/*

* jcmaster.c

*

* Copyright (C) 1991-1997, Thomas G. Lane.

* Modified 2003-2017 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 master control logic for the JPEG compressor.

* These routines are concerned with parameter validation, initial setup,

* and inter-pass control (determining the number of passes and the work

* to be done in each pass).

*/

#define JPEG_INTERNALS

#include "jinclude.h"

#include "jpeglib.h"

/* Private state */

typedef enum {

main_pass, /* input data, also do first output step */

huff_opt_pass, /* Huffman code optimization pass */

output_pass /* data output pass */

} c_pass_type;

typedef struct {

struct jpeg_comp_master pub; /* public fields */

c_pass_type pass_type; /* the type of the current pass */

int pass_number; /* # of passes completed */

int total_passes; /* total # of passes needed */

int scan_number; /* current index in scan_info[] */

} my_comp_master;

typedef my_comp_master * my_master_ptr;

/*

* Support routines that do various essential calculations.

*/

LOCAL(void)

initial_setup (j_compress_ptr cinfo)

/* Do computations that are needed before master selection phase */

{

int ci, ssize;

jpeg_component_info *compptr;

/* Sanity check on block_size */

if (cinfo->block_size < 1 || cinfo->block_size > 16)

ERREXIT2(cinfo, JERR_BAD_DCTSIZE, cinfo->block_size, cinfo->block_size);

/* Derive natural_order from block_size */

switch (cinfo->block_size) {

case 2: cinfo->natural_order = jpeg_natural_order2; break;

case 3: cinfo->natural_order = jpeg_natural_order3; break;

case 4: cinfo->natural_order = jpeg_natural_order4; break;

case 5: cinfo->natural_order = jpeg_natural_order5; break;

case 6: cinfo->natural_order = jpeg_natural_order6; break;

case 7: cinfo->natural_order = jpeg_natural_order7; break;

default: cinfo->natural_order = jpeg_natural_order; break;

}

/* Derive lim_Se from block_size */

cinfo->lim_Se = cinfo->block_size < DCTSIZE ?

cinfo->block_size * cinfo->block_size - 1 : DCTSIZE2-1;

/* Sanity check on image dimensions */

if (cinfo->jpeg_height <= 0 || cinfo->jpeg_width <= 0 ||

cinfo->num_components <= 0)

ERREXIT(cinfo, JERR_EMPTY_IMAGE);

/* Make sure image isn't bigger than I can handle */

if ((long) cinfo->jpeg_height > (long) JPEG_MAX_DIMENSION ||

(long) cinfo->jpeg_width > (long) JPEG_MAX_DIMENSION)

ERREXIT1(cinfo, JERR_IMAGE_TOO_BIG, (unsigned int) JPEG_MAX_DIMENSION);

/* Only 8 to 12 bits data precision are supported for DCT based JPEG */

if (cinfo->data_precision < 8 || cinfo->data_precision > 12)

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);

}

/* Compute dimensions of components */

for (ci = 0, compptr = cinfo->comp_info; ci < cinfo->num_components;

ci++, compptr++) {

/* Fill in the correct component_index value; don't rely on application */

compptr->component_index = ci;

/* In selecting the actual DCT scaling for each component, we try to

* scale down the chroma components via DCT scaling rather than downsampling.

* This saves time if the downsampler gets to use 1:1 scaling.

* Note this code adapts subsampling ratios which are powers of 2.

*/

ssize = 1;

#ifdef DCT_SCALING_SUPPORTED

while (cinfo->min_DCT_h_scaled_size * ssize <=

(cinfo->do_fancy_downsampling ? DCTSIZE : DCTSIZE / 2) &&

(cinfo->max_h_samp_factor % (compptr->h_samp_factor * ssize * 2)) == 0) {

ssize = ssize * 2;

}

#endif

compptr->DCT_h_scaled_size = cinfo->min_DCT_h_scaled_size * ssize;

ssize = 1;

#ifdef DCT_SCALING_SUPPORTED

while (cinfo->min_DCT_v_scaled_size * ssize <=

(cinfo->do_fancy_downsampling ? DCTSIZE : DCTSIZE / 2) &&

(cinfo->max_v_samp_factor % (compptr->v_samp_factor * ssize * 2)) == 0) {

ssize = ssize * 2;

}

#endif

compptr->DCT_v_scaled_size = cinfo->min_DCT_v_scaled_size * ssize;

