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gst/filter/gstlpwsinc.*: Specify the actual filter length instead of a weird 2N+1. Setting the property will round to...
Original commit message from CVS: * gst/filter/gstlpwsinc.c: (gst_lpwsinc_class_init), (gst_lpwsinc_init), (process_32), (process_64), (lpwsinc_build_kernel), (lpwsinc_set_property), (lpwsinc_get_property): * gst/filter/gstlpwsinc.h: Specify the actual filter length instead of a weird 2N+1. Setting the property will round to the next odd number. Also remove now obsolete FIXMEs.
This commit is contained in:
Sebastian Dröge
parent
982bf23b35
commit
11131b7a44
3 changed files with 40 additions and 28 deletions
11
ChangeLog
11
ChangeLog
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@ -1,3 +1,14 @@
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2007-08-10 Sebastian Dröge <slomo@circular-chaos.org>
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* gst/filter/gstlpwsinc.c: (gst_lpwsinc_class_init),
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(gst_lpwsinc_init), (process_32), (process_64),
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(lpwsinc_build_kernel), (lpwsinc_set_property),
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(lpwsinc_get_property):
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* gst/filter/gstlpwsinc.h:
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Specify the actual filter length instead of a weird
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2N+1. Setting the property will round to the next odd number.
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Also remove now obsolete FIXMEs.
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2007-08-10 Sebastian Dröge <slomo@circular-chaos.org>
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* gst/filter/gstlpwsinc.c: (gst_lpwsinc_window_get_type),
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@ -204,8 +204,8 @@ gst_lpwsinc_class_init (GstLPWSincClass * klass)
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g_object_class_install_property (gobject_class, PROP_LENGTH,
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g_param_spec_int ("length", "Length",
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"N such that the filter length = 2N + 1",
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1, G_MAXINT, 1, G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE));
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"Filter kernel length, will be rounded to the next odd number",
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3, G_MAXINT, 101, G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE));
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g_object_class_install_property (gobject_class, PROP_MODE,
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g_param_spec_enum ("mode", "Mode",
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@ -227,7 +227,7 @@ gst_lpwsinc_init (GstLPWSinc * self, GstLPWSincClass * g_class)
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{
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self->mode = MODE_LOW_PASS;
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self->window = WINDOW_HAMMING;
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self->wing_size = 50;
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self->kernel_length = 101;
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self->frequency = 0.0;
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self->kernel = NULL;
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self->residue = NULL;
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@ -238,7 +238,7 @@ gst_lpwsinc_init (GstLPWSinc * self, GstLPWSincClass * g_class)
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static void
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process_32 (GstLPWSinc * self, gfloat * src, gfloat * dst, guint input_samples)
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{
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gint kernel_length = self->wing_size * 2 + 1;
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gint kernel_length = self->kernel_length;
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gint i, j, k, l;
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gint channels = GST_AUDIO_FILTER (self)->format.channels;
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@ -265,7 +265,7 @@ static void
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process_64 (GstLPWSinc * self, gdouble * src, gdouble * dst,
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guint input_samples)
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{
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gint kernel_length = self->wing_size * 2 + 1;
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gint kernel_length = self->kernel_length;
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gint i, j, k, l;
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gint channels = GST_AUDIO_FILTER (self)->format.channels;
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@ -297,8 +297,8 @@ lpwsinc_build_kernel (GstLPWSinc * self)
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gdouble w;
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/* fill the kernel */
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len = self->wing_size;
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GST_DEBUG ("lpwsinc: initializing filter kernel of length %d", len * 2 + 1);
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len = self->kernel_length;
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GST_DEBUG ("lpwsinc: initializing filter kernel of length %d", len);
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if (GST_AUDIO_FILTER (self)->format.rate == 0) {
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GST_DEBUG ("rate not set yet");
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@ -318,40 +318,40 @@ lpwsinc_build_kernel (GstLPWSinc * self)
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if (self->kernel)
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g_free (self->kernel);
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self->kernel = g_new (gdouble, 2 * len + 1);
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self->kernel = g_new (gdouble, len);
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for (i = 0; i <= len * 2; ++i) {
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if (i == len)
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for (i = 0; i < len; ++i) {
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if (i == len / 2)
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self->kernel[i] = w;
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else
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self->kernel[i] = sin (w * (i - len)) / (i - len);
