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592 lines
18 KiB
C
592 lines
18 KiB
C
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/*
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* wrjpgcom.c
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*
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* This file was part of the Independent JPEG Group's software:
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* Copyright (C) 1994-1997, Thomas G. Lane.
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* libjpeg-turbo Modifications:
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* Copyright (C) 2014, D. R. Commander.
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* For conditions of distribution and use, see the accompanying README.ijg
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* file.
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*
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* This file contains a very simple stand-alone application that inserts
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* user-supplied text as a COM (comment) marker in a JFIF file.
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* This may be useful as an example of the minimum logic needed to parse
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* JPEG markers.
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*/
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#define JPEG_CJPEG_DJPEG /* to get the command-line config symbols */
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#include "jinclude.h" /* get auto-config symbols, <stdio.h> */
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#ifndef HAVE_STDLIB_H /* <stdlib.h> should declare malloc() */
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extern void *malloc();
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#endif
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#include <ctype.h> /* to declare isupper(), tolower() */
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#ifdef USE_SETMODE
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#include <fcntl.h> /* to declare setmode()'s parameter macros */
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/* If you have setmode() but not <io.h>, just delete this line: */
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#include <io.h> /* to declare setmode() */
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#endif
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#ifdef USE_CCOMMAND /* command-line reader for Macintosh */
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#ifdef __MWERKS__
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#include <SIOUX.h> /* Metrowerks needs this */
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#include <console.h> /* ... and this */
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#endif
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#ifdef THINK_C
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#include <console.h> /* Think declares it here */
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#endif
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#endif
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#ifdef DONT_USE_B_MODE /* define mode parameters for fopen() */
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#define READ_BINARY "r"
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#define WRITE_BINARY "w"
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#else
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#define READ_BINARY "rb"
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#define WRITE_BINARY "wb"
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#endif
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#ifndef EXIT_FAILURE /* define exit() codes if not provided */
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#define EXIT_FAILURE 1
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#endif
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#ifndef EXIT_SUCCESS
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#define EXIT_SUCCESS 0
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#endif
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/* Reduce this value if your malloc() can't allocate blocks up to 64K.
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* On DOS, compiling in large model is usually a better solution.
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*/
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#ifndef MAX_COM_LENGTH
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#define MAX_COM_LENGTH 65000L /* must be <= 65533 in any case */
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#endif
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/*
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* These macros are used to read the input file and write the output file.
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* To reuse this code in another application, you might need to change these.
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*/
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static FILE *infile; /* input JPEG file */
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/* Return next input byte, or EOF if no more */
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#define NEXTBYTE() getc(infile)
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static FILE *outfile; /* output JPEG file */
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/* Emit an output byte */
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#define PUTBYTE(x) putc((x), outfile)
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/* Error exit handler */
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#define ERREXIT(msg) (fprintf(stderr, "%s\n", msg), exit(EXIT_FAILURE))
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/* Read one byte, testing for EOF */
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static int
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read_1_byte(void)
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{
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int c;
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c = NEXTBYTE();
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if (c == EOF)
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ERREXIT("Premature EOF in JPEG file");
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return c;
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}
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/* Read 2 bytes, convert to unsigned int */
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/* All 2-byte quantities in JPEG markers are MSB first */
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static unsigned int
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read_2_bytes(void)
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{
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int c1, c2;
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c1 = NEXTBYTE();
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if (c1 == EOF)
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ERREXIT("Premature EOF in JPEG file");
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c2 = NEXTBYTE();
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if (c2 == EOF)
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ERREXIT("Premature EOF in JPEG file");
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return (((unsigned int)c1) << 8) + ((unsigned int)c2);
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}
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/* Routines to write data to output file */
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static void
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write_1_byte(int c)
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{
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PUTBYTE(c);
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}
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static void
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write_2_bytes(unsigned int val)
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{
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PUTBYTE((val >> 8) & 0xFF);
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PUTBYTE(val & 0xFF);
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}
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static void
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write_marker(int marker)
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{
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PUTBYTE(0xFF);
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PUTBYTE(marker);
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}
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static void
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copy_rest_of_file(void)
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{
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int c;
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while ((c = NEXTBYTE()) != EOF)
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PUTBYTE(c);
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}
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/*
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* JPEG markers consist of one or more 0xFF bytes, followed by a marker
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* code byte (which is not an FF). Here are the marker codes of interest
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* in this program. (See jdmarker.c for a more complete list.)
