Index: third_party/libjpeg_turbo/rdjpgcom.c |
=================================================================== |
--- third_party/libjpeg_turbo/rdjpgcom.c (revision 0) |
+++ third_party/libjpeg_turbo/rdjpgcom.c (revision 0) |
@@ -0,0 +1,496 @@ |
+/* |
+ * rdjpgcom.c |
+ * |
+ * Copyright (C) 1994-1997, Thomas G. Lane. |
+ * This file is part of the Independent JPEG Group's software. |
+ * For conditions of distribution and use, see the accompanying README file. |
+ * |
+ * This file contains a very simple stand-alone application that displays |
+ * the text in COM (comment) markers in a JFIF file. |
+ * This may be useful as an example of the minimum logic needed to parse |
+ * JPEG markers. |
+ */ |
+ |
+#define JPEG_CJPEG_DJPEG /* to get the command-line config symbols */ |
+#include "jinclude.h" /* get auto-config symbols, <stdio.h> */ |
+ |
+#include <ctype.h> /* to declare isupper(), tolower() */ |
+#ifdef USE_SETMODE |
+#include <fcntl.h> /* to declare setmode()'s parameter macros */ |
+/* If you have setmode() but not <io.h>, just delete this line: */ |
+#include <io.h> /* to declare setmode() */ |
+#endif |
+ |
+#ifdef USE_CCOMMAND /* command-line reader for Macintosh */ |
+#ifdef __MWERKS__ |
+#include <SIOUX.h> /* Metrowerks needs this */ |
+#include <console.h> /* ... and this */ |
+#endif |
+#ifdef THINK_C |
+#include <console.h> /* Think declares it here */ |
+#endif |
+#endif |
+ |
+#ifdef DONT_USE_B_MODE /* define mode parameters for fopen() */ |
+#define READ_BINARY "r" |
+#else |
+#ifdef VMS /* VMS is very nonstandard */ |
+#define READ_BINARY "rb", "ctx=stm" |
+#else /* standard ANSI-compliant case */ |
+#define READ_BINARY "rb" |
+#endif |
+#endif |
+ |
+#ifndef EXIT_FAILURE /* define exit() codes if not provided */ |
+#define EXIT_FAILURE 1 |
+#endif |
+#ifndef EXIT_SUCCESS |
+#ifdef VMS |
+#define EXIT_SUCCESS 1 /* VMS is very nonstandard */ |
+#else |
+#define EXIT_SUCCESS 0 |
+#endif |
+#endif |
+ |
+ |
+/* |
+ * These macros are used to read the input file. |
+ * To reuse this code in another application, you might need to change these. |
+ */ |
+ |
+static FILE * infile; /* input JPEG file */ |
+ |
+/* Return next input byte, or EOF if no more */ |
+#define NEXTBYTE() getc(infile) |
+ |
+ |
+/* Error exit handler */ |
+#define ERREXIT(msg) (fprintf(stderr, "%s\n", msg), exit(EXIT_FAILURE)) |
+ |
+ |
+/* Read one byte, testing for EOF */ |
+static int |
+read_1_byte (void) |
+{ |
+ int c; |
+ |
+ c = NEXTBYTE(); |
+ if (c == EOF) |
+ ERREXIT("Premature EOF in JPEG file"); |
+ return c; |
+} |
+ |
+/* Read 2 bytes, convert to unsigned int */ |
+/* All 2-byte quantities in JPEG markers are MSB first */ |
+static unsigned int |
+read_2_bytes (void) |
+{ |
+ int c1, c2; |
+ |
+ c1 = NEXTBYTE(); |
+ if (c1 == EOF) |
+ ERREXIT("Premature EOF in JPEG file"); |
+ c2 = NEXTBYTE(); |
+ if (c2 == EOF) |
+ ERREXIT("Premature EOF in JPEG file"); |
+ return (((unsigned int) c1) << 8) + ((unsigned int) c2); |
+} |
+ |
+ |
+/* |
+ * JPEG markers consist of one or more 0xFF bytes, followed by a marker |
+ * code byte (which is not an FF). Here are the marker codes of interest |
+ * in this program. (See jdmarker.c for a more complete list.) |
+ */ |
+ |
+#define M_SOF0 0xC0 /* Start Of Frame N */ |
+#define M_SOF1 0xC1 /* N indicates which compression process */ |
+#define M_SOF2 0xC2 /* Only SOF0-SOF2 are now in common use */ |
+#define M_SOF3 0xC3 |
+#define M_SOF5 0xC5 /* NB: codes C4 and CC are NOT SOF markers */ |
+#define M_SOF6 0xC6 |
+#define M_SOF7 0xC7 |
+#define M_SOF9 0xC9 |
+#define M_SOF10 0xCA |
+#define M_SOF11 0xCB |
