* GStreamer
* Copyright (C) 1999-2001 Erik Walthinsen <omega@cse.ogi.edu>
* 2006 Dreamlab Technologies Ltd. <mathis.hofer@dreamlab.net>
+ * 2007 Sebastian Dröge <slomo@circular-chaos.org>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* chapter 16
* available at http://www.dspguide.com/
*
- * FIXME:
- * - this filter is totally unoptimized !
- * - this might be improved upon with bytestream
+ * TODO: - Implement the convolution in place
+ * - Implement a highpass mode (spectral inversion)
+ * - Allow choosing between different windows (blackman, hanning, ...)
*/
#ifdef HAVE_CONFIG_H
"Low-pass Windowed sinc filter",
"Thomas <thomas@apestaart.org>, "
"Steven W. Smith, "
- "Dreamlab Technologies Ltd. <mathis.hofer@dreamlab.net>");
+ "Dreamlab Technologies Ltd. <mathis.hofer@dreamlab.net>, "
+ "Sebastian Dröge <slomo@circular-chaos.org>");
/* Filter signals and args */
enum
#define ALLOWED_CAPS \
"audio/x-raw-float," \
- " width = (int) 32, " \
+ " width = (int) { 32, 64 }, " \
" endianness = (int) BYTE_ORDER," \
" rate = (int) [ 1, MAX ]," \
" channels = (int) [ 1, MAX ]"
static void lpwsinc_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec);
-static GstFlowReturn lpwsinc_transform_ip (GstBaseTransform * base,
- GstBuffer * outbuf);
+static GstFlowReturn lpwsinc_transform (GstBaseTransform * base,
+ GstBuffer * inbuf, GstBuffer * outbuf);
+static gboolean lpwsinc_get_unit_size (GstBaseTransform * base, GstCaps * caps,
+ guint * size);
static gboolean lpwsinc_setup (GstAudioFilter * base,
GstRingBufferSpec * format);
static void
gst_lpwsinc_dispose (GObject * object)
{
- GstLPWSinc *this = GST_LPWSINC (object);
+ GstLPWSinc *self = GST_LPWSINC (object);
- if (this->residue) {
- g_free (this->residue);
- this->residue = NULL;
+ if (self->residue) {
+ g_free (self->residue);
+ self->residue = NULL;
}
- if (this->kernel) {
- g_free (this->kernel);
- this->kernel = NULL;
+ if (self->kernel) {
+ g_free (self->kernel);
+ self->kernel = NULL;
}
G_OBJECT_CLASS (parent_class)->dispose (object);
g_object_class_install_property (gobject_class, PROP_FREQUENCY,
g_param_spec_double ("frequency", "Frequency",
- "Cut-off Frequency relative to sample rate",
- 0.0, 0.5, 0, G_PARAM_READWRITE));
+ "Cut-off Frequency", 0.0, G_MAXDOUBLE, 0.0, G_PARAM_READWRITE));
g_object_class_install_property (gobject_class, PROP_LENGTH,
g_param_spec_int ("length", "Length",
"N such that the filter length = 2N + 1",
1, G_MAXINT, 1, G_PARAM_READWRITE));
- trans_class->transform_ip = GST_DEBUG_FUNCPTR (lpwsinc_transform_ip);
+ trans_class->transform = GST_DEBUG_FUNCPTR (lpwsinc_transform);
+ trans_class->get_unit_size = GST_DEBUG_FUNCPTR (lpwsinc_get_unit_size);
GST_AUDIO_FILTER_CLASS (klass)->setup = GST_DEBUG_FUNCPTR (lpwsinc_setup);
}
static void
-gst_lpwsinc_init (GstLPWSinc * this, GstLPWSincClass * g_class)
+gst_lpwsinc_init (GstLPWSinc * self, GstLPWSincClass * g_class)
{
- this->wing_size = 50;
- this->frequency = 0.25;
- this->kernel = NULL;
- this->residue = NULL;
+ self->wing_size = 50;
+ self->frequency = 0.0;
+ self->kernel = NULL;
+ self->residue = NULL;
+
+ self->have_kernel = FALSE;
}
+static void
+process_32 (GstLPWSinc * self, gfloat * src, gfloat * dst, guint input_samples)
+{
+ gint kernel_length = self->wing_size * 2 + 1;;
+ gint i, j;
-/* GstAudioFilter vmethod implementations */
+ /* convolution */
+ for (i = 0; i < input_samples; ++i) {
+ dst[i] = 0.0;
+ for (j = 0; j < kernel_length; ++j)
+ if (i < j)
+ dst[i] += self->residue[kernel_length + i - j] * self->kernel[j];
+ else
+ dst[i] += src[i - j] * self->kernel[j];
+ }
-/* get notified of caps and plug in the correct process function */
-static gboolean
-lpwsinc_setup (GstAudioFilter * base, GstRingBufferSpec * format)
