ref: c2fda8f3e4f3623d1766d37078fb05d3ef6dbbe8
dir: /src/tx16w.c/
/* libSoX Yamaha TX-16W sampler file support
*
* May 20, 1993
* Copyright 1993 Rob Talley (rob@aii.com)
* This source code is freely redistributable and may be used for
* any purpose. This copyright notice and the following copyright
* notice must be maintained intact. No warranty whatsoever is
* provided. This code is furnished AS-IS as a component of the
* larger work Copyright 1991 Lance Norskog and Sundry Contributors.
* Much appreciation to ross-c for his sampConv utility for SGI/IRIX
* from where these methods were derived.
*
* Jan 24, 1994
* Pat McElhatton, HP Media Technology Lab <patmc@apollo.hp.com>
* Handles reading of files which do not have the sample rate field
* set to one of the expected by looking at some other bytes in the
* attack/loop length fields, and defaulting to 33kHz if the sample
* rate is still unknown.
*
* January 12, 1995
* Copyright 1995 Mark Lakata (lakata@physics.berkeley.edu)
* Additions to tx16w.c SOX handler. This version writes as well as
* reads TX16W format.
*
* July 31, 1998
* Cleaned up by Leigh Smith (leigh@psychokiller.dialix.oz.au)
* for incorporation into the main sox distribution.
*
* September 24, 1998
* Forced output to mono signed words to match input. It was basically
* doing this anyways but now the user will see a display that it's been
* overridden. cbagwell@sprynet.com
*
*/
#include "sox_i.h"
#include <stdio.h>
#include <string.h>
#define TXMAXLEN 0x3FF80
/* Private data for TX16 file */
typedef struct {
size_t samples_out;
size_t bytes_out;
size_t rest; /* bytes remaining in sample file */
sox_sample_t odd;
sox_bool odd_flag;
} priv_t;
struct WaveHeader_ {
char filetype[6]; /* = "LM8953", */
unsigned char
nulls[10],
dummy_aeg[6], /* space for the AEG (never mind this) */
format, /* 0x49 = looped, 0xC9 = non-looped */
sample_rate, /* 1 = 33 kHz, 2 = 50 kHz, 3 = 16 kHz */
atc_length[3], /* I'll get to this... */
rpt_length[3],
unused[2]; /* set these to null, to be on the safe side */
};
static const unsigned char magic1[4] = {0, 0x06, 0x10, 0xF6};
static const unsigned char magic2[4] = {0, 0x52, 0x00, 0x52};
/*
* 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 startread(sox_format_t * ft)
{
int c;
char filetype[7];
int8_t format;
unsigned char sample_rate;
size_t num_samp_bytes = 0;
unsigned char gunk[8];
int blewIt;
uint8_t trash;
priv_t * sk = (priv_t *) ft->priv;
/* If you need to seek around the input file. */
if (! ft->seekable)
{
lsx_fail_errno(ft,SOX_EOF,"txw input file must be a file, not a pipe");
return(SOX_EOF);
}
/* This is dumb but portable, just count the bytes til EOF */
while (lsx_read_b_buf(ft, &trash, (size_t) 1) == 1)
num_samp_bytes++;
num_samp_bytes -= 32; /* calculate num samples by sub header size */
lsx_seeki(ft, (off_t)0, 0); /* rewind file */
sk->rest = num_samp_bytes; /* set how many sample bytes to read */
/* first 6 bytes are file type ID LM8953 */
lsx_readchars(ft, filetype, sizeof(filetype) - 1);
filetype[6] = '\0';
for( c = 16; c > 0 ; c-- ) /* Discard next 16 bytes */
lsx_readb(ft, &trash);
lsx_readsb(ft, &format);
lsx_readb(ft, &sample_rate);
/*
* save next 8 bytes - if sample rate is 0, then we need
* to look at gunk[2] and gunk[5] to get real rate
*/
for( c = 0; c < 8; c++ )
lsx_readb(ft, &(gunk[c]));
/*
