diff options
Diffstat (limited to 'jpeg/jdinput.c')
| -rw-r--r-- | jpeg/jdinput.c | 661 |
1 files changed, 0 insertions, 661 deletions
diff --git a/jpeg/jdinput.c b/jpeg/jdinput.c deleted file mode 100644 index 2c5c717..0000000 --- a/jpeg/jdinput.c +++ /dev/null @@ -1,661 +0,0 @@ -/* - * jdinput.c - * - * Copyright (C) 1991-1997, Thomas G. Lane. - * Modified 2002-2009 by Guido Vollbeding. - * 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 input control logic for the JPEG decompressor. - * These routines are concerned with controlling the decompressor's input - * processing (marker reading and coefficient decoding). The actual input - * reading is done in jdmarker.c, jdhuff.c, and jdarith.c. - */ - -#define JPEG_INTERNALS -#include "jinclude.h" -#include "jpeglib.h" - - -/* Private state */ - -typedef struct { - struct jpeg_input_controller pub; /* public fields */ - - int inheaders; /* Nonzero until first SOS is reached */ -} my_input_controller; - -typedef my_input_controller * my_inputctl_ptr; - - -/* Forward declarations */ -METHODDEF(int) consume_markers JPP((j_decompress_ptr cinfo)); - - -/* - * Routines to calculate various quantities related to the size of the image. - */ - - -/* - * Compute output image dimensions and related values. - * NOTE: this is exported for possible use by application. - * Hence it mustn't do anything that can't be done twice. - */ - -GLOBAL(void) -jpeg_core_output_dimensions (j_decompress_ptr cinfo) -/* Do computations that are needed before master selection phase. - * This function is used for transcoding and full decompression. - */ -{ -#ifdef IDCT_SCALING_SUPPORTED - int ci; - jpeg_component_info *compptr; - - /* Compute actual output image dimensions and DCT scaling choices. */ - if (cinfo->scale_num * cinfo->block_size <= cinfo->scale_denom) { - /* Provide 1/block_size scaling */ - cinfo->output_width = (JDIMENSION) - jdiv_round_up((long) cinfo->image_width, (long) cinfo->block_size); - cinfo->output_height = (JDIMENSION) - jdiv_round_up((long) cinfo->image_height, (long) cinfo->block_size); - cinfo->min_DCT_h_scaled_size = 1; - cinfo->min_DCT_v_scaled_size = 1; - } else if (cinfo->scale_num * cinfo->block_size <= cinfo->scale_denom * 2) { - /* Provide 2/block_size scaling */ - cinfo->output_width = (JDIMENSION) - jdiv_round_up((long) cinfo->image_width * 2L, (long) cinfo->block_size); - cinfo->output_height = (JDIMENSION) - jdiv_round_up((long) cinfo->image_height * 2L, (long) cinfo->block_size); - cinfo->min_DCT_h_scaled_size = 2; - cinfo->min_DCT_v_scaled_size = 2; - } else if (cinfo->scale_num * cinfo->block_size <= cinfo->scale_denom * 3) { - /* Provide 3/block_size scaling */ - cinfo->output_width = (JDIMENSION) - jdiv_round_up((long) cinfo->image_width * 3L, (long) cinfo->block_size); - cinfo->output_height = (JDIMENSION) - jdiv_round_up((long) cinfo->image_height * 3L, (long) cinfo->block_size); - cinfo->min_DCT_h_scaled_size = 3; - cinfo->min_DCT_v_scaled_size = 3; - } else if (cinfo->scale_num * cinfo->block_size <= cinfo->scale_denom * 4) { - /* Provide 4/block_size scaling */ - cinfo->output_width = (JDIMENSION) - jdiv_round_up((long) cinfo->image_width * 4L, (long) cinfo->block_size); - cinfo->output_height = (JDIMENSION) - jdiv_round_up((long) cinfo->image_height * 4L, (long) cinfo->block_size); - cinfo->min_DCT_h_scaled_size = 4; - cinfo->min_DCT_v_scaled_size = 4; - } else if (cinfo->scale_num * cinfo->block_size <= cinfo->scale_denom * 5) { - /* Provide 