📄 jdmarker.c
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*/
if (count > 256 || ((INT32) count) > length)
ERREXIT(cinfo, JERR_BAD_HUFF_TABLE);
for (i = 0; i < count; i++)
INPUT_BYTE(cinfo, huffval[i], return FALSE);
length -= count;
if (index & 0x10) { /* AC table definition */
index -= 0x10;
htblptr = &cinfo->ac_huff_tbl_ptrs[index];
} else { /* DC table definition */
htblptr = &cinfo->dc_huff_tbl_ptrs[index];
}
if (index < 0 || index >= NUM_HUFF_TBLS)
ERREXIT1(cinfo, JERR_DHT_INDEX, index);
if (*htblptr == NULL)
*htblptr = jpeg_alloc_huff_table((j_common_ptr) cinfo);
MEMCOPY((*htblptr)->bits, bits, SIZEOF((*htblptr)->bits));
MEMCOPY((*htblptr)->huffval, huffval, SIZEOF((*htblptr)->huffval));
}
if (length != 0)
ERREXIT(cinfo, JERR_BAD_LENGTH);
INPUT_SYNC(cinfo);
return TRUE;
}
LOCAL(boolean)
get_dqt (j_decompress_ptr cinfo)
/* Process a DQT marker */
{
INT32 length;
int n, i, prec;
unsigned int tmp;
JQUANT_TBL *quant_ptr;
INPUT_VARS(cinfo);
INPUT_2BYTES(cinfo, length, return FALSE);
length -= 2;
while (length > 0) {
INPUT_BYTE(cinfo, n, return FALSE);
prec = n >> 4;
n &= 0x0F;
TRACEMS2(cinfo, 1, JTRC_DQT, n, prec);
if (n >= NUM_QUANT_TBLS)
ERREXIT1(cinfo, JERR_DQT_INDEX, n);
if (cinfo->quant_tbl_ptrs[n] == NULL)
cinfo->quant_tbl_ptrs[n] = jpeg_alloc_quant_table((j_common_ptr) cinfo);
quant_ptr = cinfo->quant_tbl_ptrs[n];
for (i = 0; i < DCTSIZE2; i++) {
if (prec)
INPUT_2BYTES(cinfo, tmp, return FALSE);
else
INPUT_BYTE(cinfo, tmp, return FALSE);
/* We convert the zigzag-order table to natural array order. */
quant_ptr->quantval[jpeg_natural_order[i]] = (UINT16) tmp;
}
if (cinfo->err->trace_level >= 2) {
for (i = 0; i < DCTSIZE2; i += 8) {
TRACEMS8(cinfo, 2, JTRC_QUANTVALS,
quant_ptr->quantval[i], quant_ptr->quantval[i+1],
quant_ptr->quantval[i+2], quant_ptr->quantval[i+3],
quant_ptr->quantval[i+4], quant_ptr->quantval[i+5],
quant_ptr->quantval[i+6], quant_ptr->quantval[i+7]);
}
}
length -= DCTSIZE2+1;
if (prec) length -= DCTSIZE2;
}
if (length != 0)
ERREXIT(cinfo, JERR_BAD_LENGTH);
INPUT_SYNC(cinfo);
return TRUE;
}
LOCAL(boolean)
get_dri (j_decompress_ptr cinfo)
/* Process a DRI marker */
{
INT32 length;
unsigned int tmp;
INPUT_VARS(cinfo);
INPUT_2BYTES(cinfo, length, return FALSE);
if (length != 4)
ERREXIT(cinfo, JERR_BAD_LENGTH);
INPUT_2BYTES(cinfo, tmp, return FALSE);
TRACEMS1(cinfo, 1, JTRC_DRI, tmp);
cinfo->restart_interval = tmp;
INPUT_SYNC(cinfo);
return TRUE;
}
/*
* Routines for processing APPn and COM markers.
* These are either saved in memory or discarded, per application request.
* APP0 and APP14 are specially checked to see if they are
* JFIF and Adobe markers, respectively.