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*/
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#define M_SOF0 0xC0 /* Start Of Frame N */
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#define M_SOF1 0xC1 /* N indicates which compression process */
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#define M_SOF2 0xC2 /* Only SOF0-SOF2 are now in common use */
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#define M_SOF3 0xC3
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#define M_SOF5 0xC5 /* NB: codes C4 and CC are NOT SOF markers */
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#define M_SOF6 0xC6
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#define M_SOF7 0xC7
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#define M_SOF9 0xC9
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#define M_SOF10 0xCA
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#define M_SOF11 0xCB
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#define M_SOF13 0xCD
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#define M_SOF14 0xCE
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#define M_SOF15 0xCF
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#define M_SOI 0xD8 /* Start Of Image (beginning of datastream) */
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#define M_EOI 0xD9 /* End Of Image (end of datastream) */
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#define M_SOS 0xDA /* Start Of Scan (begins compressed data) */
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#define M_COM 0xFE /* COMment */
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/*
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* Find the next JPEG marker and return its marker code.
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* We expect at least one FF byte, possibly more if the compressor used FFs
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* to pad the file. (Padding FFs will NOT be replicated in the output file.)
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* There could also be non-FF garbage between markers. The treatment of such
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* garbage is unspecified; we choose to skip over it but emit a warning msg.
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* NB: this routine must not be used after seeing SOS marker, since it will
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* not deal correctly with FF/00 sequences in the compressed image data...
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*/
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static int
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next_marker(void)
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{
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int c;
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int discarded_bytes = 0;
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/* Find 0xFF byte; count and skip any non-FFs. */
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c = read_1_byte();
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while (c != 0xFF) {
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discarded_bytes++;
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c = read_1_byte();
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}
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/* Get marker code byte, swallowing any duplicate FF bytes. Extra FFs
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* are legal as pad bytes, so don't count them in discarded_bytes.
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*/
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do {
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c = read_1_byte();
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} while (c == 0xFF);
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if (discarded_bytes != 0) {
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fprintf(stderr, "Warning: garbage data found in JPEG file\n");
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}
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return c;
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}
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/*
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* Read the initial marker, which should be SOI.
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* For a JFIF file, the first two bytes of the file should be literally
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* 0xFF M_SOI. To be more general, we could use next_marker, but if the
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* input file weren't actually JPEG at all, next_marker might read the whole
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* file and then return a misleading error message...
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*/
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static int
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first_marker(void)
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{
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int c1, c2;
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c1 = NEXTBYTE();
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c2 = NEXTBYTE();
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if (c1 != 0xFF || c2 != M_SOI)
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ERREXIT("Not a JPEG file");
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return c2;
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}
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/*
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* Most types of marker are followed by a variable-length parameter segment.
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* This routine skips over the parameters for any marker we don't otherwise
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* want to process.
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* Note that we MUST skip the parameter segment explicitly in order not to
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* be fooled by 0xFF bytes that might appear within the parameter segment;
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* such bytes do NOT introduce new markers.
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*/
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static void
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copy_variable(void)
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/* Copy an unknown or uninteresting variable-length marker */
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{
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unsigned int length;
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/* Get the marker parameter length count */
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length = read_2_bytes();
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write_2_bytes(length);
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/* Length includes itself, so must be at least 2 */
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if (length < 2)
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ERREXIT("Erroneous JPEG marker length");
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length -= 2;
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/* Copy the remaining bytes */
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while (length > 0) {
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write_1_byte(read_1_byte());
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length--;
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}
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}
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static void
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skip_variable(void)
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/* Skip over an unknown or uninteresting variable-length marker */
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{
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unsigned int length;
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/* Get the marker parameter length count */
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length = read_2_bytes();
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/* Length includes itself, so must be at least 2 */
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if (length < 2)
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ERREXIT("Erroneous JPEG marker length");
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length -= 2;
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/* Skip over the remaining bytes */
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while (length > 0) {
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(void)read_1_byte();
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length--;
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}
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}
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/*
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* Parse the marker stream until SOFn or EOI is seen;
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* copy data to output, but discard COM markers unless keep_COM is true.