+#define M_SOF13 0xCD |
+#define M_SOF14 0xCE |
+#define M_SOF15 0xCF |
+#define M_SOI 0xD8 /* Start Of Image (beginning of datastream) */ |
+#define M_EOI 0xD9 /* End Of Image (end of datastream) */ |
+#define M_SOS 0xDA /* Start Of Scan (begins compressed data) */ |
+#define M_APP0 0xE0 /* Application-specific marker, type N */ |
+#define M_APP12 0xEC /* (we don't bother to list all 16 APPn's) */ |
+#define M_COM 0xFE /* COMment */ |
+ |
+ |
+/* |
+ * Find the next JPEG marker and return its marker code. |
+ * We expect at least one FF byte, possibly more if the compressor used FFs |
+ * to pad the file. |
+ * There could also be non-FF garbage between markers. The treatment of such |
+ * garbage is unspecified; we choose to skip over it but emit a warning msg. |
+ * NB: this routine must not be used after seeing SOS marker, since it will |
+ * not deal correctly with FF/00 sequences in the compressed image data... |
+ */ |
+ |
+static int |
+next_marker (void) |
+{ |
+ int c; |
+ int discarded_bytes = 0; |
+ |
+ /* Find 0xFF byte; count and skip any non-FFs. */ |
+ c = read_1_byte(); |
+ while (c != 0xFF) { |
+ discarded_bytes++; |
+ c = read_1_byte(); |
+ } |
+ /* Get marker code byte, swallowing any duplicate FF bytes. Extra FFs |
+ * are legal as pad bytes, so don't count them in discarded_bytes. |
+ */ |
+ do { |
+ c = read_1_byte(); |
+ } while (c == 0xFF); |
+ |
+ if (discarded_bytes != 0) { |
+ fprintf(stderr, "Warning: garbage data found in JPEG file\n"); |
+ } |
+ |
+ return c; |
+} |
+ |
+ |
+/* |
+ * Read the initial marker, which should be SOI. |
+ * For a JFIF file, the first two bytes of the file should be literally |
+ * 0xFF M_SOI. To be more general, we could use next_marker, but if the |
+ * input file weren't actually JPEG at all, next_marker might read the whole |
+ * file and then return a misleading error message... |
+ */ |
+ |
+static int |
+first_marker (void) |
+{ |
+ int c1, c2; |
+ |
+ c1 = NEXTBYTE(); |
+ c2 = NEXTBYTE(); |
+ if (c1 != 0xFF || c2 != M_SOI) |
+ ERREXIT("Not a JPEG file"); |
+ return c2; |
+} |
+ |
+ |
+/* |
+ * Most types of marker are followed by a variable-length parameter segment. |
+ * This routine skips over the parameters for any marker we don't otherwise |
+ * want to process. |
+ * Note that we MUST skip the parameter segment explicitly in order not to |
+ * be fooled by 0xFF bytes that might appear within the parameter segment; |
+ * such bytes do NOT introduce new markers. |
+ */ |
+ |
+static void |
+skip_variable (void) |
+/* Skip over an unknown or uninteresting variable-length marker */ |
+{ |
+ unsigned int length; |
+ |
+ /* Get the marker parameter length count */ |
+ length = read_2_bytes(); |
+ /* Length includes itself, so must be at least 2 */ |
+ if (length < 2) |
+ ERREXIT("Erroneous JPEG marker length"); |
+ length -= 2; |
+ /* Skip over the remaining bytes */ |
+ while (length > 0) { |
+ (void) read_1_byte(); |
+ length--; |
+ } |
+} |
+ |
+ |
+/* |
+ * Process a COM marker. |
+ * We want to print out the marker contents as legible text; |
+ * we must guard against non-text junk and varying newline representations. |
+ */ |
+ |
+static void |
+process_COM (void) |
+{ |
+ unsigned int length; |
+ int ch; |
+ int lastch = 0; |
+ |
+ /* Get the marker parameter length count */ |
+ length = read_2_bytes(); |
+ /* Length includes itself, so must be at least 2 */ |
+ if (length < 2) |
+ ERREXIT("Erroneous JPEG marker length"); |
+ length -= 2; |
+ |
+ while (length > 0) { |
+ ch = read_1_byte(); |
+ /* Emit the character in a readable form. |
+ * Nonprintables are converted to \nnn form, |
