Mp4Muxer

const val FILE_FORMAT_DEFAULT = 0: Int

The default MP4 format.

const val FILE_FORMAT_MP4_WITH_AUXILIARY_TRACKS_EXTENSION = 1: Int

The MP4 With Auxiliary Tracks Extension (MP4-AT) file format. In this file format all the tracks with auxiliaryTrackType set to AUXILIARY_TRACK_TYPE_ORIGINAL, AUXILIARY_TRACK_TYPE_DEPTH_LINEAR, AUXILIARY_TRACK_TYPE_DEPTH_INVERSE, or AUXILIARY_TRACK_TYPE_DEPTH_METADATA are written in the Auxiliary Tracks MP4 (axte box). The rest of the tracks are written as usual.

See the file format at https://developer.android.com/media/platform/mp4-at-file-format.

const val LAST_SAMPLE_DURATION_BEHAVIOR_SET_FROM_END_OF_STREAM_BUFFER_OR_DUPLICATE_PREVIOUS = 1: Int

Use the end of stream sample to set the duration of the last sample.

After writing all the samples for a track, the app must write an empty sample with flag BUFFER_FLAG_END_OF_STREAM. The timestamp of this sample should be equal to the desired track duration.

Once a sample with flag BUFFER_FLAG_END_OF_STREAM is written, no more samples can be written for that track.

If no explicit BUFFER_FLAG_END_OF_STREAM sample is passed, then the duration of the last sample will be same as that of the sample before that.

const val LAST_SAMPLE_DURATION_BEHAVIOR_SET_TO_ZERO = 0: Int

The duration of the last sample is set to 0.

const val SUPPORTED_AUDIO_SAMPLE_MIME_TYPES: ImmutableList<String!>!

A list of supported audio sample MIME types.

const val SUPPORTED_VIDEO_SAMPLE_MIME_TYPES: ImmutableList<String!>!

A list of supported video sample MIME types.

const val TRACK_REFERENCE_TYPE_CDSC = 1667527523: Int

Links a descriptive or metadata track to the content which it describes.

fun addMetadataEntry(metadataEntry: Metadata.Entry!): Unit

Adds metadata about the output file.

List of supported metadata entries:

• Mp4OrientationData
• Mp4LocationData
• Mp4TimestampData
• MdtaMetadataEntry: Only string type or float type value is supported.
• XmpData

fun addTrack(format: Format!): Int

Adds a track of the given media format.

All tracks must be added before any samples are written to any track.

Tracks can be added at any point before the muxer is closed, even after writing samples to other tracks.

The order of tracks remains same in which they are added.

A metadata track (TRACK_TYPE_METADATA) or a track with an unknown type (TRACK_TYPE_UNKNOWN) is written as a text metadata track, unless the sample MIME type is APPLICATION_ITUT_T35, in which case it is written as a T35 metadata track.

For a metadata track, it is recommended to add track reference.

fun addTrack(sortKey: Int, format: Format!): Int

Adds a track of the given media format.

Tracks can be added at any point before the muxer is closed, even after writing samples to other tracks.

The final order of tracks is determined by the provided sort key. Tracks with a lower sort key will be written before tracks with a higher sort key. Ordering between tracks with the same sort key is not specified.

fun addTrackReference(
    trackId: Int,
    @Mp4Muxer.TrackReferenceType referenceType: Int,
    referencedTrackIds: (Mutable)List<Int!>!
): Unit

Adds a track reference to establish a relationship between tracks in the MP4 file.

Track references are used to link one track to another. For example, a metadata track might reference a video track to indicate that the metadata describes the content of that video.

fun close(): Unit

Closes the file.

The muxer cannot be used anymore once this method returns.

fun writeSampleData(
    trackId: Int,
    byteBuffer: ByteBuffer!,
    bufferInfo: BufferInfo!
): Unit

Writes encoded sample data.

The muxer's handling of sample ByteBuffer and BufferInfo depends on the sample batching and sample copying settings:

• If sample batching is disabled: Samples are written immediately upon arrival. The caller can safely modify or reuse these objects immediately after this method returns.
• If sample batching is enabled:
  • If sample copying is enabled: The muxer makes internal copies of the provided ByteBuffer and BufferInfo. The caller can safely modify or reuse these objects immediately after this method returns.
  • If sample copying is disabled: The muxer takes ownership of the ByteBuffer and BufferInfo. The caller must not modify these objects after this method returns.