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*/
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static int
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scan_JPEG_header(int keep_COM)
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{
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int marker;
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/* Expect SOI at start of file */
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if (first_marker() != M_SOI)
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ERREXIT("Expected SOI marker first");
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write_marker(M_SOI);
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/* Scan miscellaneous markers until we reach SOFn. */
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for (;;) {
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marker = next_marker();
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switch (marker) {
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/* Note that marker codes 0xC4, 0xC8, 0xCC are not, and must not be,
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* treated as SOFn. C4 in particular is actually DHT.
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*/
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case M_SOF0: /* Baseline */
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case M_SOF1: /* Extended sequential, Huffman */
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case M_SOF2: /* Progressive, Huffman */
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case M_SOF3: /* Lossless, Huffman */
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case M_SOF5: /* Differential sequential, Huffman */
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case M_SOF6: /* Differential progressive, Huffman */
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case M_SOF7: /* Differential lossless, Huffman */
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case M_SOF9: /* Extended sequential, arithmetic */
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case M_SOF10: /* Progressive, arithmetic */
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case M_SOF11: /* Lossless, arithmetic */
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case M_SOF13: /* Differential sequential, arithmetic */
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case M_SOF14: /* Differential progressive, arithmetic */
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case M_SOF15: /* Differential lossless, arithmetic */
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return marker;
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case M_SOS: /* should not see compressed data before SOF */
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ERREXIT("SOS without prior SOFn");
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break;
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case M_EOI: /* in case it's a tables-only JPEG stream */
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return marker;
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case M_COM: /* Existing COM: conditionally discard */
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if (keep_COM) {
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write_marker(marker);
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copy_variable();
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} else {
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skip_variable();
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}
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break;
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default: /* Anything else just gets copied */
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write_marker(marker);
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copy_variable(); /* we assume it has a parameter count... */
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break;
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}
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} /* end loop */
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}
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/* Command line parsing code */
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static const char *progname; /* program name for error messages */
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static void
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usage(void)
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/* complain about bad command line */
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{
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fprintf(stderr, "wrjpgcom inserts a textual comment in a JPEG file.\n");
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fprintf(stderr, "You can add to or replace any existing comment(s).\n");
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fprintf(stderr, "Usage: %s [switches] ", progname);
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#ifdef TWO_FILE_COMMANDLINE
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fprintf(stderr, "inputfile outputfile\n");
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#else
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fprintf(stderr, "[inputfile]\n");
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#endif
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fprintf(stderr, "Switches (names may be abbreviated):\n");
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fprintf(stderr, " -replace Delete any existing comments\n");
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fprintf(stderr, " -comment \"text\" Insert comment with given text\n");
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fprintf(stderr, " -cfile name Read comment from named file\n");
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fprintf(stderr, "Notice that you must put quotes around the comment text\n");
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fprintf(stderr, "when you use -comment.\n");
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fprintf(stderr, "If you do not give either -comment or -cfile on the command line,\n");
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fprintf(stderr, "then the comment text is read from standard input.\n");
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fprintf(stderr, "It can be multiple lines, up to %u characters total.\n",
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(unsigned int)MAX_COM_LENGTH);
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#ifndef TWO_FILE_COMMANDLINE
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fprintf(stderr, "You must specify an input JPEG file name when supplying\n");
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fprintf(stderr, "comment text from standard input.\n");
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#endif
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exit(EXIT_FAILURE);
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}
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static int
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keymatch(char *arg, const char *keyword, int minchars)
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/* Case-insensitive matching of (possibly abbreviated) keyword switches. */
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/* keyword is the constant keyword (must be lower case already), */
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/* minchars is length of minimum legal abbreviation. */
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{
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register int ca, ck;
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register int nmatched = 0;
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while ((ca = *arg++) != '\0') {
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if ((ck = *keyword++) == '\0')
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return 0; /* arg longer than keyword, no good */
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if (isupper(ca)) /* force arg to lcase (assume ck is already) */
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ca = tolower(ca);
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if (ca != ck)
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return 0; /* no good */
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nmatched++; /* count matched characters */
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}
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/* reached end of argument; fail if it's too short for unique abbrev */
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if (nmatched < minchars)
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return 0;
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return 1; /* A-OK */
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}
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/*
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* The main program.
