Class: FFmpeg
Provides APIs to interact with ffmpeg web worker.
Example
const ffmpeg = new FFmpeg();
Constructors
constructor
• new FFmpeg()
Properties
#logEventCallbacks
• Private #logEventCallbacks: LogEventCallback[] = []
Defined in
#progressEventCallbacks
• Private #progressEventCallbacks: ProgressEventCallback[] = []
Defined in
#rejects
• Private #rejects: Callbacks = {}
Defined in
#resolves
• Private #resolves: Callbacks = {}
#resolves and #rejects tracks Promise resolves and rejects to be called when we receive message from web worker.
Defined in
#worker
• Private #worker: null | Worker = null
Defined in
loaded
• loaded: boolean = false
Defined in
FFmpeg Methods
exec
▸ exec(args, timeout?, __namedParameters?): Promise<number>
Execute ffmpeg command.
Remarks
To avoid common I/O issues, ["-nostdin", "-y"] are prepended to the args by default.
Example
const ffmpeg = new FFmpeg();
await ffmpeg.load();
await ffmpeg.writeFile("video.avi", ...);
// ffmpeg -i video.avi video.mp4
await ffmpeg.exec(["-i", "video.avi", "video.mp4"]);
const data = ffmpeg.readFile("video.mp4");
Parameters
| Name | Type | Default value | Description |
|---|---|---|---|
args | string[] | undefined | ffmpeg command line args |
timeout | number | -1 | milliseconds to wait before stopping the command execution. Default Value -1 |
__namedParameters | FFMessageOptions | {} | - |
Returns
Promise<number>
0 if no error, != 0 if timeout (1) or error.
Defined in
load
▸ load(__namedParameters?, __namedParameters?): Promise<boolean>
Loads ffmpeg-core inside web worker. It is required to call this method first as it initializes WebAssembly and other essential variables.
Parameters
| Name | Type |
|---|---|
__namedParameters | FFMessageLoadConfig |
__namedParameters | FFMessageOptions |
Returns
Promise<boolean>
true if ffmpeg core is loaded for the first time.
Defined in
off
▸ off(event, callback): void
Unlisten to log or prgress events from ffmpeg.exec().
Parameters
| Name | Type |
|---|---|
event | "log" |
callback | LogEventCallback |
Returns
void
Defined in
▸ off(event, callback): void
Parameters
| Name | Type |
|---|---|
event | "progress" |
callback | ProgressEventCallback |
Returns
void
Defined in
on
▸ on(event, callback): void
Listen to log or prgress events from ffmpeg.exec().
Example
ffmpeg.on("log", ({ type, message }) => {
// ...
})
Example
ffmpeg.on("progress", ({ progress, time }) => {
// ...
})
Remarks
- log includes output to stdout and stderr.
- The progress events are accurate only when the length of input and output video/audio file are the same.
Parameters
| Name | Type |
|---|---|
event | "log" |
callback | LogEventCallback |
Returns
void
Defined in
▸ on(event, callback): void
Parameters
| Name | Type |
|---|---|
event | "progress" |
callback | ProgressEventCallback |
Returns
void
Defined in
terminate
▸ terminate(): void
Terminate all ongoing API calls and terminate web worker.
FFmpeg.load() must be called again before calling any other APIs.
Returns
void
Defined in
File System Methods
createDir
▸ createDir(path, __namedParameters?): Promise<boolean>
Create a directory.
Parameters
| Name | Type |
|---|---|
path | string |
__namedParameters | FFMessageOptions |
Returns
Promise<boolean>
Defined in
deleteDir
▸ deleteDir(path, __namedParameters?): Promise<boolean>
Delete an empty directory.
Parameters
| Name | Type |
|---|---|
path | string |
__namedParameters | FFMessageOptions |
Returns
Promise<boolean>
Defined in
deleteFile
▸ deleteFile(path, __namedParameters?): Promise<boolean>
Delete a file.
Parameters
| Name | Type |
|---|---|
path | string |
__namedParameters | FFMessageOptions |
Returns
Promise<boolean>
Defined in
listDir
▸ listDir(path, __namedParameters?): Promise<FSNode[]>
List directory contents.
Parameters
| Name | Type |
|---|---|
path | string |
__namedParameters | FFMessageOptions |
Returns
Promise<FSNode[]>
Defined in
readFile
▸ readFile(path, encoding?, __namedParameters?): Promise<FileData>
Read data from ffmpeg.wasm.
Example
const ffmpeg = new FFmpeg();
await ffmpeg.load();
const data = await ffmpeg.readFile("video.mp4");
Parameters
| Name | Type | Default value | Description |
|---|---|---|---|
path | string | undefined | - |
encoding | string | "binary" | File content encoding, supports two encodings: - utf8: read file as text file, return data in string type. - binary: read file as binary file, return data in Uint8Array type. Default Value binary |
__namedParameters | FFMessageOptions | {} | - |
Returns
Promise<FileData>
Defined in
rename
▸ rename(oldPath, newPath, __namedParameters?): Promise<boolean>
Rename a file or directory.
Parameters
| Name | Type |
|---|---|
oldPath | string |
newPath | string |
__namedParameters | FFMessageOptions |
Returns
Promise<boolean>
Defined in
writeFile
▸ writeFile(path, data, __namedParameters?): Promise<boolean>
Write data to ffmpeg.wasm.
Example
const ffmpeg = new FFmpeg();
await ffmpeg.load();
await ffmpeg.writeFile("video.avi", await fetchFile("../video.avi"));
await ffmpeg.writeFile("text.txt", "hello world");
Parameters
| Name | Type |
|---|---|
path | string |
data | FileData |
__namedParameters | FFMessageOptions |
Returns
Promise<boolean>
Defined in
Other Methods
#registerHandlers
▸ Private #registerHandlers(): void
register worker message event handlers.
Returns
void
Defined in
#send
▸ Private #send(__namedParameters, trans?, signal?): Promise<CallbackData>
Generic function to send messages to web worker.
Parameters
| Name | Type | Default value |
|---|---|---|
__namedParameters | Message | undefined |
trans | Transferable[] | [] |
signal? | AbortSignal | undefined |
Returns
Promise<CallbackData>
Defined in
mount
▸ mount(fsType, options, mountPoint): Promise<boolean>
Parameters
| Name | Type |
|---|---|
fsType | FFFSType |
options | WorkerFSMountData |
mountPoint | string |
Returns
Promise<boolean>
Defined in
unmount
▸ unmount(mountPoint): Promise<boolean>
Parameters
| Name | Type |
|---|---|
mountPoint | string |
Returns
Promise<boolean>