d_soundfile.c

/* Copyright (c) 1997-1999 Miller Puckette.
* For information on usage and redistribution, and for a DISCLAIMER OF ALL
* WARRANTIES, see the file, "LICENSE.txt," in this distribution.  */

/* this file contains, first, a collection of soundfile access routines, a
sort of soundfile library.  Second, the "soundfiler" object is defined which
uses the routines to read or write soundfiles, synchronously, from garrays.
These operations are not to be done in "real time" as they may have to wait
for disk accesses (even the write routine.)  Finally, the realtime objects
readsf~ and writesf~ are defined which confine disk operations to a separate
thread so that they can be used in real time.  The readsf~ and writesf~
objects use Posix-like threads.  */

#include "config.h"

#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

#ifndef MSW
#include <fcntl.h>
#endif
#include <pthread.h>

#ifdef HAVE_IO_H
#include <io.h>
#endif

#include <stdio.h>
#include <string.h>
#include <errno.h>

#include "m_pd.h"

#define MAXSFCHANS 64

#ifdef _LARGEFILE64_SOURCE
# define open open64
# define lseek lseek64
#define off_t __off64_t
#endif
#ifdef MSW
#define off_t long
#endif

/***************** soundfile header structures ************************/

typedef unsigned short uint16;
typedef unsigned int uint32;

#define FORMAT_WAVE 0
#define FORMAT_AIFF 1
#define FORMAT_NEXT 2

/* the NeXTStep sound header structure; can be big or little endian  */

typedef struct _nextstep
{
    char ns_fileid[4];      /* magic number '.snd' if file is big-endian */
    uint32 ns_onset;        /* byte offset of first sample */
    uint32 ns_length;       /* length of sound in bytes */
    uint32 ns_format;        /* format; see below */
    uint32 ns_sr;           /* sample rate */
    uint32 ns_nchans;       /* number of channels */
    char ns_info[4];        /* comment */
} t_nextstep;

#define NS_FORMAT_LINEAR_16     3
#define NS_FORMAT_LINEAR_24     4
#define NS_FORMAT_FLOAT         6
#define SCALE (1./(1024. * 1024. * 1024. * 2.))

/* the WAVE header.  All Wave files are little endian.  We assume
    the "fmt" chunk comes first which is usually the case but perhaps not
    always; same for AIFF and the "COMM" chunk.   */

typedef unsigned word;
typedef unsigned long dword;

typedef struct _wave
{
    char  w_fileid[4];              /* chunk id 'RIFF'            */
    uint32 w_chunksize;             /* chunk size                 */
    char  w_waveid[4];              /* wave chunk id 'WAVE'       */
    char  w_fmtid[4];               /* format chunk id 'fmt '     */
    uint32 w_fmtchunksize;          /* format chunk size          */
    uint16  w_fmttag;               /* format tag (WAV_INT etc)   */
    uint16  w_nchannels;            /* number of channels         */
    uint32 w_samplespersec;         /* sample rate in hz          */
    uint32 w_navgbytespersec;       /* average bytes per second   */
    uint16  w_nblockalign;          /* number of bytes per frame  */
    uint16  w_nbitspersample;       /* number of bits in a sample */
    char  w_datachunkid[4];         /* data chunk id 'data'       */
    uint32 w_datachunksize;         /* length of data chunk       */
} t_wave;

typedef struct _fmt         /* format chunk */
{
    uint16 f_fmttag;                /* format tag, 1 for PCM      */
    uint16 f_nchannels;             /* number of channels         */
    uint32 f_samplespersec;         /* sample rate in hz          */
    uint32 f_navgbytespersec;       /* average bytes per second   */
    uint16 f_nblockalign;           /* number of bytes per frame  */
    uint16 f_nbitspersample;        /* number of bits in a sample */
} t_fmt;

typedef struct _wavechunk           /* ... and the last two items */
{
    char  wc_id[4];                 /* data chunk id, e.g., 'data' or 'fmt ' */
    uint32 wc_size;                 /* length of data chunk       */
} t_wavechunk;

#define WAV_INT 1
#define WAV_FLOAT 3

/* the AIFF header.  I'm assuming AIFC is compatible but don't really know
    that. */

typedef struct _datachunk
{
    char  dc_id[4];                 /* data chunk id 'SSND'       */
    uint32 dc_size;                 /* length of data chunk       */
    uint32 dc_offset;               /* additional offset in bytes */
    uint32 dc_block;                /* block size                 */
} t_datachunk;

typedef struct _comm
{
    uint16 c_nchannels;             /* number of channels         */
    uint16 c_nframeshi;             /* # of sample frames (hi)    */
    uint16 c_nframeslo;             /* # of sample frames (lo)    */
    uint16 c_bitspersamp;           /* bits per sample            */
    unsigned char c_samprate[10];   /* sample rate, 80-bit float! */
} t_comm;