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*/
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int
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main(int argc, char **argv)
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{
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int argn;
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char *arg;
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int keep_COM = 1;
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char *comment_arg = NULL;
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FILE *comment_file = NULL;
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unsigned int comment_length = 0;
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int marker;
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/* On Mac, fetch a command line. */
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#ifdef USE_CCOMMAND
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argc = ccommand(&argv);
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#endif
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progname = argv[0];
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if (progname == NULL || progname[0] == 0)
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progname = "wrjpgcom"; /* in case C library doesn't provide it */
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/* Parse switches, if any */
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for (argn = 1; argn < argc; argn++) {
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arg = argv[argn];
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if (arg[0] != '-')
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break; /* not switch, must be file name */
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arg++; /* advance over '-' */
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if (keymatch(arg, "replace", 1)) {
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keep_COM = 0;
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} else if (keymatch(arg, "cfile", 2)) {
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if (++argn >= argc) usage();
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if ((comment_file = fopen(argv[argn], "r")) == NULL) {
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fprintf(stderr, "%s: can't open %s\n", progname, argv[argn]);
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exit(EXIT_FAILURE);
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}
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} else if (keymatch(arg, "comment", 1)) {
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if (++argn >= argc) usage();
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comment_arg = argv[argn];
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/* If the comment text starts with '"', then we are probably running
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* under MS-DOG and must parse out the quoted string ourselves. Sigh.
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*/
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if (comment_arg[0] == '"') {
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||
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comment_arg = (char *)malloc((size_t)MAX_COM_LENGTH);
|
||
|
if (comment_arg == NULL)
|
||
|
ERREXIT("Insufficient memory");
|
||
|
if (strlen(argv[argn]) + 2 >= (size_t)MAX_COM_LENGTH) {
|
||
|
fprintf(stderr, "Comment text may not exceed %u bytes\n",
|
||
|
(unsigned int)MAX_COM_LENGTH);
|
||
|
exit(EXIT_FAILURE);
|
||
|
}
|
||
|
strcpy(comment_arg, argv[argn] + 1);
|
||
|
for (;;) {
|
||
|
comment_length = (unsigned int)strlen(comment_arg);
|
||
|
if (comment_length > 0 && comment_arg[comment_length - 1] == '"') {
|
||
|
comment_arg[comment_length - 1] = '\0'; /* zap terminating quote */
|
||
|
break;
|
||
|
}
|
||
|
if (++argn >= argc)
|
||
|
ERREXIT("Missing ending quote mark");
|
||
|
if (strlen(comment_arg) + strlen(argv[argn]) + 2 >=
|
||
|
(size_t)MAX_COM_LENGTH) {
|
||
|
fprintf(stderr, "Comment text may not exceed %u bytes\n",
|
||
|
(unsigned int)MAX_COM_LENGTH);
|
||
|
exit(EXIT_FAILURE);
|
||
|
}
|
||
|
strcat(comment_arg, " ");
|
||
|
strcat(comment_arg, argv[argn]);
|
||
|
}
|
||
|
} else if (strlen(argv[argn]) >= (size_t)MAX_COM_LENGTH) {
|
||
|
fprintf(stderr, "Comment text may not exceed %u bytes\n",
|
||
|
(unsigned int)MAX_COM_LENGTH);
|
||
|
exit(EXIT_FAILURE);
|
||
|
}
|
||
|
comment_length = (unsigned int)strlen(comment_arg);
|
||
|
} else
|
||
|
usage();
|
||
|
}
|
||
|
|
||
|
/* Cannot use both -comment and -cfile. */
|
||
|
if (comment_arg != NULL && comment_file != NULL)
|
||
|
usage();
|
||
|
/* If there is neither -comment nor -cfile, we will read the comment text
|
||
|
* from stdin; in this case there MUST be an input JPEG file name.
