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| 1 | +/* |
| 2 | +* Copyright 2020 Google Inc. |
| 3 | +* |
| 4 | +* Use of this source code is governed by a BSD-style license that can be |
| 5 | +* found in the LICENSE file. |
| 6 | +*/ |
| 7 | + |
| 8 | +#include "modules/audioplayer/SkAudioPlayer.h" |
| 9 | + |
| 10 | +#include "include/core/SkData.h" |
| 11 | +#include "oboe/Oboe.h" |
| 12 | +#include "stream/MemInputStream.h" |
| 13 | +#include "wav/WavStreamReader.h" |
| 14 | + |
| 15 | +namespace { |
| 16 | + |
| 17 | +class OboeAudioPlayer final : public SkAudioPlayer, oboe::AudioStreamCallback { |
| 18 | +public: |
| 19 | + explicit OboeAudioPlayer(sk_sp<SkData> data) |
| 20 | + : fData(std::move(data)) |
| 21 | + , fMemInputStream(const_cast<unsigned char *> |
| 22 | + (static_cast<const unsigned char *>(fData->data())), static_cast<int32_t>(fData->size())) |
| 23 | + { |
| 24 | + // wrap data in MemInputStream to parse WAV header |
| 25 | + fReader = std::make_unique<parselib::WavStreamReader>(&fMemInputStream); |
| 26 | + fReader->parse(); |
| 27 | + // set member variables and builder properties using reader |
| 28 | + fNumSampleFrames = fReader->getNumSampleFrames(); |
| 29 | + |
| 30 | + oboe::AudioStreamBuilder builder; |
| 31 | + builder.setPerformanceMode(oboe::PerformanceMode::LowLatency); |
| 32 | + builder.setSharingMode(oboe::SharingMode::Exclusive); |
| 33 | + builder.setSampleRate(fReader->getSampleRate()); |
| 34 | + builder.setChannelCount(fReader->getNumChannels()); |
| 35 | + builder.setCallback(this); |
| 36 | + builder.setFormat(oboe::AudioFormat::Float); |
| 37 | + |
| 38 | + // open the stream (must manually close it when done) |
| 39 | + fStream = nullptr; |
| 40 | + builder.openStream(fStream); |
| 41 | + } |
| 42 | + |
| 43 | +private: |
| 44 | + oboe::DataCallbackResult |
| 45 | + onAudioReady(oboe::AudioStream *oboeStream, void *audioData, int32_t numFrames) override { |
| 46 | + // we assume float samples here |
| 47 | + float *outBuffer = static_cast<float *>(audioData); |
| 48 | + int framesRead = fReader->getDataFloat(outBuffer, numFrames); |
| 49 | + fReadFrameIndex += framesRead; |
| 50 | + int remainingFrames = numFrames - framesRead; |
| 51 | + if (remainingFrames > 0) { |
| 52 | + if (fIsLooping) { |
| 53 | + // handle wrap around |
| 54 | + fReader->positionToAudio(); |
| 55 | + fReader->getDataFloat(&outBuffer[framesRead * fReader->getNumChannels()], |
| 56 | + remainingFrames); |
| 57 | + fReadFrameIndex += remainingFrames; |
| 58 | + } else { |
| 59 | + // render silence for rest |
| 60 | + renderSilence(&outBuffer[framesRead * fReader->getNumChannels()], remainingFrames); |
| 61 | + return oboe::DataCallbackResult::Stop; |
| 62 | + } |
| 63 | + } |
| 64 | + return oboe::DataCallbackResult::Continue; |
| 65 | + } |
| 66 | + |
| 67 | + void renderSilence(float *start, int numFrames) { |
| 68 | + for (int i = 0; i < numFrames * fReader->getNumChannels(); ++i) { |
| 69 | + start[i] = 0; |
| 70 | + } |
| 71 | + } |
| 72 | + double onGetDuration() const override { |
| 73 | + return fNumSampleFrames * fStream->getChannelCount() / fStream->getSampleRate(); |
| 74 | + } |
| 75 | + |
| 76 | + double onGetTime() const override { |
| 77 | + return (fReadFrameIndex * fStream->getChannelCount()) / fStream->getSampleRate(); |
| 78 | + } |
| 79 | + |
| 80 | + double onSetTime(double t) override { |
| 81 | + fReadFrameIndex = (t * fStream->getSampleRate()) / fStream->getChannelCount(); |
| 82 | + return onGetTime(); |
| 83 | + } |
| 84 | + |
| 85 | + State onSetState(State state) override { |
| 86 | + switch (state) { |
| 87 | + case State::kPlaying: fStream->start(); break; |
| 88 | + case State::kStopped: fStream->close(); break; |
| 89 | + case State::kPaused : fStream->pause(); break; |
| 90 | + } |
| 91 | + |
| 92 | + return state; |
| 93 | + } |
| 94 | + |
| 95 | + |
| 96 | + // TODO: implement rate function (change sample rate of AudioStream) |
| 97 | + float onSetRate(float r) override { |
| 98 | + return r; |
| 99 | + } |
| 100 | + |
| 101 | + // TODO: implement volume function (multiply each sample by desired amplitude) |
| 102 | + float onSetVolume(float v) override { |
| 103 | + return v; |
| 104 | + } |
| 105 | + |
| 106 | + const sk_sp<SkData> fData; |
| 107 | + std::shared_ptr<oboe::AudioStream> fStream; |
| 108 | + std::unique_ptr<parselib::WavStreamReader> fReader; |
| 109 | + parselib::MemInputStream fMemInputStream; |
| 110 | + int32_t fReadFrameIndex {0}; |
| 111 | + int fNumSampleFrames; |
| 112 | + bool fIsLooping {false}; |
| 113 | +}; |
| 114 | + |
| 115 | +} // namespace |
| 116 | + |
| 117 | +std::unique_ptr<SkAudioPlayer> SkAudioPlayer::Make(sk_sp<SkData> src) { |
| 118 | + return std::unique_ptr<SkAudioPlayer>(new OboeAudioPlayer(std::move(src))); |
| 119 | +} |
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