ref: 39b71fb516bf18304e0561d316ce2ce82814a4dd
dir: /src/smp.c/
/*
* libSoX SampleVision file format handler.
* Output is always in little-endian (80x86/VAX) order.
*
* Derived from: libSoX skeleton handler file.
*
* Add: Loop point verbose info. It's a start, anyway.
*/
/*
* June 30, 1992
* Copyright 1992 Leigh Smith And Sundry Contributors
* This source code is freely redistributable and may be used for
* any purpose. This copyright notice must be maintained.
* Leigh Smith And Sundry Contributors are not responsible for
* the consequences of using this software.
*/
#include "sox_i.h"
#include <string.h>
#include <errno.h>
#define NAMELEN 30 /* Size of Samplevision name */
#define COMMENTLEN 60 /* Size of Samplevision comment, not shared */
#define MIDI_UNITY 60 /* MIDI note number to play sample at unity */
#define MARKERLEN 10 /* Size of Marker name */
/* The header preceeding the sample data */
struct smpheader {
char Id[18]; /* File identifier */
char version[4]; /* File version */
char comments[COMMENTLEN]; /* User comments */
char name[NAMELEN + 1]; /* Sample Name, left justified */
};
#define HEADERSIZE (sizeof(struct smpheader) - 1) /* -1 for name's \0 */
/* Samplevision loop definition structure */
struct loop {
uint32_t start; /* Sample count into sample data, not byte count */
uint32_t end; /* end point */
unsigned char type; /* 0 = loop off, 1 = forward, 2 = forw/back */
unsigned short count; /* No of times to loop */
};
/* Samplevision marker definition structure */
struct marker {
char name[MARKERLEN + 1]; /* Ascii Marker name */
uint32_t position; /* Sample Number, not byte number */
};
/* The trailer following the sample data */
struct smptrailer {
struct loop loops[8]; /* loops */
struct marker markers[8]; /* markers */
char MIDInote; /* for unity pitch playback */
uint32_t rate; /* in hertz */
uint32_t SMPTEoffset; /* in subframes - huh? */
uint32_t CycleSize; /* sample count in one cycle of the */
/* sampled sound -1 if unknown */
};
/* Private data for SMP file */
typedef struct smpstuff {
uint32_t NoOfSamps; /* Sample data count in words */
sox_size_t dataStart;
/* comment memory resides in private data because it's small */
char comment[COMMENTLEN + NAMELEN + 3];
} *smp_t;
char *SVmagic = "SOUND SAMPLE DATA ", *SVvers = "2.1 ";
/*
* Read the SampleVision trailer structure.
* Returns 1 if everything was read ok, 0 if there was an error.
*/
static int readtrailer(sox_format_t * ft, struct smptrailer *trailer)
{
int i;
int16_t trash16;
sox_readw(ft, (unsigned short *)&trash16); /* read reserved word */
for(i = 0; i < 8; i++) { /* read the 8 loops */
sox_readdw(ft, &(trailer->loops[i].start));
ft->loops[i].start = trailer->loops[i].start;
sox_readdw(ft, &(trailer->loops[i].end));
ft->loops[i].length =
trailer->loops[i].end - trailer->loops[i].start;
sox_readb(ft, (unsigned char *)&(trailer->loops[i].type));
ft->loops[i].type = trailer->loops[i].type;
sox_readw(ft, (unsigned short *)&(trailer->loops[i].count));
ft->loops[i].count = trailer->loops[i].count;
}
for(i = 0; i < 8; i++) { /* read the 8 markers */
if (sox_readbuf(ft, trailer->markers[i].name, MARKERLEN) != MARKERLEN)
{
sox_fail_errno(ft,SOX_EHDR,"EOF in SMP");
return(SOX_EOF);
}
trailer->markers[i].name[MARKERLEN] = 0;
sox_readdw(ft, &(trailer->markers[i].position));
}
sox_readb(ft, (unsigned char *)&(trailer->MIDInote));
sox_readdw(ft, &(trailer->rate));
sox_readdw(ft, &(trailer->SMPTEoffset));
sox_readdw(ft, &(trailer->CycleSize));
return(SOX_SUCCESS);
}
/*
* set the trailer data - loops and markers, to reasonably benign values
*/
static void settrailer(sox_format_t * ft, struct smptrailer *trailer, sox_rate_t rate)
{
int i;
for(i = 0; i < 8; i++) { /* copy the 8 loops */
if (ft->loops[i].type != 0) {
trailer->loops[i].start = ft->loops[i].start;
/* to mark it as not set */
trailer->loops[i].end = ft->loops[i].start + ft->loops[i].length;
trailer->loops[i].type = ft->loops[i].type;
trailer->loops[i].count = ft->loops[i].count;
} else {
/* set first loop start as FFFFFFFF */
trailer->loops[i].start = ~0u;
/* to mark it as not set */
trailer->loops[i].end = 0;
trailer->loops[i].type = 0;
trailer->loops[i].count = 0;
}
}
for(i = 0; i < 8; i++) { /* write the 8 markers */
strcpy(trailer->markers[i].name, " ");
trailer->markers[i].position = ~0u;
}
trailer->MIDInote = MIDI_UNITY; /* Unity play back */
trailer->rate = rate;
trailer->SMPTEoffset = 0;
trailer->CycleSize = ~0u;
}
/*
* Write the SampleVision trailer structure.
