ComposerDesktopProject/dev/modify/pan.c

/*
 * Copyright (c) 1983-2023 Trevor Wishart and Composers Desktop Project Ltd
 * http://www.trevorwishart.co.uk
 * http://www.composersdesktop.com
 *
 This file is part of the CDP System.

 The CDP System is free software; you can redistribute it
 and/or modify it under the terms of the GNU Lesser General Public
 License as published by the Free Software Foundation; either
 version 2.1 of the License, or (at your option) any later version.

 The CDP System is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU Lesser General Public License for more details.

 You should have received a copy of the GNU Lesser General Public
 License along with the CDP System; if not, write to the Free Software
 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
 02111-1307 USA
 *
 */



/* floatsam version */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>                             /*RWD Nov 2003 */
#include <structures.h>
#include <tkglobals.h>
#include <globcon.h>
#include <modify.h>
#include <cdpmain.h>
#include <modeno.h>
#include <arrays.h>
#include <filetype.h>
#include <sfsys.h>
//TW UPDATE
#include <osbind.h>

//#ifdef unix 
#define round(x) lround((x))
//#endif

//TW UPDATES
#define SMALLARRAY      20
#define ONE_dB          1.22018

#define BSIZE           (128)
#define ROOT2           (1.4142136)
#define SIGNAL_TO_LEFT  (0)
#define SIGNAL_TO_RIGHT (1)

#define NARROW_IT       (1)
#define MONO_IT         (0)
#define MIRROR_IT       (-1)

static int newpar(int *brkindex,double *par,double *parincr,int *total_sams,dataptr dz);
static void pancalc(double position,double *leftgain,double *rightgain);
static void do_mirror(float *buffer,dataptr dz);
static void do_narrow(double narrow,double one_less_narrow,dataptr dz);
static void do_mono(dataptr dz);

static int more_space(int size_step,int *arraysize,double **brk);
static int get_sinval(double *f0,double *a0,double time,double *phase,double phase_quantum,double **p,dataptr dz);

//TW UPDATE: NEW FUNCTIONS
static int insert_point_in_envelope(int *last_postk,double basetime,int thisenv,int *cnt,
                                    double *last_posttime,double *last_postlevel,int *last_insertk,double *last_inserttime,double *last_insertlevel,
                                    double envtime,double envlevel,dataptr dz);

/* SHUDDER */
static int apply_brkpnt_envelope(dataptr dz);
static int  init_brkpnts
(int *sampno,double *starttime,double *gain,double **endbrk,double **nextbrk,
 double *nextgain,double *gain_step,double *gain_incr,int *nextbrk_sampno,int paramno,int brksize,dataptr dz);
static int  advance_brkpnts
(double starttime,double *gain,double *endbrk,double **nextbrk,double *nextgain,
 double *gain_step,double *gain_incr,int *nextbrk_sampno,dataptr dz);
static int  simple_envel_processing
(int *samps_left_to_process,double starttime,double *endbrk,double **nextbrk,double *nextgain,
 int *sampno,double *gain,double *gain_step,double *gain_incr,int *nextbrk_sampno,int chan,float *maxobuf,dataptr dz);
static int  do_mono_envelope
(int samp_cnt,double starttime,double *endbrk,double **nextbrk,double *nextgain,
 int *sampno,double *gain,double *gain_step,double *gain_incr,int *nextbrk_sampno,float *maxobuf,dataptr dz);
static int  read_ssamps(int samps_to_read,int *samps_left_to_process,int chan,dataptr dz);
static int  do_simple_read(int *samps_left_to_process,int buflen,int chan,dataptr dz);
static int other_read_samps(int samps_to_read,int fileid,int bufno,dataptr dz);
static void unlink_temp_files(int type,int ofd0, int ofd1,dataptr dz);

/************************************ MODSPACE_PCONSISTENCY *******************************/

int modspace_pconsistency(dataptr dz)
{
    switch(dz->mode) {
    case(MOD_PAN):
        if(dz->infile->channels!=MONO) {
            sprintf(errstr,"ERROR: PAN only works with MONO input files.\n");
            return(DATA_ERROR);
        }
        break;
    case(MOD_MIRROR):
        if(dz->infile->channels!=STEREO) {
            sprintf(errstr,"ERROR: MIRROR only works with STEREO input files.\n");
            return(DATA_ERROR);
        }
        break;
    case(MOD_MIRRORPAN):
        if(dz->infile->filetype!=UNRANGED_BRKFILE) {
            sprintf(errstr,"ERROR: MIRROR PAN only works with PAN textdata files.\n");
            return(DATA_ERROR);
        }
        if(dz->brksize[dz->extrabrkno] < 2) {
            sprintf(errstr,"ERROR: MIRROR PAN table too short [%d pairs < 2].\n",dz->brksize[dz->extrabrkno]);
            return(DATA_ERROR);
        }
        break;
    case(MOD_NARROW):
        if(dz->infile->channels!=STEREO) {
            sprintf(errstr,"ERROR: NARROW only works with STEREO input files.\n");
            return(DATA_ERROR);
        }
        break;
    }
    return(FINISHED);
}

/************************************ MODSPACE_PREPROCESS *******************************/

int modspace_preprocess(dataptr dz)
{
    int exit_status;
    if(dz->mode == MOD_PAN && dz->brksize[PAN_PAN]) {
        if((exit_status = force_value_at_zero_time(PAN_PAN,dz))<0)
            return(exit_status);
    }

    if(dz->mode==MOD_PAN){
        /* create stereo outfile here! */
        /* RWD 4:2002  now we can open outfile with corect params! */
        dz->infile->channels = STEREO;  /* ARRGH! */
        if((exit_status = create_sized_outfile(dz->outfilename,dz))<0)
            return(exit_status);
    }


    return(FINISHED);
}

/************************************ DOPAN *******************************/

int dopan(dataptr dz)
{
    int exit_status;
    int         i;
    int         brkindex = 1;
    int        block = 0, sams = 0, total_sams = 0;
    float  *inbuf = dz->sampbuf[0], *bufptr;
    double      leftgain,rightgain;
    double      lcoef = 0.0, rcoef = 0.0;
    double      par = 0.0, parincr = 0.0;
    /*  double  fdist = 1.0;*/          /* fdist is for listener distance: not used yet */

    if(!dz->brksize[PAN_PAN]) {
        pancalc(dz->param[PAN_PAN],&leftgain,&rightgain);
        lcoef = leftgain  * dz->param[PAN_PRESCALE];
        rcoef = rightgain * dz->param[PAN_PRESCALE];
    }
    display_virtual_time(0L,dz);
    dz->infile->channels = STEREO;      /* affects output only */
    do {
        if((exit_status = read_samps(inbuf,dz))<0) {
            sprintf(errstr,"Failed to read data from sndfile.\n");
            return(DATA_ERROR);
        }
        bufptr = dz->sampbuf[1];        /* reset output buffer pointer */

