0,0 → 1,1360 |
/* |
* jdmarker.c |
* |
* Copyright (C) 1991-1998, 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 routines to decode JPEG datastream markers. |
* Most of the complexity arises from our desire to support input |
* suspension: if not all of the data for a marker is available, |
* we must exit back to the application. On resumption, we reprocess |
* the marker. |
*/ |
|
#define JPEG_INTERNALS |
#include "jinclude.h" |
#include "jpeglib.h" |
|
|
typedef enum { /* JPEG marker codes */ |
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_APP1 = 0xe1, |
M_APP2 = 0xe2, |
M_APP3 = 0xe3, |
M_APP4 = 0xe4, |
M_APP5 = 0xe5, |
M_APP6 = 0xe6, |
M_APP7 = 0xe7, |
M_APP8 = 0xe8, |
M_APP9 = 0xe9, |
M_APP10 = 0xea, |
M_APP11 = 0xeb, |
M_APP12 = 0xec, |
M_APP13 = 0xed, |
M_APP14 = 0xee, |
M_APP15 = 0xef, |
|
M_JPG0 = 0xf0, |
M_JPG13 = 0xfd, |
M_COM = 0xfe, |
|
M_TEM = 0x01, |
|
M_ERROR = 0x100 |
} JPEG_MARKER; |
|
|
/* Private state */ |
|
typedef struct { |
struct jpeg_marker_reader pub; /* public fields */ |
|
/* Application-overridable marker processing methods */ |
jpeg_marker_parser_method process_COM; |
jpeg_marker_parser_method process_APPn[16]; |
|
/* Limit on marker data length to save for each marker type */ |
unsigned int length_limit_COM; |
unsigned int length_limit_APPn[16]; |
|
/* Status of COM/APPn marker saving */ |
jpeg_saved_marker_ptr cur_marker; /* NULL if not processing a marker */ |
unsigned int bytes_read; /* data bytes read so far in marker */ |
/* Note: cur_marker is not linked into marker_list until it's all read. */ |
} my_marker_reader; |
|
typedef my_marker_reader * my_marker_ptr; |
|
|
/* |
* Macros for fetching data from the data source module. |
* |
* At all times, cinfo->src->next_input_byte and ->bytes_in_buffer reflect |
* the current restart point; we update them only when we have reached a |
* suitable place to restart if a suspension occurs. |
*/ |
|
/* Declare and initialize local copies of input pointer/count */ |
#define INPUT_VARS(cinfo) \ |
struct jpeg_source_mgr * datasrc = (cinfo)->src; \ |
const JOCTET * next_input_byte = datasrc->next_input_byte; \ |
size_t bytes_in_buffer = datasrc->bytes_in_buffer |
|
/* Unload the local copies --- do this only at a restart boundary */ |
#define INPUT_SYNC(cinfo) \ |
( datasrc->next_input_byte = next_input_byte, \ |
datasrc->bytes_in_buffer = bytes_in_buffer ) |
|
/* Reload the local copies --- used only in MAKE_BYTE_AVAIL */ |
#define INPUT_RELOAD(cinfo) \ |
( next_input_byte = datasrc->next_input_byte, \ |
bytes_in_buffer = datasrc->bytes_in_buffer ) |
|
/* Internal macro for INPUT_BYTE and INPUT_2BYTES: make a byte available. |
* Note we do *not* do INPUT_SYNC before calling fill_input_buffer, |
* but we must reload the local copies after a successful fill. |
*/ |
#define MAKE_BYTE_AVAIL(cinfo,action) \ |
if (bytes_in_buffer == 0) { \ |
if (! (*datasrc->fill_input_buffer) (cinfo)) \ |
{ action; } \ |
INPUT_RELOAD(cinfo); \ |
} |
|
/* Read a byte into variable V. |
* If must suspend, take the specified action (typically "return FALSE"). |
*/ |
#define INPUT_BYTE(cinfo,V,action) \ |
MAKESTMT( MAKE_BYTE_AVAIL(cinfo,action); \ |
bytes_in_buffer--; \ |
V = GETJOCTET(*next_input_byte++); ) |
|
/* As above, but read two bytes interpreted as an unsigned 16-bit integer. |
