A Membrane Element for demuxing an MP4.

The MP4 must have fast start enabled, i.e. the moov box must precede the mdat box. Once the Demuxer identifies the tracks in the MP4, new_tracks_t/0 notification is sent for each of the tracks.

All pads has to be linked either before handle_playing/2 callback or after the Element sends {:new_tracks, ...} notification.

Number of pads has to be equal to the number of demuxed tracks.

If the demuxed data contains only one track, linked pad doesn't have to specify :kind option.

If there are more than one track and pads are linked before handle_playing/2, every pad has to specify :kind option.

If any of pads isn't linked before handle_playing/2, Membrane.MP4.Demuxer.ISOM will send {:new_tracks, ...} notification to the parent. Otherwise, if any of them is linked before handle_playing/3, this notification won't be sent.

If pads are linked after the {:new_tracks, ...} notfitaction, their references must match MP4 tracks ids (Pad.ref(:output, track_id)).

Element options

Passed via struct Membrane.MP4.Demuxer.ISOM.t/0

• optimize_for_non_fast_start?

  boolean()

  Default value: false
  When set to true, the demuxer is optimized for working with non-fast_start MP4 stream (that means - with a stream, in which the :moov box is put after the :mdat box) You might consider setting that option to true if the following two conditions are met:

  • you are processing large non-fast_start MP4 files
  • the source of the stream is a "seekable source" - currently the only possible option is to use a Membrane.File.Source with seekable?: true option.

  When set to false, no optimization will be performed, so in case of processing the non-fast_start MP4 stream, the whole content of the :mdat box will be stored in memory.

  Defaults to false.

Pads

:input

Accepted formats:

%RemoteStream{type: :bytestream, content_format: content_format} when content_format in [nil, MP4]

:output

Accepted formats:

%Membrane.AAC{config: {:esds, _esds}}

%Membrane.H264{stream_structure: {:avc1, _dcr}, alignment: :au}

%Membrane.H265{stream_structure: {_hevc, _dcr}, alignment: :au}

%Membrane.Opus{self_delimiting?: false}

Pad options:

• kind

  :video | :audio | nil

  Default value: nil
  Specifies, what kind of data can be handled by a pad.