+ /* copy the tail of the current input buffer to the residue */
+ for (i = 0; i < kernel_length; i++)
+ self->residue[i] = src[input_samples - kernel_length + i];
+}
+
+static void
+process_64 (GstLPWSinc * self, gdouble * src, gdouble * dst,
+ guint input_samples)
+{
+ gint kernel_length = self->wing_size * 2 + 1;;
+ gint i, j;
+
+ /* convolution */
+ for (i = 0; i < input_samples; ++i) {
+ dst[i] = 0.0;
+ for (j = 0; j < kernel_length; ++j)
+ if (i < j)
+ dst[i] += self->residue[kernel_length + i - j] * self->kernel[j];
+ else
+ dst[i] += src[i - j] * self->kernel[j];
+ }
+
+ /* copy the tail of the current input buffer to the residue */
+ for (i = 0; i < kernel_length; i++)
+ self->residue[i] = src[input_samples - kernel_length + i];
+}
+
+static void
+lpwsinc_build_kernel (GstLPWSinc * self)
{
- int i = 0;
- double sum = 0.0;
- int len = 0;
- GstLPWSinc *this = GST_LPWSINC (base);
+ gint i = 0;
+ gdouble sum = 0.0;
+ gint len = 0;
+ gdouble w;
- /* FIXME: remember to free it */
/* fill the kernel */
- g_print ("DEBUG: initing filter kernel\n");
- len = this->wing_size;
+ len = self->wing_size;
GST_DEBUG ("lpwsinc: initializing filter kernel of length %d", len * 2 + 1);
- if (this->kernel)
- g_free (this->kernel);
- this->kernel = (double *) g_malloc (sizeof (double) * (2 * len + 1));
+ if (GST_AUDIO_FILTER (self)->format.rate == 0) {
+ GST_DEBUG ("rate not set yet");
+ return;
+ }
+
+ /* Clamp cutoff frequency between 0 and the nyquist frequency */
+ self->frequency =
+ CLAMP (self->frequency, 0.0, GST_AUDIO_FILTER (self)->format.rate / 2);
+
+ w = 2 * M_PI * (self->frequency / GST_AUDIO_FILTER (self)->format.rate);
+
+ if (self->kernel)
+ g_free (self->kernel);
+ self->kernel = g_new (gdouble, 2 * len + 1);
for (i = 0; i <= len * 2; ++i) {
if (i == len)
- this->kernel[i] = 2 * M_PI * this->frequency;
+ self->kernel[i] = w;
else
- this->kernel[i] =
- sin (2 * M_PI * this->frequency * (i - len)) / (i - len);
+ self->kernel[i] = sin (w * (i - len)) / (i - len);
/* windowing */
- this->kernel[i] *= (0.54 - 0.46 * cos (M_PI * i / len));
+ self->kernel[i] *= (0.54 - 0.46 * cos (M_PI * i / len));
}
- /* normalize for unity gain at DC
- * FIXME: sure this is not supposed to be quadratic ? */
+ /* normalize for unity gain at DC */
for (i = 0; i <= len * 2; ++i)
- sum += this->kernel[i];
+ sum += self->kernel[i];
for (i = 0; i <= len * 2; ++i)
- this->kernel[i] /= sum;
+ self->kernel[i] /= sum;
/* set up the residue memory space */
- if (this->residue)
- g_free (this->residue);
- this->residue = (gfloat *) g_malloc (sizeof (gfloat) * (len * 2 + 1));
- for (i = 0; i <= len * 2; ++i)
- this->residue[i] = 0.0;
+ if (self->residue)
+ g_free (self->residue);
+ self->residue = g_new0 (gdouble, len * 2 + 1);
+
+ self->have_kernel = TRUE;
+}
+
+/* GstAudioFilter vmethod implementations */
+
+/* get notified of caps and plug in the correct process function */
+static gboolean
+lpwsinc_setup (GstAudioFilter * base, GstRingBufferSpec * format)
+{
+ GstLPWSinc *self = GST_LPWSINC (base);
+
+ gboolean ret = TRUE;
+
+ if (format->width == 32)
+ self->process = (GstLPWSincProcessFunc) process_32;
+ else if (format->width == 64)
+ self->process = (GstLPWSincProcessFunc) process_64;
+ else
+ ret = FALSE;
+
+ self->have_kernel = FALSE;
return TRUE;
}
/* GstBaseTransform vmethod implementations */
+static gboolean
+lpwsinc_get_unit_size (GstBaseTransform * base, GstCaps * caps, guint * size)
+{
+ gint width, channels;
+ GstStructure *structure;
+ gboolean ret;
+
+ g_assert (size);
+
+ structure = gst_caps_get_structure (caps, 0);
+ ret = gst_structure_get_int (structure, "width", &width);
+ ret &= gst_structure_get_int (structure, "channels", &channels);
