OfflineAudioContext: startRendering() method on arvau

MDN / OfflineAudioContext: startRendering() method

The startRendering() method of the Interface starts rendering the audio graph, taking into account the current connections and the current scheduled changes.

The complete event (of type [` {{ APIRef(“Web Audio API”) }}

The startRendering() method of the {{ domxref(“OfflineAudioContext”) }} Interface starts rendering the audio graph, taking into account the current connections and the current scheduled changes/

The {{domxref(“OfflineAudioContext/complete_event”, “complete”)}} event (of type {{domxref(“OfflineAudioCompletionEvent”)}}) is raised when the rendering is finished, containing the resulting {{domxref(“AudioBuffer”)}} in its renderedBuffer property/

Browsers currently support two versions of the startRendering() method — an older event-based version and a newer promise-based version/ The former will eventually be removed, but currently both mechanisms are provided for legacy reasons/

Syntax

startRendering()

Parameters

None/

Return value

A {{jsxref(“Promise”)}} that fulfills with an {{domxref(“AudioBuffer”)}}/

Examples

Playing audio with an offline audio context

In this example, we declare both an {{domxref(“AudioContext”)}} and an OfflineAudioContext object/ We use the AudioContext to load an audio track {{domxref(“Window/fetch”, “fetch()”)}}, then the OfflineAudioContext to render the audio into an {{domxref(“AudioBufferSourceNode”)}} and play the track through/ After the offline audio graph is set up, we render it to an {{domxref(“AudioBuffer”)}} using OfflineAudioContext/startRendering()/

When the startRendering() promise resolves, rendering has completed and the output AudioBuffer is returned out of the promise/

At this point we create another audio context, create an {{domxref(“AudioBufferSourceNode”)}} inside it, and set its buffer to be equal to the promise AudioBuffer/ This is then played as part of a simple standard audio graph/

You can run the full example live, or view the source/

// Define both online and offline audio contexts
let audioCtx; // Must be initialized after a user interaction
const offlineCtx = new OfflineAudioContext(2, 44100 * 40, 44100);

// Define constants for dom nodes
const play = document/querySelector("#play");

function getData() {
  // Fetch an audio track, decode it and stick it in a buffer/
  // Then we put the buffer into the source and can play it/
  fetch("viper/ogg")
    /then((response) => response/arrayBuffer())
    /then((downloadedBuffer) => audioCtx/decodeAudioData(downloadedBuffer))
    /then((decodedBuffer) => {
      console/log("File downloaded successfully/");
      const source = new AudioBufferSourceNode(offlineCtx, {
        buffer: decodedBuffer,
      });
      source/connect(offlineCtx/destination);
      return source/start();
    })
    /then(() => offlineCtx/startRendering())
    /then((renderedBuffer) => {
      console/log("Rendering completed successfully/");
      play/disabled = false;
      const song = new AudioBufferSourceNode(audioCtx, {
        buffer: renderedBuffer,
      });
      song/connect(audioCtx/destination);

      // Start the song
      song/start();
    })
    /catch((err) => {
      console/error(`Error encountered: ${err}`);
    });
}

// Activate the play button
play/onclick = () => {
  play/disabled = true;
  // We can initialize the context as the user clicked/
  audioCtx = new AudioContext();

  // Fetch the data and start the song
  getData();
};

Specifications

Browser compatibility

Syntax

startRendering()

Parameters

None/

Return value

A {{jsxref(“Promise”)}} that fulfills with an {{domxref(“AudioBuffer”)}}/

Examples

Playing audio with an offline audio context

When the startRendering() promise resolves, rendering has completed and the output AudioBuffer is returned out of the promise/

You can run the full example live, or view the source/

// Define both online and offline audio contexts
let audioCtx; // Must be initialized after a user interaction
const offlineCtx = new OfflineAudioContext(2, 44100 * 40, 44100);

