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.h

@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2020, Google Inc.
+ *
+ * encoder.h - Image encoding interface
+ */
+#ifndef __ANDROID_JPEG_ENCODER_H__
+#define __ANDROID_JPEG_ENCODER_H__
+
+#include <libcamera/buffer.h>
+#include <libcamera/span.h>
+#include <libcamera/stream.h>
+
+class Encoder
+{
+public:
+	virtual ~Encoder() {};
+
+	virtual int configure(const libcamera::StreamConfiguration &cfg) = 0;
+	virtual int encode(const libcamera::FrameBuffer *source,
+			   const libcamera::Span<uint8_t> &destination) = 0;
+};
+
+#endif /* __ANDROID_JPEG_ENCODER_H__ */