1361 lines
		
	
	
		
			40 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			1361 lines
		
	
	
		
			40 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
 | |
|  * 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,
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|  * 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 */
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|   M_SOF0  = 0xc0,
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|   M_SOF1  = 0xc1,
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|   M_SOF2  = 0xc2,
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|   M_SOF3  = 0xc3,
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| 
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|   M_SOF5  = 0xc5,
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|   M_SOF6  = 0xc6,
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|   M_SOF7  = 0xc7,
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| 
 | |
|   M_JPG   = 0xc8,
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|   M_SOF9  = 0xc9,
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|   M_SOF10 = 0xca,
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|   M_SOF11 = 0xcb,
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| 
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|   M_SOF13 = 0xcd,
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|   M_SOF14 = 0xce,
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|   M_SOF15 = 0xcf,
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| 
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|   M_DHT   = 0xc4,
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| 
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|   M_DAC   = 0xcc,
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| 
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|   M_RST0  = 0xd0,
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|   M_RST1  = 0xd1,
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|   M_RST2  = 0xd2,
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|   M_RST3  = 0xd3,
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|   M_RST4  = 0xd4,
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|   M_RST5  = 0xd5,
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|   M_RST6  = 0xd6,
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|   M_RST7  = 0xd7,
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| 
 | |
|   M_SOI   = 0xd8,
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|   M_EOI   = 0xd9,
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|   M_SOS   = 0xda,
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|   M_DQT   = 0xdb,
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|   M_DNL   = 0xdc,
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|   M_DRI   = 0xdd,
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|   M_DHP   = 0xde,
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|   M_EXP   = 0xdf,
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| 
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|   M_APP0  = 0xe0,
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|   M_APP1  = 0xe1,
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|   M_APP2  = 0xe2,
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|   M_APP3  = 0xe3,
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|   M_APP4  = 0xe4,
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|   M_APP5  = 0xe5,
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|   M_APP6  = 0xe6,
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|   M_APP7  = 0xe7,
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|   M_APP8  = 0xe8,
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|   M_APP9  = 0xe9,
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|   M_APP10 = 0xea,
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|   M_APP11 = 0xeb,
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|   M_APP12 = 0xec,
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|   M_APP13 = 0xed,
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|   M_APP14 = 0xee,
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|   M_APP15 = 0xef,
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| 
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|   M_JPG0  = 0xf0,
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|   M_JPG13 = 0xfd,
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|   M_COM   = 0xfe,
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| 
 | |
|   M_TEM   = 0x01,
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| 
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|   M_ERROR = 0x100
 | |
| } JPEG_MARKER;
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| 
 | |
| 
 | |
| /* Private state */
 | |
| 
 | |
| typedef struct {
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|   struct jpeg_marker_reader pub; /* public fields */
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| 
 | |
|   /* Application-overridable marker processing methods */
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|   jpeg_marker_parser_method process_COM;
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|   jpeg_marker_parser_method process_APPn[16];
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| 
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|   /* Limit on marker data length to save for each marker type */
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|   unsigned int length_limit_COM;
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|   unsigned int length_limit_APPn[16];
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| 
 | |
|   /* Status of COM/APPn marker saving */
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|   jpeg_saved_marker_ptr cur_marker;	/* NULL if not processing a marker */
 | |
|   unsigned int bytes_read;		/* data bytes read so far in marker */
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|   /* Note: cur_marker is not linked into marker_list until it's all read. */
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| } my_marker_reader;
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| 
 | |
| typedef my_marker_reader * my_marker_ptr;
 | |
| 
 | |
| 
 | |
| /*
 | |
|  * Macros for fetching data from the data source module.
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|  *
 | |
|  * 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
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|  * suitable place to restart if a suspension occurs.
 | |
|  */
 | |
| 
 | |
| /* Declare and initialize local copies of input pointer/count */
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| #define INPUT_VARS(cinfo)  \
 | |
|     struct jpeg_source_mgr * datasrc = (cinfo)->src;  \
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|     const JOCTET * next_input_byte = datasrc->next_input_byte;  \
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|     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,  \
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|       datasrc->bytes_in_buffer = bytes_in_buffer )
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| 
 | |
| /* Reload the local copies --- used only in MAKE_BYTE_AVAIL */
 | |
| #define INPUT_RELOAD(cinfo)  \
 | |
|     ( next_input_byte = datasrc->next_input_byte,  \
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|       bytes_in_buffer = datasrc->bytes_in_buffer )
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| 
 | |
| /* Internal macro for INPUT_BYTE and INPUT_2BYTES: make a byte available.
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|  * Note we do *not* do INPUT_SYNC before calling fill_input_buffer,
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|  * but we must reload the local copies after a successful fill.
 | |
|  */
 | |
| #define MAKE_BYTE_AVAIL(cinfo,action)  \
 | |
|     if (bytes_in_buffer == 0) {  \
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|       if (! (*datasrc->fill_input_buffer) (cinfo))  \
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|         { action; }  \
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|       INPUT_RELOAD(cinfo);  \
 | |
|     }
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| 
 | |
| /* Read a byte into variable V.
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|  * If must suspend, take the specified action (typically "return FALSE").
