* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
+/**
+ * SECTION:element-spectrum
+ *
+ * <refsect2>
+ * The Spectrum element analyzes the frequency spectrum of an audio signal.
+ * Analysis results are send as outgoing buffers.
+ * The buffer contains a guint8 value per frequency band.
+ * A value of 0 maps to the threshold property.
+ *
+ * It cannot be used with the gst-launch command in a sensible way. Instead the
+ * included demo shows how to use it.
+ *
+ * Last reviewed on 2006-05-21 (0.10.3)
+ */
#ifdef HAVE_CONFIG_H
#include "config.h"
GST_PAD_ALWAYS,
GST_STATIC_CAPS ("audio/x-raw-int, "
"rate = (int) [ 1, MAX ], "
- "channels = (int) 1, "
+ "channels = (int) [1, MAX], "
"endianness = (int) BYTE_ORDER, "
"width = (int) 16, " "depth = (int) 16, " "signed = (boolean) true")
);
enum
{
ARG_0,
- ARG_WIDTH
+ ARG_WIDTH,
+ ARG_THRESHOLD
};
static void gst_spectrum_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec);
+static gboolean gst_spectrum_set_sink_caps (GstPad * pad, GstCaps * caps);
+static GstCaps *gst_spectrum_get_sink_caps (GstPad * pad);
static GstFlowReturn gst_spectrum_chain (GstPad * pad, GstBuffer * buffer);
+static GstStateChangeReturn gst_spectrum_change_state (GstElement * element,
+ GstStateChange transition);
#define fixed short
extern int gst_spectrum_fix_fft (fixed fr[], fixed fi[], int m, int inverse);
static void
gst_spectrum_class_init (GstSpectrumClass * klass)
{
- GObjectClass *gobject_class = (GObjectClass *) klass;
+ GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
+ GstElementClass *element = GST_ELEMENT_CLASS (klass);
parent_class = g_type_class_peek_parent (klass);
gobject_class->set_property = gst_spectrum_set_property;
gobject_class->dispose = gst_spectrum_dispose;
+ element->change_state = gst_spectrum_change_state;
+
g_object_class_install_property (gobject_class, ARG_WIDTH,
- g_param_spec_int ("width", "width", "width",
- G_MININT, G_MAXINT, 0, G_PARAM_WRITABLE));
+ g_param_spec_uint ("width", "width", "number of frequency bands",
+ 0, G_MAXUINT, 0, G_PARAM_WRITABLE));
+
+ g_object_class_install_property (gobject_class, ARG_THRESHOLD,
+ g_param_spec_int ("threshold", "threshold",
+ "db threshold for result, maps to 0", G_MININT, 0, -60,
+ G_PARAM_WRITABLE));
}
{
spectrum->sinkpad =
gst_pad_new_from_static_template (&sink_template_factory, "sink");
- gst_element_add_pad (GST_ELEMENT (spectrum), spectrum->sinkpad);
gst_pad_set_chain_function (spectrum->sinkpad, gst_spectrum_chain);
+ gst_pad_set_setcaps_function (spectrum->sinkpad, gst_spectrum_set_sink_caps);
+ gst_pad_set_getcaps_function (spectrum->sinkpad, gst_spectrum_get_sink_caps);
+ gst_element_add_pad (GST_ELEMENT (spectrum), spectrum->sinkpad);
spectrum->srcpad =
gst_pad_new_from_static_template (&src_template_factory, "src");
gst_element_add_pad (GST_ELEMENT (spectrum), spectrum->srcpad);
- spectrum->width = 75;
- spectrum->base = 8;
- spectrum->len = 1024;
+ spectrum->adapter = gst_adapter_new ();
+
+ spectrum->width = 128;
+ spectrum->base = 9;
+ spectrum->len = 1024; /* 2 ^ (base+1) */
spectrum->loud = g_malloc (spectrum->len * sizeof (gint16));
spectrum->im = g_malloc (spectrum->len * sizeof (gint16));
{
GstSpectrum *spectrum = GST_SPECTRUM (object);
+ if (spectrum->adapter) {
+ g_object_unref (spectrum->adapter);
+ spectrum->adapter = NULL;
+ }
+
g_free (spectrum->re);
g_free (spectrum->im);
g_free (spectrum->loud);
switch (prop_id) {
case ARG_WIDTH:
- spectrum->width = g_value_get_int (value);
+ spectrum->width = g_value_get_uint (value);
+ break;
+ case ARG_THRESHOLD:
+ spectrum->threshold = g_value_get_int (value);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
}
}
+static gboolean
+gst_spectrum_set_sink_caps (GstPad * pad, GstCaps * caps)
+{
+ GstSpectrum *spectrum = GST_SPECTRUM (gst_pad_get_parent (pad));
+ GstStructure *structure = gst_caps_get_structure (caps, 0);
+ gboolean ret;
+
+ ret = gst_structure_get_int (structure, "channels", &spectrum->channels);
+ GST_INFO ("Got channels = %d", spectrum->channels);
+
+ gst_object_unref (spectrum);
+
+ return ret;
+}
+
+static GstCaps *
+gst_spectrum_get_sink_caps (GstPad * pad)
+{
+ GstSpectrum *spectrum = GST_SPECTRUM (gst_pad_get_parent (pad));
+ GstCaps *res;
+ GstStructure *structure;
+
