--- /dev/null
+/*
+ * read.c --
+ *
+ * Code for reading and processing JPEG markers. Large parts are grabbed
+ * from the IJG software
+ */
+/*
+ * $Id: read.c,v 1.1 2003/10/21 12:08:54 jpr Exp $
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "jpeg.h"
+#include "mcu.h"
+#include "io.h"
+#include "proto.h"
+
+/*
+ * To fix a memory leak (memory malloc'd then never freed) in the original
+ * version of lossless JPEG decompression, memory is allocated for 4
+ * Huffman tables once here, then pointers set later as needed
+ */
+
+HuffmanTable HuffmanTableMemory[4];
+
+/*
+ * Enumerate all the JPEG marker codes
+ */
+typedef enum {
+ M_SOF0 = 0xc0,
+ M_SOF1 = 0xc1,
+ M_SOF2 = 0xc2,
+ M_SOF3 = 0xc3,
+
+ M_SOF5 = 0xc5,
+ M_SOF6 = 0xc6,
+ M_SOF7 = 0xc7,
+
+ M_JPG = 0xc8,
+ M_SOF9 = 0xc9,
+ M_SOF10 = 0xca,
+ M_SOF11 = 0xcb,
+
+ M_SOF13 = 0xcd,
+ M_SOF14 = 0xce,
+ M_SOF15 = 0xcf,
+
+ M_DHT = 0xc4,
+
+ M_DAC = 0xcc,
+
+ M_RST0 = 0xd0,
+ M_RST1 = 0xd1,
+ M_RST2 = 0xd2,
+ M_RST3 = 0xd3,
+ M_RST4 = 0xd4,
+ M_RST5 = 0xd5,
+ M_RST6 = 0xd6,
+ M_RST7 = 0xd7,
+
+ M_SOI = 0xd8,
+ M_EOI = 0xd9,
+ M_SOS = 0xda,
+ M_DQT = 0xdb,
+ M_DNL = 0xdc,
+ M_DRI = 0xdd,
+ M_DHP = 0xde,
+ M_EXP = 0xdf,
+
+ M_APP0 = 0xe0,
+ M_APP15 = 0xef,
+
+ M_JPG0 = 0xf0,
+ M_JPG13 = 0xfd,
+ M_COM = 0xfe,
+
+ M_TEM = 0x01,
+
+ M_ERROR = 0x100
+} JpegMarker;
+
+
+/*
+ *--------------------------------------------------------------
+ *
+ * Get2bytes --
+ *
+ * Get a 2-byte unsigned integer (e.g., a marker parameter length
+ * field)
+ *
+ * Results:
+ * Next two byte of input as an integer.
+ *
+ * Side effects:
+ * Bitstream is parsed.
+ *
+ *--------------------------------------------------------------
+ */
+static Uint Get2bytes (void)
+{
+ int a;
+ a = GetJpegChar();
+ return (a << 8) + GetJpegChar();
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * SkipVariable --
+ *
+ * Skip over an unknown or uninteresting variable-length marker
+ *
+ * Results:
+ * None.
+ *
+ * Side effects:
+ * Bitstream is parsed over marker.
+ *
+ *
+ *--------------------------------------------------------------
+ */
+static void SkipVariable (DecompressInfo *dcPtr)
+{
+ int length;
+
+ length = Get2bytes () - 2;
+
+ while (length--) {
+ GetJpegChar();
+ }
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * GetDht --
+ *
+ * Process a DHT marker
+ *
+ * Results:
+ * None
+ *
+ * Side effects:
+ * A huffman table is read.
+ * Exits on error.
