JpegCompressor.h revision ffd70fc8cda1d0279408ace869d3c326dd08edfa 
1/*
2 * Copyright (C) 2011 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#ifndef HW_EMULATOR_CAMERA_JPEG_COMPRESSOR_H
18#define HW_EMULATOR_CAMERA_JPEG_COMPRESSOR_H
19
20/*
21 * Contains declaration of a class NV21JpegCompressor that encapsulates a
22 * converter between YV21, and JPEG formats.
23 */
24
25#include <utils/threads.h>
26#include "JpegStub.h"
27
28namespace android {
29
30/* Encapsulates a converter between YV12, and JPEG formats.
31 */
32class NV21JpegCompressor {
33 public:
34  /* Constructs JpegCompressor instance. */
35  NV21JpegCompressor();
36  /* Destructs JpegCompressor instance. */
37  ~NV21JpegCompressor();
38
39  /****************************************************************************
40   * Public API
41   ***************************************************************************/
42
43 public:
44  /* Compresses raw NV21 image into a JPEG.
45   * The compressed image will be saved in mStream member of this class. Use
46   * getCompressedSize method to obtain buffer size of the compressed image,
47   * and getCompressedImage to copy out the compressed image.
48   * Param:
49   *  image - Raw NV21 image.
50   *  metadata - Image metadata (dimensions, location etc).
51   *  quality - JPEG quality.
52   * Return:
53   *  NO_ERROR on success, or an appropriate error status.
54   *
55   */
56  status_t compressRawImage(const void* image, const ImageMetadata* metadata,
57                            int quality);
58
59  /* Get size of the compressed JPEG buffer.
60   * This method must be called only after a successful completion of
61   * compressRawImage call.
62   * Return:
63   *  Size of the compressed JPEG buffer.
64   */
65  size_t getCompressedSize();
66
67  /* Copies out compressed JPEG buffer.
68   * This method must be called only after a successful completion of
69   * compressRawImage call.
70   * Param:
71   *  buff - Buffer where to copy the JPEG. Must be large enough to contain the
72   *      entire image.
73   */
74  void getCompressedImage(void* buff);
75
76  /****************************************************************************
77   * Class data
78   ***************************************************************************/
79
80 protected:
81  /* Strides for Y (the first element), and UV (the second one) panes. */
82  int mStrides[2];
83
84 private:
85  // library handle to dlopen
86  static void* mDl;
87  JpegStub mStub;
88};
89
90}; /* namespace android */
91
92#endif /* HW_EMULATOR_CAMERA_JPEG_COMPRESSOR_H */
93