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FFmpegAndroid/app/src/main/cpp/sox/delay.c

163 lines
4.9 KiB

/* libSoX effect: Delay one or more channels (c) 2008 robs@users.sourceforge.net
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or (at
* your option) any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
* General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "sox_i.h"
#include <string.h>
typedef struct {
size_t argc;
struct { char *str; uint64_t delay; } *args;
uint64_t *max_delay;
uint64_t delay, pre_pad, pad;
size_t buffer_size, buffer_index;
sox_sample_t * buffer;
sox_bool drain_started;
} priv_t;
static int lsx_kill(sox_effect_t * effp)
{
priv_t * p = (priv_t *)effp->priv;
unsigned i;
for (i = 0; i < p->argc; ++i)
free(p->args[i].str);
free(p->args);
free(p->max_delay);
return SOX_SUCCESS;
}
static int create(sox_effect_t * effp, int argc, char * * argv)
{
priv_t * p = (priv_t *)effp->priv;
unsigned i;
--argc, ++argv;
p->argc = argc;
p->args = lsx_calloc(p->argc, sizeof(*p->args));
p->max_delay = lsx_malloc(sizeof(*p->max_delay));
for (i = 0; i < p->argc; ++i) {
char const * next = lsx_parseposition(0., p->args[i].str = lsx_strdup(argv[i]), NULL, (uint64_t)0, (uint64_t)0, '=');
if (!next || *next) {
lsx_kill(effp);
return lsx_usage(effp);
}
}
return SOX_SUCCESS;
}
static int stop(sox_effect_t * effp)
{
priv_t * p = (priv_t *)effp->priv;
free(p->buffer);
return SOX_SUCCESS;
}
static int start(sox_effect_t * effp)
{
priv_t * p = (priv_t *)effp->priv;
uint64_t max_delay = 0, last_seen = 0, delay;
uint64_t in_length = effp->in_signal.length != SOX_UNKNOWN_LEN ?
effp->in_signal.length / effp->in_signal.channels : SOX_UNKNOWN_LEN;
if (effp->flow == 0) {
unsigned i;
if (p->argc > effp->in_signal.channels) {
lsx_fail("too few input channels");
return SOX_EOF;
}
for (i = 0; i < p->argc; ++i) {
if (!lsx_parseposition(effp->in_signal.rate, p->args[i].str, &delay, last_seen, in_length, '=') || delay == SOX_UNKNOWN_LEN) {
lsx_fail("Position relative to end of audio specified, but audio length is unknown");
return SOX_EOF;
}
p->args[i].delay = last_seen = delay;
if (delay > max_delay) {
max_delay = delay;
}
}
*p->max_delay = max_delay;
if (max_delay == 0)
return SOX_EFF_NULL;
effp->out_signal.length = effp->in_signal.length != SOX_UNKNOWN_LEN ?
effp->in_signal.length + max_delay * effp->in_signal.channels :
SOX_UNKNOWN_LEN;
lsx_debug("extending audio by %" PRIu64 " samples", max_delay);
}
max_delay = *p->max_delay;
if (effp->flow < p->argc)
p->buffer_size = p->args[effp->flow].delay;
p->buffer_index = p->delay = p->pre_pad = 0;
p->pad = max_delay - p->buffer_size;
p->buffer = lsx_malloc(p->buffer_size * sizeof(*p->buffer));
p->drain_started = sox_false;
return SOX_SUCCESS;
}
static int flow(sox_effect_t * effp, const sox_sample_t * ibuf,
sox_sample_t * obuf, size_t * isamp, size_t * osamp)
{
priv_t * p = (priv_t *)effp->priv;
size_t len = *isamp = *osamp = min(*isamp, *osamp);
if (!p->buffer_size)
memcpy(obuf, ibuf, len * sizeof(*obuf));
else for (; len; --len) {
if (p->delay < p->buffer_size) {
p->buffer[p->delay++] = *ibuf++;
*obuf++ = 0;
} else {
*obuf++ = p->buffer[p->buffer_index];
p->buffer[p->buffer_index++] = *ibuf++;
p->buffer_index %= p->buffer_size;
}
}
return SOX_SUCCESS;
}
static int drain(sox_effect_t * effp, sox_sample_t * obuf, size_t * osamp)
{
priv_t * p = (priv_t *)effp->priv;
size_t len;
if (! p->drain_started) {
p->drain_started = sox_true;
p->pre_pad = p->buffer_size - p->delay;
/* If the input was too short to fill the buffer completely,
flow() has not yet output enough silence to reach the
desired delay. */
}
len = *osamp = min(p->pre_pad + p->delay + p->pad, *osamp);
for (; p->pre_pad && len; --p->pre_pad, --len)
*obuf++ = 0;
for (; p->delay && len; --p->delay, --len) {
*obuf++ = p->buffer[p->buffer_index++];
p->buffer_index %= p->buffer_size;
}
for (; p->pad && len; --p->pad, --len)
*obuf++ = 0;
return SOX_SUCCESS;
}
sox_effect_handler_t const * lsx_delay_effect_fn(void)
{
static sox_effect_handler_t handler = {
"delay", "{position}", SOX_EFF_LENGTH | SOX_EFF_MODIFY,
create, start, flow, drain, stop, lsx_kill, sizeof(priv_t)
};
return &handler;
}