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Diffstat (limited to 'code/jpeg-6/jdmarker.c')
-rw-r--r-- | code/jpeg-6/jdmarker.c | 1052 |
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); -} |