nuclear@2: /*
nuclear@2:  * jdmarker.c
nuclear@2:  *
nuclear@2:  * Copyright (C) 1991-1998, Thomas G. Lane.
nuclear@2:  * This file is part of the Independent JPEG Group's software.
nuclear@2:  * For conditions of distribution and use, see the accompanying README file.
nuclear@2:  *
nuclear@2:  * This file contains routines to decode JPEG datastream markers.
nuclear@2:  * Most of the complexity arises from our desire to support input
nuclear@2:  * suspension: if not all of the data for a marker is available,
nuclear@2:  * we must exit back to the application.  On resumption, we reprocess
nuclear@2:  * the marker.
nuclear@2:  */
nuclear@2: 
nuclear@2: #define JPEG_INTERNALS
nuclear@2: #include "jinclude.h"
nuclear@2: #include "jpeglib.h"
nuclear@2: 
nuclear@2: 
nuclear@2: typedef enum {			/* JPEG marker codes */
nuclear@2:   M_SOF0  = 0xc0,
nuclear@2:   M_SOF1  = 0xc1,
nuclear@2:   M_SOF2  = 0xc2,
nuclear@2:   M_SOF3  = 0xc3,
nuclear@2:   
nuclear@2:   M_SOF5  = 0xc5,
nuclear@2:   M_SOF6  = 0xc6,
nuclear@2:   M_SOF7  = 0xc7,
nuclear@2:   
nuclear@2:   M_JPG   = 0xc8,
nuclear@2:   M_SOF9  = 0xc9,
nuclear@2:   M_SOF10 = 0xca,
nuclear@2:   M_SOF11 = 0xcb,
nuclear@2:   
nuclear@2:   M_SOF13 = 0xcd,
nuclear@2:   M_SOF14 = 0xce,
nuclear@2:   M_SOF15 = 0xcf,
nuclear@2:   
nuclear@2:   M_DHT   = 0xc4,
nuclear@2:   
nuclear@2:   M_DAC   = 0xcc,
nuclear@2:   
nuclear@2:   M_RST0  = 0xd0,
nuclear@2:   M_RST1  = 0xd1,
nuclear@2:   M_RST2  = 0xd2,
nuclear@2:   M_RST3  = 0xd3,
nuclear@2:   M_RST4  = 0xd4,
nuclear@2:   M_RST5  = 0xd5,
nuclear@2:   M_RST6  = 0xd6,
nuclear@2:   M_RST7  = 0xd7,
nuclear@2:   
nuclear@2:   M_SOI   = 0xd8,
nuclear@2:   M_EOI   = 0xd9,
nuclear@2:   M_SOS   = 0xda,
nuclear@2:   M_DQT   = 0xdb,
nuclear@2:   M_DNL   = 0xdc,
nuclear@2:   M_DRI   = 0xdd,
nuclear@2:   M_DHP   = 0xde,
nuclear@2:   M_EXP   = 0xdf,
nuclear@2:   
nuclear@2:   M_APP0  = 0xe0,
nuclear@2:   M_APP1  = 0xe1,
nuclear@2:   M_APP2  = 0xe2,
nuclear@2:   M_APP3  = 0xe3,
nuclear@2:   M_APP4  = 0xe4,
nuclear@2:   M_APP5  = 0xe5,
nuclear@2:   M_APP6  = 0xe6,
nuclear@2:   M_APP7  = 0xe7,
nuclear@2:   M_APP8  = 0xe8,
nuclear@2:   M_APP9  = 0xe9,
nuclear@2:   M_APP10 = 0xea,
nuclear@2:   M_APP11 = 0xeb,
nuclear@2:   M_APP12 = 0xec,
nuclear@2:   M_APP13 = 0xed,
nuclear@2:   M_APP14 = 0xee,
nuclear@2:   M_APP15 = 0xef,
nuclear@2:   
nuclear@2:   M_JPG0  = 0xf0,
nuclear@2:   M_JPG13 = 0xfd,
nuclear@2:   M_COM   = 0xfe,
nuclear@2:   
nuclear@2:   M_TEM   = 0x01,
nuclear@2:   
nuclear@2:   M_ERROR = 0x100
nuclear@2: } JPEG_MARKER;
nuclear@2: 
nuclear@2: 
nuclear@2: /* Private state */
nuclear@2: 
nuclear@2: typedef struct {
nuclear@2:   struct jpeg_marker_reader pub; /* public fields */
nuclear@2: 
nuclear@2:   /* Application-overridable marker processing methods */
nuclear@2:   jpeg_marker_parser_method process_COM;
nuclear@2:   jpeg_marker_parser_method process_APPn[16];
nuclear@2: 
nuclear@2:   /* Limit on marker data length to save for each marker type */
nuclear@2:   unsigned int length_limit_COM;
nuclear@2:   unsigned int length_limit_APPn[16];
nuclear@2: 
nuclear@2:   /* Status of COM/APPn marker saving */
nuclear@2:   jpeg_saved_marker_ptr cur_marker;	/* NULL if not processing a marker */
nuclear@2:   unsigned int bytes_read;		/* data bytes read so far in marker */
nuclear@2:   /* Note: cur_marker is not linked into marker_list until it's all read. */
nuclear@2: } my_marker_reader;
nuclear@2: 
nuclear@2: typedef my_marker_reader * my_marker_ptr;
nuclear@2: 
nuclear@2: 
nuclear@2: /*
nuclear@2:  * Macros for fetching data from the data source module.
nuclear@2:  *
nuclear@2:  * At all times, cinfo->src->next_input_byte and ->bytes_in_buffer reflect
nuclear@2:  * the current restart point; we update them only when we have reached a
nuclear@2:  * suitable place to restart if a suspension occurs.
nuclear@2:  */
nuclear@2: 
nuclear@2: /* Declare and initialize local copies of input pointer/count */
nuclear@2: #define INPUT_VARS(cinfo)  \
nuclear@2: 	struct jpeg_source_mgr * datasrc = (cinfo)->src;  \
nuclear@2: 	const JOCTET * next_input_byte = datasrc->next_input_byte;  \
nuclear@2: 	size_t bytes_in_buffer = datasrc->bytes_in_buffer
nuclear@2: 
nuclear@2: /* Unload the local copies --- do this only at a restart boundary */
nuclear@2: #define INPUT_SYNC(cinfo)  \
nuclear@2: 	( datasrc->next_input_byte = next_input_byte,  \
nuclear@2: 	  datasrc->bytes_in_buffer = bytes_in_buffer )
nuclear@2: 
nuclear@2: /* Reload the local copies --- used only in MAKE_BYTE_AVAIL */
nuclear@2: #define INPUT_RELOAD(cinfo)  \
nuclear@2: 	( next_input_byte = datasrc->next_input_byte,  \
nuclear@2: 	  bytes_in_buffer = datasrc->bytes_in_buffer )
nuclear@2: 
nuclear@2: /* Internal macro for INPUT_BYTE and INPUT_2BYTES: make a byte available.
nuclear@2:  * Note we do *not* do INPUT_SYNC before calling fill_input_buffer,
nuclear@2:  * but we must reload the local copies after a successful fill.
nuclear@2:  */
nuclear@2: #define MAKE_BYTE_AVAIL(cinfo,action)  \
nuclear@2: 	if (bytes_in_buffer == 0) {  \
nuclear@2: 	  if (! (*datasrc->fill_input_buffer) (cinfo))  \
nuclear@2: 	    { action; }  \
nuclear@2: 	  INPUT_RELOAD(cinfo);  \
nuclear@2: 	}
nuclear@2: 
nuclear@2: /* Read a byte into variable V.
nuclear@2:  * If must suspend, take the specified action (typically "return FALSE").
nuclear@2:  */
nuclear@2: #define INPUT_BYTE(cinfo,V,action)  \
nuclear@2: 	MAKESTMT( MAKE_BYTE_AVAIL(cinfo,action); \
nuclear@2: 		  bytes_in_buffer--; \
nuclear@2: 		  V = GETJOCTET(*next_input_byte++); )
nuclear@2: 
nuclear@2: /* As above, but read two bytes interpreted as an unsigned 16-bit integer.
nuclear@2:  * V should be declared unsigned int or perhaps INT32.
nuclear@2:  */
nuclear@2: #define INPUT_2BYTES(cinfo,V,action)  \
nuclear@2: 	MAKESTMT( MAKE_BYTE_AVAIL(cinfo,action); \
nuclear@2: 		  bytes_in_buffer--; \
nuclear@2: 		  V = ((unsigned int) GETJOCTET(*next_input_byte++)) << 8; \
nuclear@2: 		  MAKE_BYTE_AVAIL(cinfo,action); \
nuclear@2: 		  bytes_in_buffer--; \
nuclear@2: 		  V += GETJOCTET(*next_input_byte++); )
nuclear@2: 
nuclear@2: 
nuclear@2: /*
nuclear@2:  * Routines to process JPEG markers.
nuclear@2:  *
nuclear@2:  * Entry condition: JPEG marker itself has been read and its code saved
nuclear@2:  *   in cinfo->unread_marker; input restart point is just after the marker.
nuclear@2:  *
nuclear@2:  * Exit: if return TRUE, have read and processed any parameters, and have
nuclear@2:  *   updated the restart point to point after the parameters.