        for (i = 0 ; i < dz->ssampsread; i++ ) {
            if(dz->brksize[PAN_PAN]) {
                if(sams-- <= 0)
                    sams = newpar(&brkindex,&par,&parincr,&total_sams,dz);
                if(block-- <= 0) {
                    pancalc(par,&leftgain,&rightgain);
                    lcoef = leftgain  * dz->param[PAN_PRESCALE];
                    rcoef = rightgain * dz->param[PAN_PRESCALE];
                    block += BSIZE;
                    par += parincr;
                }
            }
            *bufptr++ = (float) /*round*/(lcoef * inbuf[i]);
            *bufptr++ = (float) /*round*/(rcoef * inbuf[i]);
        }
        if(dz->ssampsread > 0) {
            if((exit_status = write_samps(dz->sampbuf[1],dz->ssampsread * STEREO,dz))<0)
                return(exit_status);
        }
    } while(dz->samps_left > 0);
    return(FINISHED);
}

/************************************ MIRRORING *******************************/

int mirroring(dataptr dz)
{
    int exit_status;
    float *inbuf = dz->sampbuf[0];
    do {
        if((exit_status = read_samps(inbuf,dz))<0) {
            sprintf(errstr,"Failed to read data from sndfile.\n");
            return(DATA_ERROR);
        }
        do_mirror(inbuf,dz);
        if(dz->ssampsread > 0) {
            if((exit_status = write_exact_samps(dz->sampbuf[0],dz->ssampsread,dz))<0)
                return(exit_status);
        }
    } while(dz->samps_left > 0);
    return(FINISHED);
}

/******************************** MIRROR_PANFILE ********************************/

void mirror_panfile(dataptr dz)
{
    int    panbrk = dz->extrabrkno;
    int   n;
    double *panbrktab  = dz->brk[panbrk];
    int   panbrksize = dz->brksize[panbrk];
    double *p = panbrktab + 1;
    for(n=0;n<panbrksize;n++) {
        *p = -(*p);
        p += 2;
    }
    p = panbrktab;
    for(n=0;n<panbrksize;n++) {
        fprintf(dz->fp,"%lf\t%lf\n",*p,*(p+1));
        p += 2;
    }
    return;
}

/***************************** NARROW_SOUND ***************************/

int narrow_sound(dataptr dz)
{
    int exit_status;
    int narrowing = NARROW_IT;
    double narrow = dz->param[NARROW], one_less_narrow;
    float *buffer = dz->sampbuf[0];
    display_virtual_time(0L,dz);
    if(flteq(narrow,1.0)) {
        sprintf(errstr, "WARNING: Narrowing of 1.0 has no effect on input file.\n");
        return(DATA_ERROR);
    }
    if(flteq(narrow,-1.0))              narrowing = MIRROR_IT;
    else if(flteq(narrow,0.0))  narrowing = MONO_IT;
    narrow = dz->param[NARROW] + 1.0;
    narrow /= 2.0;
    one_less_narrow = narrow;
    narrow  = 1.0 - narrow;
    while(dz->samps_left != 0) {
        if((exit_status = read_samps(buffer,dz))<0) {
            sprintf(errstr,"Failed to read data from sndfile.\n");
            return(PROGRAM_ERROR);
        }
        switch(narrowing) {
        case(NARROW_IT):        do_narrow(narrow,one_less_narrow,dz);   break;
        case(MIRROR_IT):        do_mirror(buffer,dz);                   break;
        case(MONO_IT):          do_mono(dz);                            break;
        }
        if(dz->ssampsread > 0) {
            if((exit_status= write_exact_samps(buffer,dz->ssampsread,dz))<0)
                return(exit_status);
        }
    }
    return(FINISHED);
}

/************************************ NEWPAR *******************************/

int newpar(int *brkindex,double *par,double *parincr,int *total_sams,dataptr dz)
{
    double diff, steps, nextval;
    double *thisbrk = dz->brk[PAN_PAN];
    int here;
    int sams;
    if(*brkindex < dz->brksize[PAN_PAN]) {
        here  = (*brkindex) * 2;
        sams  = round(thisbrk[here] * dz->infile->srate) - *total_sams;
        *par  = thisbrk[here-1];
        nextval = thisbrk[++here];
        diff  = nextval - (*par);
        steps = (double)sams/(double)BSIZE;
        *parincr = diff/steps;
        (*brkindex)++;
    } else {
        *parincr = 0.0;
        sams = dz->insams[0] - *total_sams;
    }
    *total_sams += sams;
    return(sams);
}

/************************************ PANCALC *******************************/

void pancalc(double position,double *leftgain,double *rightgain)
{
    int dirflag;
    double temp;
    double relpos;
    double reldist, invsquare;

    if(position < 0.0)
        dirflag = SIGNAL_TO_LEFT;               /* signal on left */
    else
        dirflag = SIGNAL_TO_RIGHT;

    if(position < 0)
        relpos = -position;
    else
        relpos = position;
    if(relpos <= 1.0){          /* between the speakers */
        temp = 1.0 + (relpos * relpos);
        reldist = ROOT2 / sqrt(temp);
        temp = (position + 1.0) / 2.0;
        *rightgain = temp * reldist;
        *leftgain = (1.0 - temp ) * reldist;
    } else {                            /* outside the speakers */
        temp = (relpos * relpos) + 1.0;
        reldist  = sqrt(temp) / ROOT2;   /* relative distance to source */
        invsquare = 1.0 / (reldist * reldist);
        if(dirflag == SIGNAL_TO_LEFT){
            *leftgain = invsquare;
            *rightgain = 0.0;
        } else {   /* SIGNAL_TO_RIGHT */
            *rightgain = invsquare;
            *leftgain = 0;
        }
    }
}

/************************************ DO_MIRROR *******************************/

void do_mirror(float *buffer,dataptr dz)
{
    register int i;
    float store;
    for(i = 0; i < dz->ssampsread; i += 2) {
        store       = buffer[i];
        buffer[i]   = buffer[i+1];
        buffer[i+1] = store;
    }
}

/******************************* DO_NARROW *************************/

void do_narrow(double narrow,double one_less_narrow,dataptr dz)
{
    register int i;
    double new_l, new_r, add_to_l, add_to_r;
    float *buffer = dz->sampbuf[0];
    for(i = 0; i < dz->ssampsread; i+=2)  {
        //TW CHANGED (casts removed)
        add_to_r    = buffer[i]   * narrow;
        add_to_l    = buffer[i+1] * narrow;
        new_l       = buffer[i]   * one_less_narrow;
        new_r       = buffer[i+1] * one_less_narrow;
        new_l      += add_to_l;
        new_r      += add_to_r;
        buffer[i]   = (float) /*round*/(new_l);
        buffer[i+1] = (float) /*round*/(new_r);
    }
}

