ref: f140e52941bed2b902411f6eab0804c81fd4a072
dir: /src/pad.c/
/* libSoX effect: Pad With Silence (c) 2006 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"
typedef struct {
unsigned npads; /* Number of pads requested */
struct {
char * str; /* Command-line argument to parse for this pad */
uint64_t start; /* Start padding when in_pos equals this */
uint64_t pad; /* Number of samples to pad */
} * pads;
uint64_t in_pos; /* Number of samples read from the input stream */
unsigned pads_pos; /* Number of pads completed so far */
uint64_t pad_pos; /* Number of samples through the current pad */
} priv_t;
static int parse(sox_effect_t * effp, char * * argv, sox_rate_t rate)
{
priv_t * p = (priv_t *)effp->priv;
char const * next;
unsigned i;
uint64_t last_seen = 0;
const uint64_t in_length = argv ? 0 :
(effp->in_signal.length != SOX_UNKNOWN_LEN ?
effp->in_signal.length / effp->in_signal.channels : SOX_UNKNOWN_LEN);
for (i = 0; i < p->npads; ++i) {
if (argv) /* 1st parse only */
p->pads[i].str = lsx_strdup(argv[i]);
next = lsx_parsesamples(rate, p->pads[i].str, &p->pads[i].pad, 't');
if (next == NULL) break;
if (*next == '\0')
p->pads[i].start = i? UINT64_MAX : 0;
else {
if (*next != '@') break;
next = lsx_parseposition(rate, next+1, argv ? NULL : &p->pads[i].start,
last_seen, in_length, '=');
if (next == NULL || *next != '\0') break;
last_seen = p->pads[i].start;
if (p->pads[i].start == SOX_UNKNOWN_LEN)
p->pads[i].start = UINT64_MAX; /* currently the same value, but ... */
}
if (!argv) {
/* Do this check only during the second pass when the actual
sample rate is known, otherwise it might fail on legal
commands like
pad 1@0.5 1@30000s
if the rate is, e.g., 48k. */
if (i > 0 && p->pads[i].start <= p->pads[i-1].start) break;
}
}
if (i < p->npads)
return lsx_usage(effp);
return SOX_SUCCESS;
}
static int create(sox_effect_t * effp, int argc, char * * argv)
{
priv_t * p = (priv_t *)effp->priv;
--argc, ++argv;
p->npads = argc;
p->pads = lsx_calloc(p->npads, sizeof(*p->pads));
return parse(effp, argv, 1e5); /* No rate yet; parse with dummy */
}
static int start(sox_effect_t * effp)
{
priv_t * p = (priv_t *)effp->priv;
unsigned i;
/* Re-parse now rate is known */
if (parse(effp, 0, effp->in_signal.rate) != SOX_SUCCESS)
return SOX_EOF;
if ((effp->out_signal.length = effp->in_signal.length) != SOX_UNKNOWN_LEN) {
for (i = 0; i < p->npads; ++i)
effp->out_signal.length +=
p->pads[i].pad * effp->in_signal.channels;
/* Check that the last pad position (except for "at the end")
is within bounds. */
i = p->npads;
if (i > 0 && p->pads[i-1].start == UINT64_MAX)
i--;
if (i > 0 &&
p->pads[i-1].start * effp->in_signal.channels
> effp->in_signal.length)
{
lsx_fail("pad position after end of audio");
return SOX_EOF;
}
}
p->in_pos = p->pad_pos = p->pads_pos = 0;
for (i = 0; i < p->npads; ++i)
if (p->pads[i].pad)
return SOX_SUCCESS;
return SOX_EFF_NULL;
}
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 c, idone = 0, odone = 0;
*isamp /= effp->in_signal.channels;
*osamp /= effp->in_signal.channels;
do {
/* Copying: */
for (; idone < *isamp && odone < *osamp && !(p->pads_pos != p->npads && p->in_pos == p->pads[p->pads_pos].start); ++idone, ++odone, ++p->in_pos)
for (c = 0; c < effp->in_signal.channels; ++c) *obuf++ = *ibuf++;
/* Padding: */
if (p->pads_pos != p->npads && p->in_pos == p->pads[p->pads_pos].start) {
for (; odone < *osamp && p->pad_pos < p->pads[p->pads_pos].pad; ++odone, ++p->pad_pos)
for (c = 0; c < effp->in_signal.channels; ++c) *obuf++ = 0;
if (p->pad_pos == p->pads[p->pads_pos].pad) { /* Move to next pad? */
++p->pads_pos;
p->pad_pos = 0;
}
}
} while (idone < *isamp && odone < *osamp);
*isamp = idone * effp->in_signal.channels;
*osamp = odone * effp->in_signal.channels;
return SOX_SUCCESS;
}
static int drain(sox_effect_t * effp, sox_sample_t * obuf, size_t * osamp)
{
priv_t * p = (priv_t *)effp->priv;
static size_t isamp = 0;
if (p->pads_pos != p->npads && p->in_pos != p->pads[p->pads_pos].start)
p->in_pos = UINT64_MAX; /* Invoke the final pad (with no given start) */
return flow(effp, 0, obuf, &isamp, osamp);
}
static int stop(sox_effect_t * effp)
{
priv_t * p = (priv_t *)effp->priv;
if (p->pads_pos != p->npads)
lsx_warn("Input audio too short; pads not applied: %u", p->npads-p->pads_pos);
return SOX_SUCCESS;
}
static int lsx_kill(sox_effect_t * effp)
{
priv_t * p = (priv_t *)effp->priv;
unsigned i;
for (i = 0; i < p->npads; ++i)
free(p->pads[i].str);
free(p->pads);
return SOX_SUCCESS;
}
sox_effect_handler_t const * lsx_pad_effect_fn(void)
{
static sox_effect_handler_t handler = {
"pad", "{length[@position]}", SOX_EFF_MCHAN|SOX_EFF_LENGTH|SOX_EFF_MODIFY,
create, start, flow, drain, stop, lsx_kill, sizeof(priv_t)
};
return &handler;
}