nuclear@2:  *   If return FALSE, was forced to suspend before reaching end of
nuclear@2:  *   marker parameters; restart point has not been moved.  Same routine
nuclear@2:  *   will be called again after application supplies more input data.
nuclear@2:  *
nuclear@2:  * This approach to suspension assumes that all of a marker's parameters
nuclear@2:  * can fit into a single input bufferload.  This should hold for "normal"
nuclear@2:  * markers.  Some COM/APPn markers might have large parameter segments
nuclear@2:  * that might not fit.  If we are simply dropping such a marker, we use
nuclear@2:  * skip_input_data to get past it, and thereby put the problem on the
nuclear@2:  * source manager's shoulders.  If we are saving the marker's contents
nuclear@2:  * into memory, we use a slightly different convention: when forced to
nuclear@2:  * suspend, the marker processor updates the restart point to the end of
nuclear@2:  * what it's consumed (ie, the end of the buffer) before returning FALSE.
nuclear@2:  * On resumption, cinfo->unread_marker still contains the marker code,
nuclear@2:  * but the data source will point to the next chunk of marker data.
nuclear@2:  * The marker processor must retain internal state to deal with this.
nuclear@2:  *
nuclear@2:  * Note that we don't bother to avoid duplicate trace messages if a
nuclear@2:  * suspension occurs within marker parameters.  Other side effects
nuclear@2:  * require more care.
nuclear@2:  */
nuclear@2: 
nuclear@2: 
nuclear@2: LOCAL(boolean)
nuclear@2: get_soi (j_decompress_ptr cinfo)
nuclear@2: /* Process an SOI marker */
nuclear@2: {
nuclear@2:   int i;
nuclear@2:   
nuclear@2:   TRACEMS(cinfo, 1, JTRC_SOI);
nuclear@2: 
nuclear@2:   if (cinfo->marker->saw_SOI)
nuclear@2:     ERREXIT(cinfo, JERR_SOI_DUPLICATE);
nuclear@2: 
nuclear@2:   /* Reset all parameters that are defined to be reset by SOI */
nuclear@2: 
nuclear@2:   for (i = 0; i < NUM_ARITH_TBLS; i++) {
nuclear@2:     cinfo->arith_dc_L[i] = 0;
nuclear@2:     cinfo->arith_dc_U[i] = 1;
nuclear@2:     cinfo->arith_ac_K[i] = 5;
nuclear@2:   }
nuclear@2:   cinfo->restart_interval = 0;
nuclear@2: 
nuclear@2:   /* Set initial assumptions for colorspace etc */
nuclear@2: 
nuclear@2:   cinfo->jpeg_color_space = JCS_UNKNOWN;
nuclear@2:   cinfo->CCIR601_sampling = FALSE; /* Assume non-CCIR sampling??? */
nuclear@2: 
nuclear@2:   cinfo->saw_JFIF_marker = FALSE;
nuclear@2:   cinfo->JFIF_major_version = 1; /* set default JFIF APP0 values */
nuclear@2:   cinfo->JFIF_minor_version = 1;
nuclear@2:   cinfo->density_unit = 0;
nuclear@2:   cinfo->X_density = 1;
nuclear@2:   cinfo->Y_density = 1;
nuclear@2:   cinfo->saw_Adobe_marker = FALSE;
nuclear@2:   cinfo->Adobe_transform = 0;
nuclear@2: 
nuclear@2:   cinfo->marker->saw_SOI = TRUE;
nuclear@2: 
nuclear@2:   return TRUE;
nuclear@2: }
nuclear@2: 
nuclear@2: 
nuclear@2: LOCAL(boolean)
nuclear@2: get_sof (j_decompress_ptr cinfo, boolean is_prog, boolean is_arith)
nuclear@2: /* Process a SOFn marker */
nuclear@2: {
nuclear@2:   INT32 length;
nuclear@2:   int c, ci;
nuclear@2:   jpeg_component_info * compptr;
nuclear@2:   INPUT_VARS(cinfo);
nuclear@2: 
nuclear@2:   cinfo->progressive_mode = is_prog;
nuclear@2:   cinfo->arith_code = is_arith;
nuclear@2: 
nuclear@2:   INPUT_2BYTES(cinfo, length, return FALSE);
nuclear@2: 
nuclear@2:   INPUT_BYTE(cinfo, cinfo->data_precision, return FALSE);
nuclear@2:   INPUT_2BYTES(cinfo, cinfo->image_height, return FALSE);
nuclear@2:   INPUT_2BYTES(cinfo, cinfo->image_width, return FALSE);
nuclear@2:   INPUT_BYTE(cinfo, cinfo->num_components, return FALSE);
nuclear@2: 
nuclear@2:   length -= 8;
nuclear@2: 
nuclear@2:   TRACEMS4(cinfo, 1, JTRC_SOF, cinfo->unread_marker,
nuclear@2: 	   (int) cinfo->image_width, (int) cinfo->image_height,
nuclear@2: 	   cinfo->num_components);
nuclear@2: 
nuclear@2:   if (cinfo->marker->saw_SOF)
nuclear@2:     ERREXIT(cinfo, JERR_SOF_DUPLICATE);
nuclear@2: 
nuclear@2:   /* We don't support files in which the image height is initially specified */
nuclear@2:   /* as 0 and is later redefined by DNL.  As long as we have to check that,  */
nuclear@2:   /* might as well have a general sanity check. */
nuclear@2:   if (cinfo->image_height <= 0 || cinfo->image_width <= 0
nuclear@2:       || cinfo->num_components <= 0)
nuclear@2:     ERREXIT(cinfo, JERR_EMPTY_IMAGE);
nuclear@2: 
nuclear@2:   if (length != (cinfo->num_components * 3))
nuclear@2:     ERREXIT(cinfo, JERR_BAD_LENGTH);
nuclear@2: 
nuclear@2:   if (cinfo->comp_info == NULL)	/* do only once, even if suspend */
nuclear@2:     cinfo->comp_info = (jpeg_component_info *) (*cinfo->mem->alloc_small)
nuclear@2: 			((j_common_ptr) cinfo, JPOOL_IMAGE,
nuclear@2: 			 cinfo->num_components * SIZEOF(jpeg_component_info));
nuclear@2:   
nuclear@2:   for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
nuclear@2:        ci++, compptr++) {
nuclear@2:     compptr->component_index = ci;
nuclear@2:     INPUT_BYTE(cinfo, compptr->component_id, return FALSE);
nuclear@2:     INPUT_BYTE(cinfo, c, return FALSE);
nuclear@2:     compptr->h_samp_factor = (c >> 4) & 15;
nuclear@2:     compptr->v_samp_factor = (c     ) & 15;
nuclear@2:     INPUT_BYTE(cinfo, compptr->quant_tbl_no, return FALSE);
nuclear@2: 
nuclear@2:     TRACEMS4(cinfo, 1, JTRC_SOF_COMPONENT,
nuclear@2: 	     compptr->component_id, compptr->h_samp_factor,
nuclear@2: 	     compptr->v_samp_factor, compptr->quant_tbl_no);
nuclear@2:   }
nuclear@2: 
nuclear@2:   cinfo->marker->saw_SOF = TRUE;
nuclear@2: 
nuclear@2:   INPUT_SYNC(cinfo);
nuclear@2:   return TRUE;
nuclear@2: }
nuclear@2: 
nuclear@2: 
nuclear@2: LOCAL(boolean)
nuclear@2: get_sos (j_decompress_ptr cinfo)
nuclear@2: /* Process a SOS marker */
nuclear@2: {
nuclear@2:   INT32 length;
nuclear@2:   int i, ci, n, c, cc;
nuclear@2:   jpeg_component_info * compptr;
nuclear@2:   INPUT_VARS(cinfo);
nuclear@2: 
nuclear@2:   if (! cinfo->marker->saw_SOF)
nuclear@2:     ERREXIT(cinfo, JERR_SOS_NO_SOF);
nuclear@2: 
nuclear@2:   INPUT_2BYTES(cinfo, length, return FALSE);
nuclear@2: 
nuclear@2:   INPUT_BYTE(cinfo, n, return FALSE); /* Number of components */
nuclear@2: 
nuclear@2:   TRACEMS1(cinfo, 1, JTRC_SOS, n);
nuclear@2: 
nuclear@2:   if (length != (n * 2 + 6) || n < 1 || n > MAX_COMPS_IN_SCAN)
nuclear@2:     ERREXIT(cinfo, JERR_BAD_LENGTH);
nuclear@2: 
nuclear@2:   cinfo->comps_in_scan = n;
nuclear@2: 
nuclear@2:   /* Collect the component-spec parameters */
nuclear@2: 
nuclear@2:   for (i = 0; i < n; i++) {
nuclear@2:     INPUT_BYTE(cinfo, cc, return FALSE);