/******************************* DO_MONO *************************/

void do_mono(dataptr dz)
{
    register int  i, j;
    register double temp;
    float *buffer =dz->sampbuf[0];
    for(i = 0; i < dz->ssampsread; i+=2)  {
        j = i+1;
        temp      = (buffer[i] + buffer[j]) /*/2.0*/ * 0.5;
        buffer[i] = (float)/*round*/(temp);
        buffer[j] = (float)/*round*/(temp);
    }
}

/****************************** GENERATE_SINTABLE *******************************/

int generate_sintable(dataptr dz)
{
    int exit_status;
    double *p, f0, a0, phase_quantum, time, phase;
    int arraysize = BIGARRAY, cnt;

    if((dz->parray[SIN_TABLE] = (double *)malloc(arraysize * sizeof(double)))==NULL) {
        sprintf(errstr,"Out of memory for breakpoint table.\n");
        return(MEMORY_ERROR);
    }
    p = dz->parray[SIN_TABLE];
    phase = (dz->param[SIN_PHASE]/360.0) * TWOPI;
    //TW UPDATE
    //  *p++ = 0.0;
    //  *p++ = phase;
    //  cnt = 2;
    time = 0.0;
    if(dz->brksize[SIN_FRQ]) {
        if((exit_status = read_value_from_brktable(time,SIN_FRQ,dz))<0)
            return(exit_status);
    }
    //TW UPDATE
    dz->param[SIN_FRQ] = 1.0/dz->param[SIN_FRQ];

    if(dz->brksize[SIN_AMP]) {
        if((exit_status = read_value_from_brktable(time,SIN_AMP,dz))<0)
            return(exit_status);
    }
    f0 = dz->param[SIN_FRQ];
    a0 = dz->param[SIN_AMP];

    phase_quantum = dz->param[SIN_QUANT] * TWOPI;
    //TW UPDATES
    if((exit_status = get_sinval(&f0,&a0,time,&phase,phase_quantum,&p,dz))<0)
        return exit_status;
    cnt = 2;

    for(time = dz->param[SIN_QUANT]; time <= dz->param[SIN_DUR]; time += dz->param[SIN_QUANT]) {
        if((cnt += 2) > arraysize) {
            if((exit_status = more_space(BIGARRAY,&arraysize,&(dz->parray[SIN_TABLE])))<0)
                return(exit_status);
            p = dz->parray[SIN_TABLE] + cnt - 2;
        }
        if((exit_status = get_sinval(&f0,&a0,time,&phase,phase_quantum,&p,dz))<0)
            return exit_status;
    }
    if(!flteq(*(p-2),dz->param[SIN_DUR])) {
        if((cnt += 2) > arraysize) {
            arraysize = cnt;
            if((exit_status = more_space(2,&arraysize,&(dz->parray[SIN_TABLE])))<0)
                return(exit_status);
            p = dz->parray[SIN_TABLE] + cnt - 2;
        }
        if((exit_status = get_sinval(&f0,&a0,dz->param[SIN_DUR],&phase,phase_quantum,&p,dz))<0)
            return exit_status;
    } else {
        *(p-2) = dz->param[SIN_DUR];
    }
    if(cnt < arraysize) {
        if((dz->parray[SIN_TABLE] = (double *)realloc((char *)(dz->parray[SIN_TABLE]),cnt * sizeof(double)))==NULL) {
            sprintf(errstr,"Memory error on shrinking breaktable to size.\n");
            return(MEMORY_ERROR);
        }
    }
    cnt /= 2;
    if((exit_status = write_brkfile(dz->fp,cnt,SIN_TABLE,dz))<0)
        return(exit_status);
    return(FINISHED);
}

/****************************** GET_SINVAL *******************************/

int get_sinval(double *f0,double *a0,double time,double *phase,double phase_quantum,double **p,dataptr dz)
{
    int exit_status;
    double frq, amp, val;
    if(dz->brksize[SIN_FRQ]) {
        if((exit_status = read_value_from_brktable(time,SIN_FRQ,dz))<0)
            return(exit_status);
        //TW UPDATE
        dz->param[SIN_FRQ] = 1.0/dz->param[SIN_FRQ];

        frq = (dz->param[SIN_FRQ] + *f0) /*/2.0 */ * 0.5;
    } else {
        frq = *f0;
    }
    if(dz->brksize[SIN_AMP]) {
        if((exit_status = read_value_from_brktable(time,SIN_AMP,dz))<0)
            return(exit_status);
        amp = (dz->param[SIN_AMP] + *a0) /* /2.0*/ * 0.5;
    } else {
        amp = *a0;
    }
    //TW UPDATE (moved line)
    val = sin(*phase) * amp;
    *phase += frq * phase_quantum;
    *phase = fmod(*phase,TWOPI);
    **p = time;
    (*p)++;
    **p = val;
    (*p)++;
    *f0 = dz->param[SIN_FRQ];
    *a0 = dz->param[SIN_AMP];
    return(FINISHED);
}

/****************************** MORE_SPACE *******************************/

int more_space(int size_step,int *arraysize,double **brk)
{
    *arraysize += size_step;
    if((*brk = (double *)realloc((char *)(*brk),(*arraysize) * sizeof(double)))==NULL) {
        sprintf(errstr,"Out of memory for breakpoint table.\n");
        return(MEMORY_ERROR);
    }
    return(FINISHED);
}

//TW NEW FUNCTIONS (updated for flotsams)
/************************************ SCALEDPAN_PREPROCESS *******************************/

int scaledpan_preprocess(dataptr dz)
{
    int exit_status, n, len;
    double endtime, scaling;
    double *thisbrk;
    if((len = (dz->brksize[PAN_PAN] * 2)) <= 0) {
        fprintf(stdout,"WARNING: Scaled pan is no different to ordinary panning, if you do not use a brkpoint file.\n");
        fflush(stdout);
        return(FINISHED);
    }
    if((exit_status = force_value_at_zero_time(PAN_PAN,dz))<0)
        return(exit_status);
    thisbrk = dz->brk[PAN_PAN];
    endtime = thisbrk[len - 2];
    scaling = dz->duration/endtime;
    for(n=0;n<len;n+=2)
        thisbrk[n] *= scaling;
    /* create stereo outfile here! */
    dz->infile->channels = STEREO;      /* ARRGH! */
    return create_sized_outfile(dz->outfilename,dz);
}