*/
#define APP0_DATA_LEN 14 /* Length of interesting data in APP0 */
#define APP14_DATA_LEN 12 /* Length of interesting data in APP14 */
#define APPN_DATA_LEN 14 /* Must be the largest of the above!! */
LOCAL(void)
examine_app0 (j_decompress_ptr cinfo, JOCTET FAR * data,
unsigned int datalen, INT32 remaining)
/* Examine first few bytes from an APP0.
* Take appropriate action if it is a JFIF marker.
* datalen is # of bytes at data[], remaining is length of rest of marker data.
*/
{
INT32 totallen = (INT32) datalen + remaining;
if (datalen >= APP0_DATA_LEN &&
GETJOCTET(data[0]) == 0x4A &&
GETJOCTET(data[1]) == 0x46 &&
GETJOCTET(data[2]) == 0x49 &&
GETJOCTET(data[3]) == 0x46 &&
GETJOCTET(data[4]) == 0) {
/* Found JFIF APP0 marker: save info */
cinfo->saw_JFIF_marker = TRUE;
cinfo->JFIF_major_version = GETJOCTET(data[5]);
cinfo->JFIF_minor_version = GETJOCTET(data[6]);
cinfo->density_unit = GETJOCTET(data[7]);
cinfo->X_density = (GETJOCTET(data[8]) << 8) + GETJOCTET(data[9]);
cinfo->Y_density = (GETJOCTET(data[10]) << 8) + GETJOCTET(data[11]);
/* Check version.
* Major version must be 1, anything else signals an incompatible change.
* (We used to treat this as an error, but now it's a nonfatal warning,
* because some bozo at Hijaak couldn't read the spec.)
* Minor version should be 0..2, but process anyway if newer.
*/
if (cinfo->JFIF_major_version != 1)
WARNMS2(cinfo, JWRN_JFIF_MAJOR,
cinfo->JFIF_major_version, cinfo->JFIF_minor_version);
/* Generate trace messages */
TRACEMS5(cinfo, 1, JTRC_JFIF,
cinfo->JFIF_major_version, cinfo->JFIF_minor_version,
cinfo->X_density, cinfo->Y_density, cinfo->density_unit);
/* Validate thumbnail dimensions and issue appropriate messages */
if (GETJOCTET(data[12]) | GETJOCTET(data[13]))
TRACEMS2(cinfo, 1, JTRC_JFIF_THUMBNAIL,
GETJOCTET(data[12]), GETJOCTET(data[13]));
totallen -= APP0_DATA_LEN;
if (totallen !=
((INT32)GETJOCTET(data[12]) * (INT32)GETJOCTET(data[13]) * (INT32) 3))
TRACEMS1(cinfo, 1, JTRC_JFIF_BADTHUMBNAILSIZE, (int) totallen);
} else if (datalen >= 6 &&
GETJOCTET(data[0]) == 0x4A &&
GETJOCTET(data[1]) == 0x46 &&
GETJOCTET(data[2]) == 0x58 &&
GETJOCTET(data[3]) == 0x58 &&
GETJOCTET(data[4]) == 0) {
/* Found JFIF "JFXX" extension APP0 marker */
/* The library doesn't actually do anything with these,
* but we try to produce a helpful trace message.
*/
switch (GETJOCTET(data[5])) {
case 0x10:
TRACEMS1(cinfo, 1, JTRC_THUMB_JPEG, (int) totallen);
break;
case 0x11:
TRACEMS1(cinfo, 1, JTRC_THUMB_PALETTE, (int) totallen);
break;
case 0x13:
TRACEMS1(cinfo, 1, JTRC_THUMB_RGB, (int) totallen);
break;
default:
TRACEMS2(cinfo, 1, JTRC_JFIF_EXTENSION,
GETJOCTET(data[5]), (int) totallen);
break;
}
} else {
/* Start of APP0 does not match "JFIF" or "JFXX", or too short */
TRACEMS1(cinfo, 1, JTRC_APP0, (int) totallen);
}
}
LOCAL(void)
examine_app14 (j_decompress_ptr cinfo, JOCTET FAR * data,
unsigned int datalen, INT32 remaining)
/* Examine first few bytes from an APP14.
* Take appropriate action if it is an Adobe marker.
