Java Media Framework JMF What is it

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Java Media Framework (JMF)What is it?

• JMF- represents a simple, unified architecture to
  synchronize and control audio, video, and other
  time based data with Java applications.
• Besides the ability to play media it allows for
  media capture, streaming, changing formats,
  plugging in new CoDecs.

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Java Media Framework (JMF)History

• JMF 1.0 was first introduced at the JavaOne
  conference, in 1996 -- a technology jointly
  developed by Sun Microsystems, Inc., Silicon
  Graphics, Inc., and Intel Corp.
• Then March 98 -- 1.0 Java Media Player
  implementation shipped (for Microsoft Windows and
  Solaris operating environments)
• Then, in late '98, JMF 1.1 was released. This
  included the previous two Solaris and Windows
  95/NT operating environment implementations, as
  well as two pure Java platform implementations.

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JMF-History.

• And finally 2.0 was released 12/98 which offers a
  plug-able architecture, allowing developers to
  easily add third-party codecs and special effects
• These new features - particularly the ability to
  capture and transmit media data - open up whole
  new market vistas to JMF 2.0-based applets and
  applications - from real-time video conferencing,
  to distance learning, to simple video-on-demand,
  to video and audio processing
• JMF 2.0 API has been developed jointly between
  Sun and IBM and is currently available in an
  early access product version through Sun's Java
  Developer Connection (http//java.sun.com/jdc).

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JMF-About JMF

• JMF-API is an application programming interface
  for incorporating audio, video and other
  time-based media into Java applications and
  applets
• JMF is an optional package which extends the
  multimedia capabilities on the Java platform.
• JMF delivers "Write Once, Run Anywhere" to
  developers who want to use media such as audio
  and video in their Java programs

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JMF-About JMF.

• Provides a unified architecture and messaging
  protocol for managing the acquisition,
  processing, and delivery of time-based media data
• Provides a common cross-platform Java API for
  accessing underlying media frameworks. JMF
  implementations can leverage the capabilities of
  the underlying operating system.
• With JMF, you can create applets and applications
  that present, capture, manipulate, and store
  time-based media.
• The framework enables advanced developers and
  technology providers to perform custom processing
  of raw media data

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JMF-How it works?

• JMF uses this same basic model. A data source
  encapsulates the media stream much like a video
  tape and a player provides processing and control
  mechanisms similar to a VCR. Playing and
  capturing audio and video with JMF requires the
  appropriate input and output devices such as
  microphones, cameras, speakers, and monitors.

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JMF-How it works.

• Data sources and players are integral parts of
  JMF's high-level API for managing the capture,
  presentation, and processing of time-based media.
  JMF also provides a lower-level API that supports
  the seamless integration of custom processing
  components and extensions

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JMF-Classes that support JMF

• Clock- uses a Time Base to keep track of the
  passage of time while a media stream is being
  presented.
• A Clock object's media time represents the
  current position within a media stream--the
  beginning of the stream is media time zero, the
  end of the stream is the maximum media time for
  the stream
• Duration of the media stream is the elapsed time
  from start to finish--the length of time that it
  takes to present the media stream.
• To keep track of the current media time, a Clock
  uses
• The time-base start-time--the time that its
  TimeBase reports when the presentation begins.
• The media start-time--the position in the media
  stream where presentation begins.

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JMF-Classes that support...

• The playback rate--how fast the Clock is running
  in relation to its TimeBase.
• A negative rate indicates that the Clock is
  running in the opposite direction from its
  TimeBase--for example, a negative rate might be
  used to play a media stream backward.

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JMF-Classes that support.

• Time-JMF keeps time to nanosecond precision. A
  particular point in time is typically represented
  by a Time object, though some classes also
  support the specification of time in nanoseconds.
• The Clock interface defines the basic timing and
  synchronization operations that are needed to
  control the presentation of media data.
• JMF-time model implement Clock to keep track of
  time for a particular media stream

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JMF-Features

• Extensibility
• Customizable-controls for new media processing
  components
• Custom downloadable- protocol handlers
• Custom downloadable- content handlers
• Support synchronization
• Provides a consistent abstraction for a media
  player/processor

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JMF-Features.

• Media playback
• A behavior which controls the JMF Player
• Restore
• attempt to open the media stream, and create the
  player
• Build
• resolve the timing dependencies between the
  player and other clocks
• prefetch the player

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JMF-Media Types it supports

• Protocols file, http, ftp, rtp
• Audio AIFF, AU, AVI, GSM, MIDI, MP2, MP3, Q2,
  RMF, WAV,
• Video AVI, MPEG-1, QT, H.261, H.263
• Other Flash 2, HotMedia

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JMF-Platforms

• Platforms supported include
• Windows 95/98/NT 4.0/2000.
• Solaris/Sparc. The pure version will run on
  Apple's MRJ 2.1.4.
• Unfortunately there is a synchronization problem
  due to a 6 second audio buffer.

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JMF-Browsers it support

• HotJava Browser 1.1
• Microsoft Internet Explorer 4.01 and later
• Netscape Communicator 4.03-4.05 with the JDK 1.1
  patch
• Netscape Communicator 4.06 and later
• All need the JMF plug in to the JVM.