Commit 5fbac0f5 authored by Sebastian Dröge's avatar Sebastian Dröge 🍵
Browse files

gst/filter/gstbpwsinc.*: Add support for a bandreject mode and allow...

gst/filter/gstbpwsinc.*: Add support for a bandreject mode and allow specifying the window function that should be used.

Original commit message from CVS:
* gst/filter/gstbpwsinc.c: (gst_bpwsinc_mode_get_type),
(gst_bpwsinc_window_get_type), (gst_bpwsinc_class_init),
(gst_bpwsinc_init), (bpwsinc_build_kernel), (bpwsinc_set_property),
(bpwsinc_get_property):
* gst/filter/gstbpwsinc.h:
Add support for a bandreject mode and allow specifying the window
function that should be used.
* gst/filter/gstlpwsinc.c:
And another small formatting fix.
parent 86dab97c
......@@ -29,8 +29,8 @@
* TODO: - Implement the convolution in place, probably only makes sense
* when using FFT convolution as currently the convolution itself
* is probably the bottleneck
* - Implement a band reject mode (spectral inversion)
* - Allow choosing between different windows (blackman, hanning, ...)
* - Maybe allow cascading the filter to get a better stopband attenuation.
* Can be done by convolving a filter kernel with itself
*/
#ifdef HAVE_CONFIG_H
......@@ -69,9 +69,63 @@ enum
PROP_0,
PROP_LENGTH,
PROP_LOWER_FREQUENCY,
PROP_UPPER_FREQUENCY
PROP_UPPER_FREQUENCY,
PROP_MODE,
PROP_WINDOW
};
enum
{
MODE_BAND_PASS = 0,
MODE_BAND_REJECT
};
#define GST_TYPE_BPWSINC_MODE (gst_bpwsinc_mode_get_type ())
static GType
gst_bpwsinc_mode_get_type (void)
{
static GType gtype = 0;
if (gtype == 0) {
static const GEnumValue values[] = {
{MODE_BAND_PASS, "Band pass (default)",
"band-pass"},
{MODE_BAND_REJECT, "Band reject",
"band-reject"},
{0, NULL, NULL}
};
gtype = g_enum_register_static ("GstBPWSincMode", values);
}
return gtype;
}
enum
{
WINDOW_HAMMING = 0,
WINDOW_BLACKMAN
};
#define GST_TYPE_BPWSINC_WINDOW (gst_bpwsinc_window_get_type ())
static GType
gst_bpwsinc_window_get_type (void)
{
static GType gtype = 0;
if (gtype == 0) {
static const GEnumValue values[] = {
{WINDOW_HAMMING, "Hamming window (default)",
"hamming"},
{WINDOW_BLACKMAN, "Blackman window",
"blackman"},
{0, NULL, NULL}
};
gtype = g_enum_register_static ("GstBPWSincWindow", values);
}
return gtype;
}
#define ALLOWED_CAPS \
"audio/x-raw-float, " \
" width = (int) { 32, 64 }, " \
......@@ -157,6 +211,16 @@ gst_bpwsinc_class_init (GstBPWSincClass * klass)
"Filter kernel length, will be rounded to the next odd number",
3, G_MAXINT, 101, G_PARAM_READWRITE));
g_object_class_install_property (gobject_class, PROP_MODE,
g_param_spec_enum ("mode", "Mode",
"Band pass or band reject mode", GST_TYPE_BPWSINC_MODE,
MODE_BAND_PASS, G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE));
g_object_class_install_property (gobject_class, PROP_WINDOW,
g_param_spec_enum ("window", "Window",
"Window function to use", GST_TYPE_BPWSINC_WINDOW,
WINDOW_HAMMING, G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE));
trans_class->transform = GST_DEBUG_FUNCPTR (bpwsinc_transform);
trans_class->get_unit_size = GST_DEBUG_FUNCPTR (bpwsinc_get_unit_size);
GST_AUDIO_FILTER_CLASS (klass)->setup = GST_DEBUG_FUNCPTR (bpwsinc_setup);
......@@ -168,6 +232,8 @@ gst_bpwsinc_init (GstBPWSinc * self, GstBPWSincClass * g_class)
self->kernel_length = 101;
self->lower_frequency = 0.0;
self->upper_frequency = 0.0;