    /* this version is more convenient for writing them out: */
typedef struct _aiff
{
    char  a_fileid[4];              /* chunk id 'FORM'            */
    uint32 a_chunksize;             /* chunk size                 */
    char  a_aiffid[4];              /* aiff chunk id 'AIFF'       */
    char  a_fmtid[4];               /* format chunk id 'COMM'     */
    uint32 a_fmtchunksize;          /* format chunk size, 18      */
    uint16 a_nchannels;             /* number of channels         */
    uint16 a_nframeshi;             /* # of sample frames (hi)    */
    uint16 a_nframeslo;             /* # of sample frames (lo)    */
    uint16 a_bitspersamp;           /* bits per sample            */
    unsigned char a_samprate[10];   /* sample rate, 80-bit float! */
} t_aiff;

#define AIFFHDRSIZE 38      /* probably not what sizeof() gives */


#define AIFFPLUS (AIFFHDRSIZE + 16)  /* header size including SSND chunk hdr */

#define WHDR1 sizeof(t_nextstep)
#define WHDR2 (sizeof(t_wave) > WHDR1 ? sizeof (t_wave) : WHDR1)
#define WRITEHDRSIZE (AIFFPLUS > WHDR2 ? AIFFPLUS : WHDR2)

#define READHDRSIZE (16 > WHDR2 + 2 ? 16 : WHDR2 + 2)

#define OBUFSIZE MAXPDSTRING  /* assume MAXPDSTRING is bigger than headers */

#ifdef MSW
#include <fcntl.h>
#define BINCREATE _O_WRONLY | _O_CREAT | _O_TRUNC | _O_BINARY
#else
#define BINCREATE O_WRONLY | O_CREAT | O_TRUNC
#endif

/* this routine returns 1 if the high order byte comes at the lower
address on our architecture (big-endianness.).  It's 1 for Motorola,
0 for Intel: */

extern int garray_ambigendian(void);

/* byte swappers */

static uint32 swap4(uint32 n, int doit)
{
    if (doit)
        return (((n & 0xff) << 24) | ((n & 0xff00) << 8) |
            ((n & 0xff0000) >> 8) | ((n & 0xff000000) >> 24));
    else return (n);
}

static uint16 swap2(uint32 n, int doit)
{
    if (doit)
        return (((n & 0xff) << 8) | ((n & 0xff00) >> 8));
    else return (n);
}

static void swapstring(char *foo, int doit)
{
    if (doit)
    {
        char a = foo[0], b = foo[1], c = foo[2], d = foo[3];
        foo[0] = d; foo[1] = c; foo[2] = b; foo[3] = a;
    }
}

/******************** soundfile access routines **********************/

/* This routine opens a file, looks for either a nextstep or "wave" header,
* seeks to end of it, and fills in bytes per sample and number of channels.
* Only 2- and 3-byte fixed-point samples and 4-byte floating point samples
* are supported.  If "headersize" is nonzero, the
* caller should supply the number of channels, endinanness, and bytes per
* sample; the header is ignored.  Otherwise, the routine tries to read the
* header and fill in the properties.
*/

int open_soundfile_via_fd(int fd, int headersize,
    int *p_bytespersamp, int *p_bigendian, int *p_nchannels, long *p_bytelimit,
    long skipframes)
{
    int format, nchannels, bigendian, bytespersamp, swap, sysrtn;
    long bytelimit = 0x7fffffff;
    errno = 0;
    if (headersize >= 0) /* header detection overridden */
    {
        bigendian = *p_bigendian;
        nchannels = *p_nchannels;
        bytespersamp = *p_bytespersamp;
        bytelimit = *p_bytelimit;
    }
    else
    {
        char buf[OBUFSIZE];
        int bytesread = read(fd, buf, READHDRSIZE);
        int format;
        if (bytesread < 4)
            goto badheader;
        if (!strncmp(buf, ".snd", 4))
            format = FORMAT_NEXT, bigendian = 1;
        else if (!strncmp(buf, "dns.", 4))
            format = FORMAT_NEXT, bigendian = 0;
        else if (!strncmp(buf, "RIFF", 4))
        {
            if (bytesread < 12 || strncmp(buf + 8, "WAVE", 4))
                goto badheader;
            format = FORMAT_WAVE, bigendian = 0;
        }
        else if (!strncmp(buf, "FORM", 4))
        {
            if (bytesread < 12 || strncmp(buf + 8, "AIFF", 4))
                goto badheader;
            format = FORMAT_AIFF, bigendian = 1;
        }
        else
            goto badheader;
        swap = (bigendian != garray_ambigendian());
        if (format == FORMAT_NEXT)   /* nextstep header */
        {
            if (bytesread < (int)sizeof(t_nextstep))
                goto badheader;
            nchannels = swap4(((t_nextstep *)buf)->ns_nchans, swap);
            format = swap4(((t_nextstep *)buf)->ns_format, swap);
            headersize = swap4(((t_nextstep *)buf)->ns_onset, swap);
            if (format == NS_FORMAT_LINEAR_16)
                bytespersamp = 2;
            else if (format == NS_FORMAT_LINEAR_24)
                bytespersamp = 3;
            else if (format == NS_FORMAT_FLOAT)
                bytespersamp = 4;
            else goto badheader;
            bytelimit = 0x7fffffff;
        }
        else if (format == FORMAT_WAVE)     /* wave header */
        {
               /*  This is awful.  You have to skip over chunks,
               except that if one happens to be a "fmt" chunk, you want to
               find out the format from that one.  The case where the
               "fmt" chunk comes after the audio isn't handled. */
            headersize = 12;
            if (bytesread < 20)
                goto badheader;
                /* First we guess a number of channels, etc., in case there's
                no "fmt" chunk to follow. */
            nchannels = 1;
            bytespersamp = 2;
                /* copy the first chunk header to beginnning of buffer. */
            memcpy(buf, buf + headersize, sizeof(t_wavechunk));
            /* post("chunk %c %c %c %c",
                    ((t_wavechunk *)buf)->wc_id[0],
                    ((t_wavechunk *)buf)->wc_id[1],
                    ((t_wavechunk *)buf)->wc_id[2],
                    ((t_wavechunk *)buf)->wc_id[3]); */
                /* read chunks in loop until we get to the data chunk */
            while (strncmp(((t_wavechunk *)buf)->wc_id, "data", 4))
            {
                long chunksize = swap4(((t_wavechunk *)buf)->wc_size,
                    swap), seekto = headersize + chunksize + 8, seekout;
                
