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-rw-r--r--code/jpeg-6/jdmarker.c1052
1 files changed, 0 insertions, 1052 deletions
diff --git a/code/jpeg-6/jdmarker.c b/code/jpeg-6/jdmarker.c
deleted file mode 100644
index 80e5f78..0000000
--- a/code/jpeg-6/jdmarker.c
+++ /dev/null
@@ -1,1052 +0,0 @@
-/*
- * 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);
-}