static void
gst_cutter_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec)
{
GstCutter *filter;
g_return_if_fail (GST_IS_CUTTER (object));
filter = GST_CUTTER (object);
switch (prop_id) {
case PROP_RUN_LENGTH:
g_value_set_uint64 (value, filter->threshold_length);
break;
case PROP_THRESHOLD:
g_value_set_double (value, filter->threshold_level);
break;
case PROP_THRESHOLD_DB:
g_value_set_double (value, 20 * log (filter->threshold_level));
break;
case PROP_PRE_LENGTH:
g_value_set_uint64 (value, filter->pre_length);
break;
case PROP_LEAKY:
g_value_set_boolean (value, filter->leaky);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gst_cutter_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec)
{
GstCutter *filter;
g_return_if_fail (GST_IS_CUTTER (object));
filter = GST_CUTTER (object);
switch (prop_id) {
case PROP_THRESHOLD:
filter->threshold_level = g_value_get_double (value);
GST_DEBUG ("DEBUG: set threshold level to %f", filter->threshold_level);
break;
case PROP_THRESHOLD_DB:
/* set the level given in dB
* value in dB = 20 * log (value)
* values in dB < 0 result in values between 0 and 1
*/
filter->threshold_level = pow (10, g_value_get_double (value) / 20);
GST_DEBUG_OBJECT (filter, "set threshold level to %f",
filter->threshold_level);
break;
case PROP_RUN_LENGTH:
/* set the minimum length of the silent run required */
filter->threshold_length =
gst_guint64_to_gdouble (g_value_get_uint64 (value));
break;
case PROP_PRE_LENGTH:
/* set the length of the pre-record block */
filter->pre_length = gst_guint64_to_gdouble (g_value_get_uint64 (value));
break;
case PROP_LEAKY:
/* set if the pre-record buffer is leaky or not */
filter->leaky = g_value_get_boolean (value);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static GstFlowReturn
gst_cutter_chain (GstPad * pad, GstBuffer * buf)
{
GstCutter *filter;
gint16 *in_data;
guint num_samples;
gdouble NCS = 0.0; /* Normalized Cumulative Square of buffer */
gdouble RMS = 0.0; /* RMS of signal in buffer */
gdouble NMS = 0.0; /* Normalized Mean Square of buffer */
GstBuffer *prebuf; /* pointer to a prebuffer element */
g_return_val_if_fail (pad != NULL, GST_FLOW_ERROR);
g_return_val_if_fail (GST_IS_PAD (pad), GST_FLOW_ERROR);
g_return_val_if_fail (buf != NULL, GST_FLOW_ERROR);
filter = GST_CUTTER (GST_OBJECT_PARENT (pad));
g_return_val_if_fail (filter != NULL, GST_FLOW_ERROR);
g_return_val_if_fail (GST_IS_CUTTER (filter), GST_FLOW_ERROR);
if (!filter->have_caps) {
if (!(gst_cutter_get_caps (pad, filter)))
return GST_FLOW_NOT_NEGOTIATED;
}
in_data = (gint16 *) GST_BUFFER_DATA (buf);
GST_LOG_OBJECT (filter, "length of prerec buffer: %" GST_TIME_FORMAT,
GST_TIME_ARGS (filter->pre_run_length));
/* calculate mean square value on buffer */
switch (filter->width) {
case 16:
num_samples = GST_BUFFER_SIZE (buf) / 2;
gst_cutter_calculate_gint16 (in_data, num_samples, &NCS);
NMS = NCS / num_samples;
break;
case 8:
num_samples = GST_BUFFER_SIZE (buf);
gst_cutter_calculate_gint8 ((gint8 *) in_data, num_samples, &NCS);
NMS = NCS / num_samples;
break;
default:
/* this shouldn't happen */
g_warning ("no mean square function for width %d\n", filter->width);
break;
}
filter->silent_prev = filter->silent;
RMS = sqrt (NMS);
/* if RMS below threshold, add buffer length to silent run length count
* if not, reset
*/
GST_LOG_OBJECT (filter, "buffer stats: NMS %f, RMS %f, audio length %f", NMS,
RMS,
gst_guint64_to_gdouble (gst_audio_duration_from_pad_buffer
(filter->sinkpad, buf)));
if (RMS < filter->threshold_level)
filter->silent_run_length +=
gst_guint64_to_gdouble (gst_audio_duration_from_pad_buffer
(filter->sinkpad, buf));
else {
filter->silent_run_length = 0 * GST_SECOND;
filter->silent = FALSE;
}
if (filter->silent_run_length > filter->threshold_length)
/* it has been silent long enough, flag it */
filter->silent = TRUE;
/* has the silent status changed ? if so, send right signal
* and, if from silent -> not silent, flush pre_record buffer
*/
if (filter->silent != filter->silent_prev) {
if (filter->silent) {
GstMessage *m =
gst_cutter_message_new (filter, FALSE, GST_BUFFER_TIMESTAMP (buf));
GST_DEBUG_OBJECT (filter, "signaling CUT_STOP");
gst_element_post_message (GST_ELEMENT (filter), m);
} else {
gint count = 0;
GstMessage *m =
gst_cutter_message_new (filter, TRUE, GST_BUFFER_TIMESTAMP (buf));
GST_DEBUG_OBJECT (filter, "signaling CUT_START");
gst_element_post_message (GST_ELEMENT (filter), m);
/* first of all, flush current buffer */
GST_DEBUG_OBJECT (filter, "flushing buffer of length %" GST_TIME_FORMAT,
GST_TIME_ARGS (filter->pre_run_length));
while (filter->pre_buffer) {
prebuf = (g_list_first (filter->pre_buffer))->data;
filter->pre_buffer = g_list_remove (filter->pre_buffer, prebuf);
gst_pad_push (filter->srcpad, prebuf);
++count;
}
GST_DEBUG_OBJECT (filter, "flushed %d buffers", count);
filter->pre_run_length = 0 * GST_SECOND;
}
}
/* now check if we have to send the new buffer to the internal buffer cache
* or to the srcpad */
if (filter->silent) {
filter->pre_buffer = g_list_append (filter->pre_buffer, buf);
filter->pre_run_length +=
gst_guint64_to_gdouble (gst_audio_duration_from_pad_buffer
(filter->sinkpad, buf));
while (filter->pre_run_length > filter->pre_length) {
prebuf = (g_list_first (filter->pre_buffer))->data;
g_assert (GST_IS_BUFFER (prebuf));
filter->pre_buffer = g_list_remove (filter->pre_buffer, prebuf);
filter->pre_run_length -=
gst_guint64_to_gdouble (gst_audio_duration_from_pad_buffer
(filter->sinkpad, prebuf));
/* only pass buffers if we don't leak */
if (!filter->leaky)
gst_pad_push (filter->srcpad, prebuf);
else
gst_buffer_unref (prebuf);
}
} else
gst_pad_push (filter->srcpad, buf);
return GST_FLOW_OK;
}