1 /*
2  *  Copyright (c) 2013 The WebRTC project authors. All Rights Reserved.
3  *
4  *  Use of this source code is governed by a BSD-style license
5  *  that can be found in the LICENSE file in the root of the source
6  *  tree. An additional intellectual property rights grant can be found
7  *  in the file PATENTS.  All contributing project authors may
8  *  be found in the AUTHORS file in the root of the source tree.
9  */
10 
11 #ifndef WEBRTC_COMMON_AUDIO_RESAMPLER_INCLUDE_PUSH_RESAMPLER_H_
12 #define WEBRTC_COMMON_AUDIO_RESAMPLER_INCLUDE_PUSH_RESAMPLER_H_
13 
14 #include "webrtc/base/scoped_ptr.h"
15 #include "webrtc/typedefs.h"
16 
17 namespace webrtc {
18 
19 class PushSincResampler;
20 
21 // Wraps PushSincResampler to provide stereo support.
22 // TODO(ajm): add support for an arbitrary number of channels.
23 template <typename T>
24 class PushResampler {
25  public:
26   PushResampler();
27   virtual ~PushResampler();
28 
29   // Must be called whenever the parameters change. Free to be called at any
30   // time as it is a no-op if parameters have not changed since the last call.
31   int InitializeIfNeeded(int src_sample_rate_hz, int dst_sample_rate_hz,
32                          int num_channels);
33 
34   // Returns the total number of samples provided in destination (e.g. 32 kHz,
35   // 2 channel audio gives 640 samples).
36   int Resample(const T* src, int src_length, T* dst, int dst_capacity);
37 
38  private:
39   rtc::scoped_ptr<PushSincResampler> sinc_resampler_;
40   rtc::scoped_ptr<PushSincResampler> sinc_resampler_right_;
41   int src_sample_rate_hz_;
42   int dst_sample_rate_hz_;
43   int num_channels_;
44   rtc::scoped_ptr<T[]> src_left_;
45   rtc::scoped_ptr<T[]> src_right_;
46   rtc::scoped_ptr<T[]> dst_left_;
47   rtc::scoped_ptr<T[]> dst_right_;
48 };
49 
50 }  // namespace webrtc
51 
52 #endif  // WEBRTC_COMMON_AUDIO_RESAMPLER_INCLUDE_PUSH_RESAMPLER_H_
53