File	Doc	Category	Size	Date	Package
Buffer.java	API Doc	JMF 2.1.1e	18340	Mon May 12 12:20:38 BST 2003	javax.media

Buffer

• java.lang.Object

Fields Summary
protected long	timeStamp The time stamp of the data held in this Buffer, in nanoseconds. The time stamp marks the time when presentation of this Buffer is to begin. If the start time for this Buffer is not known, this time stamp is set to TIME_UNKNOWN.
protected long	duration The duration of the data held in this Buffer, in nanoseconds. The duration specifies how long it will take for this Buffer to be presented when the playback rate is 1.0. If the duration for this Buffer is not known, it is set to TIME_UNKNOWN.
protected Format	format The Format of the chunk of data in this Buffer.
protected int	flags A flag mask that describes the boolean attributes enabled for this Buffer. This mask is set to the logical sum of all of the flags that are set.
protected Object	data The object that actually holds the media data chunk for this Buffer. It can be an array type (such as byte[]) or any other type of object. Use instanceOf to determine what type it is.
protected Object	header Header information (such as RTP header) for this data chunk. It can be of any type. Use instanceOf to determine what type it is.
protected int	length For array data type, states how many samples are valid in the array. (The array might be larger than the actual media length).
protected int	offset For array data type, points to the starting point (offset) into the array where the valid data begins.
protected long	sequenceNumber The sequence number of this Buffer. The sequence number of adjacent Buffer objects in a sequence should differ by 1: positive 1 if the media is playing forward, negative 1 if the media is played in reverse. If the sequence number is not known, SEQUENCE_UNKNOWN is specified.
public static final int	FLAG_EOM Indicates that this Buffer marks the end of media for the data stream. The Buffer might or might not contain valid data to be processed. The length and data attributes need to be examined to determine whether or not this Buffer contains valid data.
public static final int	FLAG_DISCARD Indicates that the media data in this Buffer should be ignored.
public static final int	FLAG_SILENCE Indicates that this Buffer contains only silence frames.
public static