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106 lines
3.5 KiB
106 lines
3.5 KiB
15 years ago
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/*
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* Copyright (C) 1991, 1992, Thomas G. Lane.
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* Part of the Independent JPEG Group's software.
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* See the file Copyright for more details.
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*
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* Copyright (c) 1993 Brian C. Smith, The Regents of the University
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* of California
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* All rights reserved.
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*
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* Copyright (c) 1994 Kongji Huang and Brian C. Smith.
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* Cornell University
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* All rights reserved.
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*
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* Permission to use, copy, modify, and distribute this software and its
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* documentation for any purpose, without fee, and without written agreement is
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* hereby granted, provided that the above copyright notice and the following
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* two paragraphs appear in all copies of this software.
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*
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* IN NO EVENT SHALL CORNELL UNIVERSITY BE LIABLE TO ANY PARTY FOR
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* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT
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* OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF CORNELL
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* UNIVERSITY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* CORNELL UNIVERSITY SPECIFICALLY DISCLAIMS ANY WARRANTIES,
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* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
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* AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
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* ON AN "AS IS" BASIS, AND CORNELL UNIVERSITY HAS NO OBLIGATION TO
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* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
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*/
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#ifndef _IO
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#define _IO
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/*
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* Size of the input and output buffer
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*/
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#define JPEG_BUF_SIZE 4096
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/*
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* The following variables keep track of the input and output
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* buffer for the JPEG data.
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*/
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extern char outputBuffer[JPEG_BUF_SIZE]; /* output buffer */
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extern int numOutputBytes; /* bytes in the output buffer */
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extern Uchar inputBuffer[JPEG_BUF_SIZE]; /* Input buffer for JPEG data */
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extern int numInputBytes; /* bytes in inputBuffer */
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extern int maxInputBytes; /* Size of inputBuffer */
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extern int inputBufferOffset; /* Offset of current byte */
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/*
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* the output file pointer.
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*/
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extern FILE *outFile;
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/*
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*--------------------------------------------------------------
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*
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* EmitByte --
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*
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* Write a single byte out to the output buffer, and
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* flush if it's full.
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*
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* Results:
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* None.
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*
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* Side effects:
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* The outp[ut buffer may get flushed.
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*
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*--------------------------------------------------------------
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*/
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#define EmitByte(val) { \
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if (numOutputBytes >= JPEG_BUF_SIZE) { \
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FlushBytes(); \
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} \
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outputBuffer[numOutputBytes++] = (char)(val); \
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}
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/*
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*--------------------------------------------------------------
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*
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* GetJpegChar, UnGetJpegChar --
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*
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* Macros to get the next character from the input stream.
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*
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* Results:
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* GetJpegChar returns the next character in the stream, or EOF
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* UnGetJpegChar returns nothing.
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*
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* Side effects:
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* A byte is consumed or put back into the inputBuffer.
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*
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*--------------------------------------------------------------
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*/
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#define GetJpegChar() \
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((inputBufferOffset < numInputBytes)? \
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inputBuffer[inputBufferOffset++]: \
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(numInputBytes = 2+ReadJpegData(inputBuffer+2,JPEG_BUF_SIZE-2), \
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inputBufferOffset = 2, \
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((inputBufferOffset < numInputBytes)? \
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inputBuffer[inputBufferOffset++]: \
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EOF)))
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#define UnGetJpegChar(ch) (inputBuffer[--inputBufferOffset]=(ch))
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#endif /* _IO */
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