Type

CmafOutputFormatOptions

CMAF-specific output options.

type CmafOutputFormatOptions = Omit<IsobmffOutputFormatOptions, 'fastStart'> & {
	minimumFragmentDuration?: number;
};

See IsobmffOutputFormatOptions.

Used by

• new CmafOutputFormat()

Properties

minimumFragmentDuration

minimumFragmentDuration?: number;

Controls the minimum duration of each fragment, in seconds. New fragments will only be created when the current fragment is longer than this value. Defaults to Infinity, meaning the file will contain only one fragment.

metadataFormat

metadataFormat?: 'auto' | 'mdir' | 'mdta' | 'udta';

The metadata format to use for writing metadata tags.

• 'auto' (default): Behaves like 'mdir' for MP4 and like 'udta' for QuickTime, matching FFmpeg's default behavior.
• 'mdir': Write tags into moov/udta/meta using the 'mdir' handler format.
• 'mdta': Write tags into moov/udta/meta using the 'mdta' handler format, equivalent to FFmpeg's use_metadata_tags flag. This allows for custom keys of arbitrary length.
• 'udta': Write tags directly into moov/udta.

Events

onFtyp

onFtyp?: (data: Uint8Array, position: number) => unknown;

Will be called once the ftyp (File Type) box of the output file has been written.

onMoov

onMoov?: (data: Uint8Array, position: number) => unknown;

Will be called once the moov (Movie) box of the output file has been written.

onMdat

onMdat?: (data: Uint8Array, position: number) => unknown;

Will be called for each finalized mdat (Media Data) box of the output file. Usage of this callback is not recommended when not using fastStart: 'fragmented', as there will be one monolithic mdat box which might require large amounts of memory.

onMoof

onMoof?: (data: Uint8Array, position: number, timestamp: number) => unknown;

Will be called for each finalized moof (Movie Fragment) box of the output file.