* Returns 1 if everything was written ok, 0 if there was an error.
*/
static int writetrailer(sox_format_t * ft, struct smptrailer *trailer)
{
int i;
sox_writew(ft, 0); /* write the reserved word */
for(i = 0; i < 8; i++) { /* write the 8 loops */
sox_writedw(ft, trailer->loops[i].start);
sox_writedw(ft, trailer->loops[i].end);
sox_writeb(ft, trailer->loops[i].type);
sox_writew(ft, trailer->loops[i].count);
}
for(i = 0; i < 8; i++) { /* write the 8 markers */
if (sox_writes(ft, trailer->markers[i].name) == SOX_EOF)
{
sox_fail_errno(ft,SOX_EHDR,"EOF in SMP");
return(SOX_EOF);
}
sox_writedw(ft, trailer->markers[i].position);
}
sox_writeb(ft, (uint8_t)(trailer->MIDInote));
sox_writedw(ft, trailer->rate);
sox_writedw(ft, trailer->SMPTEoffset);
sox_writedw(ft, trailer->CycleSize);
return(SOX_SUCCESS);
}
static int sox_smpseek(sox_format_t * ft, sox_size_t offset)
{
sox_size_t new_offset, channel_block, alignment;
smp_t smp = (smp_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 += smp->dataStart;
ft->sox_errno = sox_seeki(ft, (sox_ssize_t)new_offset, SEEK_SET);
if( ft->sox_errno == SOX_SUCCESS )
smp->NoOfSamps = ft->length - (new_offset / ft->signal.size);
return(ft->sox_errno);
}
/*
* Do anything required before you start reading samples.
* Read file header.
* Find out sampling rate,
* size and encoding of samples,
* mono/stereo/quad.
*/
static int sox_smpstartread(sox_format_t * ft)
{
smp_t smp = (smp_t) ft->priv;
int namelen, commentlen;
sox_size_t samplestart, i;
struct smpheader header;
struct smptrailer trailer;
/* If you need to seek around the input file. */
if (! ft->seekable)
{
sox_fail_errno(ft,SOX_EOF,"SMP input file must be a file, not a pipe");
return(SOX_EOF);
}
/* Read SampleVision header */
if (sox_readbuf(ft, (char *)&header, HEADERSIZE) != HEADERSIZE)
{
sox_fail_errno(ft,SOX_EHDR,"unexpected EOF in SMP header");
return(SOX_EOF);
}
if (strncmp(header.Id, SVmagic, 17) != 0)
{
sox_fail_errno(ft,SOX_EHDR,"SMP header does not begin with magic word %s", SVmagic);
return(SOX_EOF);
}
if (strncmp(header.version, SVvers, 4) != 0)
{
sox_fail_errno(ft,SOX_EHDR,"SMP header is not version %s", SVvers);
return(SOX_EOF);
}
/* Format the sample name and comments to a single comment */
/* string. We decrement the counters till we encounter non */
/* padding space chars, so the *lengths* are low by one */
for (namelen = NAMELEN-1;
namelen >= 0 && header.name[namelen] == ' '; namelen--)
;
for (commentlen = COMMENTLEN-1;
commentlen >= 0 && header.comments[commentlen] == ' '; commentlen--)
;
sprintf(smp->comment, "%.*s: %.*s", namelen+1, header.name,
commentlen+1, header.comments);
append_comments(&ft->comments, smp->comment);
/* Extract out the sample size (always intel format) */
sox_readdw(ft, &(smp->NoOfSamps));
/* mark the start of the sample data */
samplestart = sox_tell(ft);
/* seek from the current position (the start of sample data) by */
/* NoOfSamps * sizeof(int16_t) */
if (sox_seeki(ft, (sox_ssize_t)(smp->NoOfSamps * 2), 1) == -1)
{
sox_fail_errno(ft,errno,"SMP unable to seek to trailer");
return(SOX_EOF);
}
if (readtrailer(ft, &trailer))
{
sox_fail_errno(ft,SOX_EHDR,"unexpected EOF in SMP trailer");
return(SOX_EOF);
}
/* seek back to the beginning of the data */
if (sox_seeki(ft, (sox_ssize_t)samplestart, 0) == -1)
{
sox_fail_errno(ft,errno,"SMP unable to seek back to start of sample data");
return(SOX_EOF);
}
ft->signal.rate = (int) trailer.rate;
ft->signal.size = SOX_SIZE_16BIT;
ft->signal.encoding = SOX_ENCODING_SIGN2;
ft->signal.channels = 1;
smp->dataStart = samplestart;
ft->length = smp->NoOfSamps;