/* We don't support DCT ratios larger than 2. */

if (compptr->DCT_h_scaled_size > compptr->DCT_v_scaled_size * 2)

compptr->DCT_h_scaled_size = compptr->DCT_v_scaled_size * 2;

else if (compptr->DCT_v_scaled_size > compptr->DCT_h_scaled_size * 2)

compptr->DCT_v_scaled_size = compptr->DCT_h_scaled_size * 2;

/* Size in DCT blocks */

compptr->width_in_blocks = (JDIMENSION)

jdiv_round_up((long) cinfo->jpeg_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->jpeg_height * (long) compptr->v_samp_factor,

(long) (cinfo->max_v_samp_factor * cinfo->block_size));

/* Size in samples */

compptr->downsampled_width = (JDIMENSION)

jdiv_round_up((long) cinfo->jpeg_width *

(long) (compptr->h_samp_factor * compptr->DCT_h_scaled_size),

(long) (cinfo->max_h_samp_factor * cinfo->block_size));

compptr->downsampled_height = (JDIMENSION)

jdiv_round_up((long) cinfo->jpeg_height *

(long) (compptr->v_samp_factor * compptr->DCT_v_scaled_size),

(long) (cinfo->max_v_samp_factor * cinfo->block_size));

/* Don't need quantization scale after DCT,

* until color conversion says otherwise.

*/

compptr->component_needed = FALSE;

}

/* Compute number of fully interleaved MCU rows (number of times that

* main controller will call coefficient controller).

*/

cinfo->total_iMCU_rows = (JDIMENSION)

jdiv_round_up((long) cinfo->jpeg_height,

(long) (cinfo->max_v_samp_factor * cinfo->block_size));

}

#ifdef C_MULTISCAN_FILES_SUPPORTED

LOCAL(void)

validate_script (j_compress_ptr cinfo)

/* Verify that the scan script in cinfo->scan_info[] is valid; also

* determine whether it uses progressive JPEG, and set cinfo->progressive_mode.

*/

{

const jpeg_scan_info * scanptr;

int scanno, ncomps, ci, coefi, thisi;

int Ss, Se, Ah, Al;

boolean component_sent[MAX_COMPONENTS];

#ifdef C_PROGRESSIVE_SUPPORTED

int * last_bitpos_ptr;

int last_bitpos[MAX_COMPONENTS][DCTSIZE2];

/* -1 until that coefficient has been seen; then last Al for it */

#endif

if (cinfo->num_scans <= 0)

ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, 0);

/* For sequential JPEG, all scans must have Ss=0, Se=DCTSIZE2-1;

* for progressive JPEG, no scan can have this.

*/

scanptr = cinfo->scan_info;

if (scanptr->Ss != 0 || scanptr->Se != DCTSIZE2-1) {

#ifdef C_PROGRESSIVE_SUPPORTED

cinfo->progressive_mode = TRUE;

last_bitpos_ptr = & last_bitpos[0][0];

for (ci = 0; ci < cinfo->num_components; ci++)

for (coefi = 0; coefi < DCTSIZE2; coefi++)

*last_bitpos_ptr++ = -1;

#else

ERREXIT(cinfo, JERR_NOT_COMPILED);

#endif

} else {

cinfo->progressive_mode = FALSE;

for (ci = 0; ci < cinfo->num_components; ci++)

component_sent[ci] = FALSE;

}

for (scanno = 1; scanno <= cinfo->num_scans; scanptr++, scanno++) {

/* Validate component indexes */

ncomps = scanptr->comps_in_scan;

if (ncomps <= 0 || ncomps > MAX_COMPS_IN_SCAN)

ERREXIT2(cinfo, JERR_COMPONENT_COUNT, ncomps, MAX_COMPS_IN_SCAN);

for (ci = 0; ci < ncomps; ci++) {

thisi = scanptr->component_index[ci];

if (thisi < 0 || thisi >= cinfo->num_components)

ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, scanno);

/* Components must appear in SOF order within each scan */

if (ci > 0 && thisi <= scanptr->component_index[ci-1])

ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, scanno);

}

/* Validate progression parameters */

Ss = scanptr->Ss;

Se = scanptr->Se;

Ah = scanptr->Ah;

Al = scanptr->Al;

if (cinfo->progressive_mode) {

#ifdef C_PROGRESSIVE_SUPPORTED

/* The JPEG spec simply gives the ranges 0..13 for Ah and Al, but that

* seems wrong: the upper bound ought to depend on data precision.