5/block_size scaling */ - cinfo->output_width = (JDIMENSION) - jdiv_round_up((long) cinfo->image_width * 5L, (long) cinfo->block_size); - cinfo->output_height = (JDIMENSION) - jdiv_round_up((long) cinfo->image_height * 5L, (long) cinfo->block_size); - cinfo->min_DCT_h_scaled_size = 5; - cinfo->min_DCT_v_scaled_size = 5; - } else if (cinfo->scale_num * cinfo->block_size <= cinfo->scale_denom * 6) { - /* Provide 6/block_size scaling */ - cinfo->output_width = (JDIMENSION) - jdiv_round_up((long) cinfo->image_width * 6L, (long) cinfo->block_size); - cinfo->output_height = (JDIMENSION) - jdiv_round_up((long) cinfo->image_height * 6L, (long) cinfo->block_size); - cinfo->min_DCT_h_scaled_size = 6; - cinfo->min_DCT_v_scaled_size = 6; - } else if (cinfo->scale_num * cinfo->block_size <= cinfo->scale_denom * 7) { - /* Provide 7/block_size scaling */ - cinfo->output_width = (JDIMENSION) - jdiv_round_up((long) cinfo->image_width * 7L, (long) cinfo->block_size); - cinfo->output_height = (JDIMENSION) - jdiv_round_up((long) cinfo->image_height * 7L, (long) cinfo->block_size); - cinfo->min_DCT_h_scaled_size = 7; - cinfo->min_DCT_v_scaled_size = 7; - } else if (cinfo->scale_num * cinfo->block_size <= cinfo->scale_denom * 8) { - /* Provide 8/block_size scaling */ - cinfo->output_width = (JDIMENSION) - jdiv_round_up((long) cinfo->image_width * 8L, (long) cinfo->block_size); - cinfo->output_height = (JDIMENSION) - jdiv_round_up((long) cinfo->image_height * 8L, (long) cinfo->block_size); - cinfo->min_DCT_h_scaled_size = 8; - cinfo->min_DCT_v_scaled_size = 8; - } else if (cinfo->scale_num * cinfo->block_size <= cinfo->scale_denom * 9) { - /* Provide 9/block_size scaling */ - cinfo->output_width = (JDIMENSION) - jdiv_round_up((long) cinfo->image_width * 9L, (long) cinfo->block_size); - cinfo->output_height = (JDIMENSION) - jdiv_round_up((long) cinfo->image_height * 9L, (long) cinfo->block_size); - cinfo->min_DCT_h_scaled_size = 9; - cinfo->min_DCT_v_scaled_size = 9; - } else if (cinfo->scale_num * cinfo->block_size <= cinfo->scale_denom * 10) { - /* Provide 10/block_size scaling */ - cinfo->output_width = (JDIMENSION) - jdiv_round_up((long) cinfo->image_width * 10L, (long) cinfo->block_size); - cinfo->output_height = (JDIMENSION) - jdiv_round_up((long) cinfo->image_height * 10L, (long) cinfo->block_size); - cinfo->min_DCT_h_scaled_size = 10; - cinfo->min_DCT_v_scaled_size = 10; - } else if (cinfo->scale_num * cinfo->block_size <= cinfo->scale_denom * 11) { - /* Provide 11/block_size scaling */ - cinfo->output_width = (JDIMENSION) - jdiv_round_up((long) cinfo->image_width * 11L, (long) cinfo->block_size); - cinfo->output_height = (JDIMENSION) - jdiv_round_up((long) cinfo->image_height * 11L, (long) cinfo->block_size); - cinfo->min_DCT_h_scaled_size = 11; - cinfo->min_DCT_v_scaled_size = 11; - } else if (cinfo->scale_num * cinfo->block_size <= cinfo->scale_denom * 12) { - /* Provide 12/block_size scaling */ - cinfo->output_width = (JDIMENSION) - jdiv_round_up((long) cinfo->image_width * 12L, (long) cinfo->block_size); - cinfo->output_height = (JDIMENSION) - jdiv_round_up((long) cinfo->image_height * 12L, (long) cinfo->block_size); - cinfo->min_DCT_h_scaled_size = 12; - cinfo->min_DCT_v_scaled_size = 12; - } else if (cinfo->scale_num * cinfo->block_size <= cinfo->scale_denom * 13) { - /* Provide 13/block_size scaling */ - cinfo->output_width = (JDIMENSION) - jdiv_round_up((long) cinfo->image_width * 13L, (long) cinfo->block_size); - cinfo->output_height = (JDIMENSION) - jdiv_round_up((long) cinfo->image_height * 13L, (long) cinfo->block_size); - cinfo->min_DCT_h_scaled_size = 13; - cinfo->min_DCT_v_scaled_size = 13; - } else if (cinfo->scale_num * cinfo->block_size <= cinfo->scale_denom * 14) { - /* Provide 14/block_size scaling */ - cinfo->output_width = (JDIMENSION) - jdiv_round_up((long) cinfo->image_width * 14L, (long) cinfo->block_size); - cinfo->output_height = (JDIMENSION) - jdiv_round_up((long) cinfo->image_height * 14L, (long) cinfo->block_size); - cinfo->min_DCT_h_scaled_size = 14; - cinfo->min_DCT_v_scaled_size = 14; - } else if (cinfo->scale_num * cinfo->block_size <= cinfo->scale_denom * 15) { - /* Provide 15/block_size scaling */ - cinfo->output_width = (JDIMENSION) - jdiv_round_up((long) cinfo->image_width * 15L, (long) cinfo->block_size); - cinfo->output_height = (JDIMENSION) - jdiv_round_up((long) cinfo->image_height * 15L, (long) cinfo->block_size); - cinfo->min_DCT_h_scaled_size = 15; - cinfo->min_DCT_v_scaled_size = 15; - } else { - /* Provide 16/block_size scaling */ - cinfo->output_width = (JDIMENSION) - jdiv_round_up((long) cinfo->image_width * 16L, (long) cinfo->block_size); - cinfo->output_height = (JDIMENSION) - jdiv_round_up((long) cinfo->image_height * 16L, (long) cinfo->block_size); - cinfo->min_DCT_h_scaled_size = 16; - cinfo->min_DCT_v_scaled_size = 16; - } - - /* Recompute dimensions of components */ - for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; - ci++, compptr++) { - compptr->DCT_h_scaled_size = cinfo->min_DCT_h_scaled_size; - compptr->DCT_v_scaled_size = cinfo->min_DCT_v_scaled_size; - } - -#else /* !IDCT_SCALING_SUPPORTED */ - - /* Hardwire it to "no scaling" */ - cinfo->output_width = cinfo->image_width; - cinfo->output_height = cinfo->image_height; - /* jdinput.c has already initialized DCT_scaled_size, - * and has computed unscaled downsampled_width and downsampled_height. - */ - -#endif /* IDCT_SCALING_SUPPORTED */ -} - - -LOCAL(void) -initial_setup (j_decompress_ptr cinfo) -/* Called once, when first SOS marker is reached */ -{ - int ci; - jpeg_component_info *compptr; - - /* Make sure image isn't bigger than I can handle */ - if ((long) cinfo->image_height > (long) JPEG_MAX_DIMENSION || - (long) cinfo->image_width > (long) JPEG_MAX_DIMENSION) - ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) JPEG_MAX_DIMENSION); - - /* For now, precision must match compiled-in value... */ - if (cinfo->data_precision != BITS_IN_JSAMPLE) - ERREXIT1(cinfo, JERR_BAD_PRECISION, cinfo->data_precision); - - /* Check that number of components won't exceed internal array sizes */ - if (cinfo->num_components > MAX_COMPONENTS) - ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->num_components, - MAX_COMPONENTS); - - /* Compute maximum sampling factors; check factor validity */ - cinfo->max_h_samp_factor = 1; - cinfo->max_v_samp_factor = 1; - for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; - ci++, compptr++) { - if (compptr->h_samp_factor<=0 || compptr->h_samp_factor>MAX_SAMP_FACTOR || - compptr->v_samp_factor<=0 || compptr->v_samp_factor>MAX_SAMP_FACTOR) - ERREXIT(cinfo, JERR_BAD_SAMPLING); - cinfo->max_h_samp_factor = MAX(cinfo->max_h_samp_factor, - compptr->h_samp_factor); - cinfo->max_v_samp_factor = MAX(cinfo->max_v_samp_factor, - compptr->v_samp_factor); - } - - /* Derive block_size, natural_order, and lim_Se */ - if (cinfo->is_baseline || (cinfo->progressive_mode && - cinfo->comps_in_scan)) { /* no