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doom3-bfg/neo/renderer/jpeg-6/jdmarker.cpp
Brian Harris 5016f605b8 Initial commit
2012-11-26 12:58:24 -06:00

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/*
* jdmarker.c
*
* Copyright (C) 1991-1995, Thomas G. Lane.
* This file is part of the Independent JPEG Group's software.
* For conditions of distribution and use, see the accompanying README file.
*
* This file contains routines to decode JPEG datastream markers.
* Most of the complexity arises from our desire to support input
* suspension: if not all of the data for a marker is available,
* we must exit back to the application. On resumption, we reprocess
* the marker.
*/
#define JPEG_INTERNALS
#include "jinclude.h"
#include "jpeglib.h"
typedef enum { /* JPEG marker codes */
M_SOF0 = 0xc0,
M_SOF1 = 0xc1,
M_SOF2 = 0xc2,
M_SOF3 = 0xc3,
M_SOF5 = 0xc5,
M_SOF6 = 0xc6,
M_SOF7 = 0xc7,
M_JPG = 0xc8,
M_SOF9 = 0xc9,
M_SOF10 = 0xca,
M_SOF11 = 0xcb,
M_SOF13 = 0xcd,
M_SOF14 = 0xce,
M_SOF15 = 0xcf,
M_DHT = 0xc4,
M_DAC = 0xcc,
M_RST0 = 0xd0,
M_RST1 = 0xd1,
M_RST2 = 0xd2,
M_RST3 = 0xd3,
M_RST4 = 0xd4,
M_RST5 = 0xd5,
M_RST6 = 0xd6,
M_RST7 = 0xd7,
M_SOI = 0xd8,
M_EOI = 0xd9,
M_SOS = 0xda,
M_DQT = 0xdb,
M_DNL = 0xdc,
M_DRI = 0xdd,
M_DHP = 0xde,
M_EXP = 0xdf,
M_APP0 = 0xe0,
M_APP1 = 0xe1,
M_APP2 = 0xe2,
M_APP3 = 0xe3,
M_APP4 = 0xe4,
M_APP5 = 0xe5,
M_APP6 = 0xe6,
M_APP7 = 0xe7,
M_APP8 = 0xe8,
M_APP9 = 0xe9,
M_APP10 = 0xea,
M_APP11 = 0xeb,
M_APP12 = 0xec,
M_APP13 = 0xed,
M_APP14 = 0xee,
M_APP15 = 0xef,
M_JPG0 = 0xf0,
M_JPG13 = 0xfd,
M_COM = 0xfe,
M_TEM = 0x01,
M_ERROR = 0x100
} JPEG_MARKER;
/*
* Macros for fetching data from the data source module.
*
* At all times, cinfo->src->next_input_byte and ->bytes_in_buffer reflect
* the current restart point; we update them only when we have reached a
* suitable place to restart if a suspension occurs.
*/
/* Declare and initialize local copies of input pointer/count */
#define INPUT_VARS( cinfo ) \
struct jpeg_source_mgr * datasrc = ( cinfo )->src; \
const JOCTET * next_input_byte = datasrc->next_input_byte; \
size_t bytes_in_buffer = datasrc->bytes_in_buffer
/* Unload the local copies --- do this only at a restart boundary */
#define INPUT_SYNC( cinfo ) \
( datasrc->next_input_byte = next_input_byte, \
datasrc->bytes_in_buffer = bytes_in_buffer )
/* Reload the local copies --- seldom used except in MAKE_BYTE_AVAIL */
#define INPUT_RELOAD( cinfo ) \
( next_input_byte = datasrc->next_input_byte, \
bytes_in_buffer = datasrc->bytes_in_buffer )
/* Internal macro for INPUT_BYTE and INPUT_2BYTES: make a byte available.
* Note we do *not* do INPUT_SYNC before calling fill_input_buffer,
* but we must reload the local copies after a successful fill.
*/
#define MAKE_BYTE_AVAIL( cinfo, action ) \
if ( bytes_in_buffer == 0 ) { \
if ( !( *datasrc->fill_input_buffer )( cinfo ) ) \
{ action; } \
INPUT_RELOAD( cinfo ); \
} \
bytes_in_buffer--
/* Read a byte into variable V.
* If must suspend, take the specified action (typically "return FALSE").
*/
#define INPUT_BYTE( cinfo, V, action ) \
MAKESTMT( MAKE_BYTE_AVAIL( cinfo, action ); \
V = GETJOCTET( *next_input_byte++ ); )
/* As above, but read two bytes interpreted as an unsigned 16-bit integer.