* Perhaps they really meant 0..N+1 for N-bit precision.

* Here we allow 0..10 for 8-bit data; Al larger than 10 results in

* out-of-range reconstructed DC values during the first DC scan,

* which might cause problems for some decoders.

*/

if (Ss < 0 || Ss >= DCTSIZE2 || Se < Ss || Se >= DCTSIZE2 ||

Ah < 0 || Ah > (cinfo->data_precision > 8 ? 13 : 10) ||

Al < 0 || Al > (cinfo->data_precision > 8 ? 13 : 10))

ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);

if (Ss == 0) {

if (Se != 0) /* DC and AC together not OK */

ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);

} else {

if (ncomps != 1) /* AC scans must be for only one component */

ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);

}

for (ci = 0; ci < ncomps; ci++) {

last_bitpos_ptr = & last_bitpos[scanptr->component_index[ci]][0];

if (Ss != 0 && last_bitpos_ptr[0] < 0) /* AC without prior DC scan */

ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);

for (coefi = Ss; coefi <= Se; coefi++) {

if (last_bitpos_ptr[coefi] < 0) {

/* first scan of this coefficient */

if (Ah != 0)

ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);

} else {

/* not first scan */

if (Ah != last_bitpos_ptr[coefi] || Al != Ah-1)

ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);

}

last_bitpos_ptr[coefi] = Al;

}

}

#endif

} else {

/* For sequential JPEG, all progression parameters must be these: */

if (Ss != 0 || Se != DCTSIZE2-1 || Ah != 0 || Al != 0)

ERREXIT1(cinfo, JERR_BAD_PROG_SCRIPT, scanno);

/* Make sure components are not sent twice */

for (ci = 0; ci < ncomps; ci++) {

thisi = scanptr->component_index[ci];

if (component_sent[thisi])

ERREXIT1(cinfo, JERR_BAD_SCAN_SCRIPT, scanno);

component_sent[thisi] = TRUE;

}

}

}

/* Now verify that everything got sent. */

if (cinfo->progressive_mode) {

#ifdef C_PROGRESSIVE_SUPPORTED

/* For progressive mode, we only check that at least some DC data

* got sent for each component; the spec does not require that all bits

* of all coefficients be transmitted. Would it be wiser to enforce

* transmission of all coefficient bits??

*/

for (ci = 0; ci < cinfo->num_components; ci++) {

if (last_bitpos[ci][0] < 0)

ERREXIT(cinfo, JERR_MISSING_DATA);

}

#endif

} else {

for (ci = 0; ci < cinfo->num_components; ci++) {

if (! component_sent[ci])

ERREXIT(cinfo, JERR_MISSING_DATA);

}

}

}

LOCAL(void)

reduce_script (j_compress_ptr cinfo)

/* Adapt scan script for use with reduced block size;

* assume that script has been validated before.

*/

{

jpeg_scan_info * scanptr;

int idxout, idxin;

/* Circumvent const declaration for this function */

scanptr = (jpeg_scan_info *) cinfo->scan_info;

idxout = 0;

for (idxin = 0; idxin < cinfo->num_scans; idxin++) {

/* After skipping, idxout becomes smaller than idxin */

if (idxin != idxout)

/* Copy rest of data;

* note we stay in given chunk of allocated memory.

*/

scanptr[idxout] = scanptr[idxin];

if (scanptr[idxout].Ss > cinfo->lim_Se)

/* Entire scan out of range - skip this entry */

continue;

if (scanptr[idxout].Se > cinfo->lim_Se)

/* Limit scan to end of block */

scanptr[idxout].Se = cinfo->lim_Se;

idxout++;

}

cinfo->num_scans = idxout;

}

#endif /* C_MULTISCAN_FILES_SUPPORTED */

LOCAL(void)

select_scan_parameters (j_compress_ptr cinfo)

/* Set up the scan parameters for the current scan */

{

int ci;

#ifdef C_MULTISCAN_FILES_SUPPORTED

if (cinfo->scan_info != NULL) {

/* Prepare for current scan --- the script is already validated */

my_master_ptr master = (my_master_ptr) cinfo->master;

const jpeg_scan_info * scanptr = cinfo->scan_info + master->scan_number;

cinfo->comps_in_scan = scanptr->comps_in_scan;

for (ci = 0; ci < scanptr->comps_in_scan; ci++) {

cinfo->cur_comp_info[ci] =

&cinfo->comp_info[scanptr->component_index[ci]];

