sndwrite.c

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/* sndwrite.c -- write sounds to files */

/* CHANGE LOG
 * --------------------------------------------------------------------
 * 28Apr03  dm  changes for portability and fix compiler warnings
 */

#include "stdlib.h"
#include "switches.h"
#include "string.h"
#ifdef UNIX
#include "sys/types.h"
#endif
#ifdef WINDOWS
#include <io.h>
#endif
#include <stdio.h>
/* include sound.h first because it includes math.h 
 * which declares abs(). cext.h #defines abs()!
 * sound.h depends on xlisp.h
 */
#include "xlisp.h"
#include "sound.h"
#include "cext.h"
#include "userio.h"
#include "falloc.h"
#include "sndwrite.h"
#include "extern.h"
#include "snd.h"
#ifdef UNIX
#include "sys/file.h"
/* #include <sys/stat.h>*/
#include <netinet/in.h>
#else
#ifdef MACINTOSH
#include <unistd.h>
#include <stat.h>
#define L_SET SEEK_SET
#define L_INCR SEEK_CUR
#endif
#endif

#define D if (0) 

int sndwrite_trace = 0;	/* debugging */

sample_type sound_save_sound(LVAL s_as_lval, long n, snd_type snd,
                             char *buf, long *ntotal, snd_type player);

sample_type sound_save_array(LVAL sa, long n, snd_type snd, 
                             char *buf, long *ntotal, snd_type player);

unsigned char st_linear_to_ulaw(int sample);


typedef struct {
    sound_type sound;
    long cnt;
    sample_block_values_type ptr;
    double scale;
    int terminated;
} sound_state_node, *sound_state_type;


LVAL prepare_audio(LVAL play, snd_type snd, snd_type player)
{
    long flags;
    if (play == NIL) return NIL;
    player->format = snd->format;
    player->u.audio.devicename[0] = 0;
    player->u.audio.interfacename[0] = 0;
    if (snd_open(player, &flags) != SND_SUCCESS) {
        xlabort("snd_save -- could not open audio output");
    }
    /* make sure player and snd are compatible -- if not, set player to NULL
     * and print a warning message
     */
    if (player->format.channels == snd->format.channels &&
        player->format.mode == snd->format.mode &&
        player->format.bits == snd->format.bits) {
        /* ok so far, check out the sample rate */
        if (player->format.srate != snd->format.srate) {
            char msg[100];
            sprintf(msg, "%s(%g)%s(%g).\n",
                    "Warning: file sample rate ", snd->format.srate,
                    " differs from audio playback sample rate ",
                    player->format.srate);
            stdputstr(msg);
        }
    } else {
        stdputstr("File format not supported by audio output.\n");
        return NIL;
    }
    return play;
}


/* finish_audio -- flush the remaining samples, then close */
/**/
void finish_audio(snd_type player)
{
    /* note that this is a busy loop! */
    while (snd_flush(player) != SND_SUCCESS) ;
    snd_close(player);
}


/* write_to_audio -- handle audio output from buffer */
/*
 * We want to write as soon as space is available so that
 * a full sound buffer can be queued up for output. This
 * may require transferring only part of buf, so we keep
 * track of progress and output whenever space is available.
 */
void write_to_audio(snd_type player, void *buf, long buflen)
{
    long rslt;
    while (buflen) {
            /* this loop is a busy-wait loop! */
        rslt = snd_poll(player); /* wait for buffer space */
        rslt = min(rslt, buflen);
        if (rslt) {
            snd_write(player, buf, rslt);
            buf = (void *) ((char *) buf + 
                            (rslt * snd_bytes_per_frame(player)));
            buflen -= rslt;
        }
    }    
}


double sound_save(
  LVAL snd_expr,
  long n,
  unsigned char *filename,
  long format,
  long mode,
  long bits,
  long swap,
  double *sr,
  long *nchans,
  double *duration,
  LVAL play)
{
    LVAL result;
    char *buf;
    long ntotal;
    double max_sample;
    snd_node snd;
    snd_node player;
    long flags;

    snd.device = SND_DEVICE_FILE;
    snd.write_flag = SND_WRITE;
    strcpy(snd.u.file.filename, (char *) filename);
    snd.u.file.file = -1;	/* this is a marker that snd is unopened */
    snd.u.file.header = format;
    snd.format.mode = mode;
    snd.format.bits = bits;
    snd.u.file.swap = swap;

    player.device = SND_DEVICE_AUDIO;
    player.write_flag = SND_WRITE;
    player.u.audio.devicename[0] = '\0';
    player.u.audio.descriptor = NULL;
    player.u.audio.protocol = SND_COMPUTEAHEAD;
    player.u.audio.latency = 1.0;
    player.u.audio.granularity = 0.0;

    if ((buf = (char *) malloc(max_sample_block_len * MAX_SND_CHANNELS *
                                  sizeof(float))) == NULL) {
        xlabort("snd_save -- couldn't allocate memory");
    }

    result = xleval(snd_expr);
    /* BE CAREFUL - DO NOT ALLOW GC TO RUN WHILE RESULT IS UNPROTECTED */
    if (vectorp(result)) {
        /* make sure all elements are of type a_sound */
        long i = getsize(result);
        *nchans = snd.format.channels = i;
        while (i > 0) {
            i--;
            if (!exttypep(getelement(result, i), a_sound)) {
                xlerror("sound_save: array has non-sound element",
                         result);
            }
        }
        /* assume all are the same: */
        *sr = snd.format.srate = getsound(getelement(result, 0))->sr; 

