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/*
* Copyright (c) 1999 Cameron Grant <gandalf@vilnya.demon.co.uk>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <dev/sound/pcm/sound.h>
#include "feeder_if.h"
SND_DECLARE_FILE("$FreeBSD$");
MALLOC_DEFINE(M_RATEFEEDER, "ratefeed", "pcm rate feeder");
#define FEEDBUFSZ 8192
#undef FEEDER_DEBUG
struct feed_rate_info {
u_int32_t src, dst;
int srcpos, srcinc;
int16_t *buffer;
u_int16_t alpha;
};
static int
feed_rate_setup(struct pcm_feeder *f)
{
struct feed_rate_info *info = f->data;
info->srcinc = (info->src << 16) / info->dst;
/* srcinc is 16.16 fixed point increment for srcpos for each dstpos */
info->srcpos = 0;
return 0;
}
static int
feed_rate_set(struct pcm_feeder *f, int what, int value)
{
struct feed_rate_info *info = f->data;
switch(what) {
case FEEDRATE_SRC:
info->src = value;
break;
case FEEDRATE_DST:
info->dst = value;
break;
default:
return -1;
}
return feed_rate_setup(f);
}
static int
feed_rate_get(struct pcm_feeder *f, int what)
{
struct feed_rate_info *info = f->data;
switch(what) {
case FEEDRATE_SRC:
return info->src;
case FEEDRATE_DST:
return info->dst;
default:
return -1;
}
return -1;
}
static int
feed_rate_init(struct pcm_feeder *f)
{
struct feed_rate_info *info;
info = malloc(sizeof(*info), M_RATEFEEDER, M_NOWAIT | M_ZERO);
if (info == NULL)
return ENOMEM;
info->buffer = malloc(FEEDBUFSZ, M_RATEFEEDER, M_NOWAIT | M_ZERO);
if (info->buffer == NULL) {
free(info, M_RATEFEEDER);
return ENOMEM;
}
info->src = DSP_DEFAULT_SPEED;
info->dst = DSP_DEFAULT_SPEED;
info->alpha = 0;
f->data = info;
return feed_rate_setup(f);
}
static int
feed_rate_free(struct pcm_feeder *f)
{
struct feed_rate_info *info = f->data;
if (info) {
if (info->buffer)
free(info->buffer, M_RATEFEEDER);
free(info, M_RATEFEEDER);
}
f->data = NULL;
return 0;
}
static int
feed_rate(struct pcm_feeder *f, struct pcm_channel *c, u_int8_t *b, u_int32_t count, void *source)
{
struct feed_rate_info *info = f->data;
int16_t *destbuf = (int16_t *)b;
int fetch, v, alpha, hidelta, spos, dpos;
/*
* at this point:
* info->srcpos is 24.8 fixed offset into the fetchbuffer. 0 <= srcpos <= 0xff
*
* our input and output are always AFMT_S16LE stereo. this simplifies things.
*/
/*
* we start by fetching enough source data into our buffer to generate
* about as much as was requested. we put it at offset 2 in the
* buffer so that we can interpolate from the last samples in the
* previous iteration- when we finish we will move our last samples
* to the start of the buffer.
*/
spos = 0;
dpos = 0;
/* fetch is in bytes */
fetch = (count * info->srcinc) >> 16;
fetch = min(fetch, FEEDBUFSZ - 4) & ~3;
if (fetch == 0)
return 0;
fetch = FEEDER_FEED(f->source, c, ((u_int8_t *)info->buffer) + 4, fetch, source);
fetch /= 2;
alpha = info->alpha;
hidelta = min(info->srcinc >> 16, 1) * 2;
while ((spos + hidelta + 1) < fetch) {
v = (info->buffer[spos] * (0xffff - alpha)) + (info->buffer[spos + hidelta] * alpha);
destbuf[dpos++] = v >> 16;
v = (info->buffer[spos + 1] * (0xffff - alpha)) + (info->buffer[spos + hidelta + 1] * alpha);
destbuf[dpos++] = v >> 16;
alpha += info->srcinc;
spos += (alpha >> 16) * 2;
alpha &= 0xffff;
}
info->alpha = alpha & 0xffff;
info->buffer[0] = info->buffer[spos - hidelta];
info->buffer[1] = info->buffer[spos - hidelta + 1];
count = dpos * 2;
return count;
}
static struct pcm_feederdesc feeder_rate_desc[] = {
{FEEDER_RATE, AFMT_S16_LE | AFMT_STEREO, AFMT_S16_LE | AFMT_STEREO, 0},
{0},
};
static kobj_method_t feeder_rate_methods[] = {
KOBJMETHOD(feeder_init, feed_rate_init),
KOBJMETHOD(feeder_free, feed_rate_free),
KOBJMETHOD(feeder_set, feed_rate_set),
KOBJMETHOD(feeder_get, feed_rate_get),
KOBJMETHOD(feeder_feed, feed_rate),
{ 0, 0 }
};
FEEDER_DECLARE(feeder_rate, 2, NULL);
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