* V should be declared unsigned int or perhaps INT32. |
*/ |
#define INPUT_2BYTES(cinfo,V,action) \ |
MAKESTMT( MAKE_BYTE_AVAIL(cinfo,action); \ |
bytes_in_buffer--; \ |
V = ((unsigned int) GETJOCTET(*next_input_byte++)) << 8; \ |
MAKE_BYTE_AVAIL(cinfo,action); \ |
bytes_in_buffer--; \ |
V += GETJOCTET(*next_input_byte++); ) |
|
|
/* |
* Routines to process JPEG markers. |
* |
* Entry condition: JPEG marker itself has been read and its code saved |
* in cinfo->unread_marker; input restart point is just after the marker. |
* |
* Exit: if return TRUE, have read and processed any parameters, and have |
* updated the restart point to point after the parameters. |
* If return FALSE, was forced to suspend before reaching end of |
* marker parameters; restart point has not been moved. Same routine |
* will be called again after application supplies more input data. |
* |
* This approach to suspension assumes that all of a marker's parameters |
* can fit into a single input bufferload. This should hold for "normal" |
* markers. Some COM/APPn markers might have large parameter segments |
* that might not fit. If we are simply dropping such a marker, we use |
* skip_input_data to get past it, and thereby put the problem on the |
* source manager's shoulders. If we are saving the marker's contents |
* into memory, we use a slightly different convention: when forced to |
* suspend, the marker processor updates the restart point to the end of |
* what it's consumed (ie, the end of the buffer) before returning FALSE. |
* On resumption, cinfo->unread_marker still contains the marker code, |
* but the data source will point to the next chunk of marker data. |
* The marker processor must retain internal state to deal with this. |
* |
* Note that we don't bother to avoid duplicate trace messages if a |
* suspension occurs within marker parameters. Other side effects |
* require more care. |
*/ |
|
|
LOCAL(boolean) |
get_soi (j_decompress_ptr cinfo) |
/* Process an SOI marker */ |
{ |
int i; |
|
TRACEMS(cinfo, 1, JTRC_SOI); |
|
if (cinfo->marker->saw_SOI) |
ERREXIT(cinfo, JERR_SOI_DUPLICATE); |
|
/* Reset all parameters that are defined to be reset by SOI */ |
|
for (i = 0; i < NUM_ARITH_TBLS; i++) { |
cinfo->arith_dc_L[i] = 0; |
cinfo->arith_dc_U[i] = 1; |
cinfo->arith_ac_K[i] = 5; |
} |
cinfo->restart_interval = 0; |
|
/* Set initial assumptions for colorspace etc */ |
|
cinfo->jpeg_color_space = JCS_UNKNOWN; |
cinfo->CCIR601_sampling = FALSE; /* Assume non-CCIR sampling??? */ |
|
cinfo->saw_JFIF_marker = FALSE; |
cinfo->JFIF_major_version = 1; /* set default JFIF APP0 values */ |
cinfo->JFIF_minor_version = 1; |
cinfo->density_unit = 0; |
cinfo->X_density = 1; |
cinfo->Y_density = 1; |
cinfo->saw_Adobe_marker = FALSE; |
cinfo->Adobe_transform = 0; |
|
cinfo->marker->saw_SOI = TRUE; |
|
return TRUE; |
} |
|
|
LOCAL(boolean) |
get_sof (j_decompress_ptr cinfo, boolean is_prog, boolean is_arith) |
/* Process a SOFn marker */ |
{ |
INT32 length; |
int c, ci; |
jpeg_component_info * compptr; |
INPUT_VARS(cinfo); |
|
cinfo->progressive_mode = is_prog; |
cinfo->arith_code = is_arith; |
|
INPUT_2BYTES(cinfo, length, return FALSE); |
|
INPUT_BYTE(cinfo, cinfo->data_precision, return FALSE); |