* datalen is # of bytes at data[], remaining is length of rest of marker data.
*/
{
unsigned int version, flags0, flags1, transform;
if (datalen >= APP14_DATA_LEN &&
GETJOCTET(data[0]) == 0x41 &&
GETJOCTET(data[1]) == 0x64 &&
GETJOCTET(data[2]) == 0x6F &&
GETJOCTET(data[3]) == 0x62 &&
GETJOCTET(data[4]) == 0x65) {
/* Found Adobe APP14 marker */
version = (GETJOCTET(data[5]) << 8) + GETJOCTET(data[6]);
flags0 = (GETJOCTET(data[7]) << 8) + GETJOCTET(data[8]);
flags1 = (GETJOCTET(data[9]) << 8) + GETJOCTET(data[10]);
transform = GETJOCTET(data[11]);
TRACEMS4(cinfo, 1, JTRC_ADOBE, version, flags0, flags1, transform);
cinfo->saw_Adobe_marker = TRUE;
cinfo->Adobe_transform = (UINT8) transform;
} else {
/* Start of APP14 does not match "Adobe", or too short */
TRACEMS1(cinfo, 1, JTRC_APP14, (int) (datalen + remaining));
}
}
METHODDEF(boolean)
get_interesting_appn (j_decompress_ptr cinfo)
/* Process an APP0 or APP14 marker without saving it */
{
INT32 length;
JOCTET b[APPN_DATA_LEN];
unsigned int i, numtoread;
INPUT_VARS(cinfo);
INPUT_2BYTES(cinfo, length, return FALSE);
length -= 2;
/* get the interesting part of the marker data */
if (length >= APPN_DATA_LEN)
numtoread = APPN_DATA_LEN;
else if (length > 0)
numtoread = (unsigned int) length;
else
numtoread = 0;
for (i = 0; i < numtoread; i++)
INPUT_BYTE(cinfo, b[i], return FALSE);
length -= numtoread;
/* process it */
switch (cinfo->unread_marker) {
case M_APP0:
examine_app0(cinfo, (JOCTET FAR *) b, numtoread, length);
break;
case M_APP14:
examine_app14(cinfo, (JOCTET FAR *) b, numtoread, length);
break;
default:
/* can't get here unless jpeg_save_markers chooses wrong processor */
ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, cinfo->unread_marker);
break;
}
/* skip any remaining data -- could be lots */
INPUT_SYNC(cinfo);
if (length > 0)
(*cinfo->src->skip_input_data) (cinfo, (long) length);
return TRUE;
}
#ifdef SAVE_MARKERS_SUPPORTED
METHODDEF(boolean)
save_marker (j_decompress_ptr cinfo)
/* Save an APPn or COM marker into the marker list */
{
my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
jpeg_saved_marker_ptr cur_marker = marker->cur_marker;
unsigned int bytes_read, data_length;
JOCTET FAR * data;
INT32 length = 0;
INPUT_VARS(cinfo);
if (cur_marker == NULL) {
/* begin reading a marker */
INPUT_2BYTES(cinfo, length, return FALSE);
length -= 2;
if (length >= 0) { /* watch out for bogus length word */
/* figure out how much we want to save */
unsigned int limit;
if (cinfo->unread_marker == (int) M_COM)
limit = marker->length_limit_COM;
else
limit = marker->length_limit_APPn[cinfo->unread_marker - (int) M_APP0];
if ((unsigned int) length < limit)
limit = (unsigned int) length;
/* allocate and initialize the marker item */
cur_marker = (jpeg_saved_marker_ptr)
(*cinfo->mem->alloc_large) ((j_common_ptr) cinfo, JPOOL_IMAGE,
SIZEOF(struct jpeg_marker_struct) + limit);
cur_marker->next = NULL;
cur_marker->marker = (UINT8) cinfo->unread_marker;
cur_marker->original_length = (unsigned int) length;
cur_marker->data_length = limit;
/* data area is just beyond the jpeg_marker_struct */
data = cur_marker->data = (JOCTET FAR *) (cur_marker + 1);
marker->cur_marker = cur_marker;
marker->bytes_read = 0;
bytes_read = 0;
data_length = limit;
} else {
/* deal with bogus length word */
bytes_read = data_length = 0;
data = NULL;
}
} else {
/* resume reading a marker */