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self->kernel[i] = sin (w * (i - len / 2)) / (i - len / 2);
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/* windowing */
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if (self->window == WINDOW_HAMMING)
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self->kernel[i] *= (0.54 - 0.46 * cos (M_PI * i / len));
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self->kernel[i] *= (0.54 - 0.46 * cos (2 * M_PI * i / len));
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else
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self->kernel[i] *=
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(0.42 - 0.5 * cos (M_PI * i / len) + 0.08 * cos (2 * M_PI * i / len));
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(0.42 - 0.5 * cos (2 * M_PI * i / len) +
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0.08 * cos (4 * M_PI * i / len));
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}
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/* normalize for unity gain at DC */
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for (i = 0; i <= len * 2; ++i)
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for (i = 0; i < len; ++i)
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sum += self->kernel[i];
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for (i = 0; i <= len * 2; ++i)
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for (i = 0; i < len; ++i)
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self->kernel[i] /= sum;
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/* convert to highpass if specified */
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if (self->mode == MODE_HIGH_PASS) {
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for (i = 0; i <= len * 2; ++i)
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for (i = 0; i < len; ++i)
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self->kernel[i] = -self->kernel[i];
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self->kernel[len] += 1.0;
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self->kernel[len / 2] += 1.0;
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}
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/* set up the residue memory space */
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if (self->residue)
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g_free (self->residue);
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self->residue =
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g_new0 (gdouble,
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(len * 2 + 1) * GST_AUDIO_FILTER (self)->format.channels);
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g_new0 (gdouble, len * GST_AUDIO_FILTER (self)->format.channels);
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self->have_kernel = TRUE;
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}
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@ -434,12 +434,18 @@ lpwsinc_set_property (GObject * object, guint prop_id, const GValue * value,
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g_return_if_fail (GST_IS_LPWSINC (self));
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switch (prop_id) {
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case PROP_LENGTH:
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case PROP_LENGTH:{
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gint val;
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GST_BASE_TRANSFORM_LOCK (self);
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self->wing_size = g_value_get_int (value);
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val = g_value_get_int (value);
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if (val % 2 == 0)
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val++;
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self->kernel_length = val;
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lpwsinc_build_kernel (self);
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GST_BASE_TRANSFORM_UNLOCK (self);
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break;
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}
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case PROP_FREQUENCY:
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GST_BASE_TRANSFORM_LOCK (self);
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self->frequency = g_value_get_double (value);
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@ -472,7 +478,7 @@ lpwsinc_get_property (GObject * object, guint prop_id, GValue * value,
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switch (prop_id) {
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case PROP_LENGTH:
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g_value_set_int (value, self->wing_size);
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g_value_set_int (value, self->kernel_length);
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break;
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case PROP_FREQUENCY:
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g_value_set_double (value, self->frequency);
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@ -25,10 +25,6 @@
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* chapter 16
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* available at http://www.dspguide.com/
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*
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* FIXME:
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* - this filter is totally unoptimized !
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* - we do not destroy the allocated memory for filters and residue
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* - this might be improved upon with bytestream
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*/
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#ifndef __GST_LPWSINC_H__
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@ -69,8 +65,7 @@ struct _GstLPWSinc {
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gint mode;
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gint window;
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gdouble frequency;
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gint wing_size; /* length of a "wing" of the filter;
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actual length is 2 * wing_size + 1 */
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gint kernel_length; /* length of the filter kernel */
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gdouble *residue; /* buffer for left-over samples from previous buffer */
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gdouble *kernel; /* filter kernel */
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