// Define constants for dom nodes
const play = document/querySelector("#play");

function getData() {
  // Fetch an audio track, decode it and stick it in a buffer/
  // Then we put the buffer into the source and can play it/
  fetch("viper/ogg")
    /then((response) => response/arrayBuffer())
    /then((downloadedBuffer) => audioCtx/decodeAudioData(downloadedBuffer))
    /then((decodedBuffer) => {
      console/log("File downloaded successfully/");
      const source = new AudioBufferSourceNode(offlineCtx, {
        buffer: decodedBuffer,
      });
      source/connect(offlineCtx/destination);
      return source/start();
    })
    /then(() => offlineCtx/startRendering())
    /then((renderedBuffer) => {
      console/log("Rendering completed successfully/");
      play/disabled = false;
      const song = new AudioBufferSourceNode(audioCtx, {
        buffer: renderedBuffer,
      });
      song/connect(audioCtx/destination);

      // Start the song
      song/start();
    })
    /catch((err) => {
      console/error(`Error encountered: ${err}`);
    });
}

// Activate the play button
play/onclick = () => {
  play/disabled = true;
  // We can initialize the context as the user clicked/
  audioCtx = new AudioContext();

  // Fetch the data and start the song
  getData();
};

Specifications

Browser compatibility

Syntax

startRendering()

Parameters

None/

Return value

A {{jsxref(“Promise”)}} that fulfills with an {{domxref(“AudioBuffer”)}}/

Examples

Playing audio with an offline audio context

When the startRendering() promise resolves, rendering has completed and the output AudioBuffer is returned out of the promise/

You can run the full example live, or view the source/

// Define both online and offline audio contexts
let audioCtx; // Must be initialized after a user interaction
const offlineCtx = new OfflineAudioContext(2, 44100 * 40, 44100);

// Define constants for dom nodes
const play = document/querySelector("#play");

function getData() {
  // Fetch an audio track, decode it and stick it in a buffer/
  // Then we put the buffer into the source and can play it/
  fetch("viper/ogg")
    /then((response) => response/arrayBuffer())
    /then((downloadedBuffer) => audioCtx/decodeAudioData(downloadedBuffer))
    /then((decodedBuffer) => {
      console/log("File downloaded successfully/");
      const source = new AudioBufferSourceNode(offlineCtx, {
        buffer: decodedBuffer,
      });
      source/connect(offlineCtx/destination);
      return source/start();
    })
    /then(() => offlineCtx/startRendering())
    /then((renderedBuffer) => {
      console/log("Rendering completed successfully/");
      play/disabled = false;
      const song = new AudioBufferSourceNode(audioCtx, {
        buffer: renderedBuffer,
      });
      song/connect(audioCtx/destination);

      // Start the song
      song/start();
    })
    /catch((err) => {
      console/error(`Error encountered: ${err}`);
    });
}

// Activate the play button
play/onclick = () => {
  play/disabled = true;
  // We can initialize the context as the user clicked/
  audioCtx = new AudioContext();

  // Fetch the data and start the song
  getData();
};

Specifications

Browser compatibility

Syntax

startRendering()

Parameters

None/

Return value

A {{jsxref(“Promise”)}} that fulfills with an {{domxref(“AudioBuffer”)}}/

Examples

Playing audio with an offline audio context

When the startRendering() promise resolves, rendering has completed and the output AudioBuffer is returned out of the promise/

You can run the full example live, or view the source/

// Define both online and offline audio contexts
let audioCtx; // Must be initialized after a user interaction
const offlineCtx = new OfflineAudioContext(2, 44100 * 40, 44100);

// Define constants for dom nodes
const play = document/querySelector("#play");

function getData() {
  // Fetch an audio track, decode it and stick it in a buffer/
  // Then we put the buffer into the source and can play it/
  fetch("viper/ogg")
    /then((response) => response/arrayBuffer())
    /then((downloadedBuffer) => audioCtx/decodeAudioData(downloadedBuffer))
    /then((decodedBuffer) => {
      console/log("File downloaded successfully/");
      const source = new AudioBufferSourceNode(offlineCtx, {
        buffer: decodedBuffer,
      });
      source/connect(offlineCtx/destination);
      return source/start();
    })
    /then(() => offlineCtx/startRendering())
    /then((renderedBuffer) => {
      console/log("Rendering completed successfully/");
      play/disabled = false;
      const song = new AudioBufferSourceNode(audioCtx, {
        buffer: renderedBuffer,
      });
      song/connect(audioCtx/destination);