nuclear@2:     INPUT_BYTE(cinfo, c, return FALSE);
nuclear@2:     
nuclear@2:     for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
nuclear@2: 	 ci++, compptr++) {
nuclear@2:       if (cc == compptr->component_id)
nuclear@2: 	goto id_found;
nuclear@2:     }
nuclear@2: 
nuclear@2:     ERREXIT1(cinfo, JERR_BAD_COMPONENT_ID, cc);
nuclear@2: 
nuclear@2:   id_found:
nuclear@2: 
nuclear@2:     cinfo->cur_comp_info[i] = compptr;
nuclear@2:     compptr->dc_tbl_no = (c >> 4) & 15;
nuclear@2:     compptr->ac_tbl_no = (c     ) & 15;
nuclear@2:     
nuclear@2:     TRACEMS3(cinfo, 1, JTRC_SOS_COMPONENT, cc,
nuclear@2: 	     compptr->dc_tbl_no, compptr->ac_tbl_no);
nuclear@2:   }
nuclear@2: 
nuclear@2:   /* Collect the additional scan parameters Ss, Se, Ah/Al. */
nuclear@2:   INPUT_BYTE(cinfo, c, return FALSE);
nuclear@2:   cinfo->Ss = c;
nuclear@2:   INPUT_BYTE(cinfo, c, return FALSE);
nuclear@2:   cinfo->Se = c;
nuclear@2:   INPUT_BYTE(cinfo, c, return FALSE);
nuclear@2:   cinfo->Ah = (c >> 4) & 15;
nuclear@2:   cinfo->Al = (c     ) & 15;
nuclear@2: 
nuclear@2:   TRACEMS4(cinfo, 1, JTRC_SOS_PARAMS, cinfo->Ss, cinfo->Se,
nuclear@2: 	   cinfo->Ah, cinfo->Al);
nuclear@2: 
nuclear@2:   /* Prepare to scan data & restart markers */
nuclear@2:   cinfo->marker->next_restart_num = 0;
nuclear@2: 
nuclear@2:   /* Count another SOS marker */
nuclear@2:   cinfo->input_scan_number++;
nuclear@2: 
nuclear@2:   INPUT_SYNC(cinfo);
nuclear@2:   return TRUE;
nuclear@2: }
nuclear@2: 
nuclear@2: 
nuclear@2: #ifdef D_ARITH_CODING_SUPPORTED
nuclear@2: 
nuclear@2: LOCAL(boolean)
nuclear@2: get_dac (j_decompress_ptr cinfo)
nuclear@2: /* Process a DAC marker */
nuclear@2: {
nuclear@2:   INT32 length;
nuclear@2:   int index, val;
nuclear@2:   INPUT_VARS(cinfo);
nuclear@2: 
nuclear@2:   INPUT_2BYTES(cinfo, length, return FALSE);
nuclear@2:   length -= 2;
nuclear@2:   
nuclear@2:   while (length > 0) {
nuclear@2:     INPUT_BYTE(cinfo, index, return FALSE);
nuclear@2:     INPUT_BYTE(cinfo, val, return FALSE);
nuclear@2: 
nuclear@2:     length -= 2;
nuclear@2: 
nuclear@2:     TRACEMS2(cinfo, 1, JTRC_DAC, index, val);
nuclear@2: 
nuclear@2:     if (index < 0 || index >= (2*NUM_ARITH_TBLS))
nuclear@2:       ERREXIT1(cinfo, JERR_DAC_INDEX, index);
nuclear@2: 
nuclear@2:     if (index >= NUM_ARITH_TBLS) { /* define AC table */
nuclear@2:       cinfo->arith_ac_K[index-NUM_ARITH_TBLS] = (UINT8) val;
nuclear@2:     } else {			/* define DC table */
nuclear@2:       cinfo->arith_dc_L[index] = (UINT8) (val & 0x0F);
nuclear@2:       cinfo->arith_dc_U[index] = (UINT8) (val >> 4);
nuclear@2:       if (cinfo->arith_dc_L[index] > cinfo->arith_dc_U[index])
nuclear@2: 	ERREXIT1(cinfo, JERR_DAC_VALUE, val);
nuclear@2:     }
nuclear@2:   }
nuclear@2: 
nuclear@2:   if (length != 0)
nuclear@2:     ERREXIT(cinfo, JERR_BAD_LENGTH);
nuclear@2: 
nuclear@2:   INPUT_SYNC(cinfo);
nuclear@2:   return TRUE;
nuclear@2: }
nuclear@2: 
nuclear@2: #else /* ! D_ARITH_CODING_SUPPORTED */
nuclear@2: 
nuclear@2: #define get_dac(cinfo)  skip_variable(cinfo)
nuclear@2: 
nuclear@2: #endif /* D_ARITH_CODING_SUPPORTED */
nuclear@2: 
nuclear@2: 
nuclear@2: LOCAL(boolean)
nuclear@2: get_dht (j_decompress_ptr cinfo)
nuclear@2: /* Process a DHT marker */
nuclear@2: {
nuclear@2:   INT32 length;
nuclear@2:   UINT8 bits[17];
nuclear@2:   UINT8 huffval[256];
nuclear@2:   int i, index, count;
nuclear@2:   JHUFF_TBL **htblptr;
nuclear@2:   INPUT_VARS(cinfo);
nuclear@2: 
nuclear@2:   INPUT_2BYTES(cinfo, length, return FALSE);
nuclear@2:   length -= 2;
nuclear@2:   
nuclear@2:   while (length > 16) {
nuclear@2:     INPUT_BYTE(cinfo, index, return FALSE);
nuclear@2: 
nuclear@2:     TRACEMS1(cinfo, 1, JTRC_DHT, index);
nuclear@2:       
nuclear@2:     bits[0] = 0;
nuclear@2:     count = 0;
nuclear@2:     for (i = 1; i <= 16; i++) {
nuclear@2:       INPUT_BYTE(cinfo, bits[i], return FALSE);
nuclear@2:       count += bits[i];
nuclear@2:     }
nuclear@2: 
nuclear@2:     length -= 1 + 16;
nuclear@2: 
nuclear@2:     TRACEMS8(cinfo, 2, JTRC_HUFFBITS,
nuclear@2: 	     bits[1], bits[2], bits[3], bits[4],
nuclear@2: 	     bits[5], bits[6], bits[7], bits[8]);
nuclear@2:     TRACEMS8(cinfo, 2, JTRC_HUFFBITS,
nuclear@2: 	     bits[9], bits[10], bits[11], bits[12],
nuclear@2: 	     bits[13], bits[14], bits[15], bits[16]);
nuclear@2: 
nuclear@2:     /* Here we just do minimal validation of the counts to avoid walking
nuclear@2:      * off the end of our table space.  jdhuff.c will check more carefully.
nuclear@2:      */
nuclear@2:     if (count > 256 || ((INT32) count) > length)
nuclear@2:       ERREXIT(cinfo, JERR_BAD_HUFF_TABLE);
nuclear@2: 
nuclear@2:     for (i = 0; i < count; i++)
nuclear@2:       INPUT_BYTE(cinfo, huffval[i], return FALSE);
nuclear@2: 
nuclear@2:     length -= count;
nuclear@2: 
nuclear@2:     if (index & 0x10) {		/* AC table definition */
nuclear@2:       index -= 0x10;
nuclear@2:       htblptr = &cinfo->ac_huff_tbl_ptrs[index];
nuclear@2:     } else {			/* DC table definition */
nuclear@2:       htblptr = &cinfo->dc_huff_tbl_ptrs[index];
nuclear@2:     }
nuclear@2: 
nuclear@2:     if (index < 0 || index >= NUM_HUFF_TBLS)
nuclear@2:       ERREXIT1(cinfo, JERR_DHT_INDEX, index);
nuclear@2: 
nuclear@2:     if (*htblptr == NULL)
nuclear@2:       *htblptr = jpeg_alloc_huff_table((j_common_ptr) cinfo);
nuclear@2:   
nuclear@2:     MEMCOPY((*htblptr)->bits, bits, SIZEOF((*htblptr)->bits));
nuclear@2:     MEMCOPY((*htblptr)->huffval, huffval, SIZEOF((*htblptr)->huffval));
nuclear@2:   }
nuclear@2: 
nuclear@2:   if (length != 0)
nuclear@2:     ERREXIT(cinfo, JERR_BAD_LENGTH);
nuclear@2: 
nuclear@2:   INPUT_SYNC(cinfo);
nuclear@2:   return TRUE;
nuclear@2: }
nuclear@2: 
nuclear@2: 
nuclear@2: LOCAL(boolean)
nuclear@2: get_dqt (j_decompress_ptr cinfo)
nuclear@2: /* Process a DQT marker */
nuclear@2: {
nuclear@2:   INT32 length;
nuclear@2:   int n, i, prec;
nuclear@2:   unsigned int tmp;
nuclear@2:   JQUANT_TBL *quant_ptr;
nuclear@2:   INPUT_VARS(cinfo);
nuclear@2: 
nuclear@2:   INPUT_2BYTES(cinfo, length, return FALSE);
nuclear@2:   length -= 2;
nuclear@2: 
nuclear@2:   while (length > 0) {
nuclear@2:     INPUT_BYTE(cinfo, n, return FALSE);
nuclear@2:     prec = n >> 4;
nuclear@2:     n &= 0x0F;
nuclear@2: 
nuclear@2:     TRACEMS2(cinfo, 1, JTRC_DQT, n, prec);
nuclear@2: 
nuclear@2:     if (n >= NUM_QUANT_TBLS)
nuclear@2:       ERREXIT1(cinfo, JERR_DQT_INDEX, n);
nuclear@2:       
nuclear@2:     if (cinfo->quant_tbl_ptrs[n] == NULL)
nuclear@2:       cinfo->quant_tbl_ptrs[n] = jpeg_alloc_quant_table((j_common_ptr) cinfo);