/************************************* DO_SHUDDER ***********************************/

int do_shudder(dataptr dz)
{
    int left, exit_status;
    int cnt = 0, cnt2 = 0, timecnt, n, m, j, levelcnt;
    int cnt0, cnt1;
    int arraysz[2] = {SMALLARRAY,SMALLARRAY};
    double time, nexttime, lasttime, pos, leftgain, rightgain, depth, maxlevel, width, lastrealtime = -1.0;
    double envtime, envlevel, lgain, rgain, scat, realtime, levell, levelr, one_minus_depth, safety = 1.0/ROOT2;
    double last_posttime[2], last_postlevel[2], last_inserttime[2], last_insertlevel[2], basetime[2];
    int last_insertk[2], last_postk[2];

    double ee[] = {-7,-5, -3, -1, 1,  3,  5,  7};
    double ff[] = {0, 0.2,0.8,1.0,0.8,0.2,0.1,0};

    dz->tempsize = dz->insams[0] * 2;
    initrand48();
    for(n=0;n<8;n++)
        ee[n] *= 1.0/14.0;

    if((dz->parray[SHUD_TIMES] = (double *) malloc(arraysz[0] * sizeof(double)))==NULL) {
        sprintf(errstr,"Out of Memory While calculating Shudder Times\n");
        return(MEMORY_ERROR);
    }
    if((dz->parray[SHUD_LEVEL] = (double *) malloc(arraysz[1] * sizeof(double)))==NULL) {
        sprintf(errstr,"Out of Memory While calculating Shudder Levels\n");
        return(MEMORY_ERROR);
    }
    if((dz->parray[SHUD_WIDTH] = (double *) malloc(arraysz[0] * sizeof(double)))==NULL) {
        sprintf(errstr,"Out of Memory While calculating Shudder Widths\n");
        return(MEMORY_ERROR);
    }
    if((dz->parray[SHUD_DEPTH] = (double *) malloc(arraysz[0] * sizeof(double)))==NULL) {
        sprintf(errstr,"Out of Memory While calculating Shudder Widths\n");
        return(MEMORY_ERROR);
    }
    if((drand48() * 2.0) - 1.0 <= 0.0)
        left = 1;
    else
        left = -1;
    /* Get TIME, and WIDTH of initial shudder */
    time = dz->param[SHUD_STARTTIME];
    if((exit_status = read_values_from_all_existing_brktables(time,dz))<0)
        return(exit_status);
    width = ((dz->param[SHUD_MAXWIDTH] - dz->param[SHUD_MINWIDTH]) * drand48()) + dz->param[SHUD_MINWIDTH];
    dz->parray[SHUD_WIDTH][cnt] = width;
    time = max(time,width/2.0);
    dz->parray[SHUD_TIMES][cnt] = time;

    /* From STEREO-POSITION and DEPTH, calculate L and R levels */

    pos = dz->param[SHUD_SPREAD] * drand48() * left;
    pancalc(pos,&leftgain,&rightgain);

    depth = ((dz->param[SHUD_MAXDEPTH] - dz->param[SHUD_MINDEPTH]) * drand48()) + dz->param[SHUD_MINDEPTH];
    /* SHUDDER is added to existing level */
    /*... and will be automatically scaled by existing level when imposed on sound */
    dz->parray[SHUD_DEPTH][cnt] = 1.0 - depth;
    lgain = depth * leftgain;
    rgain = depth * rightgain;
    maxlevel = max(lgain,rgain);
    dz->parray[SHUD_LEVEL][cnt2++] = lgain;
    dz->parray[SHUD_LEVEL][cnt2++] = rgain;
    left = -left;
    cnt++;
    /* get, time , width and L & R level for all shudders */
    while(time < dz->duration) {
        lasttime = time;
        time = time + (1/dz->param[SHUD_FRQ]);  /* use frq from previous time, to calculate where next time is */
        if((exit_status = read_values_from_all_existing_brktables(time,dz))<0)
            return(exit_status);
        nexttime = time + (1/dz->param[SHUD_FRQ]);
        scat = ((drand48() * 2.0) - 1.0) * dz->param[SHUD_SCAT];
        if(scat >= 0)
            realtime = ((nexttime - time) * scat) + time;
        else
            realtime = time - ((time - lasttime) * scat);
        width = ((dz->param[SHUD_MAXWIDTH] - dz->param[SHUD_MINWIDTH]) * drand48()) + dz->param[SHUD_MINWIDTH];
        if((realtime <= (width/2.0) + FLTERR) || (realtime <= lastrealtime))
            continue;
        lastrealtime = realtime;
        dz->parray[SHUD_TIMES][cnt] = realtime;
        pos = dz->param[SHUD_SPREAD] * drand48() * left;
        left = -left;
        pancalc(pos,&leftgain,&rightgain);
        depth = ((dz->param[SHUD_MAXDEPTH] - dz->param[SHUD_MINDEPTH]) * drand48()) + dz->param[SHUD_MINDEPTH];
        dz->parray[SHUD_DEPTH][cnt] = 1.0 - depth;
        lgain = depth * leftgain;
        rgain = depth * rightgain;
        maxlevel = max(maxlevel,lgain);
        maxlevel = max(maxlevel,rgain);
        dz->parray[SHUD_LEVEL][cnt2++] = lgain;
        dz->parray[SHUD_LEVEL][cnt2++] = rgain;
        dz->parray[SHUD_WIDTH][cnt] = width;
        if (++cnt >= arraysz[0]) {
            arraysz[0] += SMALLARRAY;
            if((dz->parray[SHUD_TIMES] = (double *)realloc((char *)dz->parray[SHUD_TIMES],arraysz[0] * sizeof(double)))==NULL) {
                sprintf(errstr,"Out of Memory While calculating Shudder Times\n");
                return(MEMORY_ERROR);
            }
            if((dz->parray[SHUD_WIDTH] = (double *)realloc((char *)dz->parray[SHUD_WIDTH],arraysz[0] * sizeof(double)))==NULL) {
                sprintf(errstr,"Out of Memory While calculating Shudder Widths\n");
                return(MEMORY_ERROR);
            }
            if((dz->parray[SHUD_DEPTH] = (double *)realloc((char *)dz->parray[SHUD_DEPTH],arraysz[0] * sizeof(double)))==NULL) {
                sprintf(errstr,"Out of Memory While calculating Shudder Widths\n");
                return(MEMORY_ERROR);
            }
        }
        if (cnt2 >= arraysz[1]) {
            arraysz[1] += SMALLARRAY;
            if((dz->parray[SHUD_LEVEL] = (double *)realloc((char *)dz->parray[SHUD_LEVEL],arraysz[1] * sizeof(double)))==NULL) {
                sprintf(errstr,"Out of Memory While calculating Shudder Levels\n");
                return(MEMORY_ERROR);
            }
        }
    }
    if((dz->parray[SHUD_TIMES] = (double *)realloc((char *)dz->parray[SHUD_TIMES],cnt * sizeof(double)))==NULL) {
        sprintf(errstr,"Out of Memory While calculating Shudder Times\n");
        return(MEMORY_ERROR);
    }
    if((dz->parray[SHUD_WIDTH] = (double *)realloc((char *)dz->parray[SHUD_WIDTH],cnt * sizeof(double)))==NULL) {
        sprintf(errstr,"Out of Memory While calculating Shudder Widths\n");
        return(MEMORY_ERROR);
    }
    if((dz->parray[SHUD_DEPTH] = (double *)realloc((char *)dz->parray[SHUD_DEPTH],cnt * sizeof(double)))==NULL) {
        sprintf(errstr,"Out of Memory While calculating Shudder Widths\n");
        return(MEMORY_ERROR);
    }
    if((dz->parray[SHUD_LEVEL] = (double *)realloc((char *)dz->parray[SHUD_LEVEL],cnt2 * sizeof(double)))==NULL) {
        sprintf(errstr,"Out of Memory While calculating Shudder Levels\n");
        return(MEMORY_ERROR);
    }
    /* NORMALISE LEVELS */
    for(m=0;m<cnt2;m++)
        dz->parray[SHUD_LEVEL][m] /= maxlevel;

