timeside/analyzer/aubio_*.py: use downsample_blocking

diff --git a/timeside/analyzer/utils.py b/timeside/analyzer/utils.py
new file mode 100644 (file)
index 0000000..b7c8c61
--- /dev/null
+++ b/timeside/analyzer/utils.py
@@ -0,0 +1,37 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright (c) 2013 Paul Brossier <piem@piem.org>
+
+# This file is part of TimeSide.
+
+# TimeSide is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 2 of the License, or
+# (at your option) any later version.
+
+# TimeSide is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with TimeSide.  If not, see <http://www.gnu.org/licenses/>.
+
+# Author: Paul Brossier <piem@piem.org>
+
+import numpy
+
+def downsample_blocking(frames, hop_s, dtype='float32'):
+    # downmixing to one channel
+    if len(frames.shape) != 1:
+        downsampled = frames.sum(axis = -1) / frames.shape[-1]
+    else:
+        downsampled = frames
+    # zero padding to have a multiple of hop_s
+    if downsampled.shape[0] % hop_s != 0:
+        pad_length = hop_s + downsampled.shape[0] / hop_s * hop_s - downsampled.shape[0]
+        downsampled = numpy.hstack([downsampled, numpy.zeros(pad_length, dtype = dtype)])
+    # blocking
+    return downsampled.reshape(downsampled.shape[0] / hop_s, hop_s)
+
+