nuclear@2:     quant_ptr = cinfo->quant_tbl_ptrs[n];
nuclear@2: 
nuclear@2:     for (i = 0; i < DCTSIZE2; i++) {
nuclear@2:       if (prec)
nuclear@2: 	INPUT_2BYTES(cinfo, tmp, return FALSE);
nuclear@2:       else
nuclear@2: 	INPUT_BYTE(cinfo, tmp, return FALSE);
nuclear@2:       /* We convert the zigzag-order table to natural array order. */
nuclear@2:       quant_ptr->quantval[jpeg_natural_order[i]] = (UINT16) tmp;
nuclear@2:     }
nuclear@2: 
nuclear@2:     if (cinfo->err->trace_level >= 2) {
nuclear@2:       for (i = 0; i < DCTSIZE2; i += 8) {
nuclear@2: 	TRACEMS8(cinfo, 2, JTRC_QUANTVALS,
nuclear@2: 		 quant_ptr->quantval[i],   quant_ptr->quantval[i+1],
nuclear@2: 		 quant_ptr->quantval[i+2], quant_ptr->quantval[i+3],
nuclear@2: 		 quant_ptr->quantval[i+4], quant_ptr->quantval[i+5],
nuclear@2: 		 quant_ptr->quantval[i+6], quant_ptr->quantval[i+7]);
nuclear@2:       }
nuclear@2:     }
nuclear@2: 
nuclear@2:     length -= DCTSIZE2+1;
nuclear@2:     if (prec) length -= DCTSIZE2;
nuclear@2:   }
nuclear@2: 
nuclear@2:   if (length != 0)
nuclear@2:     ERREXIT(cinfo, JERR_BAD_LENGTH);
nuclear@2: 
nuclear@2:   INPUT_SYNC(cinfo);
nuclear@2:   return TRUE;
nuclear@2: }
nuclear@2: 
nuclear@2: 
nuclear@2: LOCAL(boolean)
nuclear@2: get_dri (j_decompress_ptr cinfo)
nuclear@2: /* Process a DRI marker */
nuclear@2: {
nuclear@2:   INT32 length;
nuclear@2:   unsigned int tmp;
nuclear@2:   INPUT_VARS(cinfo);
nuclear@2: 
nuclear@2:   INPUT_2BYTES(cinfo, length, return FALSE);
nuclear@2:   
nuclear@2:   if (length != 4)
nuclear@2:     ERREXIT(cinfo, JERR_BAD_LENGTH);
nuclear@2: 
nuclear@2:   INPUT_2BYTES(cinfo, tmp, return FALSE);
nuclear@2: 
nuclear@2:   TRACEMS1(cinfo, 1, JTRC_DRI, tmp);
nuclear@2: 
nuclear@2:   cinfo->restart_interval = tmp;
nuclear@2: 
nuclear@2:   INPUT_SYNC(cinfo);
nuclear@2:   return TRUE;
nuclear@2: }
nuclear@2: 
nuclear@2: 
nuclear@2: /*
nuclear@2:  * Routines for processing APPn and COM markers.
nuclear@2:  * These are either saved in memory or discarded, per application request.
nuclear@2:  * APP0 and APP14 are specially checked to see if they are
nuclear@2:  * JFIF and Adobe markers, respectively.
nuclear@2:  */
nuclear@2: 
nuclear@2: #define APP0_DATA_LEN	14	/* Length of interesting data in APP0 */
nuclear@2: #define APP14_DATA_LEN	12	/* Length of interesting data in APP14 */
nuclear@2: #define APPN_DATA_LEN	14	/* Must be the largest of the above!! */
nuclear@2: 
nuclear@2: 
nuclear@2: LOCAL(void)
nuclear@2: examine_app0 (j_decompress_ptr cinfo, JOCTET FAR * data,
nuclear@2: 	      unsigned int datalen, INT32 remaining)
nuclear@2: /* Examine first few bytes from an APP0.
nuclear@2:  * Take appropriate action if it is a JFIF marker.
nuclear@2:  * datalen is # of bytes at data[], remaining is length of rest of marker data.
nuclear@2:  */
nuclear@2: {
nuclear@2:   INT32 totallen = (INT32) datalen + remaining;
nuclear@2: 
nuclear@2:   if (datalen >= APP0_DATA_LEN &&
nuclear@2:       GETJOCTET(data[0]) == 0x4A &&
nuclear@2:       GETJOCTET(data[1]) == 0x46 &&
nuclear@2:       GETJOCTET(data[2]) == 0x49 &&
nuclear@2:       GETJOCTET(data[3]) == 0x46 &&
nuclear@2:       GETJOCTET(data[4]) == 0) {
nuclear@2:     /* Found JFIF APP0 marker: save info */
nuclear@2:     cinfo->saw_JFIF_marker = TRUE;
nuclear@2:     cinfo->JFIF_major_version = GETJOCTET(data[5]);
nuclear@2:     cinfo->JFIF_minor_version = GETJOCTET(data[6]);
nuclear@2:     cinfo->density_unit = GETJOCTET(data[7]);
nuclear@2:     cinfo->X_density = (GETJOCTET(data[8]) << 8) + GETJOCTET(data[9]);
nuclear@2:     cinfo->Y_density = (GETJOCTET(data[10]) << 8) + GETJOCTET(data[11]);
nuclear@2:     /* Check version.
nuclear@2:      * Major version must be 1, anything else signals an incompatible change.
nuclear@2:      * (We used to treat this as an error, but now it's a nonfatal warning,
nuclear@2:      * because some bozo at Hijaak couldn't read the spec.)
nuclear@2:      * Minor version should be 0..2, but process anyway if newer.
nuclear@2:      */
nuclear@2:     if (cinfo->JFIF_major_version != 1)
nuclear@2:       WARNMS2(cinfo, JWRN_JFIF_MAJOR,
nuclear@2: 	      cinfo->JFIF_major_version, cinfo->JFIF_minor_version);
nuclear@2:     /* Generate trace messages */
nuclear@2:     TRACEMS5(cinfo, 1, JTRC_JFIF,
nuclear@2: 	     cinfo->JFIF_major_version, cinfo->JFIF_minor_version,
nuclear@2: 	     cinfo->X_density, cinfo->Y_density, cinfo->density_unit);
nuclear@2:     /* Validate thumbnail dimensions and issue appropriate messages */
nuclear@2:     if (GETJOCTET(data[12]) | GETJOCTET(data[13]))
nuclear@2:       TRACEMS2(cinfo, 1, JTRC_JFIF_THUMBNAIL,
nuclear@2: 	       GETJOCTET(data[12]), GETJOCTET(data[13]));
nuclear@2:     totallen -= APP0_DATA_LEN;
nuclear@2:     if (totallen !=
nuclear@2: 	((INT32)GETJOCTET(data[12]) * (INT32)GETJOCTET(data[13]) * (INT32) 3))
nuclear@2:       TRACEMS1(cinfo, 1, JTRC_JFIF_BADTHUMBNAILSIZE, (int) totallen);
nuclear@2:   } else if (datalen >= 6 &&
nuclear@2:       GETJOCTET(data[0]) == 0x4A &&
nuclear@2:       GETJOCTET(data[1]) == 0x46 &&
nuclear@2:       GETJOCTET(data[2]) == 0x58 &&
nuclear@2:       GETJOCTET(data[3]) == 0x58 &&
nuclear@2:       GETJOCTET(data[4]) == 0) {
nuclear@2:     /* Found JFIF "JFXX" extension APP0 marker */
nuclear@2:     /* The library doesn't actually do anything with these,
nuclear@2:      * but we try to produce a helpful trace message.
nuclear@2:      */
nuclear@2:     switch (GETJOCTET(data[5])) {
nuclear@2:     case 0x10:
nuclear@2:       TRACEMS1(cinfo, 1, JTRC_THUMB_JPEG, (int) totallen);
nuclear@2:       break;
nuclear@2:     case 0x11:
nuclear@2:       TRACEMS1(cinfo, 1, JTRC_THUMB_PALETTE, (int) totallen);
nuclear@2:       break;
nuclear@2:     case 0x13:
nuclear@2:       TRACEMS1(cinfo, 1, JTRC_THUMB_RGB, (int) totallen);
nuclear@2:       break;
nuclear@2:     default:
nuclear@2:       TRACEMS2(cinfo, 1, JTRC_JFIF_EXTENSION,
nuclear@2: 	       GETJOCTET(data[5]), (int) totallen);
nuclear@2:       break;
nuclear@2:     }
nuclear@2:   } else {
nuclear@2:     /* Start of APP0 does not match "JFIF" or "JFXX", or too short */
nuclear@2:     TRACEMS1(cinfo, 1, JTRC_APP0, (int) totallen);
nuclear@2:   }
nuclear@2: }
nuclear@2: 
nuclear@2: 
nuclear@2: LOCAL(void)
nuclear@2: examine_app14 (j_decompress_ptr cinfo, JOCTET FAR * data,
nuclear@2: 	       unsigned int datalen, INT32 remaining)
nuclear@2: /* Examine first few bytes from an APP14.
nuclear@2:  * Take appropriate action if it is an Adobe marker.
nuclear@2:  * datalen is # of bytes at data[], remaining is length of rest of marker data.
