Merge beamformer

R=andrew@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/34529004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@7958 4adac7df-926f-26a2-2b94-8c16560cd09d

webrtc/modules/audio_processing/beamformer/pcm_utils.h

@@ -0,0 +1,50 @@
+/*
+ *  Copyright (c) 2014 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_MODULES_AUDIO_PROCESSING_BEAMFORMER_PCM_UTILS_H_
+#define WEBRTC_MODULES_AUDIO_PROCESSING_BEAMFORMER_PCM_UTILS_H_
+
+#include <inttypes.h>
+#include <stdio.h>
+
+// Utilities for reading from and writing to multichannel pcm files.
+// Assumes a bit depth of 16 and little-endian. Note that in these functions,
+// length refers to the number of samples to read from/write to the file,
+// such that length / num_channels is the number of frames.
+namespace webrtc {
+
+// Reads audio from a pcm into a 2D array: buffer[channel_index][frame_index].
+// Returns the number of frames written. If this is less than |length|, it's
+// safe to assume the end-of-file was reached, as otherwise this will crash.
+// In PcmReadToFloat, the floats are within the range [-1, 1].
+size_t PcmRead(FILE* file,
+               size_t length,
+               int num_channels,
+               int16_t* const* buffer);
+size_t PcmReadToFloat(FILE* file,
+                      size_t length,
+                      int num_channels,
+                      float* const* buffer);
+
+// Writes to a pcm file. The resulting file contains the channels interleaved.
+// Crashes if the correct number of frames aren't written to the file. For
+// PcmWriteFromFloat, floats must be within the range [-1, 1].
+void PcmWrite(FILE* file,
+              size_t length,
+              int num_channels,
+              const int16_t* const* buffer);
+void PcmWriteFromFloat(FILE* file,
+                       size_t length,
+                       int num_channels,
+                       const float* const* buffer);
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_MODULES_AUDIO_PROCESSING_BEAMFORMER_PCM_UTILS_H_