INPUT_2BYTES(cinfo, cinfo->image_height, return FALSE); |
INPUT_2BYTES(cinfo, cinfo->image_width, return FALSE); |
INPUT_BYTE(cinfo, cinfo->num_components, return FALSE); |
|
length -= 8; |
|
TRACEMS4(cinfo, 1, JTRC_SOF, cinfo->unread_marker, |
(int) cinfo->image_width, (int) cinfo->image_height, |
cinfo->num_components); |
|
if (cinfo->marker->saw_SOF) |
ERREXIT(cinfo, JERR_SOF_DUPLICATE); |
|
/* 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 (cinfo->image_height <= 0 || cinfo->image_width <= 0 |
|| cinfo->num_components <= 0) |
ERREXIT(cinfo, JERR_EMPTY_IMAGE); |
|
if (length != (cinfo->num_components * 3)) |
ERREXIT(cinfo, JERR_BAD_LENGTH); |
|
if (cinfo->comp_info == NULL) /* do only once, even if suspend */ |
cinfo->comp_info = (jpeg_component_info *) (*cinfo->mem->alloc_small) |
((j_common_ptr) cinfo, JPOOL_IMAGE, |
cinfo->num_components * SIZEOF(jpeg_component_info)); |
|
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; |
ci++, compptr++) { |
compptr->component_index = ci; |
INPUT_BYTE(cinfo, compptr->component_id, return FALSE); |
INPUT_BYTE(cinfo, c, return FALSE); |
compptr->h_samp_factor = (c >> 4) & 15; |
compptr->v_samp_factor = (c ) & 15; |
INPUT_BYTE(cinfo, compptr->quant_tbl_no, return FALSE); |
|
TRACEMS4(cinfo, 1, JTRC_SOF_COMPONENT, |
compptr->component_id, compptr->h_samp_factor, |
compptr->v_samp_factor, compptr->quant_tbl_no); |
} |
|
cinfo->marker->saw_SOF = TRUE; |
|
INPUT_SYNC(cinfo); |
return TRUE; |
} |
|
|
LOCAL(boolean) |
get_sos (j_decompress_ptr cinfo) |
/* Process a SOS marker */ |
{ |
INT32 length; |
int i, ci, n, c, cc; |
jpeg_component_info * compptr; |
INPUT_VARS(cinfo); |
|
if (! cinfo->marker->saw_SOF) |
ERREXIT(cinfo, JERR_SOS_NO_SOF); |
|
INPUT_2BYTES(cinfo, length, return FALSE); |
|
INPUT_BYTE(cinfo, n, return FALSE); /* Number of components */ |
|
TRACEMS1(cinfo, 1, JTRC_SOS, n); |
|
if (length != (n * 2 + 6) || n < 1 || n > MAX_COMPS_IN_SCAN) |
ERREXIT(cinfo, JERR_BAD_LENGTH); |
|
cinfo->comps_in_scan = n; |
|
/* Collect the component-spec parameters */ |
|
for (i = 0; i < n; i++) { |
INPUT_BYTE(cinfo, cc, return FALSE); |
INPUT_BYTE(cinfo, c, return FALSE); |
|
for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; |
ci++, compptr++) { |
if (cc == compptr->component_id) |
goto id_found; |
} |
|
ERREXIT1(cinfo, JERR_BAD_COMPONENT_ID, cc); |
|
id_found: |
|
cinfo->cur_comp_info[i] = compptr; |
compptr->dc_tbl_no = (c >> 4) & 15; |
compptr->ac_tbl_no = (c ) & 15; |
|
TRACEMS3(cinfo, 1, JTRC_SOS_COMPONENT, cc, |
compptr->dc_tbl_no, compptr->ac_tbl_no); |
} |
|
/* Collect the additional scan parameters Ss, Se, Ah/Al. */ |
INPUT_BYTE(cinfo, c, return FALSE); |
cinfo->Ss = c; |
INPUT_BYTE(cinfo, c, return FALSE); |
cinfo->Se = c; |
INPUT_BYTE(cinfo, c, return FALSE); |
cinfo->Ah = (c >> 4) & 15; |
cinfo->Al = (c ) & 15; |
|
TRACEMS4(cinfo, 1, JTRC_SOS_PARAMS, cinfo->Ss, cinfo->Se, |
cinfo->Ah, cinfo->Al); |
|
/* Prepare to scan data & restart markers */ |
cinfo->marker->next_restart_num = 0; |
|
/* Count another SOS marker */ |
cinfo->input_scan_number++; |
|
INPUT_SYNC(cinfo); |
return TRUE; |
} |
|
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#ifdef D_ARITH_CODING_SUPPORTED |
|
LOCAL(boolean) |
get_dac (j_decompress_ptr cinfo) |
/* Process a DAC marker */ |
{ |