    if((dz->parray[SHUD_ENV0] = (double *)malloc(((cnt * 16) + 4) * sizeof(double)))==NULL) {
        sprintf(errstr,"Out of Memory While calculating Shudder Envelopes\n");
        return(MEMORY_ERROR);
    }
    if((dz->parray[SHUD_ENV1] = (double *)malloc(((cnt * 16) + 4) * sizeof(double)))==NULL) {
        sprintf(errstr,"Out of Memory While calculating Shudder Envelopes\n");
        return(MEMORY_ERROR);
    }
    timecnt = 0;
    levelcnt = 0;
    cnt0 = 0;
    cnt1 = 0;
    basetime[0] = -1.0;
    basetime[1] = -1.0;
    arraysz[0] = SMALLARRAY;
    arraysz[1] = SMALLARRAY;
    while(timecnt< cnt) {
        time  = dz->parray[SHUD_TIMES][timecnt];
        width = dz->parray[SHUD_WIDTH][timecnt];
        one_minus_depth = dz->parray[SHUD_DEPTH][timecnt];
        levell = dz->parray[SHUD_LEVEL][levelcnt];
        levelr = dz->parray[SHUD_LEVEL][levelcnt+1];
        last_postk[0] = -1;
        last_postk[1] = -1;
        for(j=0;j<8;j++) {
            envtime = time + (ee[j] * width);
            envlevel = ((levell * ff[j]) + one_minus_depth) * safety;
            /* safety compensates for centre boost given by pan-calculation */
            insert_point_in_envelope(&(last_postk[0]),basetime[0],SHUD_ENV0,&cnt0,&(last_posttime[0]),&(last_postlevel[0]),
                                     &(last_insertk[0]),&(last_inserttime[0]),&(last_insertlevel[0]),envtime,envlevel,dz);
            envlevel = (levelr * ff[j]) + one_minus_depth;
            insert_point_in_envelope(&(last_postk[1]),basetime[1],SHUD_ENV1,&cnt1,&(last_posttime[1]),&(last_postlevel[1]),
                                     &(last_insertk[1]),&(last_inserttime[1]),&(last_insertlevel[1]),envtime,envlevel,dz);

        }
        basetime[0] = dz->parray[SHUD_ENV0][cnt0-2];    /* last envelope time in array */
        basetime[1] = dz->parray[SHUD_ENV1][cnt1-2];    /* last envelope time in array */

        timecnt++;
        levelcnt+=2;
    }
    if(dz->parray[SHUD_ENV0][0] <= FLTERR) {                    /* Force points at ZERO and at DURATION+ */
        dz->parray[SHUD_ENV0][0] = 0.0;
        dz->parray[SHUD_ENV1][0] = 0.0;
    } else {
        for(n=cnt0-1;n>=0;n--)
            dz->parray[SHUD_ENV0][n+2] = dz->parray[SHUD_ENV0][n];
        for(n=cnt1-1;n>=0;n--)
            dz->parray[SHUD_ENV1][n+2] = dz->parray[SHUD_ENV1][n];
        dz->parray[SHUD_ENV0][0] = 0.0;
        dz->parray[SHUD_ENV0][1] = dz->parray[SHUD_ENV0][3];
        dz->parray[SHUD_ENV1][0] = 0.0;
        dz->parray[SHUD_ENV1][1] = dz->parray[SHUD_ENV1][3];
        cnt0 += 2;
        cnt1 += 2;
    }
    if(dz->parray[SHUD_ENV0][cnt0 - 2] < dz->duration - FLTERR) {
        dz->parray[SHUD_ENV0][cnt0] = dz->duration + FLTERR;
        dz->parray[SHUD_ENV0][cnt0 + 1] = dz->parray[SHUD_ENV0][cnt0 - 1];
        dz->parray[SHUD_ENV1][cnt1] = dz->duration + FLTERR;
        dz->parray[SHUD_ENV1][cnt1 + 1] = dz->parray[SHUD_ENV1][cnt1 - 1];
        cnt0 += 2;
        cnt1 += 2;
    }
    if((dz->parray[SHUD_ENV0] = (double *)realloc((char *)dz->parray[SHUD_ENV0],cnt0 * sizeof(double)))==NULL) {
        sprintf(errstr,"Out of Memory While calculating Shudder Envelopes\n");
        return(MEMORY_ERROR);
    }
    if((dz->parray[SHUD_ENV1] = (double *)realloc((char *)dz->parray[SHUD_ENV1],cnt1 * sizeof(double)))==NULL) {
        sprintf(errstr,"Out of Memory While calculating Shudder Envelopes\n");
        return(MEMORY_ERROR);
    }
    dz->itemcnt = cnt0;                 /* used to store counts */
    dz->extrabrkno = cnt1;              /* used to store counts */
    if((exit_status = apply_brkpnt_envelope(dz))<0)
        return(exit_status);
    return(FINISHED);
}

/************************************* INSERT_POINT_IN_ENVELOPE ***********************************/

int insert_point_in_envelope(int *last_postk,double basetime,int thisenv,int *cnt,
                             double *last_posttime,double *last_postlevel,int *last_insertk,double *last_inserttime,double *last_insertlevel,
                             double envtime,double envlevel,dataptr dz)
{
    int k, j, last_pk;
    double pretime, posttime, prelevel, postlevel, timestep, frac, levelhere, last_ptime, last_plevel;

