Class reference

MovieWriter

Inherits Object

Abstract class for non-real-time video recording encoders.

Description

Redot can record videos with non-real-time simulation. Like the --fixed-fps command line argument, this forces the reported delta in Node._process() functions to be identical across frames, regardless of how long it actually took to render the frame. This can be used to record high-quality videos with perfect frame pacing regardless of your hardware's capabilities. Redot has 3 built-in MovieWriters: - OGV container with Theora for video and Vorbis for audio (.ogv file extension). Lossy compression, medium file sizes, fast encoding. The lossy compression quality can be adjusted by changing ProjectSettings.editor/movie_writer/video_quality and ProjectSettings.editor/movie_writer/ogv/audio_quality. The resulting file can be viewed in Redot with VideoStreamPlayer and most video players, but not web browsers as they don't support Theora. - AVI container with MJPEG for video and uncompressed audio (.avi file extension). Lossy compression, medium file sizes, fast encoding. The lossy compression quality can be adjusted by changing ProjectSettings.editor/movie_writer/video_quality. The resulting file can be viewed in most video players, but it must be converted to another format for viewing on the web or by Redot with VideoStreamPlayer. MJPEG does not support transparency. AVI output is currently limited to a file of 4 GB in size at most. - PNG image sequence for video and WAV for audio (.png file extension). Lossless compression, large file sizes, slow encoding. Designed to be encoded to a video file with another tool such as FFmpeg after recording. Transparency is currently not supported, even if the root viewport is set to be transparent. If you need to encode to a different format or pipe a stream through third-party software, you can extend the MovieWriter class to create your own movie writers. This should typically be done using GDExtension for performance reasons. Editor usage: A default movie file path can be specified in ProjectSettings.editor/movie_writer/movie_file. Alternatively, for running single scenes, a movie_file metadata can be added to the root node, specifying the path to a movie file that will be used when recording that scene. Once a path is set, click the video reel icon in the top-right corner of the editor to enable Movie Maker mode, then run any scene as usual. The engine will start recording as soon as the splash screen is finished, and it will only stop recording when the engine quits. Click the video reel icon again to disable Movie Maker mode. Note that toggling Movie Maker mode does not affect project instances that are already running. Note: MovieWriter is available for use in both the editor and exported projects, but it is not designed for use by end users to record videos while playing. Players wishing to record gameplay videos should install tools such as OBS Studio or SimpleScreenRecorder instead. Note: MJPEG support (.avi file extension) depends on the jpg module being enabled at compile time (default behavior). Note: OGV support (.ogv file extension) depends on the theora module being enabled at compile time (default behavior). Theora compression is only available in editor binaries.

Methods

`int _get_audio_mix_rate() virtual required const`

Called when the audio sample rate used for recording the audio is requested by the engine. The value returned must be specified in Hz. Defaults to 48000 Hz if _get_audio_mix_rate() is not overridden.

`int _get_audio_speaker_mode() virtual required const`

Called when the audio speaker mode used for recording the audio is requested by the engine. This can affect the number of output channels in the resulting audio file/stream. Defaults to AudioServer.SPEAKER_MODE_STEREO if _get_audio_speaker_mode() is not overridden.

`bool _handles_file(String path) virtual required const`

Called when the engine determines whether this MovieWriter is able to handle the file at path. Must return true if this MovieWriter is able to handle the given file path, false otherwise. Typically, _handles_file() is overridden as follows to allow the user to record a file at any path with a given file extension:

				func _handles_file(path):
					# Allows specifying an output file with a `.mkv` file extension (case-insensitive),
					# either in the Project Settings or with the `--write-movie <path>` command line argument.
					return path.get_extension().to_lower() == "mkv"

`int _write_begin(Vector2i movie_size, int fps, String base_path) virtual required`

Called once before the engine starts writing video and audio data. movie_size is the width and height of the video to save. fps is the number of frames per second specified in the project settings or using the --fixed-fps <fps> command line argument.

`void _write_end() virtual required`

Called when the engine finishes writing. This occurs when the engine quits by pressing the window manager's close button, or when SceneTree.quit() is called. Note: Pressing Ctrl + C on the terminal running the editor/project does not result in _write_end() being called.

`int _write_frame(Image frame_image, const void* audio_frame_block) virtual required`

Called at the end of every rendered frame. The frame_image and audio_frame_block function arguments should be written to.

`void add_writer(MovieWriter writer) static`

Adds a writer to be usable by the engine. The supported file extensions can be set by overriding _handles_file(). Note: add_writer() must be called early enough in the engine initialization to work, as movie writing is designed to start at the same time as the rest of the engine.

Source revision 5592dc3a7a61