INT32 length; |
int index, val; |
INPUT_VARS(cinfo); |
|
INPUT_2BYTES(cinfo, length, return FALSE); |
length -= 2; |
|
while (length > 0) { |
INPUT_BYTE(cinfo, index, return FALSE); |
INPUT_BYTE(cinfo, val, return FALSE); |
|
length -= 2; |
|
TRACEMS2(cinfo, 1, JTRC_DAC, index, val); |
|
if (index < 0 || index >= (2*NUM_ARITH_TBLS)) |
ERREXIT1(cinfo, JERR_DAC_INDEX, index); |
|
if (index >= NUM_ARITH_TBLS) { /* define AC table */ |
cinfo->arith_ac_K[index-NUM_ARITH_TBLS] = (UINT8) val; |
} else { /* define DC table */ |
cinfo->arith_dc_L[index] = (UINT8) (val & 0x0F); |
cinfo->arith_dc_U[index] = (UINT8) (val >> 4); |
if (cinfo->arith_dc_L[index] > cinfo->arith_dc_U[index]) |
ERREXIT1(cinfo, JERR_DAC_VALUE, val); |
} |
} |
|
if (length != 0) |
ERREXIT(cinfo, JERR_BAD_LENGTH); |
|
INPUT_SYNC(cinfo); |
return TRUE; |
} |
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#else /* ! D_ARITH_CODING_SUPPORTED */ |
|
#define get_dac(cinfo) skip_variable(cinfo) |
|
#endif /* D_ARITH_CODING_SUPPORTED */ |
|
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LOCAL(boolean) |
get_dht (j_decompress_ptr cinfo) |
/* Process a DHT marker */ |
{ |
INT32 length; |
UINT8 bits[17]; |
UINT8 huffval[256]; |
int i, index, count; |
JHUFF_TBL **htblptr; |
INPUT_VARS(cinfo); |
|
INPUT_2BYTES(cinfo, length, return FALSE); |
length -= 2; |
|
while (length > 16) { |
INPUT_BYTE(cinfo, index, return FALSE); |
|
TRACEMS1(cinfo, 1, JTRC_DHT, index); |
|
bits[0] = 0; |
count = 0; |
for (i = 1; i <= 16; i++) { |
INPUT_BYTE(cinfo, bits[i], return FALSE); |
count += bits[i]; |
} |
|
length -= 1 + 16; |
|
TRACEMS8(cinfo, 2, JTRC_HUFFBITS, |
bits[1], bits[2], bits[3], bits[4], |
bits[5], bits[6], bits[7], bits[8]); |
TRACEMS8(cinfo, 2, JTRC_HUFFBITS, |
bits[9], bits[10], bits[11], bits[12], |
bits[13], bits[14], bits[15], bits[16]); |
|
/* Here we just do minimal validation of the counts to avoid walking |
* off the end of our table space. jdhuff.c will check more carefully. |
*/ |
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) { |
WARNMS2(cinfo, JWRN_EXTRANEOUS_DATA, cinfo->marker->discarded_bytes, c); |
cinfo->marker->discarded_bytes = 0; |
} |
|
cinfo->unread_marker = c; |
|
INPUT_SYNC(cinfo); |
return TRUE; |
} |
|
|
LOCAL(boolean) |
first_marker (j_decompress_ptr cinfo) |
/* Like next_marker, but used to obtain the initial SOI marker. */ |
/* For this marker, we do not allow preceding garbage or fill; otherwise, |
* we might well scan an entire input file before realizing it ain't JPEG. |
* If an application wants to process non-JFIF files, it must seek to the |
* SOI before calling the JPEG library. |
*/ |
{ |
int c, c2; |
INPUT_VARS(cinfo); |
|
INPUT_BYTE(cinfo, c, return FALSE); |
INPUT_BYTE(cinfo, c2, return FALSE); |
if (c != 0xFF || c2 != (int) M_SOI) |
ERREXIT2(cinfo, JERR_NO_SOI, c, c2); |
|
cinfo->unread_marker = c2; |
|
INPUT_SYNC(cinfo); |
return TRUE; |
} |
|
|
/* |
* Read markers until SOS or EOI. |
* |
* Returns same codes as are defined for jpeg_consume_input: |
* JPEG_SUSPENDED, JPEG_REACHED_SOS, or JPEG_REACHED_EOI. |
*/ |
|
METHODDEF(int) |
read_markers (j_decompress_ptr cinfo) |
{ |
/* Outer loop repeats once for each marker. */ |
for (;;) { |
/* Collect the marker proper, unless we already did. */ |
