文件名称:
JSSoundRecorder 纯js 录音+处理
开发工具:
文件大小: 211kb
下载次数: 0
上传时间: 2018-04-10
详细说明： Record sounds / noises around you and turn them into music. It’s a work in progress, at the moment it enables you to record live audio straight from your browser, edit it and save these sounds as a WAV file. There's also a sequencer part where you can create small loops using these sounds with a drone synth overlaid on them. See it working: http://daaain.github.com/JSSoundRecorder Technology ---------- No servers involved, only Web Audio API with binary sound Blobs passed around! ### Web Audio API #### GetUserMedia audio for live recording Experimental API to record any system audio input (including USB soundcards, musical instruments, etc). ```javascript // shim and create AudioContext window.AudioContext = window.AudioContext || window.webkitAudioContext || window.mozAudioContext; var audio_context = new AudioContext(); // shim and start GetUserMedia audio stream navigator.getUserMedia = navigator.getUserMedia || navigator.webkitGetUserMedia || navigator.mozGetUserMedia; navigator.getUserMedia({audio: true}, startUserMedia, function(e) { console.log('No live audio input: ' + e); }); ``` #### Audio nodes for routing You can route audio stream around, with input nodes (microphone, synths, etc), filters (volume / gain, equaliser, low pass, etc) and outputs (speakers, binary streams, etc). ```javascript function startUserMedia(stream) { // create MediaStreamSource and GainNode var input = audio_context.createMediaStreamSource(stream); var volume = audio_context.createGain(); volume.gain.value = 0.7; // connect them and pipe output input.connect(volume); volume.connect(audio_context.destination); // connect recorder as well - see below var recorder = new Recorder(input); } ``` ### WebWorker Processing (interleaving) record buffer is done in the background to not block the main thread and the UI. Also WAV conversion for export is also quite heavy for longer recordings, so best left to run in the background. ```javascript this.context = input.context; this.node = this.context.createScriptProcessor(4096, 2, 2); this.node.onaudioprocess = function(e){ worker.postMessage({ command: 'record', buffer: [ e.inputBuffer.getChannelData(0), e.inputBuffer.getChannelData(1) ] }); } ``` ```javascript function record(inputBuffer){ var bufferL = inputBuffer[0]; var bufferR = inputBuffer[1]; var interleaved = interleave(bufferL, bufferR); recBuffers.push(interleaved); recLength += interleaved.length; } function interleave(inputL, inputR){ var length = inputL.length + inputR.length; var result = new Float32Array(length); var index = 0, inputIndex = 0; while (index < length){ result[index++] = inputL[inputIndex]; result[index++] = inputR[inputIndex]; inputIndex++; } return result; } ``` ```javascript function encodeWAV(samples){ var buffer = new ArrayBuffer(44 + samples.length * 2); var view = new DataView(buffer); /* RIFF identifier */ writeString(view, 0, 'RIFF'); /* file length */ view.setUint32(4, 32 + samples.length * 2, true); /* RIFF type */ writeString(view, 8, 'WAVE'); /* format chunk identifier */ writeString(view, 12, 'fmt '); /* format chunk length */ view.setUint32(16, 16, true); /* sample format (raw) */ view.setUint16(20, 1, true); /* channel count */ view.setUint16(22, 2, true); /* sample rate */ view.setUint32(24, sampleRate, true); /* byte rate (sample rate * block align) */ view.setUint32(28, sampleRate * 4, true); /* block align (channel count * bytes per sample) */ view.setUint16(32, 4, true); /* bits per sample */ view.setUint16(34, 16, true); /* data chunk identifier */ writeString(view, 36, 'data'); /* data chunk length */ view.setUint32(40, samples.length * 2, true); floatTo16BitPCM(view, 44, samples); return view; } ``` ### Binary Blob Instead of file drag and drop interface this binary blob is passed to editor. Note: BlobBuilder deprecated (but a lot of examples use it), you should use Blob constructor instead! ```javascript var f = new FileReader(); f. { audio_context.decodeAudioData(e.target.result, function(buffer) { $('#audioLayerControl')[0].handleAudio(buffer); }, function(e) { console.warn(e); }); }; f.readAsArrayBuffer(blob); ``` ```javascript function exportWAV(type){ var buffer = mergeBuffers(recBuffers, recLength); var dataview = encodeWAV(buffer); var audioBlob = new Blob([dataview], { type: type }); this.postMessage(audioBlob); } ``` ### Virtual File – URL.createObjectURL You can create file download link pointing to WAV blob, but also set it as the source of an Audio element. ```javascript var url = URL.createObjectURL(blob); var audioElement = document.createElement('audio'); var downloadAnchor = document.createElement('a'); audioElement.controls = true; audioElement.src = url; downloadAnchor.href = url; ``` TODO ---- * Sequencer top / status row should be radio buttons :) * Code cleanup / restructuring * Enable open / drag and drop files for editing * Visual feedback (levels) for live recording * Sequencer UI (and separation to a different module) Credits / license ----------------- Live recording code adapted from: http://www.phpied.com/files/webaudio/record.html Editor code adapted from: https://github.com/plucked/html5-audio-editor Copyright (c) 2012 Daniel Demmel MIT License ...展开收缩
(系统自动生成,下载前可以参看下载内容)
下载文件列表
相关说明
- 本站资源为会员上传分享交流与学习,如有侵犯您的权益,请联系我们删除.
- 本站是交换下载平台，提供交流渠道，下载内容来自于网络，除下载问题外，其它问题请自行百度。
- 本站已设置防盗链，请勿用迅雷、QQ旋风等多线程下载软件下载资源，下载后用WinRAR最新版进行解压.
- 如果您发现内容无法下载，请稍后再次尝试；或者到消费记录里找到下载记录反馈给我们.
- 下载后发现下载的内容跟说明不相乎，请到消费记录里找到下载记录反馈给我们，经确认后退回积分.
- 如下载前有疑问，可以通过点击"提供者"的名字，查看对方的联系方式，联系对方咨询.