* V should be declared unsigned int or perhaps INT32.
*/
#define INPUT_2BYTES( cinfo, V, action ) \
MAKESTMT( MAKE_BYTE_AVAIL( cinfo, action ); \
V = ( (unsigned int) GETJOCTET( *next_input_byte++ ) ) << 8; \
MAKE_BYTE_AVAIL( cinfo, action ); \
V += GETJOCTET( *next_input_byte++ ); )
/*
* Routines to process JPEG markers.
*
* Entry condition: JPEG marker itself has been read and its code saved
* in cinfo->unread_marker; input restart point is just after the marker.
*
* Exit: if return TRUE, have read and processed any parameters, and have
* updated the restart point to point after the parameters.
* If return FALSE, was forced to suspend before reaching end of
* marker parameters; restart point has not been moved. Same routine
* will be called again after application supplies more input data.
*
* This approach to suspension assumes that all of a marker's parameters can
* fit into a single input bufferload. This should hold for "normal"
* markers. Some COM/APPn markers might have large parameter segments,
* but we use skip_input_data to get past those, and thereby put the problem
* on the source manager's shoulders.
*
* Note that we don't bother to avoid duplicate trace messages if a
* suspension occurs within marker parameters. Other side effects
* require more care.
*/
LOCAL boolean
get_soi( j_decompress_ptr cinfo ) {
/* Process an SOI marker */
int i;
TRACEMS( cinfo, 1, JTRC_SOI );
if ( cinfo->marker->saw_SOI ) {
ERREXIT( cinfo, JERR_SOI_DUPLICATE );
}
/* Reset all parameters that are defined to be reset by SOI */
for ( i = 0; i < NUM_ARITH_TBLS; i++ ) {
cinfo->arith_dc_L[i] = 0;
cinfo->arith_dc_U[i] = 1;
cinfo->arith_ac_K[i] = 5;
}
cinfo->restart_interval = 0;
/* Set initial assumptions for colorspace etc */
cinfo->jpeg_color_space = JCS_UNKNOWN;
cinfo->CCIR601_sampling = FALSE;/* Assume non-CCIR sampling??? */
cinfo->saw_JFIF_marker = FALSE;
cinfo->density_unit = 0;/* set default JFIF APP0 values */
cinfo->X_density = 1;
cinfo->Y_density = 1;
cinfo->saw_Adobe_marker = FALSE;
cinfo->Adobe_transform = 0;
cinfo->marker->saw_SOI = TRUE;
return TRUE;
}
LOCAL boolean
get_sof( j_decompress_ptr cinfo, boolean is_prog, boolean is_arith ) {
/* Process a SOFn marker */
INT32 length;
int c, ci;
jpeg_component_info * compptr;
INPUT_VARS( cinfo );
cinfo->progressive_mode = is_prog;
cinfo->arith_code = is_arith;
INPUT_2BYTES( cinfo, length, return FALSE );
INPUT_BYTE( cinfo, cinfo->data_precision, return FALSE );
INPUT_2BYTES( cinfo, cinfo->image_height, return FALSE );
INPUT_2BYTES( cinfo, cinfo->image_width, return FALSE );
INPUT_BYTE( cinfo, cinfo->num_components, return FALSE );
length -= 8;
TRACEMS4( cinfo, 1, JTRC_SOF, cinfo->unread_marker,
(int) cinfo->image_width, (int) cinfo->image_height,
cinfo->num_components );
if ( cinfo->marker->saw_SOF ) {
ERREXIT( cinfo, JERR_SOF_DUPLICATE );
}
/* We don't support files in which the image height is initially specified */
/* as 0 and is later redefined by DNL. As long as we have to check that, */
/* might as well have a general sanity check. */
if ( ( cinfo->image_height <= 0 ) || ( cinfo->image_width <= 0 )
|| ( cinfo->num_components <= 0 ) ) {
ERREXIT( cinfo, JERR_EMPTY_IMAGE );
}
if ( length != ( cinfo->num_components * 3 ) ) {
ERREXIT( cinfo, JERR_BAD_LENGTH );
}
if ( cinfo->comp_info == NULL ) {/* do only once, even if suspend */
cinfo->comp_info = (jpeg_component_info *) ( *cinfo->mem->alloc_small )
( (j_common_ptr) cinfo, JPOOL_IMAGE,