pseudo SOS marker */ - cinfo->block_size = DCTSIZE; - cinfo->natural_order = jpeg_natural_order; - cinfo->lim_Se = DCTSIZE2-1; - } else - switch (cinfo->Se) { - case (1*1-1): - cinfo->block_size = 1; - cinfo->natural_order = jpeg_natural_order; /* not needed */ - cinfo->lim_Se = cinfo->Se; - break; - case (2*2-1): - cinfo->block_size = 2; - cinfo->natural_order = jpeg_natural_order2; - cinfo->lim_Se = cinfo->Se; - break; - case (3*3-1): - cinfo->block_size = 3; - cinfo->natural_order = jpeg_natural_order3; - cinfo->lim_Se = cinfo->Se; - break; - case (4*4-1): - cinfo->block_size = 4; - cinfo->natural_order = jpeg_natural_order4; - cinfo->lim_Se = cinfo->Se; - break; - case (5*5-1): - cinfo->block_size = 5; - cinfo->natural_order = jpeg_natural_order5; - cinfo->lim_Se = cinfo->Se; - break; - case (6*6-1): - cinfo->block_size = 6; - cinfo->natural_order = jpeg_natural_order6; - cinfo->lim_Se = cinfo->Se; - break; - case (7*7-1): - cinfo->block_size = 7; - cinfo->natural_order = jpeg_natural_order7; - cinfo->lim_Se = cinfo->Se; - break; - case (8*8-1): - cinfo->block_size = 8; - cinfo->natural_order = jpeg_natural_order; - cinfo->lim_Se = DCTSIZE2-1; - break; - case (9*9-1): - cinfo->block_size = 9; - cinfo->natural_order = jpeg_natural_order; - cinfo->lim_Se = DCTSIZE2-1; - break; - case (10*10-1): - cinfo->block_size = 10; - cinfo->natural_order = jpeg_natural_order; - cinfo->lim_Se = DCTSIZE2-1; - break; - case (11*11-1): - cinfo->block_size = 11; - cinfo->natural_order = jpeg_natural_order; - cinfo->lim_Se = DCTSIZE2-1; - break; - case (12*12-1): - cinfo->block_size = 12; - cinfo->natural_order = jpeg_natural_order; - cinfo->lim_Se = DCTSIZE2-1; - break; - case (13*13-1): - cinfo->block_size = 13; - cinfo->natural_order = jpeg_natural_order; - cinfo->lim_Se = DCTSIZE2-1; - break; - case (14*14-1): - cinfo->block_size = 14; - cinfo->natural_order = jpeg_natural_order; - cinfo->lim_Se = DCTSIZE2-1; - break; - case (15*15-1): - cinfo->block_size = 15; - cinfo->natural_order = jpeg_natural_order; - cinfo->lim_Se = DCTSIZE2-1; - break; - case (16*16-1): - cinfo->block_size = 16; - cinfo->natural_order = jpeg_natural_order; - cinfo->lim_Se = DCTSIZE2-1; - break; - default: - ERREXIT4(cinfo, JERR_BAD_PROGRESSION, - cinfo->Ss, cinfo->Se, cinfo->Ah, cinfo->Al); - break; - } - - /* We initialize DCT_scaled_size and min_DCT_scaled_size to block_size. - * In the full decompressor, - * this will be overridden by jpeg_calc_output_dimensions in jdmaster.c; - * but in the transcoder, - * jpeg_calc_output_dimensions is not used, so we must do it here. - */ - cinfo->min_DCT_h_scaled_size = cinfo->block_size; - cinfo->min_DCT_v_scaled_size = cinfo->block_size; - - /* Compute dimensions of components */ - for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components; - ci++, compptr++) { - compptr->DCT_h_scaled_size = cinfo->block_size; - compptr->DCT_v_scaled_size = cinfo->block_size; - /* Size in DCT blocks */ - compptr->width_in_blocks = (JDIMENSION) - jdiv_round_up((long) cinfo->image_width * (long) compptr->h_samp_factor, - (long) (cinfo->max_h_samp_factor * cinfo->block_size)); - compptr->height_in_blocks = (JDIMENSION) - jdiv_round_up((long) cinfo->image_height * (long) compptr->v_samp_factor, - (long) (cinfo->max_v_samp_factor * cinfo->block_size)); - /* downsampled_width and downsampled_height will also be overridden by - * jdmaster.c if we are doing full decompression. The transcoder library - * doesn't use these