                if (!strncmp(((t_wavechunk *)buf)->wc_id, "fmt ", 4))
                {
                    long commblockonset = headersize + 8;
                    seekout = lseek(fd, commblockonset, SEEK_SET);
                    if (seekout != commblockonset)
                        goto badheader;
                    if (read(fd, buf, sizeof(t_fmt)) < (int) sizeof(t_fmt))
                            goto badheader;
                    nchannels = swap2(((t_fmt *)buf)->f_nchannels, swap);
                    format = swap2(((t_fmt *)buf)->f_nbitspersample, swap);
                    if (format == 16)
                        bytespersamp = 2;
                    else if (format == 24)
                        bytespersamp = 3;
                    else if (format == 32)
                        bytespersamp = 4;
                    else goto badheader;
                }
                seekout = lseek(fd, seekto, SEEK_SET);
                if (seekout != seekto)
                    goto badheader;
                if (read(fd, buf, sizeof(t_wavechunk)) <
                    (int) sizeof(t_wavechunk))
                        goto badheader;
                /* post("new chunk %c %c %c %c at %d",
                    ((t_wavechunk *)buf)->wc_id[0],
                    ((t_wavechunk *)buf)->wc_id[1],
                    ((t_wavechunk *)buf)->wc_id[2],
                    ((t_wavechunk *)buf)->wc_id[3], seekto); */
                headersize = seekto;
            }
            bytelimit = swap4(((t_wavechunk *)buf)->wc_size, swap);
            headersize += 8;
        }
        else
        {
                /* AIFF.  same as WAVE; actually predates it.  Disgusting. */
            headersize = 12;
            if (bytesread < 20)
                goto badheader;
                /* First we guess a number of channels, etc., in case there's
                no COMM block to follow. */
            nchannels = 1;
            bytespersamp = 2;
                /* copy the first chunk header to beginnning of buffer. */
            memcpy(buf, buf + headersize, sizeof(t_datachunk));
                /* read chunks in loop until we get to the data chunk */
            while (strncmp(((t_datachunk *)buf)->dc_id, "SSND", 4))
            {
                long chunksize = swap4(((t_datachunk *)buf)->dc_size,
                    swap), seekto = headersize + chunksize + 8, seekout;
                /* post("chunk %c %c %c %c seek %d",
                    ((t_datachunk *)buf)->dc_id[0],
                    ((t_datachunk *)buf)->dc_id[1],
                    ((t_datachunk *)buf)->dc_id[2],
                    ((t_datachunk *)buf)->dc_id[3], seekto); */
                if (!strncmp(((t_datachunk *)buf)->dc_id, "COMM", 4))
                {
                    long commblockonset = headersize + 8;
                    seekout = lseek(fd, commblockonset, SEEK_SET);
                    if (seekout != commblockonset)
                        goto badheader;
                    if (read(fd, buf, sizeof(t_comm)) <
                        (int) sizeof(t_comm))
                            goto badheader;
                    nchannels = swap2(((t_comm *)buf)->c_nchannels, swap);
                    format = swap2(((t_comm *)buf)->c_bitspersamp, swap);
                    if (format == 16)
                        bytespersamp = 2;
                    else if (format == 24)
                        bytespersamp = 3;
                    else goto badheader;
                }
                seekout = lseek(fd, seekto, SEEK_SET);
                if (seekout != seekto)
                    goto badheader;
                if (read(fd, buf, sizeof(t_datachunk)) <
                    (int) sizeof(t_datachunk))
                        goto badheader;
                headersize = seekto;
            }
            bytelimit = swap4(((t_datachunk *)buf)->dc_size, swap);
            headersize += 8;
        }
    }
        /* seek past header and any sample frames to skip */
    sysrtn = lseek(fd,
        ((off_t)nchannels) * bytespersamp * skipframes + headersize, 0);
    if (sysrtn != nchannels * bytespersamp * skipframes + headersize)
        return (-1);
     bytelimit -= nchannels * bytespersamp * skipframes;
     if (bytelimit < 0)
        bytelimit = 0;
        /* copy sample format back to caller */
    *p_bigendian = bigendian;
    *p_nchannels = nchannels;
    *p_bytespersamp = bytespersamp;
    *p_bytelimit = bytelimit;
    return (fd);
badheader:
        /* the header wasn't recognized.  We're threadable here so let's not
        print out the error... */
    errno = EIO;
    return (-1);
}