+ * while \ is converted to \\. |
+ * Newlines in CR, CR/LF, or LF form will be printed as one newline. |
+ */ |
+ if (ch == '\r') { |
+ printf("\n"); |
+ } else if (ch == '\n') { |
+ if (lastch != '\r') |
+ printf("\n"); |
+ } else if (ch == '\\') { |
+ printf("\\\\"); |
+ } else if (isprint(ch)) { |
+ putc(ch, stdout); |
+ } else { |
+ printf("\\%03o", ch); |
+ } |
+ lastch = ch; |
+ length--; |
+ } |
+ printf("\n"); |
+} |
+ |
+ |
+/* |
+ * Process a SOFn marker. |
+ * This code is only needed if you want to know the image dimensions... |
+ */ |
+ |
+static void |
+process_SOFn (int marker) |
+{ |
+ unsigned int length; |
+ unsigned int image_height, image_width; |
+ int data_precision, num_components; |
+ const char * process; |
+ int ci; |
+ |
+ length = read_2_bytes(); /* usual parameter length count */ |
+ |
+ data_precision = read_1_byte(); |
+ image_height = read_2_bytes(); |
+ image_width = read_2_bytes(); |
+ num_components = read_1_byte(); |
+ |
+ switch (marker) { |
+ case M_SOF0: process = "Baseline"; break; |
+ case M_SOF1: process = "Extended sequential"; break; |
+ case M_SOF2: process = "Progressive"; break; |
+ case M_SOF3: process = "Lossless"; break; |
+ case M_SOF5: process = "Differential sequential"; break; |
+ case M_SOF6: process = "Differential progressive"; break; |
+ case M_SOF7: process = "Differential lossless"; break; |
+ case M_SOF9: process = "Extended sequential, arithmetic coding"; break; |
+ case M_SOF10: process = "Progressive, arithmetic coding"; break; |
+ case M_SOF11: process = "Lossless, arithmetic coding"; break; |
+ case M_SOF13: process = "Differential sequential, arithmetic coding"; break; |
+ case M_SOF14: process = "Differential progressive, arithmetic coding"; break; |
+ case M_SOF15: process = "Differential lossless, arithmetic coding"; break; |
+ default: process = "Unknown"; break; |
+ } |
+ |
+ printf("JPEG image is %uw * %uh, %d color components, %d bits per sample\n", |
+ image_width, image_height, num_components, data_precision); |
+ printf("JPEG process: %s\n", process); |
+ |
+ if (length != (unsigned int) (8 + num_components * 3)) |
+ ERREXIT("Bogus SOF marker length"); |
+ |
+ for (ci = 0; ci < num_components; ci++) { |
+ (void) read_1_byte(); /* Component ID code */ |
+ (void) read_1_byte(); /* H, V sampling factors */ |
+ (void) read_1_byte(); /* Quantization table number */ |
+ } |
+} |
+ |
+ |
+/* |
+ * Parse the marker stream until SOS or EOI is seen; |
+ * display any COM markers. |
+ * While the companion program wrjpgcom will always insert COM markers before |
+ * SOFn, other implementations might not, so we scan to SOS before stopping. |
+ * If we were only interested in the image dimensions, we would stop at SOFn. |
+ * (Conversely, if we only cared about COM markers, there would be no need |
+ * for special code to handle SOFn; we could treat it like other markers.) |
+ */ |
+ |
+static int |
+scan_JPEG_header (int verbose) |
+{ |
+ int marker; |
+ |
+ /* Expect SOI at start of file */ |
+ if (first_marker() != M_SOI) |
+ ERREXIT("Expected SOI marker first"); |
+ |
+ /* Scan miscellaneous markers until we reach SOS. */ |
+ for (;;) { |
+ marker = next_marker(); |
+ switch (marker) { |
+ /* Note that marker codes 0xC4, 0xC8, 0xCC are not, and must not be, |
+ * treated as SOFn. C4 in particular is actually DHT. |
+ */ |
+ case M_SOF0: /* Baseline */ |
+ case M_SOF1: /* Extended sequential, Huffman */ |
+ case M_SOF2: /* Progressive, Huffman */ |
+ case M_SOF3: /* Lossless, Huffman */ |
+ case M_SOF5: /* Differential sequential, Huffman */ |
+ case M_SOF6: /* Differential progressive, Huffman */ |
