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 */ 30 class JpegWriter { 31 public: 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; 68 private: 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