--- title: AudioBuffer slug: Web/API/AudioBuffer translation_of: Web/API/AudioBuffer --- <p>{{APIRef}}</p> <div> <p><code>AudioBuffer는 </code>{{ domxref("AudioContext.decodeAudioData()") }} 혹은 {{ domxref("AudioContext.createBuffer()") }}를 통해 만들어진 로우 데이터를 메모리상에 두고 사용하는 기술이다. 일단 한번 AudioBuffer 에 들어간 정보는 {{ domxref("AudioBufferSourceNode") }}를 통해 재생이 가능하다.</p> <p>이 객체는 일반적으로 45초 이하의 오디오 정보를 가지고 있다. 더 긴 시간의 소리정보는 {{domxref("MediaElementAudioSourceNode")}}를 사용하는 것이 더 적합하다. The buffer contains data in the following format: non-interleaved IEEE754 32-bit linear PCM with a nominal range between <code>-1</code> and <code>+1</code>, that is, 32bits floating point buffer, with each samples between -1.0 and 1.0. 만약에 {{domxref("AudioBuffer")}} 가 멀티 채널을 가진다면 이는 버퍼를 나눠서 저장을 합니다.</p> </div> <h2 id="Properties">Properties</h2> <dl> <dt> {{domxref("AudioBuffer.sampleRate")}} {{readonlyInline}}</dt> <dd> 버퍼에 저장된 샘플정보의 매 초당 배율을 float형으로 리턴한다.</dd> <dt> {{domxref("AudioBuffer.length")}} {{readonlyInline}}</dt> <dd> 샘플프레임안의 버퍼에 저장된 PCM정보의 길이를 정수형으로 리턴한다.</dd> <dt> {{domxref("AudioBuffer.duration")}} {{readonlyInline}}</dt> <dd> 버퍼에 저장된 PCM정보의 재생길이를 double형으로 리턴한다.</dd> <dt> {{domxref("AudioBuffer.numberOfChannels")}} {{readonlyInline}}</dt> <dd> 버퍼에 저장된 PCM정보에 의해 구분된 채널의 갯수를 정수형으로 리턴한다.</dd> </dl> <h2 id="Methods">Methods</h2> <dl> <dt> {{domxref("AudioBuffer.getChannelData()")}}</dt> <dd> {{jsxref("Float32Array")}}에 담긴 PCM데이터와 channel 파라메로 정의된 채널 정보(첫번째 채널은 0)를 리턴한다.</dd> <dt> {{domxref("AudioBuffer.copyFromChannel()")}}</dt> <dd> 특정 채널의 <span class="idlType"><code>AudioBuffer를 </code></span><code>destination배열로 복사를 한다.</code></dd> <dt> {{domxref("AudioBuffer.copyToChannel()")}}</dt> <dd> 특정 채널의 <span class="idlType"><code>AudioBuffer에 </code></span><code>source배열로 부터 정보를 복사해 온다.</code></dd> </dl> <h2 id="Example">Example</h2> <p>이 예제는 어떻게 <code>AudioBuffer 를 생성하고</code> 랜덤한 화이트 노이즈를 채우는 방법을 설명한다. <a href="https://github.com/mdn/audio-buffer">audio-buffer demo</a> 에서 전체 소스를 확인 가능하고 <a href="http://mdn.github.io/audio-buffer/">running live</a> 실시간 테스트고 가능하다.</p> <pre class="brush: js;highlight:[7,14,27]">// Stereo var channels = 2; // Create an empty two second stereo buffer at the // sample rate of the AudioContext var frameCount = audioCtx.sampleRate * 2.0; var myArrayBuffer = audioCtx.createBuffer(channels, frameCount, audioCtx.sampleRate); button.onclick = function() { // Fill the buffer with white noise; // just random values between -1.0 and 1.0 for (var channel = 0; channel < channels; channel++) { // This gives us the actual array that contains the data var nowBuffering = myArrayBuffer.getChannelData(channel); for (var i = 0; i < frameCount; i++) { // Math.random() is in [0; 1.0] // audio needs to be in [-1.0; 1.0] nowBuffering[i] = Math.random() * 2 - 1; } } // Get an AudioBufferSourceNode. // This is the AudioNode to use when we want to play an AudioBuffer var source = audioCtx.createBufferSource(); // set the buffer in the AudioBufferSourceNode source.buffer = myArrayBuffer; // connect the AudioBufferSourceNode to the // destination so we can hear the sound source.connect(audioCtx.destination); // start the source playing source.start(); } </pre> <h2 id="Specification">Specification</h2> <table class="standard-table"> <tbody> <tr> <th scope="col">Specification</th> <th scope="col">Status</th> <th scope="col">Comment</th> </tr> <tr> <td>{{SpecName('Web Audio API', '#the-audiobuffer-interface', 'AudioBuffer')}}</td> <td>{{Spec2('Web Audio API')}}</td> <td>Initial definition.</td> </tr> </tbody> </table> <h2 id="Browser_compatibility">Browser compatibility</h2> <div> {{CompatibilityTable}}</div> <div id="compat-desktop"> <table class="compat-table"> <tbody> <tr> <th>Feature</th> <th>Chrome</th> <th>Firefox (Gecko)</th> <th>Internet Explorer</th> <th>Opera</th> <th>Safari (WebKit)</th> </tr> <tr> <td>Basic support</td> <td>14 {{property_prefix("webkit")}}</td> <td>{{CompatGeckoDesktop(25)}}</td> <td>{{CompatNo}}</td> <td>15 {{property_prefix("webkit")}}<br> 22 (unprefixed)</td> <td>6 {{property_prefix("webkit")}}</td> </tr> <tr> <td><code>copyFromChannel()</code> and <code>copyToChannel()</code></td> <td>{{CompatUnknown}}</td> <td>{{CompatGeckoDesktop(27)}}</td> <td>{{CompatNo}}</td> <td>{{CompatUnknown}}</td> <td>{{CompatUnknown}}</td> </tr> </tbody> </table> </div> <div id="compat-mobile"> <table class="compat-table"> <tbody> <tr> <th>Feature</th> <th>Android</th> <th>Chrome</th> <th>Firefox Mobile (Gecko)</th> <th>Firefox OS</th> <th>IE Phone</th> <th>Opera Mobile</th> <th>Safari Mobile</th> </tr> <tr> <td>Basic support</td> <td>{{CompatNo}}</td> <td>28 {{property_prefix("webkit")}}</td> <td>{{CompatGeckoMobile(25)}}</td> <td>1.2</td> <td>{{CompatNo}}</td> <td>{{CompatNo}}</td> <td>6 {{property_prefix("webkit")}}</td> </tr> <tr> <td><code>copyFromChannel()</code> and <code>copyToChannel()</code></td> <td>{{CompatNo}}</td> <td>{{CompatUnknown}}</td> <td>{{CompatGeckoMobile(27)}}</td> <td> </td> <td>{{CompatNo}}</td> <td>{{CompatNo}}</td> <td>{{CompatUnknown}}</td> </tr> </tbody> </table> </div> <h2 id="See_also">See also</h2> <ul> <li><a href="/en-US/docs/Web/API/Web_Audio_API/Using_Web_Audio_API">Using the Web Audio API</a></li> </ul>