* We should now be pointing at start of raw sample data in file
*/
/* Check to make sure we got a good filetype ID from file */
lsx_debug("Found header filetype %s",filetype);
if(strcmp(filetype,"LM8953"))
{
lsx_fail_errno(ft,SOX_EHDR,"Invalid filetype ID in input file header, != LM8953");
return(SOX_EOF);
}
/*
* Set up the sample rate as indicated by the header
*/
switch( sample_rate ) {
case 1:
ft->signal.rate = 1e5 / 3;
break;
case 2:
ft->signal.rate = 1e5 / 2;
break;
case 3:
ft->signal.rate = 1e5 / 6;
break;
default:
blewIt = 1;
switch( gunk[2] & 0xFE ) {
case 0x06:
if ( (gunk[5] & 0xFE) == 0x52 ) {
blewIt = 0;
ft->signal.rate = 1e5 / 3;
}
break;
case 0x10:
if ( (gunk[5] & 0xFE) == 0x00 ) {
blewIt = 0;
ft->signal.rate = 1e5 / 2;
}
break;
case 0xF6:
if ( (gunk[5] & 0xFE) == 0x52 ) {
blewIt = 0;
ft->signal.rate = 1e5 / 6;
}
break;
}
if ( blewIt ) {
lsx_debug("Invalid sample rate identifier found %d", sample_rate);
ft->signal.rate = 1e5 / 3;
}
}
lsx_debug("Sample rate = %g", ft->signal.rate);
ft->signal.channels = 1 ; /* not sure about stereo sample data yet ??? */
ft->encoding.bits_per_sample = 12;
ft->encoding.encoding = SOX_ENCODING_SIGN2;
return(SOX_SUCCESS);
}
/*
* Read up to len samples from file.
* Convert to sox_sample_t.
* Place in buf[].
* Return number of samples read.
*/
static size_t read_samples(sox_format_t * ft, sox_sample_t *buf, size_t len)
{
priv_t * sk = (priv_t *) ft->priv;
size_t done = 0;
unsigned char uc1,uc2,uc3;
unsigned short s1,s2;
/*
* This gets called by the top level 'process' routine.
* We will essentially get called with a buffer pointer
* and a max length to read. Graciously, it is always
* an even amount so we don't have to worry about
* hanging onto the left over odd samples since there
* won't be any. Something to look out for though :-(
* We return the number of samples we read.
* We will get called over and over again until we return
* 0 bytes read.
*/
/*
* This is ugly but it's readable!
* Read three bytes from stream, then decompose these into
* two unsigned short samples.
* TCC 3.0 appeared to do unwanted things, so we really specify
* exactly what we want to happen.
* Convert unsigned short to sox_sample_t then shift up the result
* so that the 12-bit sample lives in the most significant
* 12-bits of the sox_sample_t.
* This gets our two samples into the internal format which we
* deposit into the given buffer and adjust our counts respectivly.
*/
for(done = 0; done < len; ) {
if(sk->rest < 3) break; /* Finished reading from file? */
lsx_readb(ft, &uc1);
lsx_readb(ft, &uc2);
lsx_readb(ft, &uc3);
sk->rest -= 3; /* adjust remaining for bytes we just read */
s1 = (unsigned short) (uc1 << 4) | (((uc2 >> 4) & 017));
s2 = (unsigned short) (uc3 << 4) | (( uc2 & 017 ));
*buf = (sox_sample_t) s1;
*buf = (*buf << 20);
buf++; /* sample one is done */
*buf = (sox_sample_t) s2;
*buf = (*buf << 20);
buf++; /* sample two is done */
done += 2; /* adjust converted & stored sample count */
}
return done;
}
static int startwrite(sox_format_t * ft)
{
priv_t * sk = (priv_t *) ft->priv;
struct WaveHeader_ WH;
lsx_debug("tx16w selected output");
memset(&WH, 0, sizeof(struct WaveHeader_));
/* If you have to seek around the output file */
if (! ft->seekable)
{
lsx_fail_errno(ft,SOX_EOF,"Output .txw file must be a file, not a pipe");
return(SOX_EOF);
}
