jcmaster.cpp

Go to the documentation of this file.

/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          http://www.mrpt.org/                          |
   |                                                                        |
   | Copyright (c) 2005-2017, Individual contributors, see AUTHORS file     |
   | See: http://www.mrpt.org/Authors - All rights reserved.                |
   | Released under BSD License. See details in http://www.mrpt.org/License |
   +------------------------------------------------------------------------+ */

#define JPEG_INTERNALS
#include "jinclude.h"
#include "mrpt_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;
        jpeg_component_info* compptr;
        long samplesperrow;
        JDIMENSION jd_samplesperrow;

        /* Sanity check on image dimensions */
        if (cinfo->image_height <= 0 || cinfo->image_width <= 0 ||
                cinfo->num_components <= 0 || cinfo->input_components <= 0)
                ERREXIT(cinfo, JERR_EMPTY_IMAGE);

        /* 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);

        /* Width of an input scanline must be representable as JDIMENSION. */
        samplesperrow = (long)cinfo->image_width * (long)cinfo->input_components;
        jd_samplesperrow = (JDIMENSION)samplesperrow;
        if ((long)jd_samplesperrow != samplesperrow)
                ERREXIT(cinfo, JERR_WIDTH_OVERFLOW);

        /* 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);
        }

        /* 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;
                /* For compression, we never do DCT scaling. */
                compptr->DCT_scaled_size = DCTSIZE;
                /* 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 * DCTSIZE));
                compptr->height_in_blocks = (JDIMENSION)jdiv_round_up(
                        (long)cinfo->image_height * (long)compptr->v_samp_factor,
                        (long)(cinfo->max_v_samp_factor * DCTSIZE));
                /* 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 (this flag isn't actually used for compression)
                 */
                compptr->component_needed = TRUE;
        }

        /* 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->image_height, (long)(cinfo->max_v_samp_factor * DCTSIZE));
}

#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 BITS_IN_JSAMPLE == 8
#define MAX_AH_AL 10
#else
#define MAX_AH_AL 13
#endif
                        if (Ss < 0 || Ss >= DCTSIZE2 || Se < Ss || Se >= DCTSIZE2 ||
                                Ah < 0 || Ah > MAX_AH_AL || Al < 0 || Al > MAX_AH_AL)
                                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);
                }
        }
}

#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 != nullptr)
        {
                /* 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]];
                }
                cinfo->Ss = scanptr->Ss;
                cinfo->Se = scanptr->Se;
                cinfo->Ah = scanptr->Ah;
                cinfo->Al = scanptr->Al;
        }
        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 = DCTSIZE2 - 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 = DCTSIZE;
                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 * DCTSIZE));
                cinfo->MCU_rows_in_scan = (JDIMENSION)jdiv_round_up(
                        (long)cinfo->image_height,
                        (long)(cinfo->max_v_samp_factor * DCTSIZE));

                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 * DCTSIZE;
                        /* 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->arith_code)
                        {
                                (*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 != nullptr)
        {
                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 = (struct jpeg_comp_master*)master;
        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 != nullptr)
        {
#ifdef C_MULTISCAN_FILES_SUPPORTED
                validate_script(cinfo);
#else
                ERREXIT(cinfo, JERR_NOT_COMPILED);
#endif
        }
        else
        {
                cinfo->progressive_mode = FALSE;
                cinfo->num_scans = 1;
        }

        if (cinfo->progressive_mode) /*  TEMPORARY HACK ??? */
                cinfo->optimize_coding =
                        TRUE; /* assume default tables no good for progressive mode */

        /* 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;
}