    if(envtime <= basetime) {
        k = *cnt - 2;
        while (dz->parray[thisenv][k] > envtime)
            k -= 2;
        pretime   = dz->parray[thisenv][k];
        prelevel  = dz->parray[thisenv][k+1];
        k += 2;
        posttime  = dz->parray[thisenv][k];
        postlevel = dz->parray[thisenv][k+1];
        timestep = posttime - pretime;
        frac      = (envtime - pretime)/timestep;
        levelhere = ((postlevel - prelevel) * frac) + prelevel;
        if(envlevel > levelhere) {
            for(j = *cnt-1;j >= k; j--)                         /* SHUFFLUP DATA ABOVE */
                dz->parray[thisenv][j+2] = dz->parray[thisenv][j];
            dz->parray[thisenv][k]   = envtime; /* INSERT NEW POINT */
            dz->parray[thisenv][k+1] = envlevel;
            *cnt += 2;
            if(*last_postk >= 0) {                                      /* IF POINTS HAVE ALREADY BEEN INSERTED */
                timestep = dz->parray[thisenv][k] - dz->parray[thisenv][*last_insertk];
                last_pk     = *last_postk;
                last_ptime  = *last_posttime;           /* CHECK POINTS INTERVENING BETWEEN THIS AND LAST INSERT */
                last_plevel = *last_postlevel;
                while(envtime > last_ptime) {
                    frac = (last_ptime - *last_inserttime)/timestep;
                    levelhere = ((envlevel - *last_insertlevel) * frac) + *last_insertlevel;
                    if(levelhere > last_plevel)
                        dz->parray[thisenv][last_pk+1] = levelhere;
                    last_pk += 2;
                    last_ptime  = dz->parray[thisenv][last_pk];
                    last_plevel = dz->parray[thisenv][last_pk+1];
                }
            }
            *last_insertk = k;                                          /* REMEMBER TIMES AND LEVELS OF LAST INSERT, AND POST-INSERT */
            *last_inserttime  = dz->parray[thisenv][k];
            *last_insertlevel = dz->parray[thisenv][k+1];
            k +=2;
            *last_postk = k;
            *last_posttime  = dz->parray[thisenv][k];
            *last_postlevel = dz->parray[thisenv][k+1];
        } else {
            *last_postk = -1;
        }
    } else {
        dz->parray[thisenv][(*cnt)++]   = envtime;
        dz->parray[thisenv][(*cnt)++]   = envlevel;
        *last_postk = -1;
    }
    return(FINISHED);
}

/******************************* APPLY_BRKPNT_ENVELOPE *******************************/

int apply_brkpnt_envelope(dataptr dz)
{
    int exit_status, ofd0, ofd1;
    int samps_left_to_process = dz->insams[0], sampout_cnt;
    int sampno, nextbrk_sampno;
    double starttime, gain, nextgain, gain_step, gain_incr, multiplier0 = 0.0, multiplier1 = 0.0;
    double *endbrk, *nextbrk;
    int total_samps_to_read, n, j, k,samps_to_read_here;
    int chan;
    float maxobuf0, maxobuf1;
    char *outfilename;

    if(sloom) {
        if((outfilename = (char *)malloc((strlen(dz->wordstor[0])+1) * sizeof(char)))==NULL) {
            sprintf(errstr,"INSUFFICIENT MEMORY for outfilename.\n");
            return(MEMORY_ERROR);
        }
    } else {
        if((outfilename = (char *)malloc((strlen(dz->outfilename)+1) * sizeof(char)))==NULL) {
            sprintf(errstr,"INSUFFICIENT MEMORY for outfilename.\n");
            return(MEMORY_ERROR);
        }
    }
    /* ENVELOPE CHANNEL 1 */
    chan = 0;
    maxobuf0 = 0.0f;
    if((exit_status = do_simple_read(&samps_left_to_process,dz->buflen,chan,dz))<0)
        return(exit_status);                                                            /* setup simple buffering option */
    if((exit_status = init_brkpnts
        (&sampno,&starttime,&gain,&endbrk,&nextbrk,&nextgain,&gain_step,&gain_incr,&nextbrk_sampno,SHUD_ENV0,dz->itemcnt,dz))<0)
        return(exit_status);
    if((exit_status = simple_envel_processing(&samps_left_to_process,starttime,endbrk,&nextbrk,&nextgain,
                                              &sampno,&gain,&gain_step,&gain_incr,&nextbrk_sampno,chan,&maxobuf0,dz))<0)
        return(exit_status);
    /* STORE CHANNEL 1 OUTFILE */
    ofd0 = dz->ofd;
    /* CREATE CHANNEL 2 OUTFILE */
    if(sloom) {
        strcpy(outfilename,dz->wordstor[0]);
        insert_new_number_at_filename_end(outfilename,2,1);
    } else {
        strcpy(outfilename,dz->outfilename);
        insert_new_number_at_filename_end(outfilename,2,1);
    }
    sampout_cnt = dz->total_samps_written;

    if((exit_status = create_sized_outfile(outfilename,dz))<0) {
        dz->ofd = ofd0;
        return(SYSTEM_ERROR);
    }
    dz->total_samps_written = sampout_cnt;
    /* RESET INFILE TO START */
    sndseekEx(dz->ifd[0],0,0);
    samps_left_to_process = dz->insams[0];

    /* ENVELOPE CHANNEL 2 */
    chan = 1;
    maxobuf1 = 0.0f;
    if((exit_status = do_simple_read(&samps_left_to_process,dz->buflen,chan,dz))<0)
        return(exit_status);                                                            /* setup simple buffering option */
    if((exit_status = init_brkpnts
        (&sampno,&starttime,&gain,&endbrk,&nextbrk,&nextgain,&gain_step,&gain_incr,&nextbrk_sampno,SHUD_ENV1,dz->extrabrkno,dz))<0)
        return(exit_status);
    if((exit_status = simple_envel_processing(&samps_left_to_process,starttime,endbrk,&nextbrk,&nextgain,
                                              &sampno,&gain,&gain_step,&gain_incr,&nextbrk_sampno,chan,&maxobuf1,dz))<0)
        return(exit_status);
    /* STORE CHANNEL 2 OUTFILE */
    ofd1 = dz->ofd;
    /* CREATE STEREO OUTFILE */
    strcpy(outfilename,dz->wordstor[0]);
    if(sloom)
        insert_new_number_at_filename_end(outfilename,0,1);
    else
        outfilename[strlen(outfilename) -9] = ENDOFSTR;

    sampout_cnt = dz->total_samps_written;
    if((exit_status = create_sized_outfile(outfilename,dz))<0) {
        unlink_temp_files(1,ofd0,ofd1,dz);
        return(SYSTEM_ERROR);
    }
    if((exit_status = reset_peak_finder(dz))<0)
        return(exit_status);
    dz->total_samps_written = sampout_cnt;
    /* RESET BOTH CHANNEL-FILES TO START */
    sndseekEx(ofd0,0,0);
    sndseekEx(ofd1,0,0);
    total_samps_to_read = dz->insams[0]/2;

