1 /* 2 * Copyright (C) 2010, Google Inc. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND 14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16 * ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE 17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 19 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 20 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH 23 * DAMAGE. 24 */ 25 26 #ifndef THIRD_PARTY_BLINK_RENDERER_PLATFORM_AUDIO_AUDIO_RESAMPLER_H_ 27 #define THIRD_PARTY_BLINK_RENDERER_PLATFORM_AUDIO_AUDIO_RESAMPLER_H_ 28 29 #include <memory> 30 31 #include "base/macros.h" 32 #include "third_party/blink/renderer/platform/audio/audio_bus.h" 33 #include "third_party/blink/renderer/platform/audio/audio_resampler_kernel.h" 34 #include "third_party/blink/renderer/platform/audio/audio_source_provider.h" 35 #include "third_party/blink/renderer/platform/wtf/allocator/allocator.h" 36 #include "third_party/blink/renderer/platform/wtf/vector.h" 37 38 namespace blink { 39 40 // AudioResampler resamples the audio stream from an AudioSourceProvider. 41 // The audio stream may be single or multi-channel. 42 // The default constructor defaults to single-channel (mono). 43 44 class PLATFORM_EXPORT AudioResampler { 45 DISALLOW_NEW(); 46 47 public: 48 AudioResampler(); 49 AudioResampler(unsigned number_of_channels); 50 ~AudioResampler() = default; 51 52 // Given an AudioSourceProvider, process() resamples the source stream into 53 // destinationBus. 54 void Process(AudioSourceProvider*, 55 AudioBus* destination_bus, 56 uint32_t frames_to_process); 57 58 // Resets the processing state. 59 void Reset(); 60 61 void ConfigureChannels(unsigned number_of_channels); 62 63 // 0 < rate <= MaxRate 64 void SetRate(double rate); Rate()65 double Rate() const { return rate_; } 66 67 static const double kMaxRate; 68 69 private: 70 double rate_; 71 Vector<std::unique_ptr<AudioResamplerKernel>> kernels_; 72 scoped_refptr<AudioBus> source_bus_; 73 74 DISALLOW_COPY_AND_ASSIGN(AudioResampler); 75 }; 76 77 } // namespace blink 78 79 #endif // THIRD_PARTY_BLINK_RENDERER_PLATFORM_AUDIO_AUDIO_RESAMPLER_H_ 80