/* dummy numbers, just for place holder, real header is written
at end of processing, since byte count is needed */
lsx_writebuf(ft, &WH, (size_t) 32);
sk->bytes_out = 32;
return(SOX_SUCCESS);
}
static size_t write_samples(sox_format_t * ft, const sox_sample_t *buf, size_t len0)
{
priv_t * sk = (priv_t *) ft->priv;
size_t last_i, i = 0, len = min(len0, TXMAXLEN - sk->samples_out);
sox_sample_t w1, w2;
while (i < len) {
last_i = i;
if (sk->odd_flag) {
w1 = sk->odd;
sk->odd_flag = sox_false;
}
else w1 = *buf++ >> 20, ++i;
if (i < len) {
w2 = *buf++ >> 20, ++i;
if (lsx_writesb(ft, (w1 >> 4) & 0xFF) ||
lsx_writesb(ft, (((w1 & 0x0F) << 4) | (w2 & 0x0F)) & 0xFF) ||
lsx_writesb(ft, (w2 >> 4) & 0xFF)) {
i = last_i;
break;
}
sk->samples_out += 2;
sk->bytes_out += 3;
}
else {
sk->odd = w1;
sk->odd_flag = sox_true;
}
}
return i;
}
static int stopwrite(sox_format_t * ft)
{
priv_t * sk = (priv_t *) ft->priv;
struct WaveHeader_ WH;
int AttackLength, LoopLength, i;
if (sk->odd_flag) {
sox_sample_t pad = 0;
write_samples(ft, &pad, (size_t) 1);
}
/* All samples are already written out. */
/* If file header needs fixing up, for example it needs the */
/* the number of samples in a field, seek back and write them here. */
lsx_debug("tx16w:output finished");
memset(&WH, 0, sizeof(struct WaveHeader_));
memcpy(WH.filetype, "LM8953", 6);
for (i=0;i<10;i++) WH.nulls[i]=0;
for (i=0;i<6;i++) WH.dummy_aeg[i]=0;
for (i=0;i<2;i++) WH.unused[i]=0;
for (i=0;i<2;i++) WH.dummy_aeg[i] = 0;
for (i=2;i<6;i++) WH.dummy_aeg[i] = 0x7F;
WH.format = 0xC9; /* loop off */
/* the actual sample rate is not that important ! */
if (ft->signal.rate < 24000) WH.sample_rate = 3;
else if (ft->signal.rate < 41000) WH.sample_rate = 1;
else WH.sample_rate = 2;
if (sk->samples_out >= TXMAXLEN) {
lsx_warn("Sound too large for TX16W. Truncating, Loop Off");
AttackLength = TXMAXLEN/2;
LoopLength = TXMAXLEN/2;
}
else if (sk->samples_out >=TXMAXLEN/2) {
AttackLength = TXMAXLEN/2;
LoopLength = sk->samples_out - TXMAXLEN/2;
if (LoopLength < 0x40) {
LoopLength +=0x40;
AttackLength -= 0x40;
}
}
else if (sk->samples_out >= 0x80) {
AttackLength = sk->samples_out -0x40;
LoopLength = 0x40;
}
else {
AttackLength = 0x40;
LoopLength = 0x40;
for(i=sk->samples_out;i<0x80;i++) {
lsx_writeb(ft, 0);
lsx_writeb(ft, 0);
lsx_writeb(ft, 0);
sk->bytes_out += 3;
}
}
/* Fill up to 256 byte blocks; the TX16W seems to like that */
while ((sk->bytes_out % 0x100) != 0) {
lsx_writeb(ft, 0);
sk->bytes_out++;
}
WH.atc_length[0] = 0xFF & AttackLength;
WH.atc_length[1] = 0xFF & (AttackLength >> 8);
WH.atc_length[2] = (0x01 & (AttackLength >> 16)) +
magic1[WH.sample_rate];
WH.rpt_length[0] = 0xFF & LoopLength;
WH.rpt_length[1] = 0xFF & (LoopLength >> 8);
WH.rpt_length[2] = (0x01 & (LoopLength >> 16)) +
magic2[WH.sample_rate];
lsx_rewind(ft);
lsx_writebuf(ft, &WH, (size_t) 32);
return(SOX_SUCCESS);
}
LSX_FORMAT_HANDLER(txw)
{
static char const * const names[] = {"txw", NULL};
static sox_rate_t const write_rates[] = {1e5/6, 1e5/3, 1e5/2, 0};
static unsigned const write_encodings[] = {SOX_ENCODING_SIGN2, 12, 0, 0};
static sox_format_handler_t const handler = {SOX_LIB_VERSION_CODE,
"Yamaha TX-16W sampler", names, SOX_FILE_MONO,
startread, read_samples, NULL,
startwrite, write_samples, stopwrite,
NULL, write_encodings, write_rates, sizeof(priv_t)
};
return &handler;
}