/* NB: first_marker() enforces the requirement that SOI appear first. */ |
if (cinfo->unread_marker == 0) { |
if (! cinfo->marker->saw_SOI) { |
if (! first_marker(cinfo)) |
return JPEG_SUSPENDED; |
} else { |
if (! next_marker(cinfo)) |
return JPEG_SUSPENDED; |
} |
} |
/* At this point cinfo->unread_marker contains the marker code and the |
* input point is just past the marker proper, but before any parameters. |
* A suspension will cause us to return with this state still true. |
*/ |
switch (cinfo->unread_marker) { |
case M_SOI: |
if (! get_soi(cinfo)) |
return JPEG_SUSPENDED; |
break; |
|
case M_SOF0: /* Baseline */ |
case M_SOF1: /* Extended sequential, Huffman */ |
if (! get_sof(cinfo, FALSE, FALSE)) |
return JPEG_SUSPENDED; |
break; |
|
case M_SOF2: /* Progressive, Huffman */ |
if (! get_sof(cinfo, TRUE, FALSE)) |
return JPEG_SUSPENDED; |
break; |
|
case M_SOF9: /* Extended sequential, arithmetic */ |
if (! get_sof(cinfo, FALSE, TRUE)) |
return JPEG_SUSPENDED; |
break; |
|
case M_SOF10: /* Progressive, arithmetic */ |
if (! get_sof(cinfo, TRUE, TRUE)) |
return JPEG_SUSPENDED; |
break; |
|
/* Currently unsupported SOFn types */ |
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_JPG: /* Reserved for JPEG extensions */ |
case M_SOF11: /* Lossless, arithmetic */ |
case M_SOF13: /* Differential sequential, arithmetic */ |
case M_SOF14: /* Differential progressive, arithmetic */ |
case M_SOF15: /* Differential lossless, arithmetic */ |
ERREXIT1(cinfo, JERR_SOF_UNSUPPORTED, cinfo->unread_marker); |
break; |
|
case M_SOS: |
if (! get_sos(cinfo)) |
return JPEG_SUSPENDED; |
cinfo->unread_marker = 0; /* processed the marker */ |
return JPEG_REACHED_SOS; |
|
case M_EOI: |
TRACEMS(cinfo, 1, JTRC_EOI); |
cinfo->unread_marker = 0; /* processed the marker */ |
return JPEG_REACHED_EOI; |
|
case M_DAC: |
if (! get_dac(cinfo)) |
return JPEG_SUSPENDED; |
break; |
|
case M_DHT: |
if (! get_dht(cinfo)) |
return JPEG_SUSPENDED; |
break; |
|
case M_DQT: |
if (! get_dqt(cinfo)) |
return JPEG_SUSPENDED; |
break; |
|
case M_DRI: |
if (! get_dri(cinfo)) |
return JPEG_SUSPENDED; |
break; |
|
case M_APP0: |
case M_APP1: |
case M_APP2: |
case M_APP3: |
case M_APP4: |
case M_APP5: |
case M_APP6: |
case M_APP7: |
case M_APP8: |
case M_APP9: |
case M_APP10: |
case M_APP11: |
case M_APP12: |
case M_APP13: |
case M_APP14: |
case M_APP15: |
if (! (*((my_marker_ptr) cinfo->marker)->process_APPn[ |
cinfo->unread_marker - (int) M_APP0]) (cinfo)) |
return JPEG_SUSPENDED; |
break; |
|
case M_COM: |
if (! (*((my_marker_ptr) cinfo->marker)->process_COM) (cinfo)) |
return JPEG_SUSPENDED; |
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: |
TRACEMS1(cinfo, 1, JTRC_PARMLESS_MARKER, cinfo->unread_marker); |
break; |
|
case M_DNL: /* Ignore DNL ... perhaps the wrong thing */ |
if (! skip_variable(cinfo)) |
return JPEG_SUSPENDED; |
break; |
|
default: /* must be DHP, EXP, JPGn, or RESn */ |
/* For now, we treat the reserved markers as fatal errors since they are |
* likely to be used to signal incompatible JPEG Part 3 extensions. |
* Once the JPEG 3 version-number marker is well defined, this code |
* ought to change! |
*/ |
ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, cinfo->unread_marker); |
break; |
} |
/* Successfully processed marker, so reset state variable */ |
