shithub: sox

ref: 9893fc49678c0ac7568ed8b95711f6ffae7ce8de
dir: /src/sndrtool.c/

/*
 * Sounder/Sndtool format handler: W V Neisius, February 1992
 *
 * June 28, 93: force output to mono.
 * 
 * March 3, 1999 - cbagwell@sprynet.com
 *   Forced extra comment fields to zero.
 */

#include "st_i.h"

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

/* Private data used by writer */
typedef struct sndpriv {
        st_size_t nsamples;
        st_size_t dataStart;
} *snd_t;

static void sndtwriteheader(ft_t ft, st_size_t nsamples)
{
    char name_buf[97];

    /* sndtool header */
    st_writes(ft, "SOUND"); /* magic */
    st_writeb(ft, 0x1a);
    st_writew (ft,0);  /* hGSound */
    st_writedw (ft,nsamples);
    st_writedw (ft,0);
    st_writedw (ft,nsamples);
    st_writew (ft,(int) ft->signal.rate);
    st_writew (ft,0);
    st_writew (ft,10);
    st_writew (ft,4);
    memset (name_buf, 0, 96);
    sprintf (name_buf,"%.62s - File created by SoX",ft->filename);
    st_writebuf(ft, name_buf, 1, 96);
}

static int st_sndseek(ft_t ft, st_size_t offset) 
{
    st_size_t new_offset, channel_block, alignment;
    snd_t snd = (snd_t ) ft->priv;

    new_offset = offset * ft->signal.size;
    /* Make sure request aligns to a channel block (ie left+right) */
    channel_block = ft->signal.channels * ft->signal.size;
    alignment = new_offset % channel_block;
    /* Most common mistaken is to compute something like
     * "skip everthing upto and including this sample" so
     * advance to next sample block in this case.
     */
    if (alignment != 0)
        new_offset += (channel_block - alignment);
    new_offset += snd->dataStart;

    return st_seeki(ft, new_offset, SEEK_SET);
}

static int st_sndtstartread(ft_t ft)
{
        snd_t snd = (snd_t ) ft->priv;

        char buf[97];

        unsigned short rate;
        int rc;

        /* Needed for rawread() */
        rc = st_rawstartread(ft);
        if (rc)
            return rc;

        rate = 0;

        /* determine file type */
        /* if first 5 bytes == SOUND then this is probably a sndtool sound */
        /* if first word (16 bits) == 0 
         and second word is between 4000 & 25000 then this is sounder sound */
        /* otherwise, its probably raw, not handled here */

        if (st_readbuf(ft, buf, 1, 2) != 2)
        {
                st_fail_errno(ft,errno,"SND: unexpected EOF");
                return(ST_EOF);
        }
        if (strncmp(buf,"\0\0",2) == 0)
        {
        /* sounder */
        st_readw(ft, &rate);
        if (rate < 4000 || rate > 25000 )
        {
                st_fail_errno(ft,ST_EFMT,"SND: sample rate out of range");
                return(ST_EOF);
        }
        st_seeki(ft, 4, SEEK_CUR);
        }
        else
        {
        /* sndtool ? */
        st_readbuf(ft, &buf[2], 1, 6);
        if (strncmp(buf,"SOUND",5))
        {
                st_fail_errno(ft,ST_EFMT,"SND: unrecognized SND format");
                return(ST_EOF);
        }
        st_seeki(ft, 12, SEEK_CUR);
        st_readw(ft, &rate);
        st_seeki(ft, 6, SEEK_CUR);
        if (st_reads(ft, buf, 96) == ST_EOF)
        {
                st_fail_errno(ft,ST_EHDR,"SND: unexpected EOF in SND header");
                return(ST_EOF);
        }
        st_debug("%s",buf);
        }

        ft->signal.channels = 1;
        ft->signal.rate = rate;
        ft->signal.encoding = ST_ENCODING_UNSIGNED;
        ft->signal.size = ST_SIZE_BYTE;

        snd->dataStart = st_tell(ft);
        ft->length = st_filelength(ft) - snd->dataStart;

        return (ST_SUCCESS);
}

static int st_sndtstartwrite(ft_t ft)
{
        snd_t p = (snd_t ) ft->priv;
        int rc;

        /* Needed for rawwrite() */
        rc = st_rawstartwrite(ft);
        if (rc)
            return rc;

        /* write header */
        ft->signal.channels = 1;
        ft->signal.encoding = ST_ENCODING_UNSIGNED;
        ft->signal.size = ST_SIZE_BYTE;
        p->nsamples = 0;
        sndtwriteheader(ft, 0);

        return(ST_SUCCESS);
}

static st_size_t st_sndtwrite(ft_t ft, const st_sample_t *buf, st_size_t len)
{
        snd_t p = (snd_t ) ft->priv;
        p->nsamples += len;
        return st_rawwrite(ft, buf, len);
}

static int st_sndtstopwrite(ft_t ft)
{
        snd_t p = (snd_t ) ft->priv;
        int rc;

        /* Flush remaining buffer out */
        rc = st_rawstopwrite(ft);
        if (rc)
            return rc;

        /* fixup file sizes in header */
        if (st_seeki(ft, 0L, 0) != 0){
                st_fail_errno(ft,errno,"can't rewind output file to rewrite SND header");
                return ST_EOF;
        }
                
        sndtwriteheader(ft, p->nsamples);
                

        return(ST_SUCCESS);
}

/* Sndtool Sound File */
static const char *sndtnames[] = {
  "sndt",
  NULL
};

const st_format_t st_snd_format = {
  sndtnames,
  NULL,
  ST_FILE_SEEK | ST_FILE_LIT_END,
  st_sndtstartread,
  st_rawread,
  st_rawstopread,
  st_sndtstartwrite,
  st_sndtwrite,
  st_sndtstopwrite,
  st_sndseek
};

const st_format_t *st_snd_format_fn(void)
{
    return &st_snd_format;
}