sox_report("SampleVision trailer:");
for(i = 0; i < 8; i++) if (1 || trailer.loops[i].count) {
sox_report("Loop %d: start: %6d", i, trailer.loops[i].start);
sox_report(" end: %6d", trailer.loops[i].end);
sox_report(" count: %6d", trailer.loops[i].count);
switch(trailer.loops[i].type) {
case 0: sox_report("type: off"); break;
case 1: sox_report("type: forward"); break;
case 2: sox_report("type: forward/backward"); break;
}
}
sox_report("MIDI Note number: %d", trailer.MIDInote);
ft->instr.nloops = 0;
for(i = 0; i < 8; i++)
if (trailer.loops[i].type)
ft->instr.nloops++;
for(i = 0; i < ft->instr.nloops; i++) {
ft->loops[i].type = trailer.loops[i].type;
ft->loops[i].count = trailer.loops[i].count;
ft->loops[i].start = trailer.loops[i].start;
ft->loops[i].length = trailer.loops[i].end
- trailer.loops[i].start;
}
ft->instr.MIDIlow = ft->instr.MIDIhi =
ft->instr.MIDInote = trailer.MIDInote;
if (ft->instr.nloops > 0)
ft->instr.loopmode = SOX_LOOP_8;
else
ft->instr.loopmode = SOX_LOOP_NONE;
return(SOX_SUCCESS);
}
/*
* Read up to len samples from file.
* Convert to signed longs.
* Place in buf[].
* Return number of samples read.
*/
static sox_size_t sox_smpread(sox_format_t * ft, sox_sample_t *buf, sox_size_t len)
{
smp_t smp = (smp_t) ft->priv;
unsigned short datum;
sox_size_t done = 0;
for(; done < len && smp->NoOfSamps; done++, smp->NoOfSamps--) {
sox_readw(ft, &datum);
/* scale signed up to long's range */
*buf++ = SOX_SIGNED_16BIT_TO_SAMPLE(datum,);
}
return done;
}
static int sox_smpstartwrite(sox_format_t * ft)
{
smp_t smp = (smp_t) ft->priv;
struct smpheader header;
char * comment = cat_comments(ft->comments);
/* If you have to seek around the output file */
if (! ft->seekable)
{
sox_fail_errno(ft,SOX_EOF,"Output .smp file must be a file, not a pipe");
return(SOX_EOF);
}
/* If your format specifies any of the following info. */
ft->signal.size = SOX_SIZE_16BIT;
ft->signal.encoding = SOX_ENCODING_SIGN2;
ft->signal.channels = 1;
memcpy(header.Id, SVmagic, sizeof(header.Id));
memcpy(header.version, SVvers, sizeof(header.version));
sprintf(header.comments, "%-*s", COMMENTLEN - 1, "Converted using Sox.");
sprintf(header.name, "%-*.*s", NAMELEN, NAMELEN, comment);
free(comment);
/* Write file header */
if(sox_writebuf(ft, &header, HEADERSIZE) != HEADERSIZE)
{
sox_fail_errno(ft,errno,"SMP: Can't write header completely");
return(SOX_EOF);
}
sox_writedw(ft, 0); /* write as zero length for now, update later */
smp->NoOfSamps = 0;
return(SOX_SUCCESS);
}
static sox_size_t sox_smpwrite(sox_format_t * ft, const sox_sample_t *buf, sox_size_t len)
{
smp_t smp = (smp_t) ft->priv;
int datum;
sox_size_t done = 0;
while(done < len) {
datum = (int) SOX_SAMPLE_TO_SIGNED_16BIT(*buf++, ft->clips);
sox_writew(ft, (uint16_t)datum);
smp->NoOfSamps++;
done++;
}
return(done);
}
static int sox_smpstopwrite(sox_format_t * ft)
{
smp_t smp = (smp_t) ft->priv;
struct smptrailer trailer;
/* Assign the trailer data */
settrailer(ft, &trailer, ft->signal.rate);
writetrailer(ft, &trailer);
if (sox_seeki(ft, 112, 0) == -1)
{
sox_fail_errno(ft,errno,"SMP unable to seek back to save size");
return(SOX_EOF);
}
sox_writedw(ft, smp->NoOfSamps);
return(SOX_SUCCESS);
}
/* SampleVision sound */
static const char *smpnames[] = {
"smp",
NULL,
};
static sox_format_handler_t sox_smp_format = {
smpnames,
SOX_FILE_LOOPS | SOX_FILE_LIT_END,
sox_smpstartread,
sox_smpread,
NULL,
sox_smpstartwrite,
sox_smpwrite,
sox_smpstopwrite,
sox_smpseek
};
const sox_format_handler_t *sox_smp_format_fn(void);
const sox_format_handler_t *sox_smp_format_fn(void)
{
return &sox_smp_format;
}