mirror of
https://gitlab.freedesktop.org/gstreamer/gstreamer.git
synced 2024-11-27 20:21:24 +00:00
152 lines
3.6 KiB
C
152 lines
3.6 KiB
C
/* GStreamer
|
|
* Copyright (C) 2009 Tiago Katcipis <tiagokatcipis@gmail.com>
|
|
* Copyright (C) 2009 Paulo Pizarro <paulo.pizarro@gmail.com>
|
|
* Copyright (C) 2009 Rogério Santos <rogerio.santos@digitro.com.br>
|
|
*
|
|
* This library is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU Library General Public
|
|
* License as published by the Free Software Foundation; either
|
|
* version 2 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
|
|
* Library General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Library General Public
|
|
* License along with this library; if not, write to the
|
|
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
|
|
* Boston, MA 02110-1301, USA.
|
|
*/
|
|
|
|
#include <string.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <glib.h>
|
|
#include "vad_private.h"
|
|
|
|
#define VAD_POWER_ALPHA 0x0800 /* Q16 */
|
|
#define VAD_POWER_THRESHOLD 0x000010C7 /* -60 dB (square wave) */
|
|
#define VAD_ZCR_THRESHOLD 0
|
|
#define VAD_BUFFER_SIZE 256
|
|
|
|
|
|
union pgen
|
|
{
|
|
guint64 a;
|
|
gpointer v;
|
|
guint64 *l;
|
|
guchar *b;
|
|
guint16 *w;
|
|
gint16 *s;
|
|
};
|
|
|
|
struct _cqueue_s
|
|
{
|
|
union pgen base;
|
|
union pgen tail;
|
|
union pgen head;
|
|
gint size;
|
|
};
|
|
|
|
typedef struct _cqueue_s cqueue_t;
|
|
|
|
struct _vad_s
|
|
{
|
|
gint16 vad_buffer[VAD_BUFFER_SIZE];
|
|
cqueue_t cqueue;
|
|
gint vad_state;
|
|
guint64 hysteresis;
|
|
guint64 vad_samples;
|
|
guint64 vad_power;
|
|
long vad_zcr;
|
|
};
|
|
|
|
VADFilter *
|
|
vad_new (guint64 hysteresis)
|
|
{
|
|
VADFilter *vad = malloc (sizeof (VADFilter));
|
|
vad_reset (vad);
|
|
vad->hysteresis = hysteresis;
|
|
return vad;
|
|
}
|
|
|
|
void
|
|
vad_reset (VADFilter * vad)
|
|
{
|
|
memset (vad, 0, sizeof (*vad));
|
|
vad->cqueue.base.s = vad->vad_buffer;
|
|
vad->cqueue.tail.a = vad->cqueue.head.a = 0;
|
|
vad->cqueue.size = VAD_BUFFER_SIZE;
|
|
vad->vad_state = VAD_SILENCE;
|
|
}
|
|
|
|
void
|
|
vad_destroy (VADFilter * p)
|
|
{
|
|
free (p);
|
|
}
|
|
|
|
void
|
|
vad_set_hysteresis (struct _vad_s *p, guint64 hysteresis)
|
|
{
|
|
p->hysteresis = hysteresis;
|
|
}
|
|
|
|
guint64
|
|
vad_get_hysteresis (struct _vad_s *p)
|
|
{
|
|
return p->hysteresis;
|
|
}
|
|
|
|
gint
|
|
vad_update (struct _vad_s * p, gint16 * data, gint len)
|
|
{
|
|
guint64 tail;
|
|
gint frame_type;
|
|
gint16 sample;
|
|
gint i;
|
|
|
|
for (i = 0; i < len; i++) {
|
|
p->vad_power = VAD_POWER_ALPHA * ((data[i] * data[i] >> 14) & 0xFFFF) +
|
|
(0xFFFF - VAD_POWER_ALPHA) * (p->vad_power >> 16) +
|
|
((0xFFFF - VAD_POWER_ALPHA) * (p->vad_power & 0xFFFF) >> 16);
|
|
/* Update VAD buffer */
|
|
p->cqueue.base.s[p->cqueue.head.a] = data[i];
|
|
p->cqueue.head.a = (p->cqueue.head.a + 1) & (p->cqueue.size - 1);
|
|
if (p->cqueue.head.a == p->cqueue.tail.a)
|
|
p->cqueue.tail.a = (p->cqueue.tail.a + 1) & (p->cqueue.size - 1);
|
|
}
|
|
|
|
tail = p->cqueue.tail.a;
|
|
p->vad_zcr = 0;
|
|
for (;;) {
|
|
sample = p->cqueue.base.s[tail];
|
|
tail = (tail + 1) & (p->cqueue.size - 1);
|
|
if (tail == p->cqueue.head.a)
|
|
break;
|
|
p->vad_zcr +=
|
|
((sample & 0x8000) != (p->cqueue.base.s[tail] & 0x8000)) ? 1 : -1;
|
|
}
|
|
|
|
frame_type = (p->vad_power > VAD_POWER_THRESHOLD
|
|
&& p->vad_zcr < VAD_ZCR_THRESHOLD) ? VAD_VOICE : VAD_SILENCE;
|
|
|
|
if (p->vad_state != frame_type) {
|
|
/* Voice to silence transition */
|
|
if (p->vad_state == VAD_VOICE) {
|
|
p->vad_samples += len;
|
|
if (p->vad_samples >= p->hysteresis) {
|
|
p->vad_state = frame_type;
|
|
p->vad_samples = 0;
|
|
}
|
|
} else {
|
|
p->vad_state = frame_type;
|
|
p->vad_samples = 0;
|
|
}
|
|
} else {
|
|
p->vad_samples = 0;
|
|
}
|
|
|
|
return p->vad_state;
|
|
}
|