.h"
+
+#include <jpeglib.h>
+
+class EncoderLibJpeg : public Encoder
+{
+public:
+	EncoderLibJpeg();
+	~EncoderLibJpeg();
+
+	int configure(const libcamera::StreamConfiguration &cfg) override;
+	int encode(const libcamera::FrameBuffer *source,
+		   const libcamera::Span<uint8_t> &destination) override;
+
+private:
+	void compressRGB(const libcamera::MappedBuffer *frame);
+	void compressNV(const libcamera::MappedBuffer *frame);
+
+	struct jpeg_compress_struct compress_;
+	struct jpeg_error_mgr jerr_;
+
+	unsigned int quality_;
+
+	const libcamera::PixelFormatInfo *pixelFormatInfo_;
+
+	bool nv_;
+	bool nvSwap_;
+};
+
+#endif /* __ANDROID_JPEG_ENCODER_LIBJPEG_H__ */