Package org.jitsi.impl.neomedia.protocol

Class CachingPushBufferStream

  • All Implemented Interfaces:
    javax.media.Controls, javax.media.protocol.Controls, javax.media.protocol.PushBufferStream, javax.media.protocol.SourceStream
    public class CachingPushBufferStream
extends Object
implements javax.media.protocol.PushBufferStream
    Enables reading from a PushBufferStream a certain maximum number of data units (e.g. bytes, shorts, ints) even if the PushBufferStream itself pushes a larger number of data units.

    An example use of this functionality is pacing a PushBufferStream which pushes more data units in a single step than a CaptureDevice. When these two undergo audio mixing, the different numbers of per-push data units will cause the PushBufferStream "play" itself faster than the CaptureDevice.

    Author:
    Lyubomir Marinov

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static long DEFAULT_BUFFER_LENGTH
      The default length in milliseconds of the buffering to be performed by CachePushBufferStreams.

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

        LENGTH_UNKNOWN

    • Constructor Summary

      Constructors 
      Constructor Description
      CachingPushBufferStream​(javax.media.protocol.PushBufferStream stream)
      Initializes a new CachingPushBufferStream instance which is to pace the number of per-push data units a specific PushBufferStream provides.

    • Field Detail

      • DEFAULT_BUFFER_LENGTH

        public static final long DEFAULT_BUFFER_LENGTH
        The default length in milliseconds of the buffering to be performed by CachePushBufferStreams.
        See Also:
        Constant Field Values

    • Constructor Detail

      • CachingPushBufferStream

        public CachingPushBufferStream​(javax.media.protocol.PushBufferStream stream)
        Initializes a new CachingPushBufferStream instance which is to pace the number of per-push data units a specific PushBufferStream provides.
        Parameters:
        stream - the PushBufferStream to be paced with respect to the number of per-push data units it provides

    • Method Detail

      • endOfStream

        public boolean endOfStream()
        Implements SourceStream.endOfStream(). Delegates to the wrapped PushBufferStream when the cache of this instance is fully read; otherwise, returns false.
        Specified by:
        endOfStream in interface javax.media.protocol.SourceStream
        Returns:
        true if this PushBufferStream has reached the end of the content it makes available; otherwise, false

      • getContentDescriptor

        public javax.media.protocol.ContentDescriptor getContentDescriptor()
        Implements SourceStream.getContentDescriptor(). Delegates to the wrapped PushBufferStream.
        Specified by:
        getContentDescriptor in interface javax.media.protocol.SourceStream
        Returns:
        a ContentDescriptor which describes the type of the content made available by the wrapped PushBufferStream

      • getContentLength

        public long getContentLength()
        Implements SourceStream.getContentLength(). Delegates to the wrapped PushBufferStream.
        Specified by:
        getContentLength in interface javax.media.protocol.SourceStream
        Returns:
        the length of the content made available by the wrapped PushBufferStream

      • getControl

        public Object getControl​(String controlType)
        Implements Controls.getControl(String). Delegates to the wrapped PushBufferStream and gives access to the BufferControl of this instance if such a controlType is specified and the wrapped PushBufferStream does not have such a control available.
        Specified by:
        getControl in interface javax.media.Controls
        Parameters:
        controlType - a String value which names the type of the control of the wrapped PushBufferStream to be retrieved
        Returns:
        an Object which represents the control of the wrapped PushBufferStream with the specified type if such a control is available; otherwise, null

      • getControls

        public Object[] getControls()
        Implements Controls.getControls(). Delegates to the wrapped PushBufferStream and adds the BufferControl of this instance if the wrapped PushBufferStream does not have a control of such type available.
        Specified by:
        getControls in interface javax.media.Controls
        Returns:
        an array of Objects which represent the control available for the wrapped PushBufferStream

      • getFormat

        public javax.media.Format getFormat()
        Implements PushBufferStream.getFormat(). Delegates to the wrapped PushBufferStream.
        Specified by:
        getFormat in interface javax.media.protocol.PushBufferStream
        Returns:
        the Format of the media data available for reading in this PushBufferStream

      • getStream

        public javax.media.protocol.PushBufferStream getStream()
        Gets the PushBufferStream wrapped by this instance.
        Returns:
        the PushBufferStream wrapped by this instance

      • read

        public void read​(javax.media.Buffer buffer)
          throws IOException
        Implements PushBufferStream.read(Buffer). If an IOException has been thrown by the wrapped stream when data was last read from it, re-throws it. If there has been no such exception, reads from the cache of this instance.
        Specified by:
        read in interface javax.media.protocol.PushBufferStream
        Parameters:
        buffer - the Buffer to receive the read media data
        Throws:
        IOException - if the wrapped stream has thrown such an exception when data was last read from it

      • setTransferHandler

        public void setTransferHandler​(javax.media.protocol.BufferTransferHandler transferHandler)
        Implements PushBufferStream.setTransferHandler(BufferTransferHandler). Delegates to the wrapped PushBufferStream but wraps the specified BufferTransferHandler in order to intercept the calls to BufferTransferHandler.transferData(PushBufferStream) and read data from the wrapped PushBufferStream into the cache during the calls in question.
        Specified by:
        setTransferHandler in interface javax.media.protocol.PushBufferStream
        Parameters:
        transferHandler - the BufferTransferHandler to be notified by this PushBufferStream when media data is available for reading

      • transferData

        protected void transferData​(javax.media.protocol.BufferTransferHandler transferHandler)
        Reads data from the wrapped/input PushBufferStream into the cache of this stream if the cache accepts it. If the cache does not accept a new read, blocks the calling thread until the cache accepts a new read and data is read from the wrapped PushBufferStream into the cache.
        Parameters:
        transferHandler - the BufferTransferHandler which has been notified