values, but the calling application might. - */ - /* Size in samples */ - compptr->downsampled_width = (JDIMENSION) - jdiv_round_up((long) cinfo->image_width * (long) compptr->h_samp_factor, - (long) cinfo->max_h_samp_factor); - compptr->downsampled_height = (JDIMENSION) - jdiv_round_up((long) cinfo->image_height * (long) compptr->v_samp_factor, - (long) cinfo->max_v_samp_factor); - /* Mark component needed, until color conversion says otherwise */ - compptr->component_needed = TRUE; - /* Mark no quantization table yet saved for component */ - compptr->quant_table = NULL; - } - - /* Compute number of fully interleaved MCU rows. */ - cinfo->total_iMCU_rows = (JDIMENSION) - jdiv_round_up((long) cinfo->image_height, - (long) (cinfo->max_v_samp_factor * cinfo->block_size)); - - /* Decide whether file contains multiple scans */ - if (cinfo->comps_in_scan < cinfo->num_components || cinfo->progressive_mode) - cinfo->inputctl->has_multiple_scans = TRUE; - else - cinfo->inputctl->has_multiple_scans = FALSE; -} - - -LOCAL(void) -per_scan_setup (j_decompress_ptr cinfo) -/* Do computations that are needed before processing a JPEG scan */ -/* cinfo->comps_in_scan and cinfo->cur_comp_info[] were set from SOS marker */ -{ - int ci, mcublks, tmp; - jpeg_component_info *compptr; - - if (cinfo->comps_in_scan == 1) { - - /* Noninterleaved (single-component) scan */ - compptr = cinfo->cur_comp_info[0]; - - /* Overall image size in MCUs */ - cinfo->MCUs_per_row = compptr->width_in_blocks; - cinfo->MCU_rows_in_scan = compptr->height_in_blocks; - - /* For noninterleaved scan, always one block per MCU */ - compptr->MCU_width = 1; - compptr->MCU_height = 1; - compptr->MCU_blocks = 1; - compptr->MCU_sample_width = compptr->DCT_h_scaled_size; - compptr->last_col_width = 1; - /* For noninterleaved scans, it is convenient to define last_row_height - * as the number of block rows present in the last iMCU row. - */ - tmp = (int) (compptr->height_in_blocks % compptr->v_samp_factor); - if (tmp == 0) tmp = compptr->v_samp_factor; - compptr->last_row_height = tmp; - - /* Prepare array describing MCU composition */ - cinfo->blocks_in_MCU = 1; - cinfo->MCU_membership[0] = 0; - - } else { - - /* Interleaved (multi-component) scan */ - if (cinfo->comps_in_scan <= 0 || cinfo->comps_in_scan > MAX_COMPS_IN_SCAN) - ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->comps_in_scan, - MAX_COMPS_IN_SCAN); - - /* Overall image size in MCUs */ - cinfo->MCUs_per_row = (JDIMENSION) - jdiv_round_up((long) cinfo->image_width, - (long) (cinfo->max_h_samp_factor * cinfo->block_size)); - cinfo->MCU_rows_in_scan = (JDIMENSION) - jdiv_round_up((long) cinfo->image_height, - (long) (cinfo->max_v_samp_factor * cinfo->block_size)); - - cinfo->blocks_in_MCU = 0; - - for (ci = 0; ci < cinfo->comps_in_scan; ci++) { - compptr = cinfo->cur_comp_info[ci]; - /* Sampling factors give # of blocks of component in each MCU */ - compptr->MCU_width = compptr->h_samp_factor; - compptr->MCU_height = compptr->v_samp_factor; - compptr->MCU_blocks = compptr->MCU_width * compptr->MCU_height; - compptr->MCU_sample_width = compptr->MCU_width * compptr->DCT_h_scaled_size; - /* Figure number of non-dummy blocks in last MCU column & row */ - tmp = (int) (compptr->width_in_blocks % compptr->MCU_width); - if (tmp == 0) tmp = compptr->MCU_width; - compptr->last_col_width = tmp; - tmp = (int) (compptr->height_in_blocks % compptr->MCU_height); - if (tmp == 0) tmp = compptr->MCU_height; - compptr->last_row_height = tmp; - /* Prepare array describing MCU composition */ - mcublks = compptr->MCU_blocks; - if (cinfo->blocks_in_MCU + mcublks > D_MAX_BLOCKS_IN_MCU) - ERREXIT(cinfo, JERR_BAD_MCU_SIZE); - while (mcublks-- > 0) { - cinfo->MCU_membership[cinfo->blocks_in_MCU++] = ci; - } - } - - } -} - - -/* - * Save away a copy of the Q-table referenced by each component present - * in the current scan, unless already saved during a prior scan. - * - * In a multiple-scan JPEG file, the encoder could assign different components - * the same Q-table slot number, but change table definitions between scans - * so that each component uses a different Q-table. (The IJG encoder is not - * currently capable of doing this, but other encoders might.) Since we want - * to be able to dequantize all the components at the end of the file, this - * means that we have to save away the table actually used for each component. - * We do this by copying the table at the start of the first scan containing - * the component. - * The JPEG spec prohibits the encoder from changing the contents of a Q-table - * slot between scans of a component using that slot. If the encoder does so - * anyway, this decoder will simply use the Q-table values that were current - * at the start of the first scan for the component. - * - * The decompressor output side looks only at the saved quant tables, - * not at the current Q-table slots. - */ - -LOCAL(void) -latch_quant_tables (j_decompress_ptr cinfo) -{ - int ci, qtblno; - jpeg_component_info *compptr; - JQUANT_TBL * qtbl; - - for (ci = 0; ci < cinfo->comps_in_scan; ci++) { - compptr = cinfo->cur_comp_info[ci]; - /* No work if we already saved Q-table for this component */ - if (compptr->quant_table != NULL) - continue; - /* Make sure specified quantization table is present */ - qtblno = compptr->quant_tbl_no; - if (qtblno < 0 || qtblno >= NUM_QUANT_TBLS || - cinfo->quant_tbl_ptrs[qtblno] == NULL) - ERREXIT1(cinfo, JERR_NO_QUANT_TABLE, qtblno); - /* OK, save away the quantization table */ - qtbl = (JQUANT_TBL *) - (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE, - SIZEOF(JQUANT_TBL)); - MEMCOPY(qtbl, cinfo->quant_tbl_ptrs[qtblno], SIZEOF(JQUANT_TBL)); - compptr->quant_table = qtbl; - } -} - - -/* - * Initialize the input modules to read a scan of compressed data. - * The first call to this is done by jdmaster.c after initializing - * the entire decompressor (during jpeg_start_decompress). - * Subsequent calls come from consume_markers, below. - */ - -METHODDEF(void) -start_input_pass (j_decompress_ptr cinfo) -{ - per_scan_setup(cinfo); - latch_quant_tables(cinfo); - (*cinfo->entropy->start_pass) (cinfo); - (*cinfo->coef->start_input_pass) (cinfo); - cinfo->inputctl->consume_input = cinfo->coef->consume_data; -} - - -/* - * Finish up after inputting a compressed-data scan. - * This is called by the coefficient controller after it's read all - * the expected data of the scan. - */ - -METHODDEF(void) -finish_input_pass (j_decompress_ptr cinfo) -{ - cinfo->inputctl->consume_input = consume_markers; -} - - -/* - * Read JPEG markers before, between, or after compressed-data scans. - * Change state as necessary when a new scan is reached. - * Return value is JPEG_SUSPENDED, JPEG_REACHED_SOS, or JPEG_REACHED_EOI. - * - * The consume_input method pointer points either here or to the - * coefficient controller's consume_data routine, depending on whether - * we are reading a compressed data segment or inter-segment