1 /*
2  *  Copyright (c) 2011 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 MODULES_AUDIO_PROCESSING_AUDIO_BUFFER_H_
12 #define MODULES_AUDIO_PROCESSING_AUDIO_BUFFER_H_
13 
14 #include <stddef.h>
15 #include <stdint.h>
16 
17 #include <memory>
18 #include <vector>
19 
20 #include "common_audio/channel_buffer.h"
21 #include "modules/audio_processing/include/audio_processing.h"
22 
23 namespace webrtc {
24 
25 class PushSincResampler;
26 class SplittingFilter;
27 
28 enum Band { kBand0To8kHz = 0, kBand8To16kHz = 1, kBand16To24kHz = 2 };
29 
30 // Stores any audio data in a way that allows the audio processing module to
31 // operate on it in a controlled manner.
32 class AudioBuffer {
33  public:
34   static const int kSplitBandSize = 160;
35   static const size_t kMaxSampleRate = 384000;
36   AudioBuffer(size_t input_rate,
37               size_t input_num_channels,
38               size_t buffer_rate,
39               size_t buffer_num_channels,
40               size_t output_rate,
41               size_t output_num_channels);
42 
43   // The constructor below will be deprecated.
44   AudioBuffer(size_t input_num_frames,
45               size_t input_num_channels,
46               size_t buffer_num_frames,
47               size_t buffer_num_channels,
48               size_t output_num_frames);
49   virtual ~AudioBuffer();
50 
51   AudioBuffer(const AudioBuffer&) = delete;
52   AudioBuffer& operator=(const AudioBuffer&) = delete;
53 
54   // Specify that downmixing should be done by selecting a single channel.
55   void set_downmixing_to_specific_channel(size_t channel);
56 
57   // Specify that downmixing should be done by averaging all channels,.
58   void set_downmixing_by_averaging();
59 
60   // Set the number of channels in the buffer. The specified number of channels
61   // cannot be larger than the specified buffer_num_channels. The number is also
62   // reset at each call to CopyFrom or InterleaveFrom.
63   void set_num_channels(size_t num_channels);
64 
num_channels()65   size_t num_channels() const { return num_channels_; }
num_frames()66   size_t num_frames() const { return buffer_num_frames_; }
num_frames_per_band()67   size_t num_frames_per_band() const { return num_split_frames_; }
num_bands()68   size_t num_bands() const { return num_bands_; }
69 
70   // Returns pointer arrays to the full-band channels.
71   // Usage:
72   // channels()[channel][sample].
73   // Where:
74   // 0 <= channel < |buffer_num_channels_|
75   // 0 <= sample < |buffer_num_frames_|
channels()76   float* const* channels() { return data_->channels(); }
channels_const()77   const float* const* channels_const() const { return data_->channels(); }
78 
79   // Returns pointer arrays to the bands for a specific channel.
80   // Usage:
81   // split_bands(channel)[band][sample].
82   // Where:
83   // 0 <= channel < |buffer_num_channels_|
84   // 0 <= band < |num_bands_|
85   // 0 <= sample < |num_split_frames_|
split_bands_const(size_t channel)86   const float* const* split_bands_const(size_t channel) const {
87     return split_data_.get() ? split_data_->bands(channel)
88                              : data_->bands(channel);
89   }
split_bands(size_t channel)90   float* const* split_bands(size_t channel) {
91     return split_data_.get() ? split_data_->bands(channel)
92                              : data_->bands(channel);
93   }
94 
95   // Returns a pointer array to the channels for a specific band.
96   // Usage:
97   // split_channels(band)[channel][sample].
98   // Where:
99   // 0 <= band < |num_bands_|
100   // 0 <= channel < |buffer_num_channels_|
101   // 0 <= sample < |num_split_frames_|
split_channels_const(Band band)102   const float* const* split_channels_const(Band band) const {
103     if (split_data_.get()) {
104       return split_data_->channels(band);
105     } else {
106       return band == kBand0To8kHz ? data_->channels() : nullptr;
107     }
108   }
109 
110   // Copies data into the buffer.
111   void CopyFrom(const int16_t* const interleaved_data,
112                 const StreamConfig& stream_config);
113   void CopyFrom(const float* const* stacked_data,
114                 const StreamConfig& stream_config);
115 
116   // Copies data from the buffer.
117   void CopyTo(const StreamConfig& stream_config,
118               int16_t* const interleaved_data);
119   void CopyTo(const StreamConfig& stream_config, float* const* stacked_data);
120   void CopyTo(AudioBuffer* buffer) const;
121 
122   // Splits the buffer data into frequency bands.
123   void SplitIntoFrequencyBands();
124 
125   // Recombines the frequency bands into a full-band signal.
126   void MergeFrequencyBands();
127 
128   // Copies the split bands data into the integer two-dimensional array.
129   void ExportSplitChannelData(size_t channel,
130                               int16_t* const* split_band_data) const;
131 
132   // Copies the data in the integer two-dimensional array into the split_bands
133   // data.
134   void ImportSplitChannelData(size_t channel,
135                               const int16_t* const* split_band_data);
136 
137   static const size_t kMaxSplitFrameLength = 160;
138   static const size_t kMaxNumBands = 3;
139 
140   // Deprecated methods, will be removed soon.
channels_f()141   float* const* channels_f() { return channels(); }
channels_const_f()142   const float* const* channels_const_f() const { return channels_const(); }
split_bands_const_f(size_t channel)143   const float* const* split_bands_const_f(size_t channel) const {
144     return split_bands_const(channel);
145   }
split_bands_f(size_t channel)146   float* const* split_bands_f(size_t channel) { return split_bands(channel); }
split_channels_const_f(Band band)147   const float* const* split_channels_const_f(Band band) const {
148     return split_channels_const(band);
149   }
150 
151  private:
152   FRIEND_TEST_ALL_PREFIXES(AudioBufferTest,
153                            SetNumChannelsSetsChannelBuffersNumChannels);
154   void RestoreNumChannels();
155 
156   const size_t input_num_frames_;
157   const size_t input_num_channels_;
158   const size_t buffer_num_frames_;
159   const size_t buffer_num_channels_;
160   const size_t output_num_frames_;
161   const size_t output_num_channels_;
162 
163   size_t num_channels_;
164   size_t num_bands_;
165   size_t num_split_frames_;
166 
167   std::unique_ptr<ChannelBuffer<float>> data_;
168   std::unique_ptr<ChannelBuffer<float>> split_data_;
169   std::unique_ptr<SplittingFilter> splitting_filter_;
170   std::vector<std::unique_ptr<PushSincResampler>> input_resamplers_;
171   std::vector<std::unique_ptr<PushSincResampler>> output_resamplers_;
172   bool downmix_by_averaging_ = true;
173   size_t channel_for_downmixing_ = 0;
174 };
175 
176 }  // namespace webrtc
177 
178 #endif  // MODULES_AUDIO_PROCESSING_AUDIO_BUFFER_H_
179