ext/soundtouch/gstbpmdetect.cc: Clean up a bit and only allocate a temporary buffer for the data if processing stereo...

Original commit message from CVS:
* ext/soundtouch/gstbpmdetect.cc:
Clean up a bit and only allocate a temporary buffer for the data
if processing stereo data as BPMDetect downmixes from stereo to
mono and stores the result in the input data. Thanks to
Stefan Kost for the suggestions.

1 files changed, 20 insertions, 11 deletions

diff --git a/ext/soundtouch/gstbpmdetect.cc b/ext/soundtouch/gstbpmdetect.cc
index d9949182..1ec5452a 100644
--- a/ext/soundtouch/gstbpmdetect.cc
+++ b/ext/soundtouch/gstbpmdetect.cc
@@ -189,23 +189,32 @@ gst_bpm_detect_transform_ip (GstBaseTransform * trans, GstBuffer * in)
   GstBPMDetect *bpm_detect = GST_BPM_DETECT (trans);
   GstAudioFilter *filter = GST_AUDIO_FILTER (trans);
   gint nsamples;
-  gfloat *data;
   gfloat bpm;
 
-  if (filter->format.channels == 0 || filter->format.rate == 0) {
-    GST_ERROR_OBJECT (bpm_detect, "No channels or rate set yet");
-    return GST_FLOW_ERROR;
-  }
-
-  nsamples = GST_BUFFER_SIZE (in) / (4 * filter->format.channels);
+  if (G_UNLIKELY (!bpm_detect->priv->detect)) {
+    if (filter->format.channels == 0 || filter->format.rate == 0) {
+      GST_ERROR_OBJECT (bpm_detect, "No channels or rate set yet");
+      return GST_FLOW_ERROR;
+    }
 
-  if (!bpm_detect->priv->detect)
     bpm_detect->priv->detect =
         new BPMDetect (filter->format.channels, filter->format.rate);
+  }
 
-  data = (gfloat *) g_memdup (GST_BUFFER_DATA (in), GST_BUFFER_SIZE (in));
-  bpm_detect->priv->detect->inputSamples (data, nsamples);
-  g_free (data);
+  nsamples = GST_BUFFER_SIZE (in) / (4 * filter->format.channels);
+
+  /* For stereo BPMDetect->inputSamples() does downmixing into the input
+   * data but our buffer data shouldn't be modified.
+   */
+  if (filter->format.channels == 1) {
+    bpm_detect->priv->detect->inputSamples ((gfloat *) GST_BUFFER_DATA (in),
+        nsamples);
+  } else {
+    gfloat *data =
+        (gfloat *) g_memdup (GST_BUFFER_DATA (in), GST_BUFFER_SIZE (in));
+    bpm_detect->priv->detect->inputSamples (data, nsamples);
+    g_free (data);
+  }
 
   bpm = bpm_detect->priv->detect->getBpm ();
   if (bpm >= 1.0 && fabs (bpm_detect->bpm - bpm) >= 1.0) {