nuclear@2:  */
nuclear@2: {
nuclear@2:   unsigned int version, flags0, flags1, transform;
nuclear@2: 
nuclear@2:   if (datalen >= APP14_DATA_LEN &&
nuclear@2:       GETJOCTET(data[0]) == 0x41 &&
nuclear@2:       GETJOCTET(data[1]) == 0x64 &&
nuclear@2:       GETJOCTET(data[2]) == 0x6F &&
nuclear@2:       GETJOCTET(data[3]) == 0x62 &&
nuclear@2:       GETJOCTET(data[4]) == 0x65) {
nuclear@2:     /* Found Adobe APP14 marker */
nuclear@2:     version = (GETJOCTET(data[5]) << 8) + GETJOCTET(data[6]);
nuclear@2:     flags0 = (GETJOCTET(data[7]) << 8) + GETJOCTET(data[8]);
nuclear@2:     flags1 = (GETJOCTET(data[9]) << 8) + GETJOCTET(data[10]);
nuclear@2:     transform = GETJOCTET(data[11]);
nuclear@2:     TRACEMS4(cinfo, 1, JTRC_ADOBE, version, flags0, flags1, transform);
nuclear@2:     cinfo->saw_Adobe_marker = TRUE;
nuclear@2:     cinfo->Adobe_transform = (UINT8) transform;
nuclear@2:   } else {
nuclear@2:     /* Start of APP14 does not match "Adobe", or too short */
nuclear@2:     TRACEMS1(cinfo, 1, JTRC_APP14, (int) (datalen + remaining));
nuclear@2:   }
nuclear@2: }
nuclear@2: 
nuclear@2: 
nuclear@2: METHODDEF(boolean)
nuclear@2: get_interesting_appn (j_decompress_ptr cinfo)
nuclear@2: /* Process an APP0 or APP14 marker without saving it */
nuclear@2: {
nuclear@2:   INT32 length;
nuclear@2:   JOCTET b[APPN_DATA_LEN];
nuclear@2:   unsigned int i, numtoread;
nuclear@2:   INPUT_VARS(cinfo);
nuclear@2: 
nuclear@2:   INPUT_2BYTES(cinfo, length, return FALSE);
nuclear@2:   length -= 2;
nuclear@2: 
nuclear@2:   /* get the interesting part of the marker data */
nuclear@2:   if (length >= APPN_DATA_LEN)
nuclear@2:     numtoread = APPN_DATA_LEN;
nuclear@2:   else if (length > 0)
nuclear@2:     numtoread = (unsigned int) length;
nuclear@2:   else
nuclear@2:     numtoread = 0;
nuclear@2:   for (i = 0; i < numtoread; i++)
nuclear@2:     INPUT_BYTE(cinfo, b[i], return FALSE);
nuclear@2:   length -= numtoread;
nuclear@2: 
nuclear@2:   /* process it */
nuclear@2:   switch (cinfo->unread_marker) {
nuclear@2:   case M_APP0:
nuclear@2:     examine_app0(cinfo, (JOCTET FAR *) b, numtoread, length);
nuclear@2:     break;
nuclear@2:   case M_APP14:
nuclear@2:     examine_app14(cinfo, (JOCTET FAR *) b, numtoread, length);
nuclear@2:     break;
nuclear@2:   default:
nuclear@2:     /* can't get here unless jpeg_save_markers chooses wrong processor */
nuclear@2:     ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, cinfo->unread_marker);
nuclear@2:     break;
nuclear@2:   }
nuclear@2: 
nuclear@2:   /* skip any remaining data -- could be lots */
nuclear@2:   INPUT_SYNC(cinfo);
nuclear@2:   if (length > 0)
nuclear@2:     (*cinfo->src->skip_input_data) (cinfo, (long) length);
nuclear@2: 
nuclear@2:   return TRUE;
nuclear@2: }
nuclear@2: 
nuclear@2: 
nuclear@2: #ifdef SAVE_MARKERS_SUPPORTED
nuclear@2: 
nuclear@2: METHODDEF(boolean)
nuclear@2: save_marker (j_decompress_ptr cinfo)
nuclear@2: /* Save an APPn or COM marker into the marker list */
nuclear@2: {
nuclear@2:   my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
nuclear@2:   jpeg_saved_marker_ptr cur_marker = marker->cur_marker;
nuclear@2:   unsigned int bytes_read, data_length;
nuclear@2:   JOCTET FAR * data;
nuclear@2:   INT32 length = 0;
nuclear@2:   INPUT_VARS(cinfo);
nuclear@2: 
nuclear@2:   if (cur_marker == NULL) {
nuclear@2:     /* begin reading a marker */
nuclear@2:     INPUT_2BYTES(cinfo, length, return FALSE);
nuclear@2:     length -= 2;
nuclear@2:     if (length >= 0) {		/* watch out for bogus length word */
nuclear@2:       /* figure out how much we want to save */
nuclear@2:       unsigned int limit;
nuclear@2:       if (cinfo->unread_marker == (int) M_COM)
nuclear@2: 	limit = marker->length_limit_COM;
nuclear@2:       else
nuclear@2: 	limit = marker->length_limit_APPn[cinfo->unread_marker - (int) M_APP0];
nuclear@2:       if ((unsigned int) length < limit)
nuclear@2: 	limit = (unsigned int) length;
nuclear@2:       /* allocate and initialize the marker item */
nuclear@2:       cur_marker = (jpeg_saved_marker_ptr)
nuclear@2: 	(*cinfo->mem->alloc_large) ((j_common_ptr) cinfo, JPOOL_IMAGE,
nuclear@2: 				    SIZEOF(struct jpeg_marker_struct) + limit);
nuclear@2:       cur_marker->next = NULL;
nuclear@2:       cur_marker->marker = (UINT8) cinfo->unread_marker;
nuclear@2:       cur_marker->original_length = (unsigned int) length;
nuclear@2:       cur_marker->data_length = limit;
nuclear@2:       /* data area is just beyond the jpeg_marker_struct */
nuclear@2:       data = cur_marker->data = (JOCTET FAR *) (cur_marker + 1);
nuclear@2:       marker->cur_marker = cur_marker;
nuclear@2:       marker->bytes_read = 0;
nuclear@2:       bytes_read = 0;
nuclear@2:       data_length = limit;
nuclear@2:     } else {
nuclear@2:       /* deal with bogus length word */
nuclear@2:       bytes_read = data_length = 0;
nuclear@2:       data = NULL;
nuclear@2:     }
nuclear@2:   } else {
nuclear@2:     /* resume reading a marker */
nuclear@2:     bytes_read = marker->bytes_read;
nuclear@2:     data_length = cur_marker->data_length;
nuclear@2:     data = cur_marker->data + bytes_read;
nuclear@2:   }
nuclear@2: 
nuclear@2:   while (bytes_read < data_length) {
nuclear@2:     INPUT_SYNC(cinfo);		/* move the restart point to here */
nuclear@2:     marker->bytes_read = bytes_read;
nuclear@2:     /* If there's not at least one byte in buffer, suspend */
nuclear@2:     MAKE_BYTE_AVAIL(cinfo, return FALSE);
nuclear@2:     /* Copy bytes with reasonable rapidity */
nuclear@2:     while (bytes_read < data_length && bytes_in_buffer > 0) {
nuclear@2:       *data++ = *next_input_byte++;
nuclear@2:       bytes_in_buffer--;
nuclear@2:       bytes_read++;
nuclear@2:     }
nuclear@2:   }
nuclear@2: 
nuclear@2:   /* Done reading what we want to read */
nuclear@2:   if (cur_marker != NULL) {	/* will be NULL if bogus length word */
nuclear@2:     /* Add new marker to end of list */
nuclear@2:     if (cinfo->marker_list == NULL) {
nuclear@2:       cinfo->marker_list = cur_marker;
nuclear@2:     } else {
nuclear@2:       jpeg_saved_marker_ptr prev = cinfo->marker_list;
nuclear@2:       while (prev->next != NULL)
nuclear@2: 	prev = prev->next;
nuclear@2:       prev->next = cur_marker;
nuclear@2:     }
nuclear@2:     /* Reset pointer & calc remaining data length */
nuclear@2:     data = cur_marker->data;
nuclear@2:     length = cur_marker->original_length - data_length;
nuclear@2:   }
nuclear@2:   /* Reset to initial state for next marker */
nuclear@2:   marker->cur_marker = NULL;
nuclear@2: 
nuclear@2:   /* Process the marker if interesting; else just make a generic trace msg */
nuclear@2:   switch (cinfo->unread_marker) {
nuclear@2:   case M_APP0:
nuclear@2:     examine_app0(cinfo, data, data_length, length);
nuclear@2:     break;
nuclear@2:   case M_APP14:
nuclear@2:     examine_app14(cinfo, data, data_length, length);
nuclear@2:     break;
nuclear@2:   default:
nuclear@2:     TRACEMS2(cinfo, 1, JTRC_MISC_MARKER, cinfo->unread_marker,
nuclear@2: 	     (int) (data_length + length));
nuclear@2:     break;
nuclear@2:   }
nuclear@2: 
nuclear@2:   /* skip any remaining data -- could be lots */
nuclear@2:   INPUT_SYNC(cinfo);		/* do before skip_input_data */
nuclear@2:   if (length > 0)
nuclear@2:     (*cinfo->src->skip_input_data) (cinfo, (long) length);
nuclear@2: 
nuclear@2:   return TRUE;
nuclear@2: }
nuclear@2: 
nuclear@2: #endif /* SAVE_MARKERS_SUPPORTED */
nuclear@2: 
nuclear@2: 
nuclear@2: METHODDEF(boolean)
nuclear@2: skip_variable (j_decompress_ptr cinfo)
nuclear@2: /* Skip over an unknown or uninteresting variable-length marker */
nuclear@2: {
nuclear@2:   INT32 length;
nuclear@2:   INPUT_VARS(cinfo);
nuclear@2: 
nuclear@2:   INPUT_2BYTES(cinfo, length, return FALSE);
nuclear@2:   length -= 2;
nuclear@2:   
nuclear@2:   TRACEMS2(cinfo, 1, JTRC_MISC_MARKER, cinfo->unread_marker, (int) length);
nuclear@2: 
nuclear@2:   INPUT_SYNC(cinfo);		/* do before skip_input_data */
nuclear@2:   if (length > 0)
nuclear@2:     (*cinfo->src->skip_input_data) (cinfo, (long) length);
nuclear@2: 
nuclear@2:   return TRUE;
nuclear@2: }
nuclear@2: 
nuclear@2: 
nuclear@2: /*
nuclear@2:  * Find the next JPEG marker, save it in cinfo->unread_marker.
