boolean
read_icc_profile (j_decompress_ptr cinfo,
JOCTET **icc_data_ptr,
unsigned int *icc_data_len)
{
jpeg_saved_marker_ptr marker;
int num_markers = 0;
int seq_no;
JOCTET *icc_data;
unsigned int total_length;
#define MAX_SEQ_NO 255 /* sufficient since marker numbers are bytes */
char marker_present[MAX_SEQ_NO+1]; /* 1 if marker found */
unsigned int data_length[MAX_SEQ_NO+1]; /* size of profile data in marker */
unsigned int data_offset[MAX_SEQ_NO+1]; /* offset for data in marker */
*icc_data_ptr = NULL; /* avoid confusion if FALSE return */
*icc_data_len = 0;
/* This first pass over the saved markers discovers whether there are
* any ICC markers and verifies the consistency of the marker numbering.
*/
for (seq_no = 1; seq_no <= MAX_SEQ_NO; seq_no++)
marker_present[seq_no] = 0;
for (marker = cinfo->marker_list; marker != NULL; marker = marker->next)
{
if (marker_is_icc(marker))
{
if (num_markers == 0)
num_markers = GETJOCTET(marker->data[13]);
else if (num_markers != GETJOCTET(marker->data[13]))
return FALSE; /* inconsistent num_markers fields */
seq_no = GETJOCTET(marker->data[12]);
if (seq_no <= 0 || seq_no > num_markers)
return FALSE; /* bogus sequence number */
if (marker_present[seq_no])
return FALSE; /* duplicate sequence numbers */
marker_present[seq_no] = 1;
data_length[seq_no] = marker->data_length - ICC_OVERHEAD_LEN;
}
}
if (num_markers == 0)
return FALSE;
/* Check for missing markers, count total space needed,
* compute offset of each marker's part of the data.
*/
total_length = 0;
for (seq_no = 1; seq_no <= num_markers; seq_no++)
{
if (marker_present[seq_no] == 0)
return FALSE; /* missing sequence number */
data_offset[seq_no] = total_length;
total_length += data_length[seq_no];
}
if (total_length <= 0)
return FALSE; /* found only empty markers? */
/* Allocate space for assembled data */
icc_data = (JOCTET *) calloc(total_length, sizeof(JOCTET));
if (icc_data == NULL)
return FALSE; /* oops, out of memory */
/* and fill it in */
for (marker = cinfo->marker_list; marker != NULL; marker = marker->next)
{
if (marker_is_icc(marker))
{
JOCTET FAR *src_ptr;
JOCTET *dst_ptr;
unsigned int length;
seq_no = GETJOCTET(marker->data[12]);
dst_ptr = icc_data + data_offset[seq_no];
src_ptr = marker->data + ICC_OVERHEAD_LEN;
length = data_length[seq_no];
while (length--)
{
*dst_ptr++ = *src_ptr++;
}
}
}
*icc_data_ptr = icc_data;
*icc_data_len = total_length;
return TRUE;
}
/**
See if there was an ICC profile in the JPEG file being read;
if so, reassemble and return the profile data.
TRUE is returned if an ICC profile was found, FALSE if not.
If TRUE is returned, *icc_data_ptr is set to point to the
returned data, and *icc_data_len is set to its length.
IMPORTANT: the data at **icc_data_ptr has been allocated with malloc()
and must be freed by the caller with free() when the caller no longer
needs it. (Alternatively, we could write this routine to use the
IJG library's memory allocator, so that the data would be freed implicitly
at jpeg_finish_decompress() time. But it seems likely that many apps
will prefer to have the data stick around after decompression finishes.)
NOTE: if the file contains invalid ICC APP2 markers, we just silently
return FALSE. You might want to issue an error message instead.
*/
static BOOL
jpeg_read_icc_profile(j_decompress_ptr cinfo, JOCTET **icc_data_ptr, unsigned *icc_data_len) {
jpeg_saved_marker_ptr marker;
int num_markers = 0;
int seq_no;
JOCTET *icc_data;
unsigned total_length;
const int MAX_SEQ_NO = 255; // sufficient since marker numbers are bytes
BYTE marker_present[MAX_SEQ_NO+1]; // 1 if marker found
unsigned data_length[MAX_SEQ_NO+1]; // size of profile data in marker
unsigned data_offset[MAX_SEQ_NO+1]; // offset for data in marker
*icc_data_ptr = NULL; // avoid confusion if FALSE return
*icc_data_len = 0;
/**
this first pass over the saved markers discovers whether there are
any ICC markers and verifies the consistency of the marker numbering.
*/
memset(marker_present, 0, (MAX_SEQ_NO + 1));
for(marker = cinfo->marker_list; marker != NULL; marker = marker->next) {
if (marker_is_icc(marker)) {
if (num_markers == 0) {
// number of markers
num_markers = GETJOCTET(marker->data[13]);
}
else if (num_markers != GETJOCTET(marker->data[13])) {
return FALSE; // inconsistent num_markers fields
}
// sequence number
seq_no = GETJOCTET(marker->data[12]);
if (seq_no <= 0 || seq_no > num_markers) {
return FALSE; // bogus sequence number
}
if (marker_present[seq_no]) {
return FALSE; // duplicate sequence numbers
}
marker_present[seq_no] = 1;
data_length[seq_no] = marker->data_length - ICC_HEADER_SIZE;
}
}
if (num_markers == 0)
return FALSE;
/**
check for missing markers, count total space needed,
compute offset of each marker's part of the data.
*/
total_length = 0;
for(seq_no = 1; seq_no <= num_markers; seq_no++) {
if (marker_present[seq_no] == 0) {
return FALSE; // missing sequence number
}
data_offset[seq_no] = total_length;
total_length += data_length[seq_no];
}
if (total_length <= 0)
return FALSE; // found only empty markers ?
// allocate space for assembled data
icc_data = (JOCTET *) malloc(total_length * sizeof(JOCTET));
if (icc_data == NULL)
return FALSE; // out of memory
// and fill it in
for (marker = cinfo->marker_list; marker != NULL; marker = marker->next) {
if (marker_is_icc(marker)) {
JOCTET FAR *src_ptr;
JOCTET *dst_ptr;
unsigned length;
seq_no = GETJOCTET(marker->data[12]);
dst_ptr = icc_data + data_offset[seq_no];
src_ptr = marker->data + ICC_HEADER_SIZE;
length = data_length[seq_no];
while (length--) {
*dst_ptr++ = *src_ptr++;
}
}
}
*icc_data_ptr = icc_data;
*icc_data_len = total_length;
return TRUE;
}