+ *
+ *--------------------------------------------------------------
+ */
+static void GetDht (DecompressInfo *dcPtr)
+{
+ int length;
+ Uchar bits[17];
+ Uchar huffval[256];
+ int i, index, count;
+ HuffmanTable **htblptr=NULL;
+
+ length = Get2bytes () - 2;
+
+ while (length) {
+ index = GetJpegChar();
+
+ bits[0] = 0;
+ count = 0;
+ for (i = 1; i <= 16; i++) {
+ bits[i] = GetJpegChar();
+ count += bits[i];
+ }
+
+ if (count > 256) {
+ fprintf (stderr, "Bogus DHT counts\n");
+ /* exit (1); */
+ dcPtr->error = -1; return;
+ }
+
+ for (i = 0; i < count; i++)
+ huffval[i] = GetJpegChar();
+
+ length -= 1 + 16 + count;
+
+ if (index & 0x10) { /* AC table definition */
+ fprintf(stderr,"Huffman table for lossless JPEG is not defined.\n");
+ }
+ else { /* DC table definition */
+ htblptr = &dcPtr->dcHuffTblPtrs[index];
+ }
+
+ if (index < 0 || index >= 4)
+ {
+ fprintf (stderr, "Bogus DHT index %d\n", index);
+ /* exit (1); */
+ dcPtr->error = -1; return;
+ }
+
+ if (*htblptr == NULL)
+ {
+ *htblptr = &HuffmanTableMemory[index];
+ if (*htblptr==NULL)
+ {
+ fprintf(stderr,"Can't malloc HuffmanTable\n");
+ /* exit(-1); */
+ dcPtr->error = -1; return;
+ }
+ }
+
+ MEMCPY((*htblptr)->bits, bits, sizeof ((*htblptr)->bits));
+ MEMCPY((*htblptr)->huffval, huffval, sizeof ((*htblptr)->huffval));
+ }
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * GetDri --
+ *
+ * Process a DRI marker
+ *
+ * Results:
+ * None
+ *
+ * Side effects:
+ * Exits on error.
+ * Bitstream is parsed.
+ *
+ *--------------------------------------------------------------
+ */
+static void GetDri (DecompressInfo *dcPtr)
+{
+ if (Get2bytes () != 4)
+ {
+ fprintf (stderr, "Bogus length in DRI\n");
+ /* exit (1); */
+ dcPtr->error = -1; return;
+ }
+
+ dcPtr->restartInterval = (Ushort) Get2bytes ();
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * GetApp0 --
+ *
+ * Process an APP0 marker.
+ *
+ * Results:
+ * None
+ *
+ * Side effects:
+ * Bitstream is parsed
+ *
+ *--------------------------------------------------------------
+ */
+static void GetApp0 (DecompressInfo *dcPtr)
+{
+ int length;
+
+ length = Get2bytes () - 2;
+ while (length-- > 0) /* skip any remaining data */
+ (void)GetJpegChar();
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * GetSof --
+ *
+ * Process a SOFn marker
+ *
+ * Results:
+ * None.
+ *
+ * Side effects:
+ * Bitstream is parsed
+ * Exits on error
+ * dcPtr structure is filled in
+ *
+ *--------------------------------------------------------------
+ */
+static void GetSof (DecompressInfo *dcPtr, int code)
+{
+ int length;
+ short ci;
+ int c;
+ JpegComponentInfo *compptr;
+
+ code = code;
+
+ length = Get2bytes ();
+
+ dcPtr->dataPrecision = GetJpegChar();
+ dcPtr->imageHeight = Get2bytes ();
+ dcPtr->imageWidth = Get2bytes ();
+ dcPtr->numComponents = GetJpegChar();
+
+ /*
+ * We don't support files in which the image height is initially
+ * specified as 0 and is later redefined by DNL. As long as we
+ * have to check that, might as well have a general sanity check.
+ */
+ if ((dcPtr->imageHeight <= 0 ) ||
+ (dcPtr->imageWidth <= 0) ||
+ (dcPtr->numComponents <= 0)) {
+ fprintf (stderr, "Empty JPEG image (DNL not supported)\n");
+ /* exit(1); */
+ dcPtr->error = -1; return;
+ }
+
+ if ((dcPtr->dataPrecision<MinPrecisionBits) ||
+ (dcPtr->dataPrecision>MaxPrecisionBits)) {
+ fprintf (stderr, "Unsupported JPEG data precision\n");
+ /* exit(1); */
+ dcPtr->error = -1; return;
+ }
+
+ if (length != (dcPtr->numComponents * 3 + 8)) {
+ fprintf (stderr, "Bogus SOF length\n");
+ /* exit (1); */
+ dcPtr->error = -1; return;
+ }
+
+ for (ci = 0; ci < dcPtr->numComponents; ci++) {
+ compptr = &dcPtr->compInfo[ci];
+ compptr->componentIndex = ci;
+ compptr->componentId = GetJpegChar();
+ c = GetJpegChar();
+ compptr->hSampFactor = (c >> 4) & 15;
+ compptr->vSampFactor = (c) & 15;
+ (void) GetJpegChar(); /* skip Tq */
+ }
+}/*endof GetSof */
+
+
+/*
+ *--------------------------------------------------------------
+ *
+ * GetSos --
+ *
+ * Process a SOS marker
+ *
+ * Results:
+ * None.
+ *
+ * Side effects:
+ * Bitstream is parsed.
+ * Exits on error.
+ *
+ *--------------------------------------------------------------
+ */
+static void GetSos (DecompressInfo *dcPtr)
+{
+ int length;
+ int i, ci, n, c, cc;
+ JpegComponentInfo *compptr;
+
+ length = Get2bytes ();
+
+ /*
+ * Get the number of image components.
+ */
+ n = GetJpegChar();
+ dcPtr->compsInScan = n;
+ length -= 3;
+
+ if (length != (n * 2 + 3) || n < 1 || n > 4) {
+ fprintf (stderr, "Bogus SOS length\n");
+ /* exit (1); */
+ dcPtr->error = -1; return;
+ }
+
+
+ for (i = 0; i < n; i++) {
+ cc = GetJpegChar();
+ c = GetJpegChar();
+ length -= 2;
+
+ for (ci = 0; ci < dcPtr->numComponents; ci++)
+ if (cc == dcPtr->compInfo[ci].componentId) {
+ break;
+ }
+
+ if (ci >= dcPtr->numComponents) {
+ fprintf (stderr, "Invalid component number in SOS\n");
+ /* exit (1); */
+ dcPtr->error = -1; return;
+ }
+
+ compptr = &dcPtr->compInfo[ci];
+ dcPtr->curCompInfo[i] = compptr;
+ compptr->dcTblNo = (c >> 4) & 15;
+ }
+
+ /*
+ * Get the PSV, skip Se, and get the point transform parameter.
+ */
+ dcPtr->Ss = GetJpegChar();
+ (void)GetJpegChar();
+ c = GetJpegChar();
+ dcPtr->Pt = c & 0x0F;
+}/*endof GetSos */
+
+
+/*
+ *--------------------------------------------------------------
+ *
+ * GetSoi --
+ *
+ * Process an SOI marker
+ *
+ * Results:
+ * None.
+ *
+ * Side effects:
+ * Bitstream is parsed.
+ * Exits on error.
+ *
+ *--------------------------------------------------------------
+ */
+static void GetSoi (DecompressInfo *dcPtr)
+{
+
+ /*
+ * Reset all parameters that are defined to be reset by SOI
+ */
+ dcPtr->restartInterval = 0;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * NextMarker --
+ *
+ * Find the next JPEG marker Note that the output might not
+ * be a valid marker code but it will never be 0 or FF
+ *
+ * Results:
+ * The marker found.
+ *
+ * Side effects:
+ * Bitstream is parsed.
+ *
+ *--------------------------------------------------------------
+ */
+static int NextMarker (void)
+{
+ int c, nbytes;
+
+ nbytes = 0;
+ do {
+ /*
+ * skip any non-FF bytes
+ */
+ do {
+ nbytes++;
+ c = GetJpegChar();
+ } while (c != 0xFF);
+ /*
+ * skip any duplicate FFs without incrementing nbytes, since
+ * extra FFs are legal
+ */
+ do {
+ c = GetJpegChar();
+ } while (c == 0xFF);
+ } while (c == 0); /* repeat if it was a stuffed FF/00 */
+
+ return c;
+}
+
+/*
+ *--------------------------------------------------------------
+ *
+ * ProcessTables --
+ *
+ * Scan and process JPEG markers that can appear in any order
+ * Return when an SOI, EOI, SOFn, or SOS is found
+ *
+ * Results:
+ * The marker found.
+ *
+ * Side effects:
+ * Bitstream is parsed.
+ *
+ *--------------------------------------------------------------
+ */
+static JpegMarker ProcessTables (dcPtr)
+ DecompressInfo *dcPtr;
+{
+ int c;
+
+ while (1) {
+ c = NextMarker ();
+
+ switch (c) {
+ case M_SOF0:
+ case M_SOF1:
+ case M_SOF2:
+ case M_SOF3:
+ case M_SOF5:
+ case M_SOF6:
+ case M_SOF7:
+ case M_JPG:
+ case M_SOF9:
+ case M_SOF10:
+ case M_SOF11:
+ case M_SOF13:
+ case M_SOF14:
+ case M_SOF15:
+ case M_SOI:
+ case M_EOI:
+ case M_SOS:
+ return ((JpegMarker)c);
+
+ case M_DHT:
+ GetDht (dcPtr); if (dcPtr->error) return 0;
+ break;
+
+ case M_DQT:
+ fprintf(stderr,"Not a lossless JPEG file.\n");
+ break;
+
+ case M_DRI:
+ GetDri (dcPtr); if (dcPtr->error) return 0;
+ break;
+
+ case M_APP0:
+ GetApp0 (dcPtr);
+ break;
+
+ case M_RST0: /* these are all parameterless */
+ case M_RST1:
+ case M_RST2:
+ case M_RST3:
+ case M_RST4:
+ case M_RST5:
+ case M_RST6:
+ case M_RST7:
+ case M_TEM:
+ fprintf (stderr, "Warning: unexpected marker 0x%02x\n", c);
+ break;
+
+ default: /* must be DNL, DHP, EXP, APPn, JPGn, COM,
+ * or RESn */
+ SkipVariable (dcPtr);
+ break;
+ }
+ }
+}/*endof ProcessTables */
+
+
+/*
+ *--------------------------------------------------------------
+ *
+ * ReadFileHeader --
+ *
+ * Initialize and read the file header (everything through
+ * the SOF marker).
+ *
+ * Results:
+ * None
+ *
+ * Side effects:
+ * Exit on error.
+ *
+ *--------------------------------------------------------------
+ */
+void ReadFileHeader (DecompressInfo *dcPtr)
+{
+ int c, c2;
+
+ /*
+ * Demand an SOI marker at the start of the file --- otherwise it's
+ * probably not a JPEG file at all.
+ */
+ c = GetJpegChar();
+ c2 = GetJpegChar();
+ if ((c != 0xFF) || (c2 != M_SOI)) {
+ if( c == EOF ) {
+ fprintf(stderr, "Reached end of input file. All done!\n");
+ /* fclose(outFile); */
+ /* exit(1); */
+ dcPtr->error = -1; return;
+ } else {
+ fprintf (stderr, "Not a JPEG file. Found %02X %02X\n", c, c2);
+ /* exit (1); */
+ dcPtr->error = -1; return;
+ }
+ }/*endif*/
+
+ GetSoi (dcPtr); if (dcPtr->error) return; /* OK, process SOI */
+
+ /*
+ * Process markers until SOF
+ */
+ c = ProcessTables (dcPtr); if (dcPtr->error) return;
+
+ switch (c) {
+ case M_SOF0:
+ case M_SOF1:
+ case M_SOF3:
+ GetSof (dcPtr, c);
+ break;
+
+ default:
+ fprintf (stderr, "Unsupported SOF marker type 0x%02x\n", c);
+ break;
+ }
+}/*endof ReadFileHeader*/
+
+
+/*
+ *--------------------------------------------------------------
+ *
+ * ReadScanHeader --
+ *
+ * Read the start of a scan (everything through the SOS marker).
+ *
+ * Results:
+ * 1 if find SOS, 0 if find EOI
+ *
+ * Side effects:
+ * Bitstream is parsed, may exit on errors.
+ *
+ *--------------------------------------------------------------
+ */
+int ReadScanHeader (DecompressInfo *dcPtr)
+{
+ int c;
+
+ /*
+ * Process markers until SOS or EOI
+ */
+ c = ProcessTables (dcPtr); if (dcPtr->error) return 0;
+
+ switch (c) {
+ case M_SOS:
+ GetSos (dcPtr);
+ return 1;
+
+ case M_EOI:
+ return 0;
+
+ default:
+ fprintf (stderr, "Unexpected marker 0x%02x\n", c);
+ break;
+ }
+ return 0;
+}/*endof ReadScanHeader*/
+
+
+/*
+ *--------------------------------------------------------------
+ *
+ * GetJpegChar, UnGetJpegChar --
+ *
+ *
+ * Results:
+ * GetJpegChar returns the next character in the stream, or EOF
+ * UnGetJpegChar returns nothing.
+ *
+ * Side effects:
+ * A byte is consumed or put back into the inputBuffer.
+ *
+ *--------------------------------------------------------------
+ */
+int GetJpegChar(void)
+{
+ return (int)inputBuffer[inputBufferOffset++];
+}
+
+void UnGetJpegChar(int ch)
+{
+ inputBuffer[--inputBufferOffset] = ch;
+}
+
git://git.creatis.insa-lyon.fr / gdcm.git / blobdiff