nuclear@2:  * Returns FALSE if had to suspend before reaching a marker;
nuclear@2:  * in that case cinfo->unread_marker is unchanged.
nuclear@2:  *
nuclear@2:  * Note that the result might not be a valid marker code,
nuclear@2:  * but it will never be 0 or FF.
nuclear@2:  */
nuclear@2: 
nuclear@2: LOCAL(boolean)
nuclear@2: next_marker (j_decompress_ptr cinfo)
nuclear@2: {
nuclear@2:   int c;
nuclear@2:   INPUT_VARS(cinfo);
nuclear@2: 
nuclear@2:   for (;;) {
nuclear@2:     INPUT_BYTE(cinfo, c, return FALSE);
nuclear@2:     /* Skip any non-FF bytes.
nuclear@2:      * This may look a bit inefficient, but it will not occur in a valid file.
nuclear@2:      * We sync after each discarded byte so that a suspending data source
nuclear@2:      * can discard the byte from its buffer.
nuclear@2:      */
nuclear@2:     while (c != 0xFF) {
nuclear@2:       cinfo->marker->discarded_bytes++;
nuclear@2:       INPUT_SYNC(cinfo);
nuclear@2:       INPUT_BYTE(cinfo, c, return FALSE);
nuclear@2:     }
nuclear@2:     /* This loop swallows any duplicate FF bytes.  Extra FFs are legal as
nuclear@2:      * pad bytes, so don't count them in discarded_bytes.  We assume there
nuclear@2:      * will not be so many consecutive FF bytes as to overflow a suspending
nuclear@2:      * data source's input buffer.
nuclear@2:      */
nuclear@2:     do {
nuclear@2:       INPUT_BYTE(cinfo, c, return FALSE);
nuclear@2:     } while (c == 0xFF);
nuclear@2:     if (c != 0)
nuclear@2:       break;			/* found a valid marker, exit loop */
nuclear@2:     /* Reach here if we found a stuffed-zero data sequence (FF/00).
nuclear@2:      * Discard it and loop back to try again.
nuclear@2:      */
nuclear@2:     cinfo->marker->discarded_bytes += 2;
nuclear@2:     INPUT_SYNC(cinfo);
nuclear@2:   }
nuclear@2: 
nuclear@2:   if (cinfo->marker->discarded_bytes != 0) {
nuclear@2:     WARNMS2(cinfo, JWRN_EXTRANEOUS_DATA, cinfo->marker->discarded_bytes, c);
nuclear@2:     cinfo->marker->discarded_bytes = 0;
nuclear@2:   }
nuclear@2: 
nuclear@2:   cinfo->unread_marker = c;
nuclear@2: 
nuclear@2:   INPUT_SYNC(cinfo);
nuclear@2:   return TRUE;
nuclear@2: }
nuclear@2: 
nuclear@2: 
nuclear@2: LOCAL(boolean)
nuclear@2: first_marker (j_decompress_ptr cinfo)
nuclear@2: /* Like next_marker, but used to obtain the initial SOI marker. */
nuclear@2: /* For this marker, we do not allow preceding garbage or fill; otherwise,
nuclear@2:  * we might well scan an entire input file before realizing it ain't JPEG.
nuclear@2:  * If an application wants to process non-JFIF files, it must seek to the
nuclear@2:  * SOI before calling the JPEG library.
nuclear@2:  */
nuclear@2: {
nuclear@2:   int c, c2;
nuclear@2:   INPUT_VARS(cinfo);
nuclear@2: 
nuclear@2:   INPUT_BYTE(cinfo, c, return FALSE);
nuclear@2:   INPUT_BYTE(cinfo, c2, return FALSE);
nuclear@2:   if (c != 0xFF || c2 != (int) M_SOI)
nuclear@2:     ERREXIT2(cinfo, JERR_NO_SOI, c, c2);
nuclear@2: 
nuclear@2:   cinfo->unread_marker = c2;
nuclear@2: 
nuclear@2:   INPUT_SYNC(cinfo);
nuclear@2:   return TRUE;
nuclear@2: }
nuclear@2: 
nuclear@2: 
nuclear@2: /*
nuclear@2:  * Read markers until SOS or EOI.
nuclear@2:  *
nuclear@2:  * Returns same codes as are defined for jpeg_consume_input:
nuclear@2:  * JPEG_SUSPENDED, JPEG_REACHED_SOS, or JPEG_REACHED_EOI.
nuclear@2:  */
nuclear@2: 
nuclear@2: METHODDEF(int)
nuclear@2: read_markers (j_decompress_ptr cinfo)
nuclear@2: {
nuclear@2:   /* Outer loop repeats once for each marker. */
nuclear@2:   for (;;) {
nuclear@2:     /* Collect the marker proper, unless we already did. */
nuclear@2:     /* NB: first_marker() enforces the requirement that SOI appear first. */
nuclear@2:     if (cinfo->unread_marker == 0) {
nuclear@2:       if (! cinfo->marker->saw_SOI) {
nuclear@2: 	if (! first_marker(cinfo))
nuclear@2: 	  return JPEG_SUSPENDED;
nuclear@2:       } else {
nuclear@2: 	if (! next_marker(cinfo))
nuclear@2: 	  return JPEG_SUSPENDED;
nuclear@2:       }
nuclear@2:     }
nuclear@2:     /* At this point cinfo->unread_marker contains the marker code and the
nuclear@2:      * input point is just past the marker proper, but before any parameters.
nuclear@2:      * A suspension will cause us to return with this state still true.