cinfo->num_components * SIZEOF( jpeg_component_info ) );
}
for ( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
ci++, compptr++ ) {
compptr->component_index = ci;
INPUT_BYTE( cinfo, compptr->component_id, return FALSE );
INPUT_BYTE( cinfo, c, return FALSE );
compptr->h_samp_factor = ( c >> 4 ) & 15;
compptr->v_samp_factor = ( c ) & 15;
INPUT_BYTE( cinfo, compptr->quant_tbl_no, return FALSE );
TRACEMS4( cinfo, 1, JTRC_SOF_COMPONENT,
compptr->component_id, compptr->h_samp_factor,
compptr->v_samp_factor, compptr->quant_tbl_no );
}
cinfo->marker->saw_SOF = TRUE;
INPUT_SYNC( cinfo );
return TRUE;
}
LOCAL boolean
get_sos( j_decompress_ptr cinfo ) {
/* Process a SOS marker */
INT32 length;
int i, ci, n, c, cc;
jpeg_component_info * compptr;
INPUT_VARS( cinfo );
if ( !cinfo->marker->saw_SOF ) {
ERREXIT( cinfo, JERR_SOS_NO_SOF );
}
INPUT_2BYTES( cinfo, length, return FALSE );
INPUT_BYTE( cinfo, n, return FALSE );/* Number of components */
if ( ( length != ( n * 2 + 6 ) || n < 1 ) || ( n > MAX_COMPS_IN_SCAN ) ) {
ERREXIT( cinfo, JERR_BAD_LENGTH );
}
TRACEMS1( cinfo, 1, JTRC_SOS, n );
cinfo->comps_in_scan = n;
/* Collect the component-spec parameters */
for ( i = 0; i < n; i++ ) {
INPUT_BYTE( cinfo, cc, return FALSE );
INPUT_BYTE( cinfo, c, return FALSE );
for ( ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;
ci++, compptr++ ) {
if ( cc == compptr->component_id ) {
goto id_found;
}
}
ERREXIT1( cinfo, JERR_BAD_COMPONENT_ID, cc );
id_found:
cinfo->cur_comp_info[i] = compptr;
compptr->dc_tbl_no = ( c >> 4 ) & 15;
compptr->ac_tbl_no = ( c ) & 15;
TRACEMS3( cinfo, 1, JTRC_SOS_COMPONENT, cc,
compptr->dc_tbl_no, compptr->ac_tbl_no );
}
/* Collect the additional scan parameters Ss, Se, Ah/Al. */
INPUT_BYTE( cinfo, c, return FALSE );
cinfo->Ss = c;
INPUT_BYTE( cinfo, c, return FALSE );
cinfo->Se = c;
INPUT_BYTE( cinfo, c, return FALSE );
cinfo->Ah = ( c >> 4 ) & 15;
cinfo->Al = ( c ) & 15;
TRACEMS4( cinfo, 1, JTRC_SOS_PARAMS, cinfo->Ss, cinfo->Se,
cinfo->Ah, cinfo->Al );
/* Prepare to scan data & restart markers */
cinfo->marker->next_restart_num = 0;
/* Count another SOS marker */
cinfo->input_scan_number++;
INPUT_SYNC( cinfo );
return TRUE;
}
METHODDEF boolean
get_app0( j_decompress_ptr cinfo ) {
/* Process an APP0 marker */
#define JFIF_LEN 14
INT32 length;
UINT8 b[JFIF_LEN];
int buffp;
INPUT_VARS( cinfo );
INPUT_2BYTES( cinfo, length, return FALSE );
length -= 2;
/* See if a JFIF APP0 marker is present */
if ( length >= JFIF_LEN ) {
for ( buffp = 0; buffp < JFIF_LEN; buffp++ ) {
INPUT_BYTE( cinfo, b[buffp], return FALSE );
}
length -= JFIF_LEN;
if ( ( b[0] == 0x4A ) && ( b[1] == 0x46 ) && ( b[2] == 0x49 ) && ( b[3] == 0x46 ) && ( b[4] == 0 ) ) {
/* Found JFIF APP0 marker: 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 ( b[5] != 1 ) {
WARNMS2( cinfo, JWRN_JFIF_MAJOR, b[5], b[6] );
} else if ( b[6] > 2 ) {
TRACEMS2( cinfo, 1, JTRC_JFIF_MINOR, b[5], b[6] );
}
/* Save info */
cinfo->saw_JFIF_marker = TRUE;
cinfo->density_unit = b[7];
cinfo->X_density = ( b[8] << 8 ) + b[9];
cinfo->Y_density = ( b[10] << 8 ) + b[11];
TRACEMS3( cinfo, 1, JTRC_JFIF,
cinfo->X_density, cinfo->Y_density, cinfo->density_unit );
if ( b[12] | b[13] ) {
TRACEMS2( cinfo, 1, JTRC_JFIF_THUMBNAIL, b[12], b[13] );
}
if ( length != ( (INT32) b[12] * (INT32) b[13] * (INT32) 3 ) ) {
TRACEMS1( cinfo, 1, JTRC_JFIF_BADTHUMBNAILSIZE, (int) length );
}
} else {
/* Start of APP0 does not match "JFIF" */
TRACEMS1( cinfo, 1, JTRC_APP0, (int) length + JFIF_LEN );
}
} else {