    /* MERGE SEPARATE CHANNELS BACK INTO STEREO */
    if(dz->vflag[SHUD_BALANCE]) {
        if(((maxobuf0 > maxobuf1) && (maxobuf0/maxobuf1 < ONE_dB))
           || (maxobuf1/maxobuf0 < ONE_dB))
            dz->vflag[0] = 0;
        else if(maxobuf0 > maxobuf1) {
            multiplier1 = maxobuf0/maxobuf1;
        } else {
            multiplier1 = -1.0;
            multiplier0 = maxobuf1/maxobuf0;
        }
    }
    while(total_samps_to_read > 0) {
        samps_to_read_here = min(total_samps_to_read,dz->buflen);
        if((exit_status = other_read_samps(samps_to_read_here,ofd0,0,dz))<0) {
            unlink_temp_files(2,ofd0,ofd1,dz);
            return(exit_status);
        }
        if((exit_status = other_read_samps(samps_to_read_here,ofd1,1,dz))<0) {
            unlink_temp_files(2,ofd0,ofd1,dz);
            return(exit_status);
        }
        if(dz->vflag[SHUD_BALANCE]) {
            if(multiplier1 > 0.0) {
                for(n=0,j=0,k=1;n<dz->ssampsread;n++,j+=2,k+=2) {
                    dz->sampbuf[2][j] = dz->sampbuf[0][n];
                    dz->sampbuf[2][k] = (float)(dz->sampbuf[1][n] * multiplier1);
                }
            } else {
                for(n=0,j=0,k=1;n<dz->ssampsread;n++,j+=2,k+=2) {
                    dz->sampbuf[2][j] = (float)(dz->sampbuf[0][n] * multiplier0);
                    dz->sampbuf[2][k] = dz->sampbuf[1][n];
                }
            }
        } else {
            for(n=0,j=0,k=1;n<dz->ssampsread;n++,j+=2,k+=2) {
                dz->sampbuf[2][j] = dz->sampbuf[0][n];
                dz->sampbuf[2][k] = dz->sampbuf[1][n];
            }
        }
        if(dz->ssampsread > 0) {
            if((exit_status = write_samps(dz->sampbuf[2],dz->ssampsread * 2,dz))<0) {
                unlink_temp_files(2,ofd0,ofd1,dz);
                return(exit_status);
            }
        }
        total_samps_to_read -= dz->ssampsread;
    }
    /* DELETE TEMPORARY OUTFILES */
    unlink_temp_files(2,ofd0,ofd1,dz);
    return FINISHED;
}

/**************************** INIT_BRKPNTS ********************************/

int init_brkpnts(int *sampno,double *starttime,double *gain,double **endbrk,double **nextbrk,
                 double *nextgain,double *gain_step,double *gain_incr,int *nextbrk_sampno,int paramno,int brksize,dataptr dz)
{
    double nexttime, time_from_start;
    *endbrk    = dz->parray[paramno] + ((brksize-1) * 2);
    *sampno    = 0;
    *starttime = dz->parray[paramno][0];
    *gain      = dz->parray[paramno][1];
    *nextbrk   = dz->parray[paramno] + 2;
    nexttime   = **nextbrk;
    *nextgain  = *((*nextbrk) + 1);
    *gain_step = *nextgain - *gain;
    time_from_start = nexttime - *starttime;
    if((*nextbrk_sampno  = (int)round(time_from_start * (double)dz->infile->srate))<0) {
        sprintf(errstr,"Impossible brkpoint time: (%.2lf secs)\n",time_from_start);
        return(PROGRAM_ERROR);
    }
    *gain_incr = (*gain_step)/(double)(*nextbrk_sampno);
    return(FINISHED);
}

/**************************** ADVANCE_BRKPNTS ******************************/

int advance_brkpnts(double starttime,double *gain,double *endbrk,double **nextbrk,
                    double *nextgain,double *gain_step,double *gain_incr,int *nextbrk_sampno,dataptr dz)
{
    double  nexttime, time_from_start;
    int   lastbrk_sampno, sampdist;
    if(*nextbrk!=endbrk) {
        *nextbrk   += 2;
        *gain      = *nextgain;
        nexttime   = **nextbrk;
        *nextgain  = *((*nextbrk) + 1);
        *gain_step = *nextgain - *gain;
        lastbrk_sampno = *nextbrk_sampno;
        time_from_start = nexttime - starttime;
        if((*nextbrk_sampno  = (int)round(time_from_start * dz->infile->srate))<0) {
            sprintf(errstr,"Impossible brkpoint time: (%.2lf secs)\n",time_from_start);
            return(PROGRAM_ERROR);
        }
        sampdist   = *nextbrk_sampno - lastbrk_sampno;
        *gain_incr = (*gain_step)/(double)sampdist;
    }
    return(FINISHED);
}

/*********************** SIMPLE_ENVEL_PROCESSING *********************************/

int simple_envel_processing
(int *samps_left_to_process,double starttime,double *endbrk,double **nextbrk,double *nextgain,
 int *sampno,double *gain,double *gain_step,double *gain_incr,int *nextbrk_sampno,int chan,float *maxobuf,dataptr dz)
{
    int exit_status;
    while(*samps_left_to_process > 0) {
        if((exit_status = do_mono_envelope
            (dz->buflen,starttime,endbrk,nextbrk,nextgain,sampno,gain,gain_step,gain_incr,nextbrk_sampno,maxobuf,dz))<0)
            return(exit_status);
        if((exit_status = write_samps(dz->sampbuf[1],dz->buflen,dz))<0)
            return(exit_status);
        if((exit_status = do_simple_read(samps_left_to_process,dz->buflen,chan,dz))<0)
            return(exit_status);
    }
    if((exit_status = do_mono_envelope
        (dz->ssampsread,starttime,endbrk,nextbrk,nextgain,sampno,gain,gain_step,gain_incr,nextbrk_sampno,maxobuf,dz))<0)
        return(exit_status);
    if(dz->ssampsread > 0)
        return write_samps(dz->sampbuf[1],dz->ssampsread,dz);
    return FINISHED;
}

/************************* DO_MONO_ENVELOPE *********************************/

int do_mono_envelope
(int sampcnt,double starttime,double *endbrk,double **nextbrk,double *nextgain,
 int *sampno,double *gain,double *gain_step,double *gain_incr,int *nextbrk_sampno,float *maxobuf,dataptr dz)
{
    int    exit_status;
    int   n;
    int   endsampno, this_endsamp, this_sampcnt;
    float  *ibuf = dz->sampbuf[0];
    float  *obuf = dz->sampbuf[1];
    float  *obufend = obuf + dz->buflen;
    int    quit = FALSE, change;
    double this_gain      = *gain;
    double this_gain_incr = *gain_incr;
    double this_gain_step = *gain_step;
    endsampno = *sampno + sampcnt;                              /* 1 */
    if(sampcnt > dz->buflen) {
        sprintf(errstr,"Buffering anomaly: do_mono_envelope()\n");
        return(PROGRAM_ERROR);
    }
    while(quit==FALSE) {
        if(*nextbrk_sampno <= endsampno) {              /* 2 */
            change = TRUE;
            this_endsamp = *nextbrk_sampno;             /* 3 */
            if(*nextbrk_sampno==endsampno)
                quit = TRUE;                                    /* 4 */
        } else {
            change = FALSE;                                             /* 5 */
            this_endsamp = endsampno;
            quit = TRUE;
        }
        this_sampcnt = this_endsamp - *sampno;  /* 6 */
        if(obuf + this_sampcnt > obufend) {
            sprintf(errstr,"array overrun: do_mono_envelope()\n");
            return(PROGRAM_ERROR);
        }
        if(flteq(this_gain,1.0) && flteq(this_gain_step,0.0)) {
            obuf += this_sampcnt;
            ibuf += this_sampcnt;                               /* no modification of sound */
        }
        else {