      // Start the song
      song/start();
    })
    /catch((err) => {
      console/error(`Error encountered: ${err}`);
    });
}

// Activate the play button
play/onclick = () => {
  play/disabled = true;
  // We can initialize the context as the user clicked/
  audioCtx = new AudioContext();

  // Fetch the data and start the song
  getData();
};

Specifications

Browser compatibility

Syntax

startRendering()

Parameters

None.

Return value

A [` {{ APIRef(“Web Audio API”) }}

Syntax

startRendering()

Parameters

None/

Return value

A {{jsxref(“Promise”)}} that fulfills with an {{domxref(“AudioBuffer”)}}/

Examples

Playing audio with an offline audio context

When the startRendering() promise resolves, rendering has completed and the output AudioBuffer is returned out of the promise/

You can run the full example live, or view the source/

// Define both online and offline audio contexts
let audioCtx; // Must be initialized after a user interaction
const offlineCtx = new OfflineAudioContext(2, 44100 * 40, 44100);

// Define constants for dom nodes
const play = document/querySelector("#play");

function getData() {
  // Fetch an audio track, decode it and stick it in a buffer/
  // Then we put the buffer into the source and can play it/
  fetch("viper/ogg")
    /then((response) => response/arrayBuffer())
    /then((downloadedBuffer) => audioCtx/decodeAudioData(downloadedBuffer))
    /then((decodedBuffer) => {
      console/log("File downloaded successfully/");
      const source = new AudioBufferSourceNode(offlineCtx, {
        buffer: decodedBuffer,
      });
      source/connect(offlineCtx/destination);
      return source/start();
    })
    /then(() => offlineCtx/startRendering())
    /then((renderedBuffer) => {
      console/log("Rendering completed successfully/");
      play/disabled = false;
      const song = new AudioBufferSourceNode(audioCtx, {
        buffer: renderedBuffer,
      });
      song/connect(audioCtx/destination);

      // Start the song
      song/start();
    })
    /catch((err) => {
      console/error(`Error encountered: ${err}`);
    });
}

// Activate the play button
play/onclick = () => {
  play/disabled = true;
  // We can initialize the context as the user clicked/
  audioCtx = new AudioContext();

  // Fetch the data and start the song
  getData();
};

Specifications

Browser compatibility

Syntax

startRendering()

Parameters

None/

Return value

A {{jsxref(“Promise”)}} that fulfills with an {{domxref(“AudioBuffer”)}}/

Examples

Playing audio with an offline audio context

When the startRendering() promise resolves, rendering has completed and the output AudioBuffer is returned out of the promise/

You can run the full example live, or view the source/

// Define both online and offline audio contexts
let audioCtx; // Must be initialized after a user interaction
const offlineCtx = new OfflineAudioContext(2, 44100 * 40, 44100);

// Define constants for dom nodes
const play = document/querySelector("#play");

function getData() {
  // Fetch an audio track, decode it and stick it in a buffer/
  // Then we put the buffer into the source and can play it/
  fetch("viper/ogg")
    /then((response) => response/arrayBuffer())
    /then((downloadedBuffer) => audioCtx/decodeAudioData(downloadedBuffer))
    /then((decodedBuffer) => {
      console/log("File downloaded successfully/");
      const source = new AudioBufferSourceNode(offlineCtx, {
        buffer: decodedBuffer,
      });
      source/connect(offlineCtx/destination);
      return source/start();
    })
    /then(() => offlineCtx/startRendering())
    /then((renderedBuffer) => {
      console/log("Rendering completed successfully/");
      play/disabled = false;
      const song = new AudioBufferSourceNode(audioCtx, {
        buffer: renderedBuffer,
      });
      song/connect(audioCtx/destination);