cinfo->unread_marker = 0; |
} /* end loop */ |
} |
|
|
/* |
* Read a restart marker, which is expected to appear next in the datastream; |
* if the marker is not there, take appropriate recovery action. |
* Returns FALSE if suspension is required. |
* |
* This is called by the entropy decoder after it has read an appropriate |
* number of MCUs. cinfo->unread_marker may be nonzero if the entropy decoder |
* has already read a marker from the data source. Under normal conditions |
* cinfo->unread_marker will be reset to 0 before returning; if not reset, |
* it holds a marker which the decoder will be unable to read past. |
*/ |
|
METHODDEF(boolean) |
read_restart_marker (j_decompress_ptr cinfo) |
{ |
/* Obtain a marker unless we already did. */ |
/* Note that next_marker will complain if it skips any data. */ |
if (cinfo->unread_marker == 0) { |
if (! next_marker(cinfo)) |
return FALSE; |
} |
|
if (cinfo->unread_marker == |
((int) M_RST0 + cinfo->marker->next_restart_num)) { |
/* Normal case --- swallow the marker and let entropy decoder continue */ |
TRACEMS1(cinfo, 3, JTRC_RST, cinfo->marker->next_restart_num); |
cinfo->unread_marker = 0; |
} else { |
/* Uh-oh, the restart markers have been messed up. */ |
/* Let the data source manager determine how to resync. */ |
if (! (*cinfo->src->resync_to_restart) (cinfo, |
cinfo->marker->next_restart_num)) |
return FALSE; |
} |
|
/* Update next-restart state */ |
cinfo->marker->next_restart_num = (cinfo->marker->next_restart_num + 1) & 7; |
|
return TRUE; |
} |
|
|
/* |
* This is the default resync_to_restart method for data source managers |
* to use if they don't have any better approach. Some data source managers |
* may be able to back up, or may have additional knowledge about the data |
* which permits a more intelligent recovery strategy; such managers would |
* presumably supply their own resync method. |
* |
* read_restart_marker calls resync_to_restart if it finds a marker other than |
* the restart marker it was expecting. (This code is *not* used unless |
* a nonzero restart interval has been declared.) cinfo->unread_marker is |
* the marker code actually found (might be anything, except 0 or FF). |
* The desired restart marker number (0..7) is passed as a parameter. |
* This routine is supposed to apply whatever error recovery strategy seems |
* appropriate in order to position the input stream to the next data segment. |
* Note that cinfo->unread_marker is treated as a marker appearing before |
* the current data-source input point; usually it should be reset to zero |
* before returning. |
* Returns FALSE if suspension is required. |
* |
* This implementation is substantially constrained by wanting to treat the |
* input as a data stream; this means we can't back up. Therefore, we have |
* only the following actions to work with: |
* 1. Simply discard the marker and let the entropy decoder resume at next |
* byte of file. |
* 2. Read forward until we find another marker, discarding intervening |
* data. (In theory we could look ahead within the current bufferload, |
* without having to discard data if we don't find the desired marker. |
* This idea is not implemented here, in part because it makes behavior |