+ case M_SOF7: /* Differential lossless, Huffman */ |
+ case M_SOF9: /* Extended sequential, arithmetic */ |
+ case M_SOF10: /* Progressive, arithmetic */ |
+ case M_SOF11: /* Lossless, arithmetic */ |
+ case M_SOF13: /* Differential sequential, arithmetic */ |
+ case M_SOF14: /* Differential progressive, arithmetic */ |
+ case M_SOF15: /* Differential lossless, arithmetic */ |
+ if (verbose) |
+ process_SOFn(marker); |
+ else |
+ skip_variable(); |
+ break; |
+ |
+ case M_SOS: /* stop before hitting compressed data */ |
+ return marker; |
+ |
+ case M_EOI: /* in case it's a tables-only JPEG stream */ |
+ return marker; |
+ |
+ case M_COM: |
+ process_COM(); |
+ break; |
+ |
+ case M_APP12: |
+ /* Some digital camera makers put useful textual information into |
+ * APP12 markers, so we print those out too when in -verbose mode. |
+ */ |
+ if (verbose) { |
+ printf("APP12 contains:\n"); |
+ process_COM(); |
+ } else |
+ skip_variable(); |
+ break; |
+ |
+ default: /* Anything else just gets skipped */ |
+ skip_variable(); /* we assume it has a parameter count... */ |
+ break; |
+ } |
+ } /* end loop */ |
+} |
+ |
+ |
+/* Command line parsing code */ |
+ |
+static const char * progname; /* program name for error messages */ |
+ |
+ |
+static void |
+usage (void) |
+/* complain about bad command line */ |
+{ |
+ fprintf(stderr, "rdjpgcom displays any textual comments in a JPEG file.\n"); |
+ |
+ fprintf(stderr, "Usage: %s [switches] [inputfile]\n", progname); |
+ |
+ fprintf(stderr, "Switches (names may be abbreviated):\n"); |
+ fprintf(stderr, " -verbose Also display dimensions of JPEG image\n"); |
+ |
+ exit(EXIT_FAILURE); |
+} |
+ |
+ |
+static int |
+keymatch (char * arg, const char * keyword, int minchars) |
+/* Case-insensitive matching of (possibly abbreviated) keyword switches. */ |
+/* keyword is the constant keyword (must be lower case already), */ |
+/* minchars is length of minimum legal abbreviation. */ |
+{ |
+ register int ca, ck; |
+ register int nmatched = 0; |
+ |
+ while ((ca = *arg++) != '\0') { |
+ if ((ck = *keyword++) == '\0') |
+ return 0; /* arg longer than keyword, no good */ |
+ if (isupper(ca)) /* force arg to lcase (assume ck is already) */ |
+ ca = tolower(ca); |
+ if (ca != ck) |
+ return 0; /* no good */ |
+ nmatched++; /* count matched characters */ |
+ } |
+ /* reached end of argument; fail if it's too short for unique abbrev */ |
+ if (nmatched < minchars) |
+ return 0; |
+ return 1; /* A-OK */ |
+} |
+ |
+ |
+/* |
+ * The main program. |
+ */ |
+ |
+int |
+main (int argc, char **argv) |
+{ |
+ int argn; |
+ char * arg; |
+ int verbose = 0; |
+ |
+ /* On Mac, fetch a command line. */ |
+#ifdef USE_CCOMMAND |
+ argc = ccommand(&argv); |
+#endif |
+ |
+ progname = argv[0]; |
+ if (progname == NULL || progname[0] == 0) |
+ progname = "rdjpgcom"; /* in case C library doesn't provide it */ |
+ |
+ /* Parse switches, if any */ |
+ for (argn = 1; argn < argc; argn++) { |
+ arg = argv[argn]; |
+ if (arg[0] != '-') |
+ break; /* not switch, must be file name */ |
+ arg++; /* advance over '-' */ |
+ if (keymatch(arg, "verbose", 1)) { |
+ verbose++; |
+ } else |
+ usage(); |
+ } |
+ |
+ /* Open the input file. */ |
+ /* Unix style: expect zero or one file name */ |
+ if (argn < argc-1) { |
+ fprintf(stderr, "%s: only one input file\n", progname); |
+ usage(); |
+ } |
+ 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 |
+ } |
+ |
+ /* Scan the JPEG headers. */ |
+ (void) scan_JPEG_header(verbose); |
+ |
+ /* All done. */ |
+ exit(EXIT_SUCCESS); |
+ return 0; /* suppress no-return-value warnings */ |
+} |