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renderFrames()

Part of the @remotion/renderer package.

Renders a series of images using Puppeteer and computes information for mixing audio.

If you want to render only a still image, use renderStill().

info

In Remotion 3.0, we added the renderMedia() API which combines renderFrames() and stitchFramesToVideo() into one simplified step and performs the render faster. Prefer renderMedia() if you can.

info

Configuration in remotion.config.ts and CLI flags do not apply to this function. You must pass all options explicitly.

Arguments​

Takes an object with the following keys:

composition​

A video config, consisting out of id, width, height, durationInFrames and fps, where id is the composition ID. You can obtain an array of available compositions using getCompositions().

onStart​

A callback that fires after the setup process (validation, browser launch) has finished. Example value

ts
const onStart = () => {
  console.log("Starting rendering...");
};
ts
const onStart = () => {
  console.log("Starting rendering...");
};

onFrameUpdate​

A callback function that gets called whenever a frame finished rendering. An argument is passed containing how many frames have been rendered (not the frame number of the rendered frame).

In v3.0.0, a second argument was added: frame, returning the frame number that was just rendered.

In v3.2.30, a third argument was rendered: timeToRenderInMilliseconds, describing the time it took to render that frame in milliseconds.

ts
const onFrameUpdate = (
  framesRendered: number,
  frame: number,
  timeToRenderInMilliseconds: number
) => {
  console.log(`${framesRendered} frames rendered.`);
 
  // From v3.0.0
  console.log(`${frame} was just rendered.`);
 
  // From v3.2.30
  console.log(`It took ${timeToRenderInMilliseconds}ms to render that frame.`);
};
ts
const onFrameUpdate = (
  framesRendered: number,
  frame: number,
  timeToRenderInMilliseconds: number
) => {
  console.log(`${framesRendered} frames rendered.`);
 
  // From v3.0.0
  console.log(`${frame} was just rendered.`);
 
  // From v3.2.30
  console.log(`It took ${timeToRenderInMilliseconds}ms to render that frame.`);
};

outputDir​

A string specifying the directory (absolute path) to which frames should be saved. Pass null to this option and use the onFrameBuffer callback instead to get a Buffer of the frame rather than to write it to any location.

inputProps​

Custom props which will be passed to the component. Useful for rendering videos with dynamic content. Can be an object of any shape.

serveUrl​

Either a Webpack bundle or a URL pointing to a bundled Remotion project. Call bundle() to generate a bundle. You can either pass the file location or deploy it as a website and pass the URL.

imageFormat​

A string which must be either png, jpeg or none.

  • Choose jpeg by default because it is the fastest.
  • Choose png if you want your image sequence to have an alpha channel (for transparency).
  • Choose none if you only want to render audio.

concurrency?​

optional

A number specifying how many render processes should be started in parallel, a string specifying the percentage of the CPU threads to use, or null to let Remotion decide based on the CPU of the host machine. Default is half of the CPU threads available.

parallelism?​

Renamed to concurrency in v3.2.17.

scale? v2.6.7​

number - default: 1

Scales the output frames by the factor you pass in. For example, a 1280x720px frame will become a 1920x1080px frame with a scale factor of 1.5. Vector elements like fonts and HTML markups will be rendered with extra details.

quality?​

optional

Sets the quality of the generated JPEG images. Must be an integer between 0 and 100. Default is to leave it up to the browser, current default is 80.

Only applies if imageFormat is 'jpeg', otherwise this option is invalid.

frameRange?​

optional

Specify a single frame (passing a number) or a range of frames (passing a tuple [number, number]) to be rendered. By passing null (default) all frames of a composition get rendered.

muted v3.2.1​

optional

Disables audio output. This option may only be set in combination with a video codec and should also be passed to stitchFramesToVideo().

dumpBrowserLogs?​

optional

Passes the dumpio flag to Puppeteer which will log all browser logs to the console. Useful for debugging. boolean flag, default is false.

puppeteerInstance?​

optional

An already open Puppeteer Browser instance. Use openBrowser() to create a new instance. Reusing a browser across multiple function calls can speed up the rendering process. You are responsible for opening and closing the browser yourself. If you don't specify this option, a new browser will be opened and closed at the end.