markers. - * - * Note: This function should NOT return a pseudo SOS marker (with zero - * component number) to the caller. A pseudo marker received by - * read_markers is processed and then skipped for other markers. - */ - -METHODDEF(int) -consume_markers (j_decompress_ptr cinfo) -{ - my_inputctl_ptr inputctl = (my_inputctl_ptr) cinfo->inputctl; - int val; - - if (inputctl->pub.eoi_reached) /* After hitting EOI, read no further */ - return JPEG_REACHED_EOI; - - for (;;) { /* Loop to pass pseudo SOS marker */ - val = (*cinfo->marker->read_markers) (cinfo); - - switch (val) { - case JPEG_REACHED_SOS: /* Found SOS */ - if (inputctl->inheaders) { /* 1st SOS */ - if (inputctl->inheaders == 1) - initial_setup(cinfo); - if (cinfo->comps_in_scan == 0) { /* pseudo SOS marker */ - inputctl->inheaders = 2; - break; - } - inputctl->inheaders = 0; - /* Note: start_input_pass must be called by jdmaster.c - * before any more input can be consumed. jdapimin.c is - * responsible for enforcing this sequencing. - */ - } else { /* 2nd or later SOS marker */ - if (! inputctl->pub.has_multiple_scans) - ERREXIT(cinfo, JERR_EOI_EXPECTED); /* Oops, I wasn't expecting this! */ - if (cinfo->comps_in_scan == 0) /* unexpected pseudo SOS marker */ - break; - start_input_pass(cinfo); - } - return val; - case JPEG_REACHED_EOI: /* Found EOI */ - inputctl->pub.eoi_reached = TRUE; - if (inputctl->inheaders) { /* Tables-only datastream, apparently */ - if (cinfo->marker->saw_SOF) - ERREXIT(cinfo, JERR_SOF_NO_SOS); - } else { - /* Prevent infinite loop in coef ctlr's decompress_data routine - * if user set output_scan_number larger than number of scans. - */ - if (cinfo->output_scan_number > cinfo->input_scan_number) - cinfo->output_scan_number = cinfo->input_scan_number; - } - return val; - case JPEG_SUSPENDED: - return val; - default: - return val; - } - } -} - - -/* - * Reset state to begin a fresh datastream. - */ - -METHODDEF(void) -reset_input_controller (j_decompress_ptr cinfo) -{ - my_inputctl_ptr inputctl = (my_inputctl_ptr) cinfo->inputctl; - - inputctl->pub.consume_input = consume_markers; - inputctl->pub.has_multiple_scans = FALSE; /* "unknown" would be better */ - inputctl->pub.eoi_reached = FALSE; - inputctl->inheaders = 1; - /* Reset other modules */ - (*cinfo->err->reset_error_mgr) ((j_common_ptr) cinfo); - (*cinfo->marker->reset_marker_reader) (cinfo); - /* Reset progression state -- would be cleaner if entropy decoder did this */ - cinfo->coef_bits = NULL; -} - - -/* - * Initialize the input controller module. - * This is called only once, when the decompression object is created. - */ - -GLOBAL(void) -jinit_input_controller (j_decompress_ptr cinfo) -{ - my_inputctl_ptr inputctl; - - /* Create subobject in permanent pool */ - inputctl = (my_inputctl_ptr) - (*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_PERMANENT, - SIZEOF(my_input_controller)); - cinfo->inputctl = (struct jpeg_input_controller *) inputctl; - /* Initialize method pointers */ - inputctl->pub.consume_input = consume_markers; - inputctl->pub.reset_input_controller = reset_input_controller; - inputctl->pub.start_input_pass = start_input_pass; - inputctl->pub.finish_input_pass = finish_input_pass; - /* Initialize state: can't use reset_input_controller since we don't - * want to try to reset other modules yet. - */ - inputctl->pub.has_multiple_scans = FALSE; /* "unknown" would be better */ - inputctl->pub.eoi_reached = FALSE; - inputctl->inheaders = 1; -} |