| /* |
| * jdmarker.c |
| * |
| * This file was part of the Independent JPEG Group's software: |
| * Copyright (C) 1991-1998, Thomas G. Lane. |
| * Lossless JPEG Modifications: |
| * Copyright (C) 1999, Ken Murchison. |
| * libjpeg-turbo Modifications: |
| * Copyright (C) 2012, 2015, 2022, D. R. Commander. |
| * For conditions of distribution and use, see the accompanying README.ijg |
| * 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; |
| |
| |
| /* Private state */ |
| |
| typedef struct { |
| struct jpeg_marker_reader pub; /* public fields */ |
| |
| /* Application-overridable marker processing methods */ |
| jpeg_marker_parser_method process_COM; |
| jpeg_marker_parser_method process_APPn[16]; |
| |
| /* Limit on marker data length to save for each marker type */ |
| unsigned int length_limit_COM; |
| unsigned int length_limit_APPn[16]; |
| |
| /* Status of COM/APPn marker saving */ |
| jpeg_saved_marker_ptr cur_marker; /* NULL if not processing a marker */ |
| unsigned int bytes_read; /* data bytes read so far in marker */ |
| /* Note: cur_marker is not linked into marker_list until it's all read. */ |
| } my_marker_reader; |
| |
| typedef my_marker_reader *my_marker_ptr; |
| |
| |
| /* |
| * 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 --- used only 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); \ |
| } |
| |
| /* 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); \ |
| bytes_in_buffer--; \ |
| V = *next_input_byte++; ) |
| |
| /* As above, but read two bytes interpreted as an unsigned 16-bit integer. |
| * V should be declared unsigned int or perhaps JLONG. |
| */ |
| #define INPUT_2BYTES(cinfo, V, action) \ |
| MAKESTMT( MAKE_BYTE_AVAIL(cinfo, action); \ |
| bytes_in_buffer--; \ |
| V = ((unsigned int)(*next_input_byte++)) << 8; \ |
| MAKE_BYTE_AVAIL(cinfo, action); \ |
| bytes_in_buffer--; \ |
| V += *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 |
| * 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 |
| * what it's consumed (ie, the end of the buffer) before returning FALSE. |
| * On resumption, cinfo->unread_marker still contains the marker code, |
| * 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 |
| * 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->JFIF_major_version = 1; /* set default JFIF APP0 values */ |
| cinfo->JFIF_minor_version = 1; |
| cinfo->density_unit = 0; |
| 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_lossless, |
| boolean is_arith) |
| /* Process a SOFn marker */ |
| { |
| JLONG length; |
| int c, ci; |
| jpeg_component_info *compptr; |
| INPUT_VARS(cinfo); |
| |
| cinfo->progressive_mode = is_prog; |
| cinfo->master->lossless = is_lossless; |
| 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 */ |
| { |
| JLONG length; |
| int i, ci, n, c, cc, pi; |
| 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 < MAX_COMPS_IN_SCAN; i++) |
| cinfo->cur_comp_info[i] = NULL; |
| |
| 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 < MAX_COMPS_IN_SCAN; |
| ci++, compptr++) { |
| if (cc == compptr->component_id && !cinfo->cur_comp_info[ci]) |
| 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); |
| |
| /* This CSi (cc) should differ from the previous CSi */ |
| for (pi = 0; pi < i; pi++) { |
| if (cinfo->cur_comp_info[pi] == compptr) { |
| ERREXIT1(cinfo, JERR_BAD_COMPONENT_ID, cc); |
| } |
| } |
| } |
| |
| /* 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 */ |
| { |
| JLONG 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 */ |
| { |
| JLONG 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 || ((JLONG)count) > length) |
| ERREXIT(cinfo, JERR_BAD_HUFF_TABLE); |
| |
| for (i = 0; i < count; i++) |
| INPUT_BYTE(cinfo, huffval[i], return FALSE); |
| |
