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/* -*- Mode: c; c-basic-offset: 2 -*- */
_FORMAT *in_data, *out_data;
static gint64 offset = 0, timestamp = 0;
/* get a buffer here so that we can have something to interpolate
* against for the first few samples if speed < 0.5 */
in_data = (_FORMAT*) GST_BUFFER_DATA(in);
nin = GST_BUFFER_SIZE(in)/sizeof(_FORMAT);
lower = in_data[0];
i_float = 0.5 * (speed - 1.0);
i = i_float + 1.0; /* ciel(i_float) for ints */
do {
speed = filter->speed; /* update this, it might have changed */
out = gst_buffer_new();
GST_BUFFER_DATA(out) = (gchar*) g_new(_FORMAT,SPEED_BUFSIZE/sizeof(_FORMAT));
GST_BUFFER_SIZE(out) = SPEED_BUFSIZE;
out_data = (_FORMAT*) GST_BUFFER_DATA(out);
nout = GST_BUFFER_SIZE(out) / sizeof(_FORMAT);
GST_BUFFER_TIMESTAMP (out) = timestamp;
offset += nout;
timestamp = offset * GST_SECOND / filter->rate;
for (j=0; j<nout; j++) {
/* index of upper bounds of interpolation for
* new sample, got it by trial&error on the chalkboard */
i_float += speed;
i = i_float + 1.0; /* ciel(i_float) for ints */
while (i >= nin) {
i = i % nin;
i_float = i_float - nin;
lower = in_data[nin-1];
gst_buffer_unref(in);
in = GST_BUFFER (gst_pad_pull (filter->sinkpad));
while (GST_IS_EVENT (in)) {
gst_pad_event_default (filter->srcpad, GST_EVENT (in));
in = GST_BUFFER (gst_pad_pull (filter->sinkpad));
}
in_data = (_FORMAT*) GST_BUFFER_DATA(in);
nin = GST_BUFFER_SIZE(in) / sizeof(_FORMAT);
}
if (i>0)
lower = in_data[i-1];
interp = i_float - floor(i_float);
out_data[j] = lower*(1-interp) + in_data[i]*interp;
lower = in_data[i];
}
gst_pad_push(filter->srcpad, GST_DATA (out));
gst_element_yield (element);
} while (TRUE);
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