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/*
* FILE: convert_extra.c
* PROGRAM: RAT
* AUTHOR: O.Hodson <O.Hodson@cs.ucl.ac.uk>
*
* Copyright (c) 1998-2001 University College London
* All rights reserved.
*/
#ifndef HIDE_SOURCE_STRINGS
static const char cvsid[] =
"$Id: convert_extra.c,v 1.12 2001/01/14 20:53:46 ucacoxh Exp $";
#endif /* HIDE_SOURCE_STRINGS */
#include "config_unix.h"
#include "config_win32.h"
#include "audio_types.h"
#include "converter_types.h"
#include "convert_extra.h"
#include "convert_util.h"
#include "util.h"
#include "memory.h"
#include "debug.h"
/* Extrusion *************************************************************
* This is the cheap and nasty, for upsampling we drag out samples and
* downsamping we just subsample and suffer aliasing effects (v. dumb).
*/
typedef void (*extra_cf)(int offset, int channels, sample *src, int src_len, sample *dst, int dst_len);
typedef struct {
short scale;
int steps;
sample *tmp_buf;
short tmp_len;
extra_cf convert_f;
} extra_state_t;
static void
extra_upsample(int offset, int channels, sample *src, int src_len, sample *dst, int dst_len)
{
register short *sp, *dp;
register int dstep, loop;
sp = src + offset;
dp = dst + offset;
dstep = channels * dst_len / src_len;
loop = min(dst_len / dstep, src_len / channels);
#ifdef DEBUG_CONVERT
debug_msg("loop %d choice (%d, %d)\n", loop, dst_len/dstep, src_len/channels);
#endif
dstep /= channels;
switch(dstep) {
case 6:
while (loop--) {
*dp = *sp; dp += channels;
*dp = *sp; dp += channels;
*dp = *sp; dp += channels;
*dp = *sp; dp += channels;
*dp = *sp; dp += channels;
*dp = *sp; dp += channels;
sp += channels;
}
break;
case 5:
while (loop--) {
*dp = *sp; dp += channels;
*dp = *sp; dp += channels;
*dp = *sp; dp += channels;
*dp = *sp; dp += channels;
*dp = *sp; dp += channels;
sp += channels;
}
break;
case 4:
while (loop--) {
*dp = *sp; dp += channels;
*dp = *sp; dp += channels;
*dp = *sp; dp += channels;
*dp = *sp; dp += channels;
sp += channels;
}
break;
case 3:
while (loop--) {
*dp = *sp; dp += channels;
*dp = *sp; dp += channels;
*dp = *sp; dp += channels;
sp += channels;
}
break;
case 2:
while (loop--) {
*dp = *sp; dp += channels;
*dp = *sp; dp += channels;
sp += channels;
}
break;
case 1:
while (loop--) {
*dp = *sp; dp += channels;
sp += channels;
}
break;
}
}
static void
extra_downsample(int offset, int channels, sample *src, int src_len, sample *dst, int dst_len)
{
register short *sp, *dp;
register int src_step, loop;
src_step = channels * src_len / dst_len;
sp = src + offset;
dp = dst + offset;
loop = min(src_len / src_step, dst_len / channels);
while(loop--) {
*dp = *sp;
dp += channels;
sp += src_step;
}
}
static void
extra_init_state(extra_state_t *e, int src_freq, int dst_freq)
{
if (src_freq > dst_freq) {
e->convert_f = extra_downsample;
e->scale = src_freq / dst_freq;
} else if (src_freq < dst_freq) {
e->convert_f = extra_upsample;
e->scale = dst_freq / src_freq;
}
e->tmp_buf = NULL;
e->tmp_len = 0;
}
int
extra_create (const converter_fmt_t *cfmt, u_char **state, uint32_t *state_len)
{
extra_state_t *e;
int denom, steps, g;
if (((cfmt->src_freq % 8000) == 0 && (cfmt->dst_freq % 8000)) ||
((cfmt->src_freq % 11025) == 0 && (cfmt->dst_freq % 11025))) {
/* 11025 - 8000 not supported */
return FALSE;
}
g = gcd(cfmt->src_freq, cfmt->dst_freq);
steps = conversion_steps(cfmt->src_freq, cfmt->dst_freq);
e = (extra_state_t*)xmalloc(steps * sizeof(extra_state_t));
e->steps = steps;
switch(e->steps) {
case 1:
extra_init_state(e, cfmt->src_freq, cfmt->dst_freq);
break;
case 2:
denom = g;
extra_init_state(e, cfmt->src_freq, denom);
extra_init_state(e + 1, denom, cfmt->dst_freq);
break;
}
*state = (u_char*)e;
*state_len = steps * sizeof(extra_state_t);
return TRUE;
}
void
extra_convert (const converter_fmt_t *cfmt, u_char *state, sample* src_buf, int src_len, sample *dst_buf, int dst_len)
{
extra_state_t *e;
int i, channels;
channels = cfmt->src_channels;
e = (extra_state_t*)state;
if (cfmt->src_channels == 2 && cfmt->dst_channels == 1) {
/* stereo->mono then sample rate change */
if (e->steps) {
/* inplace conversion needed */
converter_change_channels(src_buf, src_len, 2, src_buf, src_len / 2, 1);
src_len /= 2;
} else {
/* this is only conversion */
converter_change_channels(src_buf, src_len, 2, dst_buf, dst_len, 1);
}
channels = 1;
} else if (cfmt->src_channels == 1 && cfmt->dst_channels == 2) {
dst_len /= 2;
}
switch(e->steps) {
case 1:
assert(e[0].convert_f);
for(i = 0; i < channels; i++) {
e[0].convert_f(i, channels, src_buf, src_len, dst_buf, dst_len);
}
break;
case 2:
/* first step is always downsampling for moment */
if (e->tmp_buf == NULL) {
e->tmp_len = src_len / e->scale;
e->tmp_buf = (sample*)xmalloc(sizeof(sample) * e->tmp_len);
}
assert(e[0].convert_f);
assert(e[1].convert_f);
for(i = 0; i < channels; i++)
e[0].convert_f(i, channels, src_buf, src_len, e->tmp_buf, e->tmp_len);
for(i = 0; i < channels; i++)
e[1].convert_f(i, channels, e->tmp_buf, e->tmp_len, dst_buf, dst_len);
break;
}
if (cfmt->src_channels == 1 && cfmt->dst_channels == 2) {
/* sample rate change before mono-> stereo */
if (e->steps) {
/* in place needed */
converter_change_channels(dst_buf, dst_len, 1, dst_buf, dst_len * 2, 2);
} else {
/* this is our only conversion here */
converter_change_channels(src_buf, src_len, 1, dst_buf, dst_len * 2, 2);
}
}
}
static void
extra_state_free(extra_state_t *e)
{
if (e->tmp_buf) {
xfree(e->tmp_buf);
e->tmp_buf = NULL;
e->tmp_len = 0;
}
}
void
extra_destroy (u_char **state, uint32_t *state_len)
{
int i;
extra_state_t *e = (extra_state_t*)*state;
assert(*state_len == e->steps * sizeof(extra_state_t));
for(i = 0; i < e->steps; i++) {
extra_state_free(e + i);
}
xfree(e);
*state = NULL;
*state_len = 0;
}
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