* dependent on buffer size and chance buffer-boundary positions.) |
* 3. Leave the marker unread (by failing to zero cinfo->unread_marker). |
* This will cause the entropy decoder to process an empty data segment, |
* inserting dummy zeroes, and then we will reprocess the marker. |
* |
* #2 is appropriate if we think the desired marker lies ahead, while #3 is |
* appropriate if the found marker is a future restart marker (indicating |
* that we have missed the desired restart marker, probably because it got |
* corrupted). |
* We apply #2 or #3 if the found marker is a restart marker no more than |
* two counts behind or ahead of the expected one. We also apply #2 if the |
* found marker is not a legal JPEG marker code (it's certainly bogus data). |
* If the found marker is a restart marker more than 2 counts away, we do #1 |
* (too much risk that the marker is erroneous; with luck we will be able to |
* resync at some future point). |
* For any valid non-restart JPEG marker, we apply #3. This keeps us from |
* overrunning the end of a scan. An implementation limited to single-scan |
* files might find it better to apply #2 for markers other than EOI, since |
* any other marker would have to be bogus data in that case. |
*/ |
|
GLOBAL(boolean) |
jpeg_resync_to_restart (j_decompress_ptr cinfo, int desired) |
{ |
int marker = cinfo->unread_marker; |
int action = 1; |
|
/* Always put up a warning. */ |
WARNMS2(cinfo, JWRN_MUST_RESYNC, marker, desired); |
|
/* Outer loop handles repeated decision after scanning forward. */ |
for (;;) { |
if (marker < (int) M_SOF0) |
action = 2; /* invalid marker */ |
else if (marker < (int) M_RST0 || marker > (int) M_RST7) |
action = 3; /* valid non-restart marker */ |
else { |
if (marker == ((int) M_RST0 + ((desired+1) & 7)) || |
marker == ((int) M_RST0 + ((desired+2) & 7))) |
action = 3; /* one of the next two expected restarts */ |
else if (marker == ((int) M_RST0 + ((desired-1) & 7)) || |
marker == ((int) M_RST0 + ((desired-2) & 7))) |
action = 2; /* a prior restart, so advance */ |
else |
action = 1; /* desired restart or too far away */ |
} |
TRACEMS2(cinfo, 4, JTRC_RECOVERY_ACTION, marker, action); |
switch (action) { |
case 1: |
/* Discard marker and let entropy decoder resume processing. */ |
cinfo->unread_marker = 0; |
return TRUE; |
case 2: |
/* Scan to the next marker, and repeat the decision loop. */ |
if (! next_marker(cinfo)) |
return FALSE; |
marker = cinfo->unread_marker; |
break; |
case 3: |
/* Return without advancing past this marker. */ |
/* Entropy decoder will be forced to process an empty segment. */ |
return TRUE; |
} |
} /* end loop */ |
} |
|
|
/* |
* Reset marker processing state to begin a fresh datastream. |
*/ |
|
METHODDEF(void) |
reset_marker_reader (j_decompress_ptr cinfo) |
{ |
my_marker_ptr marker = (my_marker_ptr) cinfo->marker; |
|
cinfo->comp_info = NULL; /* until allocated by get_sof */ |
cinfo->input_scan_number = 0; /* no SOS seen yet */ |
cinfo->unread_marker = 0; /* no pending marker */ |
marker->pub.saw_SOI = FALSE; /* set internal state too */ |
marker->pub.saw_SOF = FALSE; |
marker->pub.discarded_bytes = 0; |
marker->cur_marker = NULL; |
} |
|
|
/* |
* Initialize the marker reader module. |
* This is called only once, when the decompression object is created. |
*/ |
|