| memset(&huffval[count], 0, (256 - count) * sizeof(UINT8)); |
| |
| length -= count; |
| |
| if (index & 0x10) { /* AC table definition */ |
| index -= 0x10; |
| if (index < 0 || index >= NUM_HUFF_TBLS) |
| ERREXIT1(cinfo, JERR_DHT_INDEX, index); |
| htblptr = &cinfo->ac_huff_tbl_ptrs[index]; |
| } else { /* DC table definition */ |
| if (index < 0 || index >= NUM_HUFF_TBLS) |
| ERREXIT1(cinfo, JERR_DHT_INDEX, index); |
| htblptr = &cinfo->dc_huff_tbl_ptrs[index]; |
| } |
| |
| if (*htblptr == NULL) |
| *htblptr = jpeg_alloc_huff_table((j_common_ptr)cinfo); |
| |
| memcpy((*htblptr)->bits, bits, sizeof((*htblptr)->bits)); |
| memcpy((*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 */ |
| { |
| JLONG 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 */ |
| { |
| JLONG 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 *data, unsigned int datalen, |
| JLONG 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. |
| */ |
| { |
| JLONG totallen = (JLONG)datalen + remaining; |
| |
| if (datalen >= APP0_DATA_LEN && |
| data[0] == 0x4A && |
| data[1] == 0x46 && |
| data[2] == 0x49 && |
| data[3] == 0x46 && |
| data[4] == 0) { |
| /* Found JFIF APP0 marker: save info */ |
| cinfo->saw_JFIF_marker = TRUE; |
| cinfo->JFIF_major_version = data[5]; |
| cinfo->JFIF_minor_version = data[6]; |
| cinfo->density_unit = data[7]; |
| cinfo->X_density = (data[8] << 8) + data[9]; |
| cinfo->Y_density = (data[10] << 8) + 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 (data[12] | data[13]) |
| TRACEMS2(cinfo, 1, JTRC_JFIF_THUMBNAIL, data[12], data[13]); |
| totallen -= APP0_DATA_LEN; |
| if (totallen != ((JLONG)data[12] * (JLONG)data[13] * (JLONG)3)) |
| TRACEMS1(cinfo, 1, JTRC_JFIF_BADTHUMBNAILSIZE, (int)totallen); |
| } else if (datalen >= 6 && |
| data[0] == 0x4A && |
| data[1] == 0x46 && |
| data[2] == 0x58 && |
| data[3] == 0x58 && |
| 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 (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, 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 *data, unsigned int datalen, |
| JLONG 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 && |
| data[0] == 0x41 && |
| data[1] == 0x64 && |
| data[2] == 0x6F && |
| data[3] == 0x62 && |
| data[4] == 0x65) { |
| /* Found Adobe APP14 marker */ |
| version = (data[5] << 8) + data[6]; |
| flags0 = (data[7] << 8) + data[8]; |
| flags1 = (data[9] << 8) + data[10]; |
| transform = 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 */ |
| { |
| JLONG 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 *)b, numtoread, length); |
| break; |
| case M_APP14: |
| examine_app14(cinfo, (JOCTET *)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 *data; |
| JLONG 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 *)(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 */ |
| { |
| JLONG 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, FALSE)) |
| return JPEG_SUSPENDED; |
| break; |
| |
| case M_SOF2: /* Progressive, Huffman */ |
| if (!get_sof(cinfo, TRUE, FALSE, FALSE)) |
| return JPEG_SUSPENDED; |
| break; |
| |
| case M_SOF3: /* Lossless, Huffman */ |
| if (!get_sof(cinfo, FALSE, TRUE, FALSE)) |
| return JPEG_SUSPENDED; |
| break; |
| |
| case M_SOF9: /* Extended sequential, arithmetic */ |
| if (!get_sof(cinfo, FALSE, FALSE, TRUE)) |
| return JPEG_SUSPENDED; |
| break; |
| |
| case M_SOF10: /* Progressive, arithmetic */ |
| if (!get_sof(cinfo, TRUE, FALSE, TRUE)) |
| return JPEG_SUSPENDED; |
| break; |
| |
| case M_SOF11: /* Lossless, arithmetic */ |
| if (!get_sof(cinfo, FALSE, TRUE, TRUE)) |
| return JPEG_SUSPENDED; |
| break; |
| |
| /* Currently unsupported SOFn types */ |
| 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_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); |
| } |