Package org.jitsi.impl.neomedia.jmfext.media.protocol.wasapi

Class WASAPIStream

  • All Implemented Interfaces:
    javax.media.Controls, javax.media.protocol.Controls, javax.media.protocol.PushBufferStream, javax.media.protocol.SourceStream
    public class WASAPIStream
extends AbstractPushBufferStream<DataSource>
    Implements a PullBufferStream using Windows Audio Session API (WASAPI) and related Core Audio APIs such as Multimedia Device (MMDevice) API.
    Author:
    Lyubomir Marinov

    • Field Summary

      Fields 
      Modifier and Type Field Description
      protected T dataSource
      The DataSource which has created this instance and which contains it as one of its streams.
      protected javax.media.control.FormatControl formatControl
      The FormatControl which gives access to the Format of the media data provided by this SourceStream and which, optionally, allows setting it.

      • Fields inherited from interface javax.media.protocol.SourceStream

        LENGTH_UNKNOWN

    • Constructor Summary

      Constructors 
      Constructor Description
      WASAPIStream​(DataSource dataSource, javax.media.control.FormatControl formatControl)
      Initializes a new WASAPIStream instance which is to have its Format-related information abstracted by a specific FormatControl.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void close()
      Releases the resources used by this instance throughout its existence and makes it available for garbage collection.
      protected javax.media.Format doGetFormat()
      Gets the Format of this AbstractBufferStream as directly known by it.
      protected javax.media.Format doSetFormat​(javax.media.Format format)
      Attempts to set the Format of this AbstractBufferStream.
      boolean endOfStream()
      Determines whether the end of this SourceStream has been reached.
      javax.media.protocol.ContentDescriptor getContentDescriptor()
      Gets a ContentDescriptor which describes the type of the content made available by this SourceStream.
      long getContentLength()
      Gets the length in bytes of the content made available by this SourceStream.
      Object[] getControls()
      Implements Controls.getControls().
      javax.media.Format getFormat()
      Gets the Format of the media data made available by this AbstractBufferStream.
      void read​(javax.media.Buffer buffer)
      If resampler is non-null, uses it to resample the media data read from capture or processed into format.
      void start()
      Starts the transfer of media data from this AbstractBufferStream.
      void stop()
      Stops the transfer of media data from this AbstractBufferStream.

      • Methods inherited from interface javax.media.Controls

        getControl, getControls

      • Methods inherited from interface javax.media.protocol.SourceStream

        endOfStream, getContentDescriptor, getContentLength

    • Field Detail

      • dataSource

        protected final T extends javax.media.protocol.DataSource dataSource
        The DataSource which has created this instance and which contains it as one of its streams.

      • formatControl

        protected final javax.media.control.FormatControl formatControl
        The FormatControl which gives access to the Format of the media data provided by this SourceStream and which, optionally, allows setting it.

    • Constructor Detail

      • WASAPIStream

        public WASAPIStream​(DataSource dataSource,
                    javax.media.control.FormatControl formatControl)
        Initializes a new WASAPIStream instance which is to have its Format-related information abstracted by a specific FormatControl.
        Parameters:
        dataSource - the DataSource which is initializing the new instance so that it becomes one of its streams
        formatControl - the FormatControl which is to abstract the Format-related information of the new instance

    • Method Detail

      • doGetFormat

        protected javax.media.Format doGetFormat()
        Gets the Format of this AbstractBufferStream as directly known by it. Allows extenders to override the Format known to the DataSource which created this instance and possibly provide more details on the currently set Format.
        Returns:
        the Format of this AbstractBufferStream as directly known by it or null if this AbstractBufferStream does not directly know its Format and it relies on the DataSource which created it to report its Format

      • getFormat

        public javax.media.Format getFormat()
        Gets the Format of the media data made available by this AbstractBufferStream. Overrides the super implementation to avoid a deadlock with stop(). The stop() method is generally invoked with a certain synchronization root locked, the implementation of WASAPIStream waits for processThread to quit but processThread indirectly invokes AbstractBufferStream.getFormat() which in turn results in an attempt to lock the mentioned synchronization root i.e. the thread invoking the stop() method and processThread fall into a deadlock.
        Specified by:
        getFormat in interface javax.media.protocol.PushBufferStream
        Returns:
        the Format of the media data made available by this AbstractBufferStream

      • start

        public void start()
           throws IOException
        Starts the transfer of media data from this AbstractBufferStream.
        Throws:
        IOException - if anything goes wrong while starting the transfer of media data from this AbstractBufferStream

      • stop

        public void stop()
          throws IOException
        Stops the transfer of media data from this AbstractBufferStream.
        Throws:
        IOException - if anything goes wrong while stopping the transfer of media data from this AbstractBufferStream

      • close

        public void close()
        Releases the resources used by this instance throughout its existence and makes it available for garbage collection. This instance is considered unusable after closing.

        Warning: The method is not invoked by the framework, extenders may choose to invoke it.

      • doSetFormat

        protected javax.media.Format doSetFormat​(javax.media.Format format)
        Attempts to set the Format of this AbstractBufferStream. Allows extenders to enable setting the Format of an existing AbstractBufferStream (in contract to setting it before the AbstractBufferStream is created by the DataSource which will provide it).
        Parameters:
        format - the Format to be set as the format of this AbstractBufferStream
        Returns:
        the Format of this AbstractBufferStream or null if the attempt to set the Format did not succeed and any last-known Format is to be left in effect

      • endOfStream

        public boolean endOfStream()
        Determines whether the end of this SourceStream has been reached. The AbstractBufferStream implementation always returns false.
        Specified by:
        endOfStream in interface javax.media.protocol.SourceStream
        Returns:
        true if the end of this SourceStream has been reached; otherwise, false

      • getContentDescriptor

        public javax.media.protocol.ContentDescriptor getContentDescriptor()
        Gets a ContentDescriptor which describes the type of the content made available by this SourceStream. The AbstractBufferStream implementation always returns a ContentDescriptor with content type equal to ContentDescriptor#RAW.
        Specified by:
        getContentDescriptor in interface javax.media.protocol.SourceStream
        Returns:
        a ContentDescriptor which describes the type of the content made available by this SourceStream

      • getContentLength

        public long getContentLength()
        Gets the length in bytes of the content made available by this SourceStream. The AbstractBufferStream implementation always returns LENGTH_UNKNOWN.
        Specified by:
        getContentLength in interface javax.media.protocol.SourceStream
        Returns:
        the length in bytes of the content made available by this SourceStream if it is known; otherwise, LENGTH_UKNOWN

      • getControls

        public Object[] getControls()
        Implements Controls.getControls(). Gets the controls available for this instance.
        Specified by:
        getControls in interface javax.media.Controls
        Returns:
        an array of Objects which represent the controls available for this instance