Godot 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.
Godot has 2 built-in MovieWriters:
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/mjpeg_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 Godot 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.
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.
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.
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:
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.
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.
Called at the end of every rendered frame. The frame_image
and audio_frame_block
function arguments should be written to.
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.