 | |
|  */
 | |
| #define INPUT_BYTE(cinfo,V,action)  \
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|     MAKESTMT( MAKE_BYTE_AVAIL(cinfo,action); \
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|           bytes_in_buffer--; \
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|           V = GETJOCTET(*next_input_byte++); )
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| 
 | |
| /* 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)  \
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|     MAKESTMT( MAKE_BYTE_AVAIL(cinfo,action); \
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|           bytes_in_buffer--; \
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|           V = ((unsigned int) GETJOCTET(*next_input_byte++)) << 8; \
 | |
|           MAKE_BYTE_AVAIL(cinfo,action); \
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|           bytes_in_buffer--; \
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|           V += GETJOCTET(*next_input_byte++); )
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| 
 | |
| 
 | |
| /*
 | |
|  * 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
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|  * what it's consumed (ie, the end of the buffer) before returning FALSE.
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|  * On resumption, cinfo->unread_marker still contains the marker code,
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|  * 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
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|  * 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)
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|     ERREXIT(cinfo, JERR_SOI_DUPLICATE);
 | |
| 
 | |
|   /* Reset all parameters that are defined to be reset by SOI */
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| 
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|   for (i = 0; i < NUM_ARITH_TBLS; i++) {
 | |
|     cinfo->arith_dc_L[i] = 0;
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|     cinfo->arith_dc_U[i] = 1;
 | |
|     cinfo->arith_ac_K[i] = 5;
 | |
|   }
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|   cinfo->restart_interval = 0;
 | |
| 
 | |
|   /* Set initial assumptions for colorspace etc */
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| 
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|   cinfo->jpeg_color_space = JCS_UNKNOWN;
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|   cinfo->CCIR601_sampling = FALSE; /* Assume non-CCIR sampling??? */
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| 
 | |
|   cinfo->saw_JFIF_marker = FALSE;
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|   cinfo->JFIF_major_version = 1; /* set default JFIF APP0 values */
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|   cinfo->JFIF_minor_version = 1;
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|   cinfo->density_unit = 0;
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|   cinfo->X_density = 1;
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|   cinfo->Y_density = 1;
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|   cinfo->saw_Adobe_marker = FALSE;
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|   cinfo->Adobe_transform = 0;
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| 
 | |
|   cinfo->marker->saw_SOI = TRUE;
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| 
 | |
|   return TRUE;
 | |
| }
 | |
| 
 | |
| 
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| LOCAL(boolean)
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| get_sof (j_decompress_ptr cinfo, boolean is_prog, boolean is_arith)
 | |
| /* Process a SOFn marker */
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| {
 | |
|   INT32 length;
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|   int c, ci;
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|   jpeg_component_info * compptr;
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|   INPUT_VARS(cinfo);
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| 
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|   cinfo->progressive_mode = is_prog;
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|   cinfo->arith_code = is_arith;
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| 
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|   INPUT_2BYTES(cinfo, length, return FALSE);
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| 
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|   INPUT_BYTE(cinfo, cinfo->data_precision, return FALSE);
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|   INPUT_2BYTES(cinfo, cinfo->image_height, return FALSE);
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|   INPUT_2BYTES(cinfo, cinfo->image_width, return FALSE);
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|   INPUT_BYTE(cinfo, cinfo->num_components, return FALSE);
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| 
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|   length -= 8;
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| 
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|   TRACEMS4(cinfo, 1, JTRC_SOF, cinfo->unread_marker,
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|        (int) cinfo->image_width, (int) cinfo->image_height,
 | |
|        cinfo->num_components);
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| 
 | |
|   if (cinfo->marker->saw_SOF)
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|     ERREXIT(cinfo, JERR_SOF_DUPLICATE);
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| 
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|   /* We don't support files in which the image height is initially specified */
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|   /* as 0 and is later redefined by DNL.  As long as we have to check that,  */
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|   /* might as well have a general sanity check. */
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|   if (cinfo->image_height <= 0 || cinfo->image_width <= 0
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|       || cinfo->num_components <= 0)
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|     ERREXIT(cinfo, JERR_EMPTY_IMAGE);
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| 
 | |
|   if (length != (cinfo->num_components * 3))
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|     ERREXIT(cinfo, JERR_BAD_LENGTH);
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| 
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|   if (cinfo->comp_info == NULL)	/* do only once, even if suspend */
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|     cinfo->comp_info = (jpeg_component_info *) (*cinfo->mem->alloc_small)
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|             ((j_common_ptr) cinfo, JPOOL_IMAGE,
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|              cinfo->num_components * SIZEOF(jpeg_component_info));
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| 
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|   for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
 | |
|        ci++, compptr++) {
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|     compptr->component_index = ci;
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|     INPUT_BYTE(cinfo, compptr->component_id, return FALSE);
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|     INPUT_BYTE(cinfo, c, return FALSE);
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|     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,
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|          compptr->component_id, compptr->h_samp_factor,
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|          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,
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|          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;
 | |
| }
 | |
| 
 | |
| 
 | |
| #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;
 | |
| }
 | |
| 
 | |
| #else /* ! D_ARITH_CODING_SUPPORTED */
 | |
| 
 | |
| #define get_dac(cinfo)  skip_variable(cinfo)
 | |
| 
 | |
| #endif /* D_ARITH_CODING_SUPPORTED */
 | |
| 
 | |
| 
 | |
| 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);
 | |
| }
 | 
