예제 #1
0
static GstFlowReturn
gst_cutter_chain (GstPad * pad, GstObject * parent, GstBuffer * buf)
{
  GstFlowReturn ret = GST_FLOW_OK;
  GstCutter *filter;
  GstMapInfo map;
  gint16 *in_data;
  gint bpf, rate;
  gsize in_size;
  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 */
  GstClockTime duration;

  filter = GST_CUTTER (parent);

  if (GST_AUDIO_INFO_FORMAT (&filter->info) == GST_AUDIO_FORMAT_UNKNOWN)
    goto not_negotiated;

  bpf = GST_AUDIO_INFO_BPF (&filter->info);
  rate = GST_AUDIO_INFO_RATE (&filter->info);

  gst_buffer_map (buf, &map, GST_MAP_READ);
  in_data = (gint16 *) map.data;
  in_size = map.size;

  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 (GST_AUDIO_INFO_FORMAT (&filter->info)) {
    case GST_AUDIO_FORMAT_S16:
      num_samples = in_size / 2;
      gst_cutter_calculate_gint16 (in_data, num_samples, &NCS);
      NMS = NCS / num_samples;
      break;
    case GST_AUDIO_FORMAT_S8:
      num_samples = in_size;
      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 format");
      break;
  }

  gst_buffer_unmap (buf, &map);

  filter->silent_prev = filter->silent;

  duration = gst_util_uint64_scale (in_size / bpf, GST_SECOND, rate);

  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 (duration));

  if (RMS < filter->threshold_level)
    filter->silent_run_length += gst_guint64_to_gdouble (duration);
  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 (duration);

    while (filter->pre_run_length > filter->pre_length) {
      GstClockTime pduration;
      gsize psize;

      prebuf = (g_list_first (filter->pre_buffer))->data;
      g_assert (GST_IS_BUFFER (prebuf));

      psize = gst_buffer_get_size (prebuf);
      pduration = gst_util_uint64_scale (psize / bpf, GST_SECOND, rate);

      filter->pre_buffer = g_list_remove (filter->pre_buffer, prebuf);
      filter->pre_run_length -= gst_guint64_to_gdouble (pduration);

      /* only pass buffers if we don't leak */
      if (!filter->leaky)
        ret = gst_pad_push (filter->srcpad, prebuf);
      else
        gst_buffer_unref (prebuf);
    }
  } else
    ret = gst_pad_push (filter->srcpad, buf);

  return ret;

  /* ERRORS */
not_negotiated:
  {
    return GST_FLOW_NOT_NEGOTIATED;
  }
}
예제 #2
0
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;
}