一个基于Sonic(声音处理算法)的,音频Speed,Pitch,Rate调节Demo
该Demo支持音频打开方式后直接可进行相关音频参数的调节,
或者手动选择本地音频,或者直接播放本Demo内置音频,
要播放在线音频可手动修改源码音频Uri

该Demo支持两种媒体引擎,都支持音频的变速功能.
一个是,基于Exo和Sonic Java算法
另一个是,基于Presto和Sonic C算法
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另外界面部分中
含有一个PlusMinusNum自定义控件
支持数字的累加/递减(float/int:需要自己再修改)
支持长按连续累加/递减.....

protected boolean processOutputBuffer(long positionUs, long elapsedRealtimeUs, MediaCodec codec, ByteBuffer buffer, int bufferIndex, int bufferFlags, long bufferPresentationTimeUs, boolean shouldSkip) throws ExoPlaybackException {
    if (bufferIndex != this.bufferIndex) {
      this.bufferIndex = bufferIndex;
      if ((speed != 1.0f || pitch != 1.0f || rate != 1.0f) && initSonic(buffer.remaining())) {
        // =========@Sonic@=========
        int sonicProcessingSize;
        int position = buffer.position();

        // =========@Get the data and processing
        sonicProcessingSize = buffer.remaining();
        buffer.get(sonicBuffer, 0, sonicProcessingSize);
        sonic.writeBytesToStream(sonicBuffer, sonicProcessingSize);
        sonicProcessingSize = sonic.readBytesFromStream(sonicBuffer, sonicBuffer.length);

        // =========@Put the sonic processing data
        if (!buffer.isReadOnly()) {
          buffer.position(position);
          buffer.limit(position + sonicProcessingSize);
          buffer.put(sonicBuffer, 0, sonicProcessingSize);
          buffer.position(position);
        } else {//Use bufferSub replace buffer
          if (bufferSub == null || bufferSub.capacity() != sonicBuffer.length)
            bufferSub = ByteBuffer.wrap(sonicBuffer, 0, 0);
          bufferSub.position(0);
          bufferSub.limit(sonicProcessingSize);
        }
      } else if (bufferSub != null)
        bufferSub = null;
    }
    if (bufferSub != null && buffer.isReadOnly())
      buffer = bufferSub;

    return super.processOutputBuffer(positionUs, elapsedRealtimeUs, codec, buffer, bufferIndex, bufferFlags, bufferPresentationTimeUs, shouldSkip);
}

直接引用K-Sonic项目中的library
library-exo: minSdkVer:JELLY_BEAN(16), SDK_INT<23 构建SonicMediaCodecAudioRenderer 实现<23兼容加速
library-presto: minSdkVer:GINGERBREAD(9), MediaExtractor MediaCodec Sonic 实现加速播放

MIT License

Copyright (c) 2017 K Sun <jcodeing@gmail.com>

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
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copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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SOFTWARE.