|
||
|
*/
|
||
|
if (comment_arg == NULL && comment_file == NULL && argn >= argc)
|
||
|
usage();
|
||
|
|
||
|
/* Open the input file. */
|
||
|
if (argn < argc) {
|
||
|
if ((infile = fopen(argv[argn], READ_BINARY)) == NULL) {
|
||
|
fprintf(stderr, "%s: can't open %s\n", progname, argv[argn]);
|
||
|
exit(EXIT_FAILURE);
|
||
|
}
|
||
|
} else {
|
||
|
/* default input file is stdin */
|
||
|
#ifdef USE_SETMODE /* need to hack file mode? */
|
||
|
setmode(fileno(stdin), O_BINARY);
|
||
|
#endif
|
||
|
#ifdef USE_FDOPEN /* need to re-open in binary mode? */
|
||
|
if ((infile = fdopen(fileno(stdin), READ_BINARY)) == NULL) {
|
||
|
fprintf(stderr, "%s: can't open stdin\n", progname);
|
||
|
exit(EXIT_FAILURE);
|
||
|
}
|
||
|
#else
|
||
|
infile = stdin;
|
||
|
#endif
|
||
|
}
|
||
|
|
||
|
/* Open the output file. */
|
||
|
#ifdef TWO_FILE_COMMANDLINE
|
||
|
/* Must have explicit output file name */
|
||
|
if (argn != argc - 2) {
|
||
|
fprintf(stderr, "%s: must name one input and one output file\n", progname);
|
||
|
usage();
|
||
|
}
|
||
|
if ((outfile = fopen(argv[argn + 1], WRITE_BINARY)) == NULL) {
|
||
|
fprintf(stderr, "%s: can't open %s\n", progname, argv[argn + 1]);
|
||
|
exit(EXIT_FAILURE);
|
||
|
}
|
||
|
#else
|
||
|
/* Unix style: expect zero or one file name */
|
||
|
if (argn < argc - 1) {
|
||
|
fprintf(stderr, "%s: only one input file\n", progname);
|
||
|
usage();
|
||
|
}
|
||
|
/* default output file is stdout */
|
||
|
#ifdef USE_SETMODE /* need to hack file mode? */
|
||
|
setmode(fileno(stdout), O_BINARY);
|
||
|
#endif
|
||
|
#ifdef USE_FDOPEN /* need to re-open in binary mode? */
|
||
|
if ((outfile = fdopen(fileno(stdout), WRITE_BINARY)) == NULL) {
|
||
|
fprintf(stderr, "%s: can't open stdout\n", progname);
|
||
|
exit(EXIT_FAILURE);
|
||
|
}
|
||
|
#else
|
||
|
outfile = stdout;
|
||
|
#endif
|
||
|
#endif /* TWO_FILE_COMMANDLINE */
|
||
|
|
||
|
/* Collect comment text from comment_file or stdin, if necessary */
|
||
|
if (comment_arg == NULL) {
|
||
|
FILE *src_file;
|
||
|
int c;
|
||
|
|
||
|
comment_arg = (char *)malloc((size_t)MAX_COM_LENGTH);
|
||
|
if (comment_arg == NULL)
|
||
|
ERREXIT("Insufficient memory");
|
||
|
comment_length = 0;
|
||
|
src_file = (comment_file != NULL ? comment_file : stdin);
|
||
|
while ((c = getc(src_file)) != EOF) {
|
||
|
if (comment_length >= (unsigned int)MAX_COM_LENGTH) {
|
||
|
fprintf(stderr, "Comment text may not exceed %u bytes\n",
|
||
|
(unsigned int)MAX_COM_LENGTH);
|
||
|
exit(EXIT_FAILURE);
|
||
|
}
|
||
|
comment_arg[comment_length++] = (char)c;
|
||
|
}
|
||
|
if (comment_file != NULL)
|
||
|
fclose(comment_file);
|
||
|
}
|
||
|
|
||
|
/* Copy JPEG headers until SOFn marker;
|
||
|
* we will insert the new comment marker just before SOFn.
|
||
|
* This (a) causes the new comment to appear after, rather than before,
|
||
|
* existing comments; and (b) ensures that comments come after any JFIF
|
||
|
* or JFXX markers, as required by the JFIF specification.
|
||
|
*/
|
||
|
marker = scan_JPEG_header(keep_COM);
|
||
|
/* Insert the new COM marker, but only if nonempty text has been supplied */
|
||
|
if (comment_length > 0) {
|
||
|
write_marker(M_COM);
|
||
|
write_2_bytes(comment_length + 2);
|
||
|
while (comment_length > 0) {
|
||
|
write_1_byte(*comment_arg++);
|
||
|
comment_length--;
|
||
|
}
|
||
|
}
|
||
|
/* Duplicate the remainder of the source file.
|
||
|
* Note that any COM markers occurring after SOF will not be touched.
|
||
|
*/
|
||
|
write_marker(marker);
|
||
|
copy_rest_of_file();
|
||
|
|
||
|
/* All done. */
|
||
|
exit(EXIT_SUCCESS);
|
||
|
return 0; /* suppress no-return-value warnings */
|
||
|
}
|