self->mode = MODE_BAND_PASS;
self->window = WINDOW_HAMMING;
self->kernel = NULL;
self->have_kernel = FALSE;
self->residue = NULL;
......@@ -273,9 +339,13 @@ bpwsinc_build_kernel (GstBPWSinc * self)
else
kernel_lp[i] = sin (w * (i - len / 2))
/ (i - len / 2);
/* Blackman windowing */
kernel_lp[i] *= (0.42 - 0.5 * cos (2 * M_PI * i / len)
+ 0.08 * cos (4 * M_PI * i / len));
/* Windowing */
if (self->window == WINDOW_HAMMING)
kernel_lp[i] *= (0.54 - 0.46 * cos (2 * M_PI * i / len));
else
kernel_lp[i] *=
(0.42 - 0.5 * cos (2 * M_PI * i / len) +
0.08 * cos (4 * M_PI * i / len));
}
/* normalize for unity gain at DC */
......@@ -297,9 +367,13 @@ bpwsinc_build_kernel (GstBPWSinc * self)
else
kernel_hp[i] = sin (w * (i - len / 2))
/ (i - len / 2);
/* Blackman windowing */
kernel_hp[i] *= (0.42 - 0.5 * cos (2 * M_PI * i / len)
+ 0.08 * cos (4 * M_PI * i / len));
/* Windowing */
if (self->window == WINDOW_HAMMING)
kernel_hp[i] *= (0.54 - 0.46 * cos (2 * M_PI * i / len));
else
kernel_hp[i] *=
(0.42 - 0.5 * cos (2 * M_PI * i / len) +
0.08 * cos (4 * M_PI * i / len));
}
/* normalize for unity gain at DC */
......@@ -326,10 +400,13 @@ bpwsinc_build_kernel (GstBPWSinc * self)
g_free (kernel_lp);
g_free (kernel_hp);
/* do spectral inversion to go from bandreject to bandpass */
for (i = 0; i < len; ++i)
self->kernel[i] = -self->kernel[i];
self->kernel[len / 2] += 1;
/* do spectral inversion to go from bandreject to bandpass
* if specified */
if (self->mode == MODE_BAND_PASS) {
for (i = 0; i < len; ++i)
self->kernel[i] = -self->kernel[i];
self->kernel[len / 2] += 1;
}
/* set up the residue memory space */
if (self->residue)
......@@ -441,6 +518,18 @@ bpwsinc_set_property (GObject * object, guint prop_id, const GValue * value,
bpwsinc_build_kernel (self);
GST_BASE_TRANSFORM_UNLOCK (self);
break;
case PROP_MODE:
GST_BASE_TRANSFORM_LOCK (self);
self->mode = g_value_get_enum (value);
bpwsinc_build_kernel (self);
GST_BASE_TRANSFORM_UNLOCK (self);
break;
case PROP_WINDOW:
GST_BASE_TRANSFORM_LOCK (self);
self->window = g_value_get_enum (value);
bpwsinc_build_kernel (self);
GST_BASE_TRANSFORM_UNLOCK (self);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
......@@ -463,6 +552,12 @@ bpwsinc_get_property (GObject * object, guint prop_id, GValue * value,
case PROP_UPPER_FREQUENCY:
g_value_set_double (value, self->upper_frequency);
break;
case PROP_MODE:
g_value_set_enum (value, self->mode);
break;
case PROP_WINDOW:
g_value_set_enum (value, self->window);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
......
......@@ -62,7 +62,8 @@ struct _GstBPWSinc {
GstBPWSincProcessFunc process;
gdouble frequency;
gint mode;
gint window;
gdouble lower_frequency, upper_frequency;
gint kernel_length; /* length of the filter kernel */
......
......@@ -28,7 +28,7 @@
*
* TODO: - Implement the convolution in place, probably only makes sense
* when using FFT convolution as currently the convolution itself
* is probably the bottleneck.
* is probably the bottleneck
* - Maybe allow cascading the filter to get a better stopband attenuation.
* Can be done by convolving a filter kernel with itself.
*/
......@@ -124,7 +124,6 @@ gst_lpwsinc_window_get_type (void)
return gtype;
}
#define ALLOWED_CAPS \
"audio/x-raw-float, " \
" width = (int) { 32, 64 }, " \
......
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