bytes_read = marker->bytes_read;
data_length = cur_marker->data_length;
data = cur_marker->data + bytes_read;
}
while (bytes_read < data_length) {
INPUT_SYNC(cinfo); /* move the restart point to here */
marker->bytes_read = bytes_read;
/* If there's not at least one byte in buffer, suspend */
MAKE_BYTE_AVAIL(cinfo, return FALSE);
/* Copy bytes with reasonable rapidity */
while (bytes_read < data_length && bytes_in_buffer > 0) {
*data++ = *next_input_byte++;
bytes_in_buffer--;
bytes_read++;
}
}
/* Done reading what we want to read */
if (cur_marker != NULL) { /* will be NULL if bogus length word */
/* Add new marker to end of list */
if (cinfo->marker_list == NULL) {
cinfo->marker_list = cur_marker;
} else {
jpeg_saved_marker_ptr prev = cinfo->marker_list;
while (prev->next != NULL)
prev = prev->next;
prev->next = cur_marker;
}
/* Reset pointer & calc remaining data length */
data = cur_marker->data;
length = cur_marker->original_length - data_length;
}
/* Reset to initial state for next marker */
marker->cur_marker = NULL;
/* Process the marker if interesting; else just make a generic trace msg */
switch (cinfo->unread_marker) {
case M_APP0:
examine_app0(cinfo, data, data_length, length);
break;
case M_APP14:
examine_app14(cinfo, data, data_length, length);
break;
default:
TRACEMS2(cinfo, 1, JTRC_MISC_MARKER, cinfo->unread_marker,
(int) (data_length + length));
break;
}
/* skip any remaining data -- could be lots */
INPUT_SYNC(cinfo); /* do before skip_input_data */
if (length > 0)
(*cinfo->src->skip_input_data) (cinfo, (long) length);
return TRUE;
}
#endif /* SAVE_MARKERS_SUPPORTED */
METHODDEF(boolean)
skip_variable (j_decompress_ptr cinfo)
/* Skip over an unknown or uninteresting variable-length marker */
{
INT32 length;
INPUT_VARS(cinfo);
INPUT_2BYTES(cinfo, length, return FALSE);
length -= 2;
TRACEMS2(cinfo, 1, JTRC_MISC_MARKER, cinfo->unread_marker, (int) length);
INPUT_SYNC(cinfo); /* do before skip_input_data */
if (length > 0)
(*cinfo->src->skip_input_data) (cinfo, (long) length);
return TRUE;
}
/*
* Find the next JPEG marker, save it in cinfo->unread_marker.
* Returns FALSE if had to suspend before reaching a marker;
* in that case cinfo->unread_marker is unchanged.
*
* Note that the result might not be a valid marker code,
* but it will never be 0 or FF.
*/
LOCAL(boolean)
next_marker (j_decompress_ptr cinfo)
{
int c;
INPUT_VARS(cinfo);
for (;;) {
INPUT_BYTE(cinfo, c, return FALSE);
/* Skip any non-FF bytes.
* This may look a bit inefficient, but it will not occur in a valid file.
* We sync after each discarded byte so that a suspending data source
* can discard the byte from its buffer.
*/
while (c != 0xFF) {
cinfo->marker->discarded_bytes++;
INPUT_SYNC(cinfo);
INPUT_BYTE(cinfo, c, return FALSE);
}
/* This loop swallows any duplicate FF bytes. Extra FFs are legal as
* pad bytes, so don't count them in discarded_bytes. We assume there
* will not be so many consecutive FF bytes as to overflow a suspending
* data source's input buffer.
*/
do {
INPUT_BYTE(cinfo, c, return FALSE);
} while (c == 0xFF);
if (c != 0)
break; /* found a valid marker, exit loop */
/* Reach here if we found a stuffed-zero data sequence (FF/00).
* Discard it and loop back to try again.
*/
cinfo->marker->discarded_bytes += 2;
INPUT_SYNC(cinfo);
}
if (cinfo->marker->discarded_bytes != 0) {
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