    /* open a soundfile, using open_via_path().  This is used by readsf~ in
    a not-perfectly-threadsafe way.  LATER replace with a thread-hardened
    version of open_soundfile_via_canvas() */
int open_soundfile(const char *dirname, const char *filename, int headersize,
    int *p_bytespersamp, int *p_bigendian, int *p_nchannels, long *p_bytelimit,
    long skipframes)
{
    char buf[FILENAME_MAX], *bufptr;
    int fd;
    fd = open_via_path(dirname, filename, "", buf, &bufptr, FILENAME_MAX, 1);
    if (fd < 0)
        return (-1);
    else return (open_soundfile_via_fd(fd, headersize, p_bytespersamp,
        p_bigendian, p_nchannels, p_bytelimit, skipframes));
}

    /* open a soundfile, using open_via_canvas().  This is used by readsf~ in
    a not-perfectly-threadsafe way.  LATER replace with a thread-hardened
    version of open_soundfile_via_canvas() */
int open_soundfile_via_canvas(t_canvas *canvas, const char *filename, int headersize,
    int *p_bytespersamp, int *p_bigendian, int *p_nchannels, long *p_bytelimit,
    long skipframes)
{
    char buf[FILENAME_MAX], *bufptr;
    int fd;
    fd = canvas_open(canvas, filename, "", buf, &bufptr, FILENAME_MAX, 1);
    if (fd < 0)
        return (-1);
    else return (open_soundfile_via_fd(fd, headersize, p_bytespersamp,
        p_bigendian, p_nchannels, p_bytelimit, skipframes));
}

static void soundfile_xferin_sample(int sfchannels, int nvecs, t_sample **vecs,
    long itemsread, unsigned char *buf, int nitems, int bytespersamp,
    int bigendian, int spread)
{
    int i, j;
    unsigned char *sp, *sp2;
    t_sample *fp;
    int nchannels = (sfchannels < nvecs ? sfchannels : nvecs);
    int bytesperframe = bytespersamp * sfchannels;
    for (i = 0, sp = buf; i < nchannels; i++, sp += bytespersamp)
    {
        if (bytespersamp == 2)
        {
            if (bigendian)
            {
                for (j = 0, sp2 = sp, fp=vecs[i] + spread * itemsread;
                    j < nitems; j++, sp2 += bytesperframe, fp += spread)
                        *fp = SCALE * ((sp2[0] << 24) | (sp2[1] << 16));
            }
            else
            {
                for (j = 0, sp2 = sp, fp=vecs[i] + spread * itemsread;
                    j < nitems; j++, sp2 += bytesperframe, fp += spread)
                        *fp = SCALE * ((sp2[1] << 24) | (sp2[0] << 16));
            }
        }
        else if (bytespersamp == 3)
        {
            if (bigendian)
            {
                for (j = 0, sp2 = sp, fp=vecs[i] + spread * itemsread;
                    j < nitems; j++, sp2 += bytesperframe, fp += spread)
                        *fp = SCALE * ((sp2[0] << 24) | (sp2[1] << 16)
                            | (sp2[2] << 8));
            }
            else
            {
                for (j = 0, sp2 = sp, fp=vecs[i] + spread * itemsread;
                    j < nitems; j++, sp2 += bytesperframe, fp += spread)
                        *fp = SCALE * ((sp2[2] << 24) | (sp2[1] << 16)
                            | (sp2[0] << 8));
            }
        }
        else if (bytespersamp == 4)
        {
            if (bigendian)
            {
                for (j = 0, sp2 = sp, fp=vecs[i] + spread * itemsread;
                    j < nitems; j++, sp2 += bytesperframe, fp += spread)
                        *(long *)fp = ((sp2[0] << 24) | (sp2[1] << 16)
                            | (sp2[2] << 8) | sp2[3]);
            }
            else
            {
                for (j = 0, sp2 = sp, fp=vecs[i] + spread * itemsread;
                    j < nitems; j++, sp2 += bytesperframe, fp += spread)
                        *(long *)fp = ((sp2[3] << 24) | (sp2[2] << 16)
                            | (sp2[1] << 8) | sp2[0]);
            }
        }
    }
        /* zero out other outputs */
    for (i = sfchannels; i < nvecs; i++)
        for (j = nitems, fp = vecs[i]; j--; )
            *fp++ = 0;

