common/jpeg_compressor_impl.h

/*
 * Copyright 2018 The Chromium OS Authors. All rights reserved.
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#ifndef COMMON_JPEG_COMPRESSOR_IMPL_H_
#define COMMON_JPEG_COMPRESSOR_IMPL_H_

#include "cros-camera/jpeg_compressor.h"

// We must include cstdio before jpeglib.h. It is a requirement of libjpeg.
#include <cstdio>
#include <memory>
#include <string>
#include <vector>

extern "C" {
#include <jerror.h>
#include <jpeglib.h>
}

namespace cros {

class JpegEncodeAccelerator;

// Implementation of JpegCompressor. This class is not thread-safe.
class JpegCompressorImpl : public JpegCompressor {
 public:
  JpegCompressorImpl();
  ~JpegCompressorImpl() override;

  bool CompressImage(const void* image,
                     int width,
                     int height,
                     int quality,
                     const void* app1_buffer,
                     uint32_t app1_size,
                     uint32_t out_buffer_size,
                     void* out_buffer,
                     uint32_t* out_data_size,
                     JpegCompressor::Mode mode =
                         JpegCompressor::Mode::kDefault) override;

  bool GenerateThumbnail(const void* image,
                         int image_width,
                         int image_height,
                         int thumbnail_width,
                         int thumbnail_height,
                         int quality,
                         uint32_t out_buffer_size,
                         void* out_buffer,
                         uint32_t* out_data_size) override;

 private:
  // InitDestination(), EmptyOutputBuffer() and TerminateDestination() are
  // callback functions to be passed into jpeg library.
  static void InitDestination(j_compress_ptr cinfo);
  static boolean EmptyOutputBuffer(j_compress_ptr cinfo);
  static void TerminateDestination(j_compress_ptr cinfo);
  static void OutputErrorMessage(j_common_ptr cinfo);

  // Returns false if errors occur during HW encode.
  bool EncodeHw(const uint8_t* input_buffer,
                uint32_t input_buffer_size,
                int width,
                int height,
                const uint8_t* app1_buffer,
                uint32_t app1_size,
                uint32_t out_buffer_size,
                void* out_buffer,
                uint32_t* out_data_size);

  // Returns false if errors occur.
  bool Encode(const void* inYuv,
              int width,
              int height,
              int jpegQuality,
              const void* app1_buffer,
              unsigned int app1_size,
              uint32_t out_buffer_size,
              void* out_buffer,
              uint32_t* out_data_size);
  void SetJpegDestination(jpeg_compress_struct* cinfo);
  void SetJpegCompressStruct(int width,
                             int height,
                             int quality,
                             jpeg_compress_struct* cinfo);
  // Returns false if errors occur.
  bool Compress(jpeg_compress_struct* cinfo, const uint8_t* yuv);

  std::unique_ptr<cros::JpegEncodeAccelerator> hw_encoder_;
  bool hw_encoder_started_;

  // Process 16 lines of Y and 16 lines of U/V each time.
  // We must pass at least 16 scanlines according to libjpeg documentation.
  static const int kCompressBatchSize = 16;

  // Point to output buffer. JpegCompressorImpl doesn't own this buffer.
  JOCTET* out_buffer_ptr_;

  // Output buffer size.
  uint32_t out_buffer_size_;

  // Final JPEG encoded size.
  uint32_t out_data_size_;

  // Since output buffer is passed from caller, use a variable to indicate
  // buffer is enough to encode or not.
  bool is_encode_success_;
};

}  // namespace cros

#endif  // COMMON_JPEG_COMPRESSOR_IMPL_H_