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/*
* Copyright (C) 2013 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef JPEG_READER_H_
#define JPEG_READER_H_
#include "jerr_hook.h"
#include "jni_defines.h"
#include "jpeg_config.h"
#include <stdint.h>
/**
* JpegReader wraps libjpeg's decompression functionality and a
* java InputStream object. Read calls return data from the
* InputStream that has been decompressed.
*/
class JpegReader {
public:
JpegReader();
~JpegReader();
/**
* Call setup with a valid InputStream reference and pixel format.
* If this method is successful, the contents of width and height will
* be set to the dimensions of the bitmap to be read.
*
* ***This method will result in the jpeg file header being read
* from the InputStream***
*
* Returns J_SUCCESS on success or a negative error code.
*/
int32_t setup(JNIEnv *env, jobject in, int32_t* width, int32_t* height,
Jpeg_Config::Format format);
/**
* Decompresses bytes from the InputStream and writes at most count
* bytes into the buffer, bytes, starting at some offset. Passing a
* NULL as the bytes pointer effectively skips those bytes.
*
* ***This method will result in bytes being read from the InputStream***
*
* Returns the number of bytes written into the input buffer or a
* negative error code.
*/
int32_t read(int8_t * bytes, int32_t offset, int32_t count);
/**
* Updates the environment pointer. Call this before read or reset
* in any jni function call.
*/
void updateEnv(JNIEnv *env);
/**
* Frees any java global references held by the JpegReader, destroys
* the decompress structure, and frees allocations in libjpeg's pools.
*/
int32_t reset();
private:
void formatPixels(uint8_t* buf, int32_t len);
struct jpeg_decompress_struct mInfo;
ErrManager mErrorManager;
JSAMPLE* mScanlineBuf;
JSAMPLE* mScanlineIter;
int32_t mScanlineBuflen;
int32_t mScanlineUnformattedBuflen;
int32_t mScanlineBytesRemaining;
Jpeg_Config::Format mFormat;
bool mFinished;
bool mSetup;
};
#endif // JPEG_READER_H_
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