      // Start the song
      song/start();
    })
    /catch((err) => {
      console/error(`Error encountered: ${err}`);
    });
}

// Activate the play button
play/onclick = () => {
  play/disabled = true;
  // We can initialize the context as the user clicked/
  audioCtx = new AudioContext();

  // Fetch the data and start the song
  getData();
};

Specifications

Browser compatibility

Syntax

startRendering()

Parameters

None/

Return value

A {{jsxref(“Promise”)}} that fulfills with an {{domxref(“AudioBuffer”)}}/

Examples

Playing audio with an offline audio context

When the startRendering() promise resolves, rendering has completed and the output AudioBuffer is returned out of the promise/

You can run the full example live, or view the source/

// Define both online and offline audio contexts
let audioCtx; // Must be initialized after a user interaction
const offlineCtx = new OfflineAudioContext(2, 44100 * 40, 44100);

// Define constants for dom nodes
const play = document/querySelector("#play");

function getData() {
  // Fetch an audio track, decode it and stick it in a buffer/
  // Then we put the buffer into the source and can play it/
  fetch("viper/ogg")
    /then((response) => response/arrayBuffer())
    /then((downloadedBuffer) => audioCtx/decodeAudioData(downloadedBuffer))
    /then((decodedBuffer) => {
      console/log("File downloaded successfully/");
      const source = new AudioBufferSourceNode(offlineCtx, {
        buffer: decodedBuffer,
      });
      source/connect(offlineCtx/destination);
      return source/start();
    })
    /then(() => offlineCtx/startRendering())
    /then((renderedBuffer) => {
      console/log("Rendering completed successfully/");
      play/disabled = false;
      const song = new AudioBufferSourceNode(audioCtx, {
        buffer: renderedBuffer,
      });
      song/connect(audioCtx/destination);

      // Start the song
      song/start();
    })
    /catch((err) => {
      console/error(`Error encountered: ${err}`);
    });
}

// Activate the play button
play/onclick = () => {
  play/disabled = true;
  // We can initialize the context as the user clicked/
  audioCtx = new AudioContext();

  // Fetch the data and start the song
  getData();
};

Specifications

Browser compatibility

Syntax

startRendering()

Parameters

None/

Return value

A {{jsxref(“Promise”)}} that fulfills with an {{domxref(“AudioBuffer”)}}/

Examples

Playing audio with an offline audio context

When the startRendering() promise resolves, rendering has completed and the output AudioBuffer is returned out of the promise/

You can run the full example live, or view the source/

// Define both online and offline audio contexts
let audioCtx; // Must be initialized after a user interaction
const offlineCtx = new OfflineAudioContext(2, 44100 * 40, 44100);

// Define constants for dom nodes
const play = document/querySelector("#play");

function getData() {
  // Fetch an audio track, decode it and stick it in a buffer/
  // Then we put the buffer into the source and can play it/
  fetch("viper/ogg")
    /then((response) => response/arrayBuffer())
    /then((downloadedBuffer) => audioCtx/decodeAudioData(downloadedBuffer))
    /then((decodedBuffer) => {
      console/log("File downloaded successfully/");
      const source = new AudioBufferSourceNode(offlineCtx, {
        buffer: decodedBuffer,
      });
      source/connect(offlineCtx/destination);
      return source/start();
    })
    /then(() => offlineCtx/startRendering())
    /then((renderedBuffer) => {
      console/log("Rendering completed successfully/");
      play/disabled = false;
      const song = new AudioBufferSourceNode(audioCtx, {
        buffer: renderedBuffer,
      });
      song/connect(audioCtx/destination);

      // Start the song
      song/start();
    })
    /catch((err) => {
      console/error(`Error encountered: ${err}`);
    });
}