/* Too short to be JFIF marker */
TRACEMS1( cinfo, 1, JTRC_APP0, (int) length );
}
INPUT_SYNC( cinfo );
if ( length > 0 ) { /* skip any remaining data -- could be lots */
( *cinfo->src->skip_input_data )( cinfo, (long) length );
}
return TRUE;
}
METHODDEF boolean
get_app14( j_decompress_ptr cinfo ) {
/* Process an APP14 marker */
#define ADOBE_LEN 12
INT32 length;
UINT8 b[ADOBE_LEN];
int buffp;
unsigned int version, flags0, flags1, transform;
INPUT_VARS( cinfo );
INPUT_2BYTES( cinfo, length, return FALSE );
length -= 2;
/* See if an Adobe APP14 marker is present */
if ( length >= ADOBE_LEN ) {
for ( buffp = 0; buffp < ADOBE_LEN; buffp++ ) {
INPUT_BYTE( cinfo, b[buffp], return FALSE );
}
length -= ADOBE_LEN;
if ( ( b[0] == 0x41 ) && ( b[1] == 0x64 ) && ( b[2] == 0x6F ) && ( b[3] == 0x62 ) && ( b[4] == 0x65 ) ) {
/* Found Adobe APP14 marker */
version = ( b[5] << 8 ) + b[6];
flags0 = ( b[7] << 8 ) + b[8];
flags1 = ( b[9] << 8 ) + b[10];
transform = b[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" */
TRACEMS1( cinfo, 1, JTRC_APP14, (int) length + ADOBE_LEN );
}
} else {
/* Too short to be Adobe marker */
TRACEMS1( cinfo, 1, JTRC_APP14, (int) length );
}
INPUT_SYNC( cinfo );
if ( length > 0 ) { /* skip any remaining data -- could be lots */
( *cinfo->src->skip_input_data )( cinfo, (long) length );
}
return TRUE;
}
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 );
}
}
}
INPUT_SYNC( cinfo );
return TRUE;
}
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 > 0 ) {
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] );
if ( ( count > 256 ) || ( ( (INT32) count ) > length ) ) {
ERREXIT( cinfo, JERR_DHT_COUNTS );
}
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 ) );
}
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 );
}
quant_ptr->quantval[i] = (UINT16) tmp;
}
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;
}
}
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;
}
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 );
TRACEMS2( cinfo, 1, JTRC_MISC_MARKER, cinfo->unread_marker, (int) length );
INPUT_SYNC( cinfo ); /* do before skip_input_data */
( *cinfo->src->skip_input_data )( cinfo, (long) length - 2L );
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 ( !( *cinfo->marker->process_APPn[cinfo->unread_marker - (int) M_APP0] )( cinfo ) ) {
return JPEG_SUSPENDED;
}
break;
case M_COM:
if ( !( *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, 2, 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 ) {
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 */
cinfo->marker->saw_SOI = FALSE; /* set internal state too */
cinfo->marker->saw_SOF = FALSE;
cinfo->marker->discarded_bytes = 0;
}
/*
* 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 ) {
int i;
/* Create subobject in permanent pool */
cinfo->marker = (struct jpeg_marker_reader *)
( * cinfo->mem->alloc_small )( (j_common_ptr) cinfo, JPOOL_PERMANENT,
SIZEOF( struct jpeg_marker_reader ) );
/* Initialize method pointers */
cinfo->marker->reset_marker_reader = reset_marker_reader;
cinfo->marker->read_markers = read_markers;
cinfo->marker->read_restart_marker = read_restart_marker;
cinfo->marker->process_COM = skip_variable;
for ( i = 0; i < 16; i++ ) {
cinfo->marker->process_APPn[i] = skip_variable;
}
cinfo->marker->process_APPn[0] = get_app0;
cinfo->marker->process_APPn[14] = get_app14;
/* Reset marker processing state */
reset_marker_reader( cinfo );
}
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