mj2mux

mj2mux — Muxer for Motion JPEG-2000 (.mj2) files

Properties

GstQTMuxDtsMethods dts-method Read / Write / Construct
gboolean faststart Read / Write
gchar * faststart-file Read / Write / Construct
guint fragment-duration Read / Write / Construct
gchar * moov-recovery-file Read / Write / Construct
guint movie-timescale Read / Write / Construct
gboolean presentation-time Read / Write / Construct
gboolean streamable Read / Write / Construct
guint trak-timescale Read / Write / Construct

Types and Values

Object Hierarchy

    GObject
    ╰── GInitiallyUnowned
        ╰── GstObject
            ╰── GstElement
                ╰── GstMJ2Mux

Implemented Interfaces

GstMJ2Mux implements GstTagSetter and GstTagXmpWriter.

Description

This element merges streams (audio and video) into MJ2 (.mj2) files.

The following background intends to explain why various similar muxers are present in this plugin.

The QuickTime file format specification served as basis for the MP4 file format specification (mp4mux), and as such the QuickTime file structure is nearly identical to the so-called ISO Base Media file format defined in ISO 14496-12 (except for some media specific parts). In turn, the latter ISO Base Media format was further specialized as a Motion JPEG-2000 file format in ISO 15444-3 (mj2mux) and in various 3GPP(2) specs (3gppmux). The fragmented file features defined (only) in ISO Base Media are used by ISMV files making up (a.o.) Smooth Streaming (ismlmux).

A few properties (“movie-timescale”, “trak-timescale”) allow adjusting some technical parameters, which might be useful in (rare) cases to resolve compatibility issues in some situations.

Some other properties influence the result more fundamentally. A typical mov/mp4 file's metadata (aka moov) is located at the end of the file, somewhat contrary to this usually being called "the header". However, a “faststart” file will (with some effort) arrange this to be located near start of the file, which then allows it e.g. to be played while downloading. Alternatively, rather than having one chunk of metadata at start (or end), there can be some metadata at start and most of the other data can be spread out into fragments of “fragment-duration”. If such fragmented layout is intended for streaming purposes, then “streamable” allows foregoing to add index metadata (at the end of file).

Example pipelines

1
gst-launch-1.0 v4l2src num-buffers=50 ! queue ! jp2kenc ! mj2mux ! filesink location=video.mj2
Records a video stream captured from a v4l2 device, encodes it into JPEG-2000 and muxes it into an mj2 file.

Documentation last reviewed on 2011-04-21

Synopsis

Element Information

plugin

isomp4

author

Thiago Sousa Santos <thiagoss@embedded.ufcg.edu.br>

class

Codec/Muxer

Element Pads

name

audio_%u

direction

sink

presence

request

details

audio/x-raw, format=(string){ S8, U8 }, layout=(string)interleaved, channels=(int)[ 1, 2 ], rate=(int)[ 1, 2147483647 ]

audio/x-raw, format=(string){ S16LE, S16BE }, layout=(string)interleaved, channels=(int)[ 1, 2 ], rate=(int)[ 1, 2147483647 ]

name

video_%u

direction

sink

presence

request

details

image/x-j2c, width=(int)[ 16, 4096 ], height=(int)[ 16, 4096 ]

image/x-jpc, width=(int)[ 16, 4096 ], height=(int)[ 16, 4096 ]

name

src

direction

source

presence

always

details

video/mj2

Functions

Types and Values

GstMJ2Mux

typedef struct _GstMJ2Mux GstMJ2Mux;

Property Details

The “dts-method” property

  “dts-method”               GstQTMuxDtsMethods

(DEPRECATED) Method to determine DTS time.

Flags: Read / Write / Construct

Default value: reorder


The “faststart” property

  “faststart”                gboolean

If the file should be formatted for faststart (headers first).

Flags: Read / Write

Default value: FALSE


The “faststart-file” property

  “faststart-file”           gchar *

File that will be used temporarily to store data from the stream when creating a faststart file. If null a filepath will be created automatically.

Flags: Read / Write / Construct

Default value: NULL


The “fragment-duration” property

  “fragment-duration”        guint

Fragment durations in ms (produce a fragmented file if > 0).

Flags: Read / Write / Construct

Default value: 0


The “moov-recovery-file” property

  “moov-recovery-file”       gchar *

File to be used to store data for moov atom making movie file recovery possible in case of a crash during muxing. Null for disabled. (Experimental).

Flags: Read / Write / Construct

Default value: NULL


The “movie-timescale” property

  “movie-timescale”          guint

Timescale to use in the movie (units per second).

Flags: Read / Write / Construct

Allowed values: >= 1

Default value: 1000


The “presentation-time” property

  “presentation-time”        gboolean

Calculate and include presentation/composition time (in addition to decoding time).

Flags: Read / Write / Construct

Default value: TRUE


The “streamable” property

  “streamable”               gboolean

If set to true, the output should be as if it is to be streamed and hence no indexes written or duration written. (DEPRECATED, only valid for fragmented MP4).

Flags: Read / Write / Construct

Default value: FALSE


The “trak-timescale” property

  “trak-timescale”           guint

Timescale to use for the tracks (units per second, 0 is automatic).

Flags: Read / Write / Construct

Default value: 0