+
+ *size = width * channels / 8;
+
+ return ret;
+}
+
static GstFlowReturn
-lpwsinc_transform_ip (GstBaseTransform * base, GstBuffer * outbuf)
+lpwsinc_transform (GstBaseTransform * base, GstBuffer * inbuf,
+ GstBuffer * outbuf)
{
- GstLPWSinc *this = GST_LPWSINC (base);
+ GstLPWSinc *self = GST_LPWSINC (base);
GstClockTime timestamp;
-
- gfloat *src;
- gfloat *input;
- int residue_samples;
- gint input_samples;
- gint total_samples;
- int i, j;
+ gint input_samples =
+ GST_BUFFER_SIZE (outbuf) / (GST_AUDIO_FILTER (self)->format.width / 8);
/* don't process data in passthrough-mode */
if (gst_base_transform_is_passthrough (base))
/* FIXME: subdivide GST_BUFFER_SIZE into small chunks for smooth fades */
timestamp = GST_BUFFER_TIMESTAMP (outbuf);
-
if (GST_CLOCK_TIME_IS_VALID (timestamp))
- gst_object_sync_values (G_OBJECT (this), timestamp);
-
- /* FIXME: out of laziness, we copy the left-over bit from last buffer
- * together with the incoming buffer to a new buffer to make the loop
- * easy; this could be a lot more optimized though
- * to make amends we keep the incoming buffer around and write our
- * output samples there */
-
- src = (gfloat *) GST_BUFFER_DATA (outbuf);
- residue_samples = this->wing_size * 2 + 1;
- input_samples = GST_BUFFER_SIZE (outbuf) / sizeof (gfloat);
- total_samples = residue_samples + input_samples;
+ gst_object_sync_values (G_OBJECT (self), timestamp);
- input = (gfloat *) g_malloc (sizeof (gfloat) * total_samples);
-
- /* copy the left-over bit */
- memcpy (input, this->residue, sizeof (gfloat) * residue_samples);
-
- /* copy the new buffer */
- memcpy (&input[residue_samples], src, sizeof (gfloat) * input_samples);
- /* copy the tail of the current input buffer to the residue */
- memcpy (this->residue, &src[input_samples - residue_samples],
- sizeof (gfloat) * residue_samples);
-
- /* convolution */
- /* since we copied the previous set of samples we needed before the actual
- * input data, we need to add the filter length to our indices for input */
- for (i = 0; i < input_samples; ++i) {
- src[i] = 0.0;
- for (j = 0; j < residue_samples; ++j)
- src[i] += input[i - j + residue_samples] * this->kernel[j];
- }
+ if (!self->have_kernel)
+ lpwsinc_build_kernel (self);
- g_free (input);
+ self->process (self, GST_BUFFER_DATA (inbuf), GST_BUFFER_DATA (outbuf),
+ input_samples);
return GST_FLOW_OK;
}
lpwsinc_set_property (GObject * object, guint prop_id, const GValue * value,
GParamSpec * pspec)
{
- GstLPWSinc *this = GST_LPWSINC (object);
+ GstLPWSinc *self = GST_LPWSINC (object);
- g_return_if_fail (GST_IS_LPWSINC (this));
+ g_return_if_fail (GST_IS_LPWSINC (self));
switch (prop_id) {
case PROP_LENGTH:
- this->wing_size = g_value_get_int (value);
+ GST_BASE_TRANSFORM_LOCK (self);
+ self->wing_size = g_value_get_int (value);
+ lpwsinc_build_kernel (self);
+ GST_BASE_TRANSFORM_UNLOCK (self);
break;
case PROP_FREQUENCY:
- this->frequency = g_value_get_double (value);
+ GST_BASE_TRANSFORM_LOCK (self);
+ self->frequency = g_value_get_double (value);
+ lpwsinc_build_kernel (self);
+ GST_BASE_TRANSFORM_UNLOCK (self);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
lpwsinc_get_property (GObject * object, guint prop_id, GValue * value,
GParamSpec * pspec)
{
- GstLPWSinc *this = GST_LPWSINC (object);
+ GstLPWSinc *self = GST_LPWSINC (object);
switch (prop_id) {
case PROP_LENGTH:
- g_value_set_int (value, this->wing_size);
+ g_value_set_int (value, self->wing_size);
break;
case PROP_FREQUENCY:
- g_value_set_double (value, this->frequency);
+ g_value_set_double (value, self->frequency);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
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