            for(n=0;n<this_sampcnt;n++) {               /* 7 */
                this_gain += this_gain_incr;
                *obuf = (float)(*ibuf * this_gain);
                *maxobuf = max(*maxobuf,*obuf);
                obuf++;
                ibuf++;
            }
        }
        *sampno += this_sampcnt;                                /* 8 */
        if(change) {                                                    /* 9 */
            if((exit_status = advance_brkpnts
                (starttime,gain,endbrk,nextbrk,nextgain,gain_step,gain_incr,nextbrk_sampno,dz))<0)
                return(exit_status);
            this_gain = *gain;
            this_gain_incr = *gain_incr;
            this_gain_step = *gain_step;
        }
    }
    *gain = this_gain;                                                  /* 10 */
    return(FINISHED);
}

/************************* READ_SSAMPS ******************************/

int read_ssamps(int samps_to_read,int *samps_left_to_process,int chan,dataptr dz)
{
    int n, m;
    if((dz->ssampsread = fgetfbufEx(dz->sampbuf[2],samps_to_read,dz->ifd[0],0))<0) {
        sprintf(errstr,"Can't read samps from input soundfile: read_ssamps()\n");
        return(SYSTEM_ERROR);
    }
    if(dz->ssampsread!=samps_to_read) {
        sprintf(errstr,"Error in buffering arithmetic: read_ssamps()\n");
        return(PROGRAM_ERROR);
    }
    *samps_left_to_process -= dz->ssampsread;
    dz->ssampsread /= 2;
    for(n=0,m=chan;n<dz->ssampsread;n++,m+=2)
        dz->sampbuf[0][n] = dz->sampbuf[2][m];
    return(FINISHED);
}

/******************************** DO_SIMPLE_READ **********************************/

int do_simple_read(int *samps_left_to_process,int buflen,int chan,dataptr dz)
{
    int exit_status;
    if(*samps_left_to_process < buflen * 2)
        exit_status = read_ssamps(*samps_left_to_process,samps_left_to_process,chan,dz);
    else
        exit_status = read_ssamps(buflen * 2,samps_left_to_process,chan,dz);
    return(exit_status);
}

/**************************** OTHER_READ_SAMPS *****************************/

int other_read_samps(int samps_to_read,int fileid,int bufno,dataptr dz)
{
    if((dz->ssampsread = fgetfbufEx(dz->sampbuf[bufno],samps_to_read,fileid,0)) < 0) {
        sprintf(errstr,"Can't read samps from input soundfile: other_read_samps()\n");
        return(SYSTEM_ERROR);
    }
    if(dz->ssampsread < samps_to_read) {
        sprintf(errstr,"Error in buffering arithmetic: other_read_samps()\n");
        return(PROGRAM_ERROR);
    }
    return(FINISHED);
}

/**************************** UNLINK_TEMP_FILES *****************************/

void unlink_temp_files(int type,int ofd0, int ofd1,dataptr dz)
{
    switch(type) {
    case(1):
        if(sndunlink(ofd1) < 0)
            fprintf(stdout, "ERROR: Can't set temporary output soundfile for deletion.\n");
        if(sndcloseEx(ofd1) < 0)
            fprintf(stdout, "WARNING: Can't close temporary output soundfile.\n");
        else
            ofd1 = -1;
        dz->ofd = ofd0;         /* closed at finish() */
        break;
    case(2):
        if(sndunlink(ofd0) < 0)
            fprintf(stdout, "ERROR: Can't set 1st temporary output soundfile for deletion.\n");
        if(sndcloseEx(ofd0) < 0)
            fprintf(stdout, "WARNING: Can't close 1st temporary output soundfile.\n");
        else
            ofd0 = -1;
        if(sndunlink(ofd1) < 0)
            fprintf(stdout, "ERROR: Can't set 2nd temporary output soundfile for deletion.\n");
        if(sndcloseEx(ofd1) < 0)
            fprintf(stdout, "WARNING: Can't close 2nd temporary output soundfile.\n");
        else
            ofd1 = -1;
        break;
    }
}

/************************************ FINDPAN *******************************/

int findpan(dataptr dz)
{
    int exit_status;
    int n, m, k, samppos, secpos;
    double panpos;
    float *inbuf = dz->sampbuf[0];
    float maxL = 0.0, maxR = 0.0;
    if(dz->param[PAN_PAN] > 0.0) {              /* Assesses One Sector at given time */
        samppos =  round(dz->param[PAN_PAN] * dz->infile->srate) * dz->infile->channels;
        secpos = samppos;
        if (secpos >= dz->insams[0]) {
            if((secpos -= F_SECSIZE) < 0)
                secpos = 0;
        }
        secpos = (secpos/F_SECSIZE) * F_SECSIZE;
        sndseekEx(dz->ifd[0],secpos,0);
        if((exit_status = read_samps(inbuf,dz))<0) {
            sprintf(errstr,"Failed to read data from sndfile.\n");
            return(DATA_ERROR);
        }
        k = min(dz->ssampsread,F_SECSIZE);
        for(n=0,m=1;n<k;n+=2,m+=2) {
            maxL = (float)max(fabs(inbuf[n]),maxL);
            maxR = (float)max(fabs(inbuf[m]),maxR);
        }
    } else {                                                    /* Assesses whole file */
        do {
            if((exit_status = read_samps(inbuf,dz))<0) {
                sprintf(errstr,"Failed to read data from sndfile.\n");
                return(DATA_ERROR);
            }
            for(n=0,m=1;n<dz->ssampsread;n+=2,m+=2) {
                maxL = (float)max(fabs(inbuf[n]),maxL);
                maxR = (float)max(fabs(inbuf[m]),maxR);
            }
        } while(dz->samps_left > 0);
    }
    if(maxL < SMP_FLTERR && maxR < SMP_FLTERR)
        fprintf(stdout,"INFO: levels are ZERO\n");
    else {
        panpos = maxR/(maxR + maxL);
        panpos = (panpos * 2.0) - 1.0;
        fprintf(stdout,"INFO: levels LEFT %.3lf RIGHT %.3lf : Panning position is %.2lf\n",maxL,maxR,panpos);
    }
    fflush(stdout);
    return(FINISHED);
}