+ res = gst_caps_copy (gst_pad_get_pad_template_caps (spectrum->sinkpad));
+ if (spectrum->channels) {
+ structure = gst_caps_get_structure (res, 0);
+ gst_structure_set (structure, "channels", G_TYPE_INT, spectrum->channels,
+ NULL);
+ GST_INFO ("Fixate channels = %d", spectrum->channels);
+ }
+ gst_object_unref (spectrum);
+ return res;
+}
+
static GstFlowReturn
gst_spectrum_chain (GstPad * pad, GstBuffer * buffer)
{
- GstSpectrum *spectrum;
+ GstSpectrum *spectrum = GST_SPECTRUM (gst_pad_get_parent (pad));
gint16 *samples;
- gint step, pos, num, i;
+ gint wanted;
+ gint i, j, k;
+ gint32 acc;
+ gfloat pos, step;
guchar *spect;
- GstBuffer *newbuf;
-
- spectrum = GST_SPECTRUM (GST_OBJECT_PARENT (pad));
- samples = (gint16 *) GST_BUFFER_DATA (buffer);
-
- GST_LOG ("buffer-size = %ld", GST_BUFFER_SIZE (buffer));
-
- /* FIXME:need a gst_adapter */
- num = GST_BUFFER_SIZE (buffer) / 2;
- num = MIN (num, spectrum->len);
-
- for (i = 0; i < num; i++)
- spectrum->re[i] = (samples[(i * 2)] + samples[(i * 2) + 1]) >> 1;
-
- gst_spectrum_window (spectrum->re, spectrum->len);
- gst_spectrum_fix_fft (spectrum->re, spectrum->im, spectrum->base, FALSE);
- gst_spectrum_fix_loud (spectrum->loud, spectrum->re, spectrum->im,
- spectrum->len, 0);
-
- /* resample to requested width */
- step = spectrum->len / (spectrum->width * 4); /* <-- shouldn't this be 2 instead of 4? */
- spect = (guchar *) g_malloc (spectrum->width);
- for (i = 0, pos = 0; i < spectrum->width; i++, pos += step) {
- /* > -60 db? */
- if (spectrum->loud[pos] > -60) {
- spect[i] = spectrum->loud[pos] + 60;
- /*
- if (spect[i] > 15);
- spect[i] = 15;
- */
- } else
- /* treat as silence */
- spect[i] = 0;
+ GstBuffer *outbuf;
+ GstFlowReturn ret = GST_FLOW_OK;
+
+ gst_adapter_push (spectrum->adapter, buffer);
+ /* required number of bytes */
+ wanted = spectrum->channels * spectrum->len * 2;
+ /* FIXME: 4.0 was 2.0 before, but that include the mirrored spectrum */
+ step = (gfloat) spectrum->len / (spectrum->width * 4.0);
+
+ while (gst_adapter_available (spectrum->adapter) > wanted &&
+ (ret == GST_FLOW_OK)) {
+
+ samples = (gint16 *) gst_adapter_take (spectrum->adapter, wanted);
+
+ for (i = 0, j = 0; i < spectrum->len; i++) {
+ for (k = 0, acc = 0; k < spectrum->channels; k++)
+ acc += samples[j++];
+ spectrum->re[i] = (gint16) (acc / spectrum->channels);
+ }
+
+ gst_spectrum_window (spectrum->re, spectrum->len);
+ gst_spectrum_fix_fft (spectrum->re, spectrum->im, spectrum->base, FALSE);
+ gst_spectrum_fix_loud (spectrum->loud, spectrum->re, spectrum->im,
+ spectrum->len, 0);
+
+ ret = gst_pad_alloc_buffer_and_set_caps (spectrum->srcpad,
+ GST_BUFFER_OFFSET_NONE, spectrum->width,
+ GST_PAD_CAPS (spectrum->srcpad), &outbuf);
+
+ /* resample to requested width */
+ spect = GST_BUFFER_DATA (outbuf);
+ for (i = 0, pos = 0.0; i < spectrum->width; i++, pos += step) {
+ /* > -60 db? FIXME: make this a gobject property */
+ if (spectrum->loud[(gint) pos] > spectrum->threshold) {
+ spect[i] = spectrum->loud[(gint) pos] - spectrum->threshold;
+ /*
+ if (spect[i] > 15);
+ spect[i] = 15;
+ */
+ } else
+ /* treat as silence */
+ spect[i] = 0;
+ }
+
+ ret = gst_pad_push (spectrum->srcpad, outbuf);
}
- gst_buffer_unref (buffer);
- newbuf = gst_buffer_new ();
- GST_BUFFER_DATA (newbuf) = spect;
- GST_BUFFER_SIZE (newbuf) = spectrum->width;
+ gst_object_unref (spectrum);
+ return ret;
+}
+
+static GstStateChangeReturn
+gst_spectrum_change_state (GstElement * element, GstStateChange transition)
+{
+ GstSpectrum *spectrum = GST_SPECTRUM (element);
+ GstStateChangeReturn ret;
- return gst_pad_push (spectrum->srcpad, newbuf);
+ switch (transition) {
+ case GST_STATE_CHANGE_NULL_TO_READY:
+ break;
+ case GST_STATE_CHANGE_READY_TO_PAUSED:
+ gst_adapter_clear (spectrum->adapter);
+ break;
+ case GST_STATE_CHANGE_PAUSED_TO_PLAYING:
+ break;
+ default:
+ break;
+ }
+
+ ret = GST_ELEMENT_CLASS (parent_class)->change_state (element, transition);
+
+ switch (transition) {
+ case GST_STATE_CHANGE_PLAYING_TO_PAUSED:
+ break;
+ case GST_STATE_CHANGE_PAUSED_TO_READY:
+ break;
+ case GST_STATE_CHANGE_READY_TO_NULL:
+ break;
+ default:
+ break;
+ }
+
+ return ret;
}
+
static gboolean
plugin_init (GstPlugin * plugin)
{
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