nuclear@2:      */
nuclear@2:     switch (cinfo->unread_marker) {
nuclear@2:     case M_SOI:
nuclear@2:       if (! get_soi(cinfo))
nuclear@2: 	return JPEG_SUSPENDED;
nuclear@2:       break;
nuclear@2: 
nuclear@2:     case M_SOF0:		/* Baseline */
nuclear@2:     case M_SOF1:		/* Extended sequential, Huffman */
nuclear@2:       if (! get_sof(cinfo, FALSE, FALSE))
nuclear@2: 	return JPEG_SUSPENDED;
nuclear@2:       break;
nuclear@2: 
nuclear@2:     case M_SOF2:		/* Progressive, Huffman */
nuclear@2:       if (! get_sof(cinfo, TRUE, FALSE))
nuclear@2: 	return JPEG_SUSPENDED;
nuclear@2:       break;
nuclear@2: 
nuclear@2:     case M_SOF9:		/* Extended sequential, arithmetic */
nuclear@2:       if (! get_sof(cinfo, FALSE, TRUE))
nuclear@2: 	return JPEG_SUSPENDED;
nuclear@2:       break;
nuclear@2: 
nuclear@2:     case M_SOF10:		/* Progressive, arithmetic */
nuclear@2:       if (! get_sof(cinfo, TRUE, TRUE))
nuclear@2: 	return JPEG_SUSPENDED;
nuclear@2:       break;
nuclear@2: 
nuclear@2:     /* Currently unsupported SOFn types */
nuclear@2:     case M_SOF3:		/* Lossless, Huffman */
nuclear@2:     case M_SOF5:		/* Differential sequential, Huffman */
nuclear@2:     case M_SOF6:		/* Differential progressive, Huffman */
nuclear@2:     case M_SOF7:		/* Differential lossless, Huffman */
nuclear@2:     case M_JPG:			/* Reserved for JPEG extensions */
nuclear@2:     case M_SOF11:		/* Lossless, arithmetic */
nuclear@2:     case M_SOF13:		/* Differential sequential, arithmetic */
nuclear@2:     case M_SOF14:		/* Differential progressive, arithmetic */
nuclear@2:     case M_SOF15:		/* Differential lossless, arithmetic */
nuclear@2:       ERREXIT1(cinfo, JERR_SOF_UNSUPPORTED, cinfo->unread_marker);
nuclear@2:       break;
nuclear@2: 
nuclear@2:     case M_SOS:
nuclear@2:       if (! get_sos(cinfo))
nuclear@2: 	return JPEG_SUSPENDED;
nuclear@2:       cinfo->unread_marker = 0;	/* processed the marker */
nuclear@2:       return JPEG_REACHED_SOS;
nuclear@2:     
nuclear@2:     case M_EOI:
nuclear@2:       TRACEMS(cinfo, 1, JTRC_EOI);
nuclear@2:       cinfo->unread_marker = 0;	/* processed the marker */
nuclear@2:       return JPEG_REACHED_EOI;
nuclear@2:       
nuclear@2:     case M_DAC:
nuclear@2:       if (! get_dac(cinfo))
nuclear@2: 	return JPEG_SUSPENDED;
nuclear@2:       break;
nuclear@2:       
nuclear@2:     case M_DHT:
nuclear@2:       if (! get_dht(cinfo))
nuclear@2: 	return JPEG_SUSPENDED;
nuclear@2:       break;
nuclear@2:       
nuclear@2:     case M_DQT:
nuclear@2:       if (! get_dqt(cinfo))
nuclear@2: 	return JPEG_SUSPENDED;
nuclear@2:       break;
nuclear@2:       
nuclear@2:     case M_DRI:
nuclear@2:       if (! get_dri(cinfo))
nuclear@2: 	return JPEG_SUSPENDED;
nuclear@2:       break;
nuclear@2:       
nuclear@2:     case M_APP0:
nuclear@2:     case M_APP1:
nuclear@2:     case M_APP2:
nuclear@2:     case M_APP3:
nuclear@2:     case M_APP4:
nuclear@2:     case M_APP5:
nuclear@2:     case M_APP6:
nuclear@2:     case M_APP7:
nuclear@2:     case M_APP8:
nuclear@2:     case M_APP9:
nuclear@2:     case M_APP10:
nuclear@2:     case M_APP11:
nuclear@2:     case M_APP12:
nuclear@2:     case M_APP13:
nuclear@2:     case M_APP14:
nuclear@2:     case M_APP15:
nuclear@2:       if (! (*((my_marker_ptr) cinfo->marker)->process_APPn[
nuclear@2: 		cinfo->unread_marker - (int) M_APP0]) (cinfo))
nuclear@2: 	return JPEG_SUSPENDED;
nuclear@2:       break;
nuclear@2:       
nuclear@2:     case M_COM:
nuclear@2:       if (! (*((my_marker_ptr) cinfo->marker)->process_COM) (cinfo))
nuclear@2: 	return JPEG_SUSPENDED;
nuclear@2:       break;
nuclear@2: 
nuclear@2:     case M_RST0:		/* these are all parameterless */
nuclear@2:     case M_RST1:
nuclear@2:     case M_RST2:
nuclear@2:     case M_RST3:
nuclear@2:     case M_RST4:
nuclear@2:     case M_RST5:
nuclear@2:     case M_RST6:
nuclear@2:     case M_RST7:
nuclear@2:     case M_TEM:
nuclear@2:       TRACEMS1(cinfo, 1, JTRC_PARMLESS_MARKER, cinfo->unread_marker);
nuclear@2:       break;
nuclear@2: 
nuclear@2:     case M_DNL:			/* Ignore DNL ... perhaps the wrong thing */
nuclear@2:       if (! skip_variable(cinfo))
nuclear@2: 	return JPEG_SUSPENDED;
nuclear@2:       break;
nuclear@2: 
nuclear@2:     default:			/* must be DHP, EXP, JPGn, or RESn */
nuclear@2:       /* For now, we treat the reserved markers as fatal errors since they are
nuclear@2:        * likely to be used to signal incompatible JPEG Part 3 extensions.
nuclear@2:        * Once the JPEG 3 version-number marker is well defined, this code
nuclear@2:        * ought to change!
nuclear@2:        */
nuclear@2:       ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, cinfo->unread_marker);
nuclear@2:       break;
nuclear@2:     }
nuclear@2:     /* Successfully processed marker, so reset state variable */
nuclear@2:     cinfo->unread_marker = 0;
nuclear@2:   } /* end loop */
nuclear@2: }
nuclear@2: 
nuclear@2: 
nuclear@2: /*
nuclear@2:  * Read a restart marker, which is expected to appear next in the datastream;
nuclear@2:  * if the marker is not there, take appropriate recovery action.
nuclear@2:  * Returns FALSE if suspension is required.
nuclear@2:  *
nuclear@2:  * This is called by the entropy decoder after it has read an appropriate
nuclear@2:  * number of MCUs.  cinfo->unread_marker may be nonzero if the entropy decoder
nuclear@2:  * has already read a marker from the data source.  Under normal conditions
nuclear@2:  * cinfo->unread_marker will be reset to 0 before returning; if not reset,
nuclear@2:  * it holds a marker which the decoder will be unable to read past.
nuclear@2:  */
nuclear@2: 
nuclear@2: METHODDEF(boolean)
nuclear@2: read_restart_marker (j_decompress_ptr cinfo)
nuclear@2: {
nuclear@2:   /* Obtain a marker unless we already did. */
nuclear@2:   /* Note that next_marker will complain if it skips any data. */
nuclear@2:   if (cinfo->unread_marker == 0) {
nuclear@2:     if (! next_marker(cinfo))
nuclear@2:       return FALSE;
nuclear@2:   }
nuclear@2: 
nuclear@2:   if (cinfo->unread_marker ==
nuclear@2:       ((int) M_RST0 + cinfo->marker->next_restart_num)) {
nuclear@2:     /* Normal case --- swallow the marker and let entropy decoder continue */
nuclear@2:     TRACEMS1(cinfo, 3, JTRC_RST, cinfo->marker->next_restart_num);
nuclear@2:     cinfo->unread_marker = 0;
nuclear@2:   } else {
nuclear@2:     /* Uh-oh, the restart markers have been messed up. */
nuclear@2:     /* Let the data source manager determine how to resync. */
nuclear@2:     if (! (*cinfo->src->resync_to_restart) (cinfo,
nuclear@2: 					    cinfo->marker->next_restart_num))
nuclear@2:       return FALSE;
nuclear@2:   }
nuclear@2: 
nuclear@2:   /* Update next-restart state */
nuclear@2:   cinfo->marker->next_restart_num = (cinfo->marker->next_restart_num + 1) & 7;
nuclear@2: 
nuclear@2:   return TRUE;
nuclear@2: }
nuclear@2: 
nuclear@2: 
nuclear@2: /*
nuclear@2:  * This is the default resync_to_restart method for data source managers
nuclear@2:  * to use if they don't have any better approach.  Some data source managers
nuclear@2:  * may be able to back up, or may have additional knowledge about the data
nuclear@2:  * which permits a more intelligent recovery strategy; such managers would
nuclear@2:  * presumably supply their own resync method.
nuclear@2:  *
nuclear@2:  * read_restart_marker calls resync_to_restart if it finds a marker other than
nuclear@2:  * the restart marker it was expecting.  (This code is *not* used unless
nuclear@2:  * a nonzero restart interval has been declared.)  cinfo->unread_marker is
nuclear@2:  * the marker code actually found (might be anything, except 0 or FF).
nuclear@2:  * The desired restart marker number (0..7) is passed as a parameter.
nuclear@2:  * This routine is supposed to apply whatever error recovery strategy seems
nuclear@2:  * appropriate in order to position the input stream to the next data segment.
nuclear@2:  * Note that cinfo->unread_marker is treated as a marker appearing before
nuclear@2:  * the current data-source input point; usually it should be reset to zero
nuclear@2:  * before returning.
nuclear@2:  * Returns FALSE if suspension is required.
nuclear@2:  *
nuclear@2:  * This implementation is substantially constrained by wanting to treat the
nuclear@2:  * input as a data stream; this means we can't back up.  Therefore, we have
nuclear@2:  * only the following actions to work with:
nuclear@2:  *   1. Simply discard the marker and let the entropy decoder resume at next
nuclear@2:  *      byte of file.
nuclear@2:  *   2. Read forward until we find another marker, discarding intervening
nuclear@2:  *      data.  (In theory we could look ahead within the current bufferload,
nuclear@2:  *      without having to discard data if we don't find the desired marker.
nuclear@2:  *      This idea is not implemented here, in part because it makes behavior
nuclear@2:  *      dependent on buffer size and chance buffer-boundary positions.)
nuclear@2:  *   3. Leave the marker unread (by failing to zero cinfo->unread_marker).
nuclear@2:  *      This will cause the entropy decoder to process an empty data segment,
nuclear@2:  *      inserting dummy zeroes, and then we will reprocess the marker.
nuclear@2:  *
nuclear@2:  * #2 is appropriate if we think the desired marker lies ahead, while #3 is
nuclear@2:  * appropriate if the found marker is a future restart marker (indicating
nuclear@2:  * that we have missed the desired restart marker, probably because it got
nuclear@2:  * corrupted).
nuclear@2:  * We apply #2 or #3 if the found marker is a restart marker no more than
nuclear@2:  * two counts behind or ahead of the expected one.  We also apply #2 if the
nuclear@2:  * found marker is not a legal JPEG marker code (it's certainly bogus data).
nuclear@2:  * If the found marker is a restart marker more than 2 counts away, we do #1
nuclear@2:  * (too much risk that the marker is erroneous; with luck we will be able to
nuclear@2:  * resync at some future point).