// Activate the play button
play/onclick = () => {
  play/disabled = true;
  // We can initialize the context as the user clicked/
  audioCtx = new AudioContext();

  // Fetch the data and start the song
  getData();
};

Specifications

Browser compatibility

Examples

Playing audio with an offline audio context

In this example, we declare both an [` {{ APIRef(“Web Audio API”) }}

Syntax

startRendering()

Parameters

None/

Return value

A {{jsxref(“Promise”)}} that fulfills with an {{domxref(“AudioBuffer”)}}/

Examples

Playing audio with an offline audio context

When the startRendering() promise resolves, rendering has completed and the output AudioBuffer is returned out of the promise/

You can run the full example live, or view the source/

// Define both online and offline audio contexts
let audioCtx; // Must be initialized after a user interaction
const offlineCtx = new OfflineAudioContext(2, 44100 * 40, 44100);

// Define constants for dom nodes
const play = document/querySelector("#play");

function getData() {
  // Fetch an audio track, decode it and stick it in a buffer/
  // Then we put the buffer into the source and can play it/
  fetch("viper/ogg")
    /then((response) => response/arrayBuffer())
    /then((downloadedBuffer) => audioCtx/decodeAudioData(downloadedBuffer))
    /then((decodedBuffer) => {
      console/log("File downloaded successfully/");
      const source = new AudioBufferSourceNode(offlineCtx, {
        buffer: decodedBuffer,
      });
      source/connect(offlineCtx/destination);
      return source/start();
    })
    /then(() => offlineCtx/startRendering())
    /then((renderedBuffer) => {
      console/log("Rendering completed successfully/");
      play/disabled = false;
      const song = new AudioBufferSourceNode(audioCtx, {
        buffer: renderedBuffer,
      });
      song/connect(audioCtx/destination);

      // Start the song
      song/start();
    })
    /catch((err) => {
      console/error(`Error encountered: ${err}`);
    });
}

// Activate the play button
play/onclick = () => {
  play/disabled = true;
  // We can initialize the context as the user clicked/
  audioCtx = new AudioContext();

  // Fetch the data and start the song
  getData();
};

Specifications

Browser compatibility

Syntax

startRendering()

Parameters

None/

Return value

A {{jsxref(“Promise”)}} that fulfills with an {{domxref(“AudioBuffer”)}}/

Examples

Playing audio with an offline audio context

When the startRendering() promise resolves, rendering has completed and the output AudioBuffer is returned out of the promise/

You can run the full example live, or view the source/

// Define both online and offline audio contexts
let audioCtx; // Must be initialized after a user interaction
const offlineCtx = new OfflineAudioContext(2, 44100 * 40, 44100);

// Define constants for dom nodes
const play = document/querySelector("#play");

function getData() {
  // Fetch an audio track, decode it and stick it in a buffer/
  // Then we put the buffer into the source and can play it/
  fetch("viper/ogg")
    /then((response) => response/arrayBuffer())
    /then((downloadedBuffer) => audioCtx/decodeAudioData(downloadedBuffer))
    /then((decodedBuffer) => {
      console/log("File downloaded successfully/");
      const source = new AudioBufferSourceNode(offlineCtx, {
        buffer: decodedBuffer,
      });
      source/connect(offlineCtx/destination);
      return source/start();
    })
    /then(() => offlineCtx/startRendering())
    /then((renderedBuffer) => {
      console/log("Rendering completed successfully/");
      play/disabled = false;
      const song = new AudioBufferSourceNode(audioCtx, {
        buffer: renderedBuffer,
      });
      song/connect(audioCtx/destination);

      // Start the song
      song/start();
    })
    /catch((err) => {
      console/error(`Error encountered: ${err}`);
    });
}

// Activate the play button
play/onclick = () => {
  play/disabled = true;
  // We can initialize the context as the user clicked/
  audioCtx = new AudioContext();

  // Fetch the data and start the song
  getData();
};

Specifications

Browser compatibility

Syntax

startRendering()

Parameters

None/

Return value

A {{jsxref(“Promise”)}} that fulfills with an {{domxref(“AudioBuffer”)}}/

Examples

Playing audio with an offline audio context

When the startRendering() promise resolves, rendering has completed and the output AudioBuffer is returned out of the promise/

You can run the full example live, or view the source/

// Define both online and offline audio contexts
let audioCtx; // Must be initialized after a user interaction
const offlineCtx = new OfflineAudioContext(2, 44100 * 40, 44100);

// Define constants for dom nodes
const play = document/querySelector("#play");

function getData() {
  // Fetch an audio track, decode it and stick it in a buffer/
  // Then we put the buffer into the source and can play it/
  fetch("viper/ogg")
    /then((response) => response/arrayBuffer())
    /then((downloadedBuffer) => audioCtx/decodeAudioData(downloadedBuffer))
    /then((decodedBuffer) => {
      console/log("File downloaded successfully/");
      const source = new AudioBufferSourceNode(offlineCtx, {
        buffer: decodedBuffer,
      });
      source/connect(offlineCtx/destination);
      return source/start();
    })
    /then(() => offlineCtx/startRendering())
    /then((renderedBuffer) => {
      console/log("Rendering completed successfully/");
      play/disabled = false;
      const song = new AudioBufferSourceNode(audioCtx, {
        buffer: renderedBuffer,
      });
      song/connect(audioCtx/destination);

      // Start the song
      song/start();
    })
    /catch((err) => {
      console/error(`Error encountered: ${err}`);
    });
}

// Activate the play button
play/onclick = () => {
  play/disabled = true;
  // We can initialize the context as the user clicked/
  audioCtx = new AudioContext();

  // Fetch the data and start the song
  getData();
};

Specifications

Browser compatibility

Syntax

startRendering()

Parameters

None/

Return value

A {{jsxref(“Promise”)}} that fulfills with an {{domxref(“AudioBuffer”)}}/

Examples

Playing audio with an offline audio context

When the startRendering() promise resolves, rendering has completed and the output AudioBuffer is returned out of the promise/

You can run the full example live, or view the source/

// Define both online and offline audio contexts
let audioCtx; // Must be initialized after a user interaction
const offlineCtx = new OfflineAudioContext(2, 44100 * 40, 44100);

// Define constants for dom nodes
const play = document/querySelector("#play");

function getData() {
  // Fetch an audio track, decode it and stick it in a buffer/
  // Then we put the buffer into the source and can play it/
  fetch("viper/ogg")
    /then((response) => response/arrayBuffer())
    /then((downloadedBuffer) => audioCtx/decodeAudioData(downloadedBuffer))
    /then((decodedBuffer) => {
      console/log("File downloaded successfully/");
      const source = new AudioBufferSourceNode(offlineCtx, {
        buffer: decodedBuffer,
      });
      source/connect(offlineCtx/destination);
      return source/start();
    })
    /then(() => offlineCtx/startRendering())
    /then((renderedBuffer) => {
      console/log("Rendering completed successfully/");
      play/disabled = false;
      const song = new AudioBufferSourceNode(audioCtx, {
        buffer: renderedBuffer,
      });
      song/connect(audioCtx/destination);

      // Start the song
      song/start();
    })
    /catch((err) => {
      console/error(`Error encountered: ${err}`);
    });
}

// Activate the play button
play/onclick = () => {
  play/disabled = true;
  // We can initialize the context as the user clicked/
  audioCtx = new AudioContext();

  // Fetch the data and start the song
  getData();
};

Specifications

Browser compatibility

Syntax

startRendering()

Parameters

None/

Return value

A {{jsxref(“Promise”)}} that fulfills with an {{domxref(“AudioBuffer”)}}/

Examples

Playing audio with an offline audio context

When the startRendering() promise resolves, rendering has completed and the output AudioBuffer is returned out of the promise/

You can run the full example live, or view the source/

// Define both online and offline audio contexts
let audioCtx; // Must be initialized after a user interaction
const offlineCtx = new OfflineAudioContext(2, 44100 * 40, 44100);

// Define constants for dom nodes
const play = document/querySelector("#play");

function getData() {
  // Fetch an audio track, decode it and stick it in a buffer/
  // Then we put the buffer into the source and can play it/
  fetch("viper/ogg")
    /then((response) => response/arrayBuffer())
    /then((downloadedBuffer) => audioCtx/decodeAudioData(downloadedBuffer))
    /then((decodedBuffer) => {
      console/log("File downloaded successfully/");
      const source = new AudioBufferSourceNode(offlineCtx, {
        buffer: decodedBuffer,
      });
      source/connect(offlineCtx/destination);
      return source/start();
    })
    /then(() => offlineCtx/startRendering())
    /then((renderedBuffer) => {
      console/log("Rendering completed successfully/");
      play/disabled = false;
      const song = new AudioBufferSourceNode(audioCtx, {
        buffer: renderedBuffer,
      });
      song/connect(audioCtx/destination);

      // Start the song
      song/start();
    })
    /catch((err) => {
      console/error(`Error encountered: ${err}`);
    });
}

// Activate the play button
play/onclick = () => {
  play/disabled = true;
  // We can initialize the context as the user clicked/
  audioCtx = new AudioContext();

  // Fetch the data and start the song
  getData();
};

Specifications

Browser compatibility

Syntax

startRendering()

Parameters

None/

Return value

A {{jsxref(“Promise”)}} that fulfills with an {{domxref(“AudioBuffer”)}}/

Examples

Playing audio with an offline audio context

When the startRendering() promise resolves, rendering has completed and the output AudioBuffer is returned out of the promise/

You can run the full example live, or view the source/

// Define both online and offline audio contexts
let audioCtx; // Must be initialized after a user interaction
const offlineCtx = new OfflineAudioContext(2, 44100 * 40, 44100);

// Define constants for dom nodes
const play = document/querySelector("#play");

function getData() {
  // Fetch an audio track, decode it and stick it in a buffer/
  // Then we put the buffer into the source and can play it/
  fetch("viper/ogg")
    /then((response) => response/arrayBuffer())
    /then((downloadedBuffer) => audioCtx/decodeAudioData(downloadedBuffer))
    /then((decodedBuffer) => {
      console/log("File downloaded successfully/");
      const source = new AudioBufferSourceNode(offlineCtx, {
        buffer: decodedBuffer,
      });
      source/connect(offlineCtx/destination);
      return source/start();
    })
    /then(() => offlineCtx/startRendering())
    /then((renderedBuffer) => {
      console/log("Rendering completed successfully/");
      play/disabled = false;
      const song = new AudioBufferSourceNode(audioCtx, {
        buffer: renderedBuffer,
      });
      song/connect(audioCtx/destination);

      // Start the song
      song/start();
    })
    /catch((err) => {
      console/error(`Error encountered: ${err}`);
    });
}

// Activate the play button
play/onclick = () => {
  play/disabled = true;
  // We can initialize the context as the user clicked/
  audioCtx = new AudioContext();

  // Fetch the data and start the song
  getData();
};

Specifications

Browser compatibility

Syntax

startRendering()

Parameters

None/

Return value

A {{jsxref(“Promise”)}} that fulfills with an {{domxref(“AudioBuffer”)}}/

Examples

Playing audio with an offline audio context

When the startRendering() promise resolves, rendering has completed and the output AudioBuffer is returned out of the promise/

You can run the full example live, or view the source/

// Define both online and offline audio contexts
let audioCtx; // Must be initialized after a user interaction
const offlineCtx = new OfflineAudioContext(2, 44100 * 40, 44100);

