Commit de3d1d62 authored by Sebastian Dröge's avatar Sebastian Dröge 🍵
Browse files

gst/filter/gstlpwsinc.*: Add double support, replace "this" with "self" as the...

gst/filter/gstlpwsinc.*: Add double support, replace "this" with "self" as the former is a C++ keyword.

Original commit message from CVS:
* gst/filter/gstlpwsinc.c: (gst_lpwsinc_dispose),
(gst_lpwsinc_class_init), (gst_lpwsinc_init), (process_32),
(process_64), (lpwsinc_build_kernel), (lpwsinc_setup),
(lpwsinc_get_unit_size), (lpwsinc_transform),
(lpwsinc_set_property), (lpwsinc_get_property):
* gst/filter/gstlpwsinc.h:
Add double support, replace "this" with "self" as the former
is a C++ keyword.
Implement the frequency property in Hz instead of fraction
of sampling frequency.
Remove some unecessary FIXMEs and add some TODOs, add some
required locking and refactor the kernel generation into a
separate function that is also called when the properties
change now.
And use BaseTransform::transform instead of transform_ip
as the convolution is done out of place anyway. Should
be done in place later.
parent 488e0e23
......@@ -3,6 +3,7 @@
* 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
......@@ -25,9 +26,9 @@
* 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
......@@ -51,7 +52,8 @@ GST_ELEMENT_DETAILS ("Low-pass Windowed sinc filter",
"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
......@@ -69,7 +71,7 @@ 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 ]"
......@@ -85,8 +87,10 @@ static void lpwsinc_set_property (GObject * object, guint prop_id,
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);
......@@ -95,16 +99,16 @@ static gboolean lpwsinc_setup (GstAudioFilter * base,
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);
......@@ -139,90 +143,172 @@ gst_lpwsinc_class_init (GstLPWSincClass * klass)
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))
......@@ -230,42 +316,14 @@ lpwsinc_transform_ip (GstBaseTransform * base, GstBuffer * outbuf)
/* 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;
}
......@@ -274,16 +332,22 @@ static void
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);
......@@ -295,14 +359,14 @@ static void
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);
......
......@@ -54,6 +54,8 @@ G_BEGIN_DECLS
typedef struct _GstLPWSinc GstLPWSinc;
typedef struct _GstLPWSincClass GstLPWSincClass;
typedef void (*GstLPWSincProcessFunc) (GstLPWSinc *, guint8 *, guint8 *, guint);
/**
* GstLPWSinc:
*
......@@ -62,14 +64,15 @@ typedef struct _GstLPWSincClass GstLPWSincClass;
struct _GstLPWSinc {
GstAudioFilter element;
void (*process)(GstLPWSinc*, gpointer, gint);
GstLPWSincProcessFunc process;
double frequency;
int wing_size; /* length of a "wing" of the filter;
gdouble frequency;
gint wing_size; /* length of a "wing" of the filter;
actual length is 2 * wing_size + 1 */
gfloat *residue; /* buffer for left-over samples from previous buffer */
double *kernel;
gdouble *residue; /* buffer for left-over samples from previous buffer */
gdouble *kernel; /* filter kernel */
gboolean have_kernel;
};
struct _GstLPWSincClass {
......
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