}

if (cinfo->progressive_mode) {

cinfo->Ss = scanptr->Ss;

cinfo->Se = scanptr->Se;

cinfo->Ah = scanptr->Ah;

cinfo->Al = scanptr->Al;

return;

}

}

else

#endif

{

/* Prepare for single sequential-JPEG scan containing all components */

if (cinfo->num_components > MAX_COMPS_IN_SCAN)

ERREXIT2(cinfo, JERR_COMPONENT_COUNT, cinfo->num_components,

MAX_COMPS_IN_SCAN);

cinfo->comps_in_scan = cinfo->num_components;

for (ci = 0; ci < cinfo->num_components; ci++) {

cinfo->cur_comp_info[ci] = &cinfo->comp_info[ci];

}

}

cinfo->Ss = 0;

cinfo->Se = cinfo->block_size * cinfo->block_size - 1;

cinfo->Ah = 0;

cinfo->Al = 0;

}

LOCAL(void)

per_scan_setup (j_compress_ptr cinfo)

/* Do computations that are needed before processing a JPEG scan */

/* cinfo->comps_in_scan and cinfo->cur_comp_info[] are already set */

{

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->jpeg_width,

(long) (cinfo->max_h_samp_factor * cinfo->block_size));

cinfo->MCU_rows_in_scan = (JDIMENSION)

jdiv_round_up((long) cinfo->jpeg_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 > C_MAX_BLOCKS_IN_MCU)

ERREXIT(cinfo, JERR_BAD_MCU_SIZE);

while (mcublks-- > 0) {

cinfo->MCU_membership[cinfo->blocks_in_MCU++] = ci;

}

}

}

/* Convert restart specified in rows to actual MCU count. */

/* Note that count must fit in 16 bits, so we provide limiting. */

if (cinfo->restart_in_rows > 0) {

long nominal = (long) cinfo->restart_in_rows * (long) cinfo->MCUs_per_row;

cinfo->restart_interval = (unsigned int) MIN(nominal, 65535L);

}

}

/*

* Per-pass setup.

* This is called at the beginning of each pass. We determine which modules

* will be active during this pass and give them appropriate start_pass calls.

* We also set is_last_pass to indicate whether any more passes will be

* required.

*/

METHODDEF(void)

prepare_for_pass (j_compress_ptr cinfo)

{

my_master_ptr master = (my_master_ptr) cinfo->master;

switch (master->pass_type) {

case main_pass:

/* Initial pass: will collect input data, and do either Huffman

* optimization or data output for the first scan.

*/

select_scan_parameters(cinfo);

per_scan_setup(cinfo);

if (! cinfo->raw_data_in) {

(*cinfo->cconvert->start_pass) (cinfo);

(*cinfo->downsample->start_pass) (cinfo);

(*cinfo->prep->start_pass) (cinfo, JBUF_PASS_THRU);

}

(*cinfo->fdct->start_pass) (cinfo);

(*cinfo->entropy->start_pass) (cinfo, cinfo->optimize_coding);

(*cinfo->coef->start_pass) (cinfo,

(master->total_passes > 1 ?

JBUF_SAVE_AND_PASS : JBUF_PASS_THRU));

(*cinfo->main->start_pass) (cinfo, JBUF_PASS_THRU);

if (cinfo->optimize_coding) {

/* No immediate data output; postpone writing frame/scan headers */

master->pub.call_pass_startup = FALSE;

} else {

/* Will write frame/scan headers at first jpeg_write_scanlines call */

master->pub.call_pass_startup = TRUE;

}

break;

#ifdef ENTROPY_OPT_SUPPORTED

case huff_opt_pass:

/* Do Huffman optimization for a scan after the first one. */

select_scan_parameters(cinfo);

per_scan_setup(cinfo);

if (cinfo->Ss != 0 || cinfo->Ah == 0) {

(*cinfo->entropy->start_pass) (cinfo, TRUE);

(*cinfo->coef->start_pass) (cinfo, JBUF_CRANK_DEST);

master->pub.call_pass_startup = FALSE;

break;

}

/* Special case: Huffman DC refinement scans need no Huffman table

* and therefore we can skip the optimization pass for them.

