1/*
2 * Copyright (C) 2013 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#ifndef JPEG_WRITER_H_
17#define JPEG_WRITER_H_
18
19#include "jerr_hook.h"
20#include "jni_defines.h"
21#include "jpeg_config.h"
22
23#include <stdint.h>
24
25/**
26 * JpegWriter wraps libjpeg's compression functionality and a
27 * java OutputStream object.  Write calls result in input data
28 * being compressed and written to the OuputStream.
29 */
30class JpegWriter {
31public:
32    JpegWriter();
33    ~JpegWriter();
34
35    /**
36     * Call setup with a valid OutputStream reference, bitmap height and
37     * width, pixel format, and compression quality in range (0, 100].
38     *
39     * Returns J_SUCCESS on success or a negative error code.
40     */
41    int32_t setup(JNIEnv *env, jobject out, int32_t width, int32_t height,
42            Jpeg_Config::Format format, int32_t quality);
43
44    /**
45     * Compresses bytes from the input buffer.
46     *
47     * ***This method will result in bytes being written to the OutputStream***
48     *
49     * Returns J_SUCCESS on success or a negative error code.
50     */
51    int32_t write(int8_t* bytes, int32_t length);
52
53    /**
54     * Updates the environment pointer.  Call this before write or reset
55     * in any jni function call.
56     */
57    void updateEnv(JNIEnv *env);
58
59    /**
60     * Frees any java global references held by the JpegWriter, destroys
61     * the compress structure, and frees allocations in libjpeg's pools.
62     */
63    int32_t reset();
64
65    static const int32_t DEFAULT_X_DENSITY;
66    static const int32_t DEFAULT_Y_DENSITY;
67    static const int32_t DEFAULT_DENSITY_UNIT;
68private:
69    void formatPixels(uint8_t* buf, int32_t len);
70    struct jpeg_compress_struct mInfo;
71    ErrManager mErrorManager;
72
73    JSAMPLE* mScanlineBuf;
74    JSAMPLE* mScanlineIter;
75    int32_t mScanlineBuflen;
76    int32_t mScanlineBytesRemaining;
77
78    Jpeg_Config::Format mFormat;
79    bool mFinished;
80    bool mSetup;
81};
82
83#endif // JPEG_WRITER_H_
84