}

static void soundfile_xferin_float(int sfchannels, int nvecs, t_float **vecs,
    long itemsread, unsigned char *buf, int nitems, int bytespersamp,
    int bigendian, int spread)
{
    int i, j;
    unsigned char *sp, *sp2;
    t_float *fp;
    int nchannels = (sfchannels < nvecs ? sfchannels : nvecs);
    int bytesperframe = bytespersamp * sfchannels;
    for (i = 0, sp = buf; i < nchannels; i++, sp += bytespersamp)
    {
        if (bytespersamp == 2)
        {
            if (bigendian)
            {
                for (j = 0, sp2 = sp, fp=vecs[i] + spread * itemsread;
                    j < nitems; j++, sp2 += bytesperframe, fp += spread)
                        *fp = SCALE * ((sp2[0] << 24) | (sp2[1] << 16));
            }
            else
            {
                for (j = 0, sp2 = sp, fp=vecs[i] + spread * itemsread;
                    j < nitems; j++, sp2 += bytesperframe, fp += spread)
                        *fp = SCALE * ((sp2[1] << 24) | (sp2[0] << 16));
            }
        }
        else if (bytespersamp == 3)
        {
            if (bigendian)
            {
                for (j = 0, sp2 = sp, fp=vecs[i] + spread * itemsread;
                    j < nitems; j++, sp2 += bytesperframe, fp += spread)
                        *fp = SCALE * ((sp2[0] << 24) | (sp2[1] << 16)
                            | (sp2[2] << 8));
            }
            else
            {
                for (j = 0, sp2 = sp, fp=vecs[i] + spread * itemsread;
                    j < nitems; j++, sp2 += bytesperframe, fp += spread)
                        *fp = SCALE * ((sp2[2] << 24) | (sp2[1] << 16)
                            | (sp2[0] << 8));
            }
        }
        else if (bytespersamp == 4)
        {
            if (bigendian)
            {
                for (j = 0, sp2 = sp, fp=vecs[i] + spread * itemsread;
                    j < nitems; j++, sp2 += bytesperframe, fp += spread)
                        *(long *)fp = ((sp2[0] << 24) | (sp2[1] << 16)
                            | (sp2[2] << 8) | sp2[3]);
            }
            else
            {
                for (j = 0, sp2 = sp, fp=vecs[i] + spread * itemsread;
                    j < nitems; j++, sp2 += bytesperframe, fp += spread)
                        *(long *)fp = ((sp2[3] << 24) | (sp2[2] << 16)
                            | (sp2[1] << 8) | sp2[0]);
            }
        }
    }
        /* zero out other outputs */
    for (i = sfchannels; i < nvecs; i++)
        for (j = nitems, fp = vecs[i]; j--; )
            *fp++ = 0;

}

    /* soundfiler_write ...
 
    usage: write [flags] filename table ...
    flags:
        -nframes <frames>
        -skip <frames>
        -bytes <bytes per sample>
        -normalize
        -nextstep
        -wave
        -big
        -little
    */

    /* the routine which actually does the work should LATER also be called
    from garray_write16. */


    /* Parse arguments for writing.  The "obj" argument is only for flagging
    errors.  For streaming to a file the "normalize", "onset" and "nframes"
    arguments shouldn't be set but the calling routine flags this. */

static int soundfiler_writeargparse(void *obj, int *p_argc, t_atom **p_argv,
    t_symbol **p_filesym,
    int *p_filetype, int *p_bytespersamp, int *p_swap, int *p_bigendian,
    int *p_normalize, long *p_onset, long *p_nframes, t_float *p_rate)
{
    int argc = *p_argc;
    t_atom *argv = *p_argv;
    int bytespersamp = 2, bigendian = 0,
        endianness = -1, swap, filetype = -1, normalize = 0;
    long onset = 0, nframes = 0x7fffffff;
    t_symbol *filesym;
    t_float rate = -1;
    