GLOBAL(void) |
jinit_marker_reader (j_decompress_ptr cinfo) |
{ |
my_marker_ptr marker; |
int i; |
|
/* Create subobject in permanent pool */ |
marker = (my_marker_ptr) |
(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT, |
SIZEOF(my_marker_reader)); |
cinfo->marker = (struct jpeg_marker_reader *) marker; |
/* Initialize public method pointers */ |
marker->pub.reset_marker_reader = reset_marker_reader; |
marker->pub.read_markers = read_markers; |
marker->pub.read_restart_marker = read_restart_marker; |
/* Initialize COM/APPn processing. |
* By default, we examine and then discard APP0 and APP14, |
* but simply discard COM and all other APPn. |
*/ |
marker->process_COM = skip_variable; |
marker->length_limit_COM = 0; |
for (i = 0; i < 16; i++) { |
marker->process_APPn[i] = skip_variable; |
marker->length_limit_APPn[i] = 0; |
} |
marker->process_APPn[0] = get_interesting_appn; |
marker->process_APPn[14] = get_interesting_appn; |
/* Reset marker processing state */ |
reset_marker_reader(cinfo); |
} |
|
|
/* |
* Control saving of COM and APPn markers into marker_list. |
*/ |
|
#ifdef SAVE_MARKERS_SUPPORTED |
|
GLOBAL(void) |
jpeg_save_markers (j_decompress_ptr cinfo, int marker_code, |
unsigned int length_limit) |
{ |
my_marker_ptr marker = (my_marker_ptr) cinfo->marker; |
long maxlength; |
jpeg_marker_parser_method processor; |
|
/* Length limit mustn't be larger than what we can allocate |
* (should only be a concern in a 16-bit environment). |
*/ |
maxlength = cinfo->mem->max_alloc_chunk - SIZEOF(struct jpeg_marker_struct); |
if (((long) length_limit) > maxlength) |
length_limit = (unsigned int) maxlength; |
|
/* Choose processor routine to use. |
* APP0/APP14 have special requirements. |
*/ |
if (length_limit) { |
processor = save_marker; |
/* If saving APP0/APP14, save at least enough for our internal use. */ |
if (marker_code == (int) M_APP0 && length_limit < APP0_DATA_LEN) |
length_limit = APP0_DATA_LEN; |
else if (marker_code == (int) M_APP14 && length_limit < APP14_DATA_LEN) |
length_limit = APP14_DATA_LEN; |
} else { |
processor = skip_variable; |
/* If discarding APP0/APP14, use our regular on-the-fly processor. */ |
if (marker_code == (int) M_APP0 || marker_code == (int) M_APP14) |
processor = get_interesting_appn; |
} |
|
if (marker_code == (int) M_COM) { |
marker->process_COM = processor; |
marker->length_limit_COM = length_limit; |
} else if (marker_code >= (int) M_APP0 && marker_code <= (int) M_APP15) { |
marker->process_APPn[marker_code - (int) M_APP0] = processor; |
marker->length_limit_APPn[marker_code - (int) M_APP0] = length_limit; |
} else |
ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, marker_code); |
} |
|
#endif /* SAVE_MARKERS_SUPPORTED */ |
|
|
/* |
* Install a special processing method for COM or APPn markers. |
*/ |
|
GLOBAL(void) |
jpeg_set_marker_processor (j_decompress_ptr cinfo, int marker_code, |
jpeg_marker_parser_method routine) |
{ |
my_marker_ptr marker = (my_marker_ptr) cinfo->marker; |
|
if (marker_code == (int) M_COM) |
marker->process_COM = routine; |
else if (marker_code >= (int) M_APP0 && marker_code <= (int) M_APP15) |
marker->process_APPn[marker_code - (int) M_APP0] = routine; |
else |
ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, marker_code); |
} |