envVariables? v2.2.0​

optional

An object containing key-value pairs of environment variables which will be injected into your Remotion projected and which can be accessed by reading the global process.env object.

onBrowserLog? v3.0.0​

optional

Gets called when your project calls console.log or another method from console. A browser log has three properties:

  • text: The message being printed
  • stackTrace: An array of objects containing the following properties:
    • url: URL of the resource that logged.
    • lineNumber: 0-based line number in the file where the log got called.
    • columnNumber: 0-based column number in the file where the log got called.
  • type: The console method - one of log, debug, info, error, warning, dir, dirxml, table, trace, clear, startGroup, startGroupCollapsed, endGroup, assert, profile, profileEnd, count, timeEnd, verbose
tsx
renderFrames({
  onBrowserLog: (info) => {
    console.log(`${info.type}: ${info.text}`);
    console.log(
      info.stackTrace
        .map((stack) => {
          return `  ${stack.url}:${stack.lineNumber}:${stack.columnNumber}`;
        })
        .join("\n")
    );
  },
});
tsx
renderFrames({
  onBrowserLog: (info) => {
    console.log(`${info.type}: ${info.text}`);
    console.log(
      info.stackTrace
        .map((stack) => {
          return `  ${stack.url}:${stack.lineNumber}:${stack.columnNumber}`;
        })
        .join("\n")
    );
  },
});

ffmpegExecutable? v3.0.11​

optional

An absolute path overriding the ffmpeg executable to use.

ffprobeExecutable? v3.0.17​

optional

An absolute path overriding the ffprobe executable to use.

browserExecutable? v3.0.11​

optional

A string defining the absolute path on disk of the browser executable that should be used. By default Remotion will try to detect it automatically and download one if none is available. If puppeteerInstance is defined, it will take precedence over browserExecutable.

cancelSignal? v3.0.15​

optional

A token that allows the render to be cancelled. See: makeCancelSignal()

onFrameBuffer? v3.0.0​

optional

If you passed null to outputDir, this method will be called passing a buffer of the current frame. This is mostly used internally by Remotion to implement renderMedia() and might have limited usefulness for end users.

timeoutInMilliseconds? v2.6.3​

optional

A number describing how long one frame may take to resolve all delayRender() calls before the [render times out and fails(/docs/timeout). Default: 30000

everyNthFrame v3.1.0​

optional

Renders only every nth frame. For example only every second frame, every third frame and so on. Only meant for rendering GIFs. See here for more details.

chromiumOptions? v2.6.5​

optional

Allows you to set certain Chromium / Google Chrome flags. See: Chromium flags.

note

Chromium flags need to be set at browser launch. If you pass an instance using puppeteerInstance, options passed to renderFrames() will not apply, but rather the flags that have been passed to openBrowser().

disableWebSecurity​

boolean - default false

This will most notably disable CORS among other security features.

ignoreCertificateErrors​

boolean - default false

Results in invalid SSL certificates, such as self-signed ones, being ignored.

headless​

boolean - default true

If disabled, the render will open an actual Chrome window where you can see the render happen.

gl​

string

Changelog
  • From Remotion v2.6.7 until v3.0.7, the default for Remotion Lambda was swiftshader, but from v3.0.8 the default is swangle (Swiftshader on Angle) since Chrome 101 added support for it.
  • From Remotion v2.4.3 until v2.6.6, the default was angle, however it turns out to have a small memory leak that could crash long Remotion renders.

Select the OpenGL renderer backend for Chromium. Accepted values:

  • "angle",
  • "egl",
  • "swiftshader"
  • "swangle"
  • null - Chromiums default

Default for local rendering: null.
Default for Lambda rendering: "swangle".

userAgent v3.3.83​

Lets you set a custom user agent that the headless Chrome browser assumes.

Return value​

A promise resolving to an object containing the following properties:

  • frameCount: number - describing how many frames got rendered.
  • assetsInfo: RenderAssetInfo - information that can be passed to stitchFramesToVideo() to mix audio. The shape of this object should be considered as Remotion internals and may change across Remotion versions.

See also​