*/

master->pass_type = output_pass;

master->pass_number++;

/*FALLTHROUGH*/

#endif

case output_pass:

/* Do a data-output pass. */

/* We need not repeat per-scan setup if prior optimization pass did it. */

if (! cinfo->optimize_coding) {

select_scan_parameters(cinfo);

per_scan_setup(cinfo);

}

(*cinfo->entropy->start_pass) (cinfo, FALSE);

(*cinfo->coef->start_pass) (cinfo, JBUF_CRANK_DEST);

/* We emit frame/scan headers now */

if (master->scan_number == 0)

(*cinfo->marker->write_frame_header) (cinfo);

(*cinfo->marker->write_scan_header) (cinfo);

master->pub.call_pass_startup = FALSE;

break;

default:

ERREXIT(cinfo, JERR_NOT_COMPILED);

}

master->pub.is_last_pass = (master->pass_number == master->total_passes-1);

/* Set up progress monitor's pass info if present */

if (cinfo->progress != NULL) {

cinfo->progress->completed_passes = master->pass_number;

cinfo->progress->total_passes = master->total_passes;

}

}

/*

* Special start-of-pass hook.

* This is called by jpeg_write_scanlines if call_pass_startup is TRUE.

* In single-pass processing, we need this hook because we don't want to

* write frame/scan headers during jpeg_start_compress; we want to let the

* application write COM markers etc. between jpeg_start_compress and the

* jpeg_write_scanlines loop.

* In multi-pass processing, this routine is not used.

*/

METHODDEF(void)

pass_startup (j_compress_ptr cinfo)

{

cinfo->master->call_pass_startup = FALSE; /* reset flag so call only once */

(*cinfo->marker->write_frame_header) (cinfo);

(*cinfo->marker->write_scan_header) (cinfo);

}

/*

* Finish up at end of pass.

*/

METHODDEF(void)

finish_pass_master (j_compress_ptr cinfo)

{

my_master_ptr master = (my_master_ptr) cinfo->master;

/* The entropy coder always needs an end-of-pass call,

* either to analyze statistics or to flush its output buffer.

*/

(*cinfo->entropy->finish_pass) (cinfo);

/* Update state for next pass */

switch (master->pass_type) {

case main_pass:

/* next pass is either output of scan 0 (after optimization)

* or output of scan 1 (if no optimization).

*/

master->pass_type = output_pass;

if (! cinfo->optimize_coding)

master->scan_number++;

break;

case huff_opt_pass:

/* next pass is always output of current scan */

master->pass_type = output_pass;

break;

case output_pass:

/* next pass is either optimization or output of next scan */

if (cinfo->optimize_coding)

master->pass_type = huff_opt_pass;

master->scan_number++;

break;

}

master->pass_number++;

}

/*

* Initialize master compression control.

*/

GLOBAL(void)

jinit_c_master_control (j_compress_ptr cinfo, boolean transcode_only)

{

my_master_ptr master;

master = (my_master_ptr)

(*cinfo->mem->alloc_small) ((j_common_ptr) cinfo, JPOOL_IMAGE,

SIZEOF(my_comp_master));

cinfo->master = &master->pub;

master->pub.prepare_for_pass = prepare_for_pass;

master->pub.pass_startup = pass_startup;

master->pub.finish_pass = finish_pass_master;

master->pub.is_last_pass = FALSE;

/* Validate parameters, determine derived values */

initial_setup(cinfo);

if (cinfo->scan_info != NULL) {

#ifdef C_MULTISCAN_FILES_SUPPORTED

validate_script(cinfo);

if (cinfo->block_size < DCTSIZE)

reduce_script(cinfo);

#else

ERREXIT(cinfo, JERR_NOT_COMPILED);

#endif

} else {

cinfo->progressive_mode = FALSE;

cinfo->num_scans = 1;

}

if (cinfo->optimize_coding)

cinfo->arith_code = FALSE; /* disable arithmetic coding */

else if (! cinfo->arith_code &&

(cinfo->progressive_mode ||

(cinfo->block_size > 1 && cinfo->block_size < DCTSIZE)))

/* TEMPORARY HACK ??? */

/* assume default tables no good for progressive or reduced AC mode */

cinfo->optimize_coding = TRUE; /* force Huffman optimization */

/* Initialize my private state */

if (transcode_only) {

/* no main pass in transcoding */

if (cinfo->optimize_coding)

master->pass_type = huff_opt_pass;

else

master->pass_type = output_pass;

} else {

/* for normal compression, first pass is always this type: */

master->pass_type = main_pass;

}

master->scan_number = 0;

master->pass_number = 0;

if (cinfo->optimize_coding)

master->total_passes = cinfo->num_scans * 2;

else

master->total_passes = cinfo->num_scans;

}