    while (argc > 0 && argv->a_type == A_SYMBOL &&
        *argv->a_w.w_symbol->s_name == '-')
    {
        char *flag = argv->a_w.w_symbol->s_name + 1;
        if (!strcmp(flag, "skip"))
        {
            if (argc < 2 || argv[1].a_type != A_FLOAT ||
                ((onset = argv[1].a_w.w_float) < 0))
                    goto usage;
            argc -= 2; argv += 2;
        }
        else if (!strcmp(flag, "nframes"))
        {
            if (argc < 2 || argv[1].a_type != A_FLOAT ||
                ((nframes = argv[1].a_w.w_float) < 0))
                    goto usage;
            argc -= 2; argv += 2;
        }
        else if (!strcmp(flag, "bytes"))
        {
            if (argc < 2 || argv[1].a_type != A_FLOAT ||
                ((bytespersamp = argv[1].a_w.w_float) < 2) ||
                    bytespersamp > 4)
                        goto usage;
            argc -= 2; argv += 2;
        }
        else if (!strcmp(flag, "normalize"))
        {
            normalize = 1;
            argc -= 1; argv += 1;
        }
        else if (!strcmp(flag, "wave"))
        {
            filetype = FORMAT_WAVE;
            argc -= 1; argv += 1;
        }
        else if (!strcmp(flag, "nextstep"))
        {
            filetype = FORMAT_NEXT;
            argc -= 1; argv += 1;
        }
        else if (!strcmp(flag, "aiff"))
        {
            filetype = FORMAT_AIFF;
            argc -= 1; argv += 1;
        }
        else if (!strcmp(flag, "big"))
        {
            endianness = 1;
            argc -= 1; argv += 1;
        }
        else if (!strcmp(flag, "little"))
        {
            endianness = 0;
            argc -= 1; argv += 1;
        }
        else if (!strcmp(flag, "r") || !strcmp(flag, "rate"))
        {
            if (argc < 2 || argv[1].a_type != A_FLOAT ||
                ((rate = argv[1].a_w.w_float) <= 0))
                    goto usage;
            argc -= 2; argv += 2;
        }
        else goto usage;
    }
    if (!argc || argv->a_type != A_SYMBOL)
        goto usage;
    filesym = argv->a_w.w_symbol;
    
        /* check if format not specified and fill in */
    if (filetype < 0) 
    {
        if (strlen(filesym->s_name) >= 5 &&
                        (!strcmp(filesym->s_name + strlen(filesym->s_name) - 4, ".aif") ||
                        !strcmp(filesym->s_name + strlen(filesym->s_name) - 4, ".AIF")))
                filetype = FORMAT_AIFF;
        if (strlen(filesym->s_name) >= 6 &&
                        (!strcmp(filesym->s_name + strlen(filesym->s_name) - 5, ".aiff") ||
                        !strcmp(filesym->s_name + strlen(filesym->s_name) - 5, ".AIFF")))
                filetype = FORMAT_AIFF;
        if (strlen(filesym->s_name) >= 5 &&
                        (!strcmp(filesym->s_name + strlen(filesym->s_name) - 4, ".snd") ||
                        !strcmp(filesym->s_name + strlen(filesym->s_name) - 4, ".SND")))
                filetype = FORMAT_NEXT;
        if (strlen(filesym->s_name) >= 4 &&
                        (!strcmp(filesym->s_name + strlen(filesym->s_name) - 3, ".au") ||
                        !strcmp(filesym->s_name + strlen(filesym->s_name) - 3, ".AU")))
                filetype = FORMAT_NEXT;
        if (filetype < 0)
            filetype = FORMAT_WAVE;
    }
        /* don't handle AIFF floating point samples */
    if (bytespersamp == 4)
    {
        if (filetype == FORMAT_AIFF)
        {
            pd_error(obj, "AIFF floating-point file format unavailable");
            goto usage;
        }
    }
        /* for WAVE force little endian; for nextstep use machine native */
    if (filetype == FORMAT_WAVE)
    {
        bigendian = 0;
        if (endianness == 1)
            pd_error(obj, "WAVE file forced to little endian");
    }
    else if (filetype == FORMAT_AIFF)
    {
        bigendian = 1;
        if (endianness == 0)
            pd_error(obj, "AIFF file forced to big endian");
    }
    else if (endianness == -1)
    {
        bigendian = garray_ambigendian();
    }
    else bigendian = endianness;
    swap = (bigendian != garray_ambigendian());
    
    argc--; argv++;
    
    *p_argc = argc;
    *p_argv = argv;
    *p_filesym = filesym;
    *p_filetype = filetype;
    *p_bytespersamp = bytespersamp;
    *p_swap = swap;
    *p_normalize = normalize;
    *p_onset = onset;
    *p_nframes = nframes;
    *p_bigendian = bigendian;
    *p_rate = rate;
    return (0);
usage:
    return (-1);
}

static int create_soundfile(t_canvas *canvas, const char *filename,
    int filetype, int nframes, int bytespersamp,
    int bigendian, int nchannels, int swap, t_float samplerate)
{
    char filenamebuf[FILENAME_MAX], buf2[FILENAME_MAX];
    char headerbuf[WRITEHDRSIZE];
    t_wave *wavehdr = (t_wave *)headerbuf;
    t_nextstep *nexthdr = (t_nextstep *)headerbuf;
    t_aiff *aiffhdr = (t_aiff *)headerbuf;
    int fd, headersize = 0;
    
    strncpy(filenamebuf, filename, FILENAME_MAX-10);
    filenamebuf[FILENAME_MAX-10] = 0;