nuclear@2:  * For any valid non-restart JPEG marker, we apply #3.  This keeps us from
nuclear@2:  * overrunning the end of a scan.  An implementation limited to single-scan
nuclear@2:  * files might find it better to apply #2 for markers other than EOI, since
nuclear@2:  * any other marker would have to be bogus data in that case.
nuclear@2:  */
nuclear@2: 
nuclear@2: GLOBAL(boolean)
nuclear@2: jpeg_resync_to_restart (j_decompress_ptr cinfo, int desired)
nuclear@2: {
nuclear@2:   int marker = cinfo->unread_marker;
nuclear@2:   int action = 1;
nuclear@2:   
nuclear@2:   /* Always put up a warning. */
nuclear@2:   WARNMS2(cinfo, JWRN_MUST_RESYNC, marker, desired);
nuclear@2:   
nuclear@2:   /* Outer loop handles repeated decision after scanning forward. */
nuclear@2:   for (;;) {
nuclear@2:     if (marker < (int) M_SOF0)
nuclear@2:       action = 2;		/* invalid marker */
nuclear@2:     else if (marker < (int) M_RST0 || marker > (int) M_RST7)
nuclear@2:       action = 3;		/* valid non-restart marker */
nuclear@2:     else {
nuclear@2:       if (marker == ((int) M_RST0 + ((desired+1) & 7)) ||
nuclear@2: 	  marker == ((int) M_RST0 + ((desired+2) & 7)))
nuclear@2: 	action = 3;		/* one of the next two expected restarts */
nuclear@2:       else if (marker == ((int) M_RST0 + ((desired-1) & 7)) ||
nuclear@2: 	       marker == ((int) M_RST0 + ((desired-2) & 7)))
nuclear@2: 	action = 2;		/* a prior restart, so advance */
nuclear@2:       else
nuclear@2: 	action = 1;		/* desired restart or too far away */
nuclear@2:     }
nuclear@2:     TRACEMS2(cinfo, 4, JTRC_RECOVERY_ACTION, marker, action);
nuclear@2:     switch (action) {
nuclear@2:     case 1:
nuclear@2:       /* Discard marker and let entropy decoder resume processing. */
nuclear@2:       cinfo->unread_marker = 0;
nuclear@2:       return TRUE;
nuclear@2:     case 2:
nuclear@2:       /* Scan to the next marker, and repeat the decision loop. */
nuclear@2:       if (! next_marker(cinfo))
nuclear@2: 	return FALSE;
nuclear@2:       marker = cinfo->unread_marker;
nuclear@2:       break;
nuclear@2:     case 3:
nuclear@2:       /* Return without advancing past this marker. */
nuclear@2:       /* Entropy decoder will be forced to process an empty segment. */
nuclear@2:       return TRUE;
nuclear@2:     }
nuclear@2:   } /* end loop */
nuclear@2: }
nuclear@2: 
nuclear@2: 
nuclear@2: /*
nuclear@2:  * Reset marker processing state to begin a fresh datastream.
nuclear@2:  */
nuclear@2: 
nuclear@2: METHODDEF(void)
nuclear@2: reset_marker_reader (j_decompress_ptr cinfo)
nuclear@2: {
nuclear@2:   my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
nuclear@2: 
nuclear@2:   cinfo->comp_info = NULL;		/* until allocated by get_sof */
nuclear@2:   cinfo->input_scan_number = 0;		/* no SOS seen yet */
nuclear@2:   cinfo->unread_marker = 0;		/* no pending marker */
nuclear@2:   marker->pub.saw_SOI = FALSE;		/* set internal state too */
nuclear@2:   marker->pub.saw_SOF = FALSE;
nuclear@2:   marker->pub.discarded_bytes = 0;
nuclear@2:   marker->cur_marker = NULL;
nuclear@2: }
nuclear@2: 
nuclear@2: 
nuclear@2: /*
nuclear@2:  * Initialize the marker reader module.
nuclear@2:  * This is called only once, when the decompression object is created.
nuclear@2:  */
nuclear@2: 
nuclear@2: GLOBAL(void)
nuclear@2: jinit_marker_reader (j_decompress_ptr cinfo)
nuclear@2: {
nuclear@2:   my_marker_ptr marker;
nuclear@2:   int i;
nuclear@2: 
nuclear@2:   /* Create subobject in permanent pool */
nuclear@2:   marker = (my_marker_ptr)
nuclear@2:     (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT,
nuclear@2: 				SIZEOF(my_marker_reader));
nuclear@2:   cinfo->marker = (struct jpeg_marker_reader *) marker;
nuclear@2:   /* Initialize public method pointers */
nuclear@2:   marker->pub.reset_marker_reader = reset_marker_reader;
nuclear@2:   marker->pub.read_markers = read_markers;
nuclear@2:   marker->pub.read_restart_marker = read_restart_marker;
nuclear@2:   /* Initialize COM/APPn processing.
nuclear@2:    * By default, we examine and then discard APP0 and APP14,
nuclear@2:    * but simply discard COM and all other APPn.
nuclear@2:    */
nuclear@2:   marker->process_COM = skip_variable;
nuclear@2:   marker->length_limit_COM = 0;
nuclear@2:   for (i = 0; i < 16; i++) {
nuclear@2:     marker->process_APPn[i] = skip_variable;
nuclear@2:     marker->length_limit_APPn[i] = 0;
nuclear@2:   }
nuclear@2:   marker->process_APPn[0] = get_interesting_appn;
nuclear@2:   marker->process_APPn[14] = get_interesting_appn;
nuclear@2:   /* Reset marker processing state */
nuclear@2:   reset_marker_reader(cinfo);
nuclear@2: }
nuclear@2: 
nuclear@2: 
nuclear@2: /*
nuclear@2:  * Control saving of COM and APPn markers into marker_list.
nuclear@2:  */
nuclear@2: 
nuclear@2: #ifdef SAVE_MARKERS_SUPPORTED
nuclear@2: 
nuclear@2: GLOBAL(void)
nuclear@2: jpeg_save_markers (j_decompress_ptr cinfo, int marker_code,
nuclear@2: 		   unsigned int length_limit)
nuclear@2: {
nuclear@2:   my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
nuclear@2:   long maxlength;
nuclear@2:   jpeg_marker_parser_method processor;
nuclear@2: 
nuclear@2:   /* Length limit mustn't be larger than what we can allocate
nuclear@2:    * (should only be a concern in a 16-bit environment).
nuclear@2:    */
nuclear@2:   maxlength = cinfo->mem->max_alloc_chunk - SIZEOF(struct jpeg_marker_struct);
nuclear@2:   if (((long) length_limit) > maxlength)
nuclear@2:     length_limit = (unsigned int) maxlength;
nuclear@2: 
nuclear@2:   /* Choose processor routine to use.
nuclear@2:    * APP0/APP14 have special requirements.
nuclear@2:    */
nuclear@2:   if (length_limit) {
nuclear@2:     processor = save_marker;
nuclear@2:     /* If saving APP0/APP14, save at least enough for our internal use. */
nuclear@2:     if (marker_code == (int) M_APP0 && length_limit < APP0_DATA_LEN)
nuclear@2:       length_limit = APP0_DATA_LEN;
nuclear@2:     else if (marker_code == (int) M_APP14 && length_limit < APP14_DATA_LEN)
nuclear@2:       length_limit = APP14_DATA_LEN;
nuclear@2:   } else {
nuclear@2:     processor = skip_variable;
nuclear@2:     /* If discarding APP0/APP14, use our regular on-the-fly processor. */
nuclear@2:     if (marker_code == (int) M_APP0 || marker_code == (int) M_APP14)
nuclear@2:       processor = get_interesting_appn;
nuclear@2:   }
nuclear@2: 
nuclear@2:   if (marker_code == (int) M_COM) {
nuclear@2:     marker->process_COM = processor;
nuclear@2:     marker->length_limit_COM = length_limit;
nuclear@2:   } else if (marker_code >= (int) M_APP0 && marker_code <= (int) M_APP15) {
nuclear@2:     marker->process_APPn[marker_code - (int) M_APP0] = processor;
nuclear@2:     marker->length_limit_APPn[marker_code - (int) M_APP0] = length_limit;
nuclear@2:   } else
nuclear@2:     ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, marker_code);
nuclear@2: }
nuclear@2: 
nuclear@2: #endif /* SAVE_MARKERS_SUPPORTED */
nuclear@2: 
nuclear@2: 
nuclear@2: /*
nuclear@2:  * Install a special processing method for COM or APPn markers.
nuclear@2:  */
nuclear@2: 
nuclear@2: GLOBAL(void)
nuclear@2: jpeg_set_marker_processor (j_decompress_ptr cinfo, int marker_code,
nuclear@2: 			   jpeg_marker_parser_method routine)
nuclear@2: {
nuclear@2:   my_marker_ptr marker = (my_marker_ptr) cinfo->marker;
nuclear@2: 
nuclear@2:   if (marker_code == (int) M_COM)
nuclear@2:     marker->process_COM = routine;
nuclear@2:   else if (marker_code >= (int) M_APP0 && marker_code <= (int) M_APP15)
nuclear@2:     marker->process_APPn[marker_code - (int) M_APP0] = routine;
nuclear@2:   else
nuclear@2:     ERREXIT1(cinfo, JERR_UNKNOWN_MARKER, marker_code);
nuclear@2: }