WEBMRecorder

class NatML.Recorders.WEBMRecorder : IMediaRecorder

The WEBMRecorder records *.webm video files.

The WEBMRecorder uses the VP8 codec for video and the OPUS codec for audio.

The WEBMRecorder is not supported on iOS, macOS, or Windows.

Creating the Recorder

/// <summary>
/// Create a WEBM recorder.
/// </summary>
/// <param name="width">Video width.</param>
/// <param name="height">Video height.</param>
/// <param name="frameRate">Video frame rate.</param>
/// <param name="sampleRate">Audio sample rate. Pass 0 for no audio.</param>
/// <param name="channelCount">Audio channel count. Pass 0 for no audio.</param>
/// <param name="bitrate">Video bitrate in bits per second.</param>
WEBMRecorder (int width, int height, float frameRate, int sampleRate = ..., int channelCaount = ..., int bitrate = ...);

The WEBMRecorder can be created to record video with optional audio. To record video only, simply provide the video width, video height, and video frameRate.

// Record video only at 720p30
var recorder = new WEBMRecorder(1280, 720, 60);

To record video with audio, you will provide the audio format along with the video format. The audio format comprises of the sampleRate and channelCount.

// Record 480p video with 24KHz mono audio
var recorder = new WEBMRecorder(640, 480, 30, 24000, 1);

When recording audio from Unity (e.g. using an AudioInput):

• Set the sampleRate to AudioSettings.outputSampleRate.

• Set the channelCount to (int)AudioSettings.speakerMode.

Video Size

/// <summary>
/// Video size.
/// </summary>
(int width, int height) frameSize { get; }

Refer to the Frame Size section of the IMediaRecorder interface for more information.

Committing Video Frames

/// <summary>
/// Commit a video pixel buffer for encoding.
/// The pixel buffer MUST have an RGBA8888 pixel layout.
/// </summary>
/// <param name="pixelBuffer">Pixel buffer containing video frame to commit.</param>
/// <param name="timestamp">Pixel buffer timestamp in nanoseconds.</param>
void CommitFrame<T> (T[] pixelBuffer, long timestamp) where T : struct;

Refer to the Committing Video Frames section of the IMediaRecorder interface for more information.

Committing Audio Frames

/// <summary>
/// Commit an audio sample buffer for encoding.
/// </summary>
/// <param name="sampleBuffer">Linear PCM audio sample buffer, interleaved by channel.</param>
/// <param name="timestamp">Sample buffer timestamp in nanoseconds.</param>
void CommitSamples (float[] sampleBuffer, long timestamp);

Refer to the Committing Audio Frames section of the IMediaRecorder interface for more information.

Finishing Recording

/// <summary>
/// Finish writing and return the path to the recorded media file.
/// </summary>
Task<string> FinishWriting ();

Refer to the Finishing Recording section of the IMediaRecorder interface for more information.