    if (filetype == FORMAT_NEXT)
    {
        if (strcmp(filenamebuf + strlen(filenamebuf)-4, ".snd"))
            strcat(filenamebuf, ".snd");
        if (bigendian)
            strncpy(nexthdr->ns_fileid, ".snd", 4);
        else strncpy(nexthdr->ns_fileid, "dns.", 4);
        nexthdr->ns_onset = swap4(sizeof(*nexthdr), swap);
        nexthdr->ns_length = 0;
        nexthdr->ns_format = swap4((bytespersamp == 3 ? NS_FORMAT_LINEAR_24 :
           (bytespersamp == 4 ? NS_FORMAT_FLOAT : NS_FORMAT_LINEAR_16)), swap);
        nexthdr->ns_sr = swap4(samplerate, swap);
        nexthdr->ns_nchans = swap4(nchannels, swap);
        strcpy(nexthdr->ns_info, "Pd ");
        swapstring(nexthdr->ns_info, swap);
        headersize = sizeof(t_nextstep);
    }
    else if (filetype == FORMAT_AIFF)
    {
        long datasize = nframes * nchannels * bytespersamp;
        long longtmp;
        static unsigned char dogdoo[] =
            {0x40, 0x0e, 0xac, 0x44, 0, 0, 0, 0, 0, 0, 'S', 'S', 'N', 'D'};
        if (strcmp(filenamebuf + strlen(filenamebuf)-4, ".aif") &&
            strcmp(filenamebuf + strlen(filenamebuf)-5, ".aiff"))
                strcat(filenamebuf, ".aif");
        strncpy(aiffhdr->a_fileid, "FORM", 4);
        aiffhdr->a_chunksize = swap4(datasize + sizeof(*aiffhdr) + 4, swap);
        strncpy(aiffhdr->a_aiffid, "AIFF", 4);
        strncpy(aiffhdr->a_fmtid, "COMM", 4);
        aiffhdr->a_fmtchunksize = swap4(18, swap);
        aiffhdr->a_nchannels = swap2(nchannels, swap);
        longtmp = swap4(nframes, swap);
        memcpy(&aiffhdr->a_nframeshi, &longtmp, 4);
        aiffhdr->a_bitspersamp = swap2(8 * bytespersamp, swap);
        memcpy(aiffhdr->a_samprate, dogdoo, sizeof(dogdoo));
        longtmp = swap4(datasize, swap);
        memcpy(aiffhdr->a_samprate + sizeof(dogdoo), &longtmp, 4);
        memset(aiffhdr->a_samprate + sizeof(dogdoo) + 4, 0, 8);
        headersize = AIFFPLUS;
    }
    else    /* WAVE format */
    {
        long datasize = nframes * nchannels * bytespersamp;
        if (strcmp(filenamebuf + strlen(filenamebuf)-4, ".wav"))
            strcat(filenamebuf, ".wav");
        strncpy(wavehdr->w_fileid, "RIFF", 4);
        wavehdr->w_chunksize = swap4(datasize + sizeof(*wavehdr) - 8, swap);
        strncpy(wavehdr->w_waveid, "WAVE", 4);
        strncpy(wavehdr->w_fmtid, "fmt ", 4);
        wavehdr->w_fmtchunksize = swap4(16, swap);
        wavehdr->w_fmttag =
            swap2((bytespersamp == 4 ? WAV_FLOAT : WAV_INT), swap);
        wavehdr->w_nchannels = swap2(nchannels, swap);
        wavehdr->w_samplespersec = swap4(samplerate, swap);
        wavehdr->w_navgbytespersec =
            swap4((int)(samplerate * nchannels * bytespersamp), swap);
        wavehdr->w_nblockalign = swap2(nchannels * bytespersamp, swap);
        wavehdr->w_nbitspersample = swap2(8 * bytespersamp, swap);
        strncpy(wavehdr->w_datachunkid, "data", 4);
        wavehdr->w_datachunksize = swap4(datasize, swap);
        headersize = sizeof(t_wave);
    }

    canvas_makefilename(canvas, filenamebuf, buf2, FILENAME_MAX);
    sys_bashfilename(buf2, buf2);
    if ((fd = open(buf2, BINCREATE, 0666)) < 0)
        return (-1);

    if (write(fd, headerbuf, headersize) < headersize)
    {
        close (fd);
        return (-1);
    }
    return (fd);
}

static void soundfile_finishwrite(void *obj, char *filename, int fd,
    int filetype, long nframes, long itemswritten, int bytesperframe, int swap)
{
    if (itemswritten < nframes) 
    {
        if (nframes < 0x7fffffff)
            pd_error(obj, "soundfiler_write: %ld out of %ld bytes written",
                itemswritten, nframes);
            /* try to fix size fields in header */
        if (filetype == FORMAT_WAVE)
        {
            long datasize = itemswritten * bytesperframe, mofo;
            
