/*

* 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;

}