        /* note: if filename is "", then don't write file; therefore,
         * write the file if (filename[0])
         */ 
        if (filename[0] && snd_open(&snd, &flags) != SND_SUCCESS) {
            xlabort("snd_save -- could not open sound file");
        }
        
        play = prepare_audio(play, &snd, &player);

        max_sample = sound_save_array(result, n, &snd,
                         buf, &ntotal, (play == NIL ? NULL : &player));
        *duration = ntotal / *sr;
        if (filename[0]) snd_close(&snd);
        if (play != NIL) finish_audio(&player);
    } else if (exttypep(result, a_sound)) {
        *nchans = snd.format.channels = 1;
        *sr = snd.format.srate = (getsound(result))->sr;
        if (filename[0] && snd_open(&snd, &flags) != SND_SUCCESS) {
            xlabort("snd_save -- could not open sound file");
        }

        play = prepare_audio(play, &snd, &player);

        max_sample = sound_save_sound(result, n, &snd,
                        buf, &ntotal, (play == NIL ? NULL : &player));
        *duration = ntotal / *sr;
        if (filename[0]) snd_close(&snd);
        if (play != NIL) finish_audio(&player);
    } else {
        xlerror("sound_save: expression did not return a sound",
                 result);
        max_sample = 0.0;
    }
    free(buf);
    return max_sample;
}


double sound_overwrite(
  LVAL snd_expr,
  long n,
  unsigned char *filename,
  long byte_offset,
  long header,
  long mode,
  long bits,
  long swap,
  double sr,
  long nchans,
  double *duration)
{
    LVAL result;
    char *buf;
    char error[140];
    long ntotal;
    double max_sample;
    snd_node snd;
    long flags;

    snd.device = SND_DEVICE_FILE;
    snd.write_flag = SND_OVERWRITE;
    strcpy(snd.u.file.filename, (char *) filename);
    snd.u.file.header = header;
    snd.u.file.byte_offset = byte_offset;
    snd.format.channels = nchans;
    snd.format.mode = mode;
    snd.format.bits = bits;
    snd.u.file.swap = swap;
    snd.format.srate = sr;

    if ((buf = (char *) malloc(max_sample_block_len * MAX_SND_CHANNELS *
                                  sizeof(float))) == NULL) {
        xlabort("snd_overwrite: couldn't allocate memory");
    }

    if (snd_open(&snd, &flags) != SND_SUCCESS) {
        sprintf(error,
                "snd_overwrite: cannot open file %s and seek to %d", 
                filename, (int)byte_offset);
        free(buf);
        xlabort(error);
    }

    result = xleval(snd_expr);
    /* BE CAREFUL - DO NOT ALLOW GC TO RUN WHILE RESULT IS UNPROTECTED */
    if (vectorp(result)) {
        /* make sure all elements are of type a_sound */
        long i = getsize(result);
        if (nchans != i) {
            sprintf(error, "%s%d%s%d%s", 
                    "snd_overwrite: number of channels in sound (",
                    (int)i,
                    ") does not match\n    number of channels in file (",
                    (int)nchans,
                    ")");
            free(buf);
            snd_close(&snd);
            xlabort(error);
        }
        while (i > 0) {
            i--;
            if (!exttypep(getelement(result, i), a_sound)) {
                free(buf);
                snd_close(&snd);
                xlerror("sound_save: array has non-sound element",
                         result);
            }
        }
        /* assume all are the same: */
        if (sr != getsound(getelement(result, 0))->sr) {
            sprintf(error, "%s%g%s%g%s",
                    "snd_overwrite: sample rate in sound (",
                    getsound(getelement(result, 0))->sr,
                    ") does not match\n    sample rate in file (",
                    sr,
                    ")"); 
            free(buf);
            snd_close(&snd);
            xlabort(error);
        }
        
        max_sample = sound_save_array(result, n, &snd, buf, &ntotal, NULL);
        *duration = ntotal / sr;
    } else if (exttypep(result, a_sound)) {
        if (nchans != 1) {
            sprintf(error, "%s%s%d%s", 
                    "snd_overwrite: number of channels in sound (1",
                    ") does not match\n    number of channels in file (",
                    (int)nchans,
                    ")");