            if (lseek(fd,
                ((char *)(&((t_wave *)0)->w_chunksize)) - (char *)0,
                    SEEK_SET) == 0)
                        goto baddonewrite;
            mofo = swap4(datasize + sizeof(t_wave) - 8, swap);
            if (write(fd, (char *)(&mofo), 4) < 4)
                goto baddonewrite;
            if (lseek(fd,
                ((char *)(&((t_wave *)0)->w_datachunksize)) - (char *)0,
                    SEEK_SET) == 0)
                        goto baddonewrite;
            mofo = swap4(datasize, swap);
            if (write(fd, (char *)(&mofo), 4) < 4)
                goto baddonewrite;
        }
        if (filetype == FORMAT_AIFF)
        {
            long mofo;
            if (lseek(fd,
                ((char *)(&((t_aiff *)0)->a_nframeshi)) - (char *)0,
                    SEEK_SET) == 0)
                        goto baddonewrite;
            mofo = swap4(itemswritten, swap);
            if (write(fd, (char *)(&mofo), 4) < 4)
                goto baddonewrite;
            if (lseek(fd,
                ((char *)(&((t_aiff *)0)->a_chunksize)) - (char *)0,
                    SEEK_SET) == 0)
                        goto baddonewrite;
            mofo = swap4(itemswritten*bytesperframe+AIFFHDRSIZE, swap);
            if (write(fd, (char *)(&mofo), 4) < 4)
                goto baddonewrite;
            if (lseek(fd, (AIFFHDRSIZE+4), SEEK_SET) == 0)
                goto baddonewrite;
            mofo = swap4(itemswritten*bytesperframe, swap);
            if (write(fd, (char *)(&mofo), 4) < 4)
                goto baddonewrite;
        }
        if (filetype == FORMAT_NEXT)
        {
            /* do it the lazy way: just set the size field to 'unknown size'*/
            uint32 nextsize = 0xffffffff;
            if (lseek(fd, 8, SEEK_SET) == 0)
            {
                goto baddonewrite;
            }
            if (write(fd, &nextsize, 4) < 4)
            {
                goto baddonewrite;
            }
        }
    }
    return;
baddonewrite:
    post("%s: %s", filename, strerror(errno));
}

static void soundfile_xferout_sample(int nchannels, t_sample **vecs,
    unsigned char *buf, int nitems, long onset, int bytespersamp,
    int bigendian, t_sample normalfactor, int spread)
{
    int i, j;
    unsigned char *sp, *sp2;
    t_sample *fp;
    int bytesperframe = bytespersamp * nchannels;
    long xx;
    for (i = 0, sp = buf; i < nchannels; i++, sp += bytespersamp)
    {
        if (bytespersamp == 2)
        {
            t_sample ff = normalfactor * 32768.;
            if (bigendian)
            {
                for (j = 0, sp2 = sp, fp = vecs[i] + onset;
                    j < nitems; j++, sp2 += bytesperframe, fp += spread)
                {
                    int xx = 32768. + (*fp * ff);
                    xx -= 32768;
                    if (xx < -32767)
                        xx = -32767;
                    if (xx > 32767)
                        xx = 32767;
                    sp2[0] = (xx >> 8);
                    sp2[1] = xx;
                }
            }
            else
            {
                for (j = 0, sp2 = sp, fp=vecs[i] + onset;
                    j < nitems; j++, sp2 += bytesperframe, fp += spread)
                {
                    int xx = 32768. + (*fp * ff);
                    xx -= 32768;
                    if (xx < -32767)
                        xx = -32767;
                    if (xx > 32767)
                        xx = 32767;
                    sp2[1] = (xx >> 8);
                    sp2[0] = xx;
                }
            }
        }
        else if (bytespersamp == 3)
        {
            t_sample ff = normalfactor * 8388608.;
            if (bigendian)
            {
                for (j = 0, sp2 = sp, fp=vecs[i] + onset;
                    j < nitems; j++, sp2 += bytesperframe, fp += spread)
                {
                    int xx = 8388608. + (*fp * ff);
                    xx -= 8388608;
                    if (xx < -8388607)
                        xx = -8388607;
                    if (xx > 8388607)
                        xx = 8388607;
                    sp2[0] = (xx >> 16);
                    sp2[1] = (xx >> 8);
                    sp2[2] = xx;
                }
            }
            else
            {
                for (j = 0, sp2 = sp, fp=vecs[i] + onset;
                    j < nitems; j++, sp2 += bytesperframe, fp += spread)
                {
                    int xx = 8388608. + (*fp * ff);
                    xx -= 8388608;
                    if (xx < -8388607)
                        xx = -8388607;
                    if (xx > 8388607)
                        xx = 8388607;
                    sp2[2] = (xx >> 16);
                    sp2[1] = (xx >> 8);
                    sp2[0] = xx;
                }
            }
        }
        else if (bytespersamp == 4)
        {
            if (bigendian)
            {
                for (j = 0, sp2 = sp, fp=vecs[i] + onset;
                    j < nitems; j++, sp2 += bytesperframe, fp += spread)
                {
                    t_sample f2 = *fp * normalfactor;
                    xx = *(long *)&f2;
                    sp2[0] = (xx >> 24); sp2[1] = (xx >> 16);
                    sp2[2] = (xx >> 8); sp2[3] = xx;
                }
            }
            else
            {
                for (j = 0, sp2 = sp, fp=vecs[i] + onset;