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bufferWriter

warning

We are phasing out Remotion WebCodecs and are moving to Mediabunny!

💼 Important License Disclaimer
This package is licensed under the Remotion License.
We consider a team of 4 or more people a "company".

For "companies": A Remotion Company license needs to be obtained to use this package.
In a future version of @remotion/webcodecs, this package will also require the purchase of a newly created "WebCodecs Conversion Seat". Get in touch with us if you are planning to use this package.

For individuals and teams up to 3: You can use this package for free.

This is a short, non-binding explanation of our license. See the License itself for more details.
warning

Unstable API: The writer interface is experimental. The API may change in the future.

A writer for @remotion/webcodecs that writes to an in-memory resizable ArrayBuffer.

Can be used for convertMedia() to write the converted output to memory as a buffer.

Example​

Using bufferWriter
import {convertMedia} from '@remotion/webcodecs';
import {bufferWriter} from '@remotion/webcodecs/buffer';

const result = await convertMedia({
  src: 'https://remotion.media/BigBuckBunny.mp4',
  container: 'webm',
  writer: bufferWriter,
});

const blob = await result.save();

Memory limitations​

The bufferWriter uses a resizable ArrayBuffer with a maximum size of 2GB. If your output file would exceed this limit, the conversion will fail.

Error handling for large files
import {convertMedia} from '@remotion/webcodecs';
import {bufferWriter} from '@remotion/webcodecs/buffer';

try {
  const result = await convertMedia({
    src: 'very-large-video.mp4',
    container: 'webm',
    writer: bufferWriter,
  });
} catch (error) {
  if ((error as Error).message.includes('Could not create buffer writer')) {
    // Handle case where ArrayBuffer cannot be resized further
    console.log('File too large for buffer writer, consider using webFsWriter');
  }
}

See also​