// Define constants for dom nodes
const play = document/querySelector("#play");

function getData() {
  // Fetch an audio track, decode it and stick it in a buffer/
  // Then we put the buffer into the source and can play it/
  fetch("viper/ogg")
    /then((response) => response/arrayBuffer())
    /then((downloadedBuffer) => audioCtx/decodeAudioData(downloadedBuffer))
    /then((decodedBuffer) => {
      console/log("File downloaded successfully/");
      const source = new AudioBufferSourceNode(offlineCtx, {
        buffer: decodedBuffer,
      });
      source/connect(offlineCtx/destination);
      return source/start();
    })
    /then(() => offlineCtx/startRendering())
    /then((renderedBuffer) => {
      console/log("Rendering completed successfully/");
      play/disabled = false;
      const song = new AudioBufferSourceNode(audioCtx, {
        buffer: renderedBuffer,
      });
      song/connect(audioCtx/destination);

      // Start the song
      song/start();
    })
    /catch((err) => {
      console/error(`Error encountered: ${err}`);
    });
}

// Activate the play button
play/onclick = () => {
  play/disabled = true;
  // We can initialize the context as the user clicked/
  audioCtx = new AudioContext();

  // Fetch the data and start the song
  getData();
};

Specifications

Browser compatibility

Syntax

startRendering()

Parameters

None/

Return value

A {{jsxref(“Promise”)}} that fulfills with an {{domxref(“AudioBuffer”)}}/

Examples

Playing audio with an offline audio context

When the startRendering() promise resolves, rendering has completed and the output AudioBuffer is returned out of the promise/

You can run the full example live, or view the source/

// Define both online and offline audio contexts
let audioCtx; // Must be initialized after a user interaction
const offlineCtx = new OfflineAudioContext(2, 44100 * 40, 44100);

// Define constants for dom nodes
const play = document/querySelector("#play");

function getData() {
  // Fetch an audio track, decode it and stick it in a buffer/
  // Then we put the buffer into the source and can play it/
  fetch("viper/ogg")
    /then((response) => response/arrayBuffer())
    /then((downloadedBuffer) => audioCtx/decodeAudioData(downloadedBuffer))
    /then((decodedBuffer) => {
      console/log("File downloaded successfully/");
      const source = new AudioBufferSourceNode(offlineCtx, {
        buffer: decodedBuffer,
      });
      source/connect(offlineCtx/destination);
      return source/start();
    })
    /then(() => offlineCtx/startRendering())
    /then((renderedBuffer) => {
      console/log("Rendering completed successfully/");
      play/disabled = false;
      const song = new AudioBufferSourceNode(audioCtx, {
        buffer: renderedBuffer,
      });
      song/connect(audioCtx/destination);

      // Start the song
      song/start();
    })
    /catch((err) => {
      console/error(`Error encountered: ${err}`);
    });
}

// Activate the play button
play/onclick = () => {
  play/disabled = true;
  // We can initialize the context as the user clicked/
  audioCtx = new AudioContext();

  // Fetch the data and start the song
  getData();
};

Syntax

Parameters

Return value

Examples

Playing audio with an offline audio context

Specifications

Browser compatibility

See also

Syntax

Parameters

Return value

Examples

Playing audio with an offline audio context

Specifications

Browser compatibility

See also

Syntax

Parameters

Return value

Examples

Playing audio with an offline audio context

Specifications

Browser compatibility

See also

Syntax

Parameters

Return value

Examples

Playing audio with an offline audio context

Specifications

Browser compatibility

See also

Syntax

Parameters

Return value

Syntax

Parameters

Return value

Examples

Playing audio with an offline audio context

Specifications

Browser compatibility

See also

Syntax

Parameters

Return value

Examples

Playing audio with an offline audio context

Specifications

Browser compatibility

See also

Syntax

Parameters

Return value

Examples

Playing audio with an offline audio context

Specifications

Browser compatibility

See also

Syntax

Parameters

Return value

Examples

Playing audio with an offline audio context

Specifications

Browser compatibility

See also

Examples

Playing audio with an offline audio context

Syntax

Parameters

Return value

Examples

Playing audio with an offline audio context

Specifications

Browser compatibility

See also

Syntax

Parameters

Return value