/
manchestermod.c
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/
manchestermod.c
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/*
* Manchester modulator.
*
* Copyright Jeroen Vreeken (pe1rxq@amsat.org), 2005
*
* This software is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*/
#include "gstiq.h"
#include <string.h>
#include <math.h>
static GstElementDetails manchestermod_details = GST_ELEMENT_DETAILS(
"Manchester modulator plugin",
"Filter/Effect/Audio",
"Manchester modulator",
"Jeroen Vreeken (pe1rxq@amsat.org)"
);
static GstStaticPadTemplate sink_template = GST_STATIC_PAD_TEMPLATE(
"sink",
GST_PAD_SINK,
GST_PAD_ALWAYS,
GST_STATIC_CAPS(
"application/x-raw-float, "
"endianness = (int) BYTE_ORDER, "
"depth = (int) 32, "
"width = (int) 32, "
"rate = (int) [ 1, MAX ], "
"channels = (int) 1"
)
);
static GstStaticPadTemplate src_template = GST_STATIC_PAD_TEMPLATE(
"src",
GST_PAD_SRC,
GST_PAD_ALWAYS,
GST_STATIC_CAPS(
"audio/x-raw-float, "
"endianness = (int) BYTE_ORDER, "
"depth = (int) 32, "
"width = (int) 32, "
"rate = (int) [ 1, MAX ], "
"buffer-frames = (int) 0, "
"channels = (int) 1"
)
);
static GstElementClass *parent_class = NULL;
static GstFlowReturn gst_manchestermod_chain(GstPad *pad, GstBuffer *buf)
{
Gst_manchestermod *mod;
GstBuffer *outbuf;
GstCaps *caps;
gfloat *bufout, *bufin;
int i, j;
mod = GST_MANCHESTERMOD(gst_pad_get_parent(pad));
caps = gst_pad_get_caps(mod->srcpad);
if (!gst_caps_is_fixed(caps) || mod->symbollen < 0) {
GstStructure *structure;
gst_caps_unref(caps);
caps = gst_pad_get_allowed_caps(mod->srcpad);
structure = gst_caps_get_structure(caps, 0);
gst_structure_get_int(structure, "rate", &mod->rate);
mod->symbollen =
(float)mod->rate/(float)mod->symbolrate;
gst_pad_use_fixed_caps(mod->srcpad);
}
outbuf = gst_buffer_new_and_alloc(GST_BUFFER_SIZE(buf) * mod->symbollen);
GST_BUFFER_OFFSET(outbuf) = GST_BUFFER_OFFSET(buf);
GST_BUFFER_TIMESTAMP(outbuf) = GST_BUFFER_TIMESTAMP(buf);
bufin = (gfloat *)GST_BUFFER_DATA(buf);
bufout = (gfloat *)GST_BUFFER_DATA(outbuf);
for (i = 0; i < GST_BUFFER_SIZE(buf)/sizeof(gfloat); i ++) {
for (j = 0; j < mod->symbollen; j++) {
bufout[(i * mod->symbollen + j)] =
sin((j * M_PI * 2) / mod->symbollen) *
bufin[i] * 0.999;
}
}
gst_buffer_unref(buf);
gst_buffer_set_caps(outbuf, caps);
gst_caps_unref(caps);
gst_pad_push(mod->srcpad, outbuf);
return GST_FLOW_OK;
}
static GstStateChangeReturn gst_manchestermod_change_state(GstElement *element,
GstStateChange transition)
{
return parent_class->change_state(element, transition);
}
static void gst_manchester_set_property(GObject *object, guint prop_id,
const GValue *value, GParamSpec *pspec)
{
}
static void gst_manchester_get_property(GObject *object, guint prop_id,
GValue *value, GParamSpec *pspec)
{
switch(prop_id) {
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
break;
}
}
static gboolean gst_manchestermod_setcaps(GstPad *pad, GstCaps *caps)
{
GstStructure *structure;
Gst_manchestermod *mod;
mod = GST_MANCHESTERMOD(gst_pad_get_parent(pad));
structure = gst_caps_get_structure(caps, 0);
gst_structure_get_int(structure, "rate", &mod->symbolrate);
return TRUE;
}
static void gst_manchestermod_class_init(Gst_manchestermod_class *klass)
{
GObjectClass *gobject_class;
GstElementClass *gstelement_class;
gobject_class = (GObjectClass *) klass;
gstelement_class = (GstElementClass *) klass;
parent_class = g_type_class_ref(GST_TYPE_ELEMENT);
gstelement_class->change_state = gst_manchestermod_change_state;
gst_element_class_set_details(gstelement_class, &manchestermod_details);
gobject_class->set_property = gst_manchester_set_property;
gobject_class->get_property = gst_manchester_get_property;
gst_element_class_add_pad_template(gstelement_class,
gst_static_pad_template_get(&sink_template));
gst_element_class_add_pad_template(gstelement_class,
gst_static_pad_template_get(&src_template));
}
static void gst_manchestermod_init(Gst_manchestermod *mod)
{
mod->sinkpad = gst_pad_new_from_template(
gst_static_pad_template_get (&sink_template), "sink");
gst_pad_set_chain_function (mod->sinkpad, gst_manchestermod_chain);
gst_element_add_pad (GST_ELEMENT(mod), mod->sinkpad);
mod->srcpad = gst_pad_new_from_template(
gst_static_pad_template_get(&src_template), "src");
gst_element_add_pad(GST_ELEMENT(mod), mod->srcpad);
gst_pad_set_setcaps_function(mod->sinkpad, gst_manchestermod_setcaps);
gst_pad_use_fixed_caps(mod->sinkpad);
mod->symbollen = -1;
}
GType gst_manchestermod_get_type(void)
{
static GType manchestermod_type = 0;
if (!manchestermod_type) {
static const GTypeInfo manchestermod_info = {
sizeof(Gst_manchestermod_class),
NULL,
NULL,
(GClassInitFunc)gst_manchestermod_class_init,
NULL,
NULL,
sizeof(Gst_manchestermod),
0,
(GInstanceInitFunc)gst_manchestermod_init,
};
manchestermod_type = g_type_register_static(GST_TYPE_ELEMENT,
"GstManchestermod", &manchestermod_info, 0);
}
return manchestermod_type;
}