/*
*--------------------------------------------------------------
*
* 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 ();
}
/*
*--------------------------------------------------------------
*
* 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 */
/*
*--------------------------------------------------------------
*
* 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));
}
}
/*
*--------------------------------------------------------------
*
* 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();
}
/*
*--------------------------------------------------------------
*
* 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();
}
}
/*
*--------------------------------------------------------------
*
* 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 */
BMPHeader *loadBMPHeader( struct timidity_file *fp ) {
static BMPHeader h;
int i;
/* file header */
if ( (ugetc(fp) != 'B') || (ugetc(fp) != 'M') ) return NULL;
h.size = Get4bytes( fp ); /* size */
if ( h.size < 0 ) return NULL;
i = Get2bytes( fp ); /* reserved 1 */
i = Get2bytes( fp ); /* reserved 2 */
h.offbits = Get4bytes( fp ); /* offbits */
if ( h.offbits < 0 ) return NULL;
/* information header */
h.hsize = Get4bytes( fp ); /* header size */
if ( h.hsize < 0 ) return NULL;
if ( h.hsize == 40 ) {
h.w = Get4bytes( fp ); /* width */
h.h = Get4bytes( fp ); /* height */
} else {
h.w = Get2bytes( fp ); /* width */
h.h = Get2bytes( fp ); /* height */
}
if ( h.h < 0 ) return NULL;
i = Get2bytes( fp ); /* planes */
if ( i != 1 ) return NULL;
h.bitcounts = Get2bytes(fp); /* bit-counts */
if ( h.bitcounts != 4 && h.bitcounts != 8 && h.bitcounts != 24 )
return NULL;
if ( h.hsize==40 || h.hsize==64 ) {
i = Get4bytes( fp ); /* compress */
h.compress = i;
h.ncolors = ( h.offbits - h.hsize - 14 ) / 4;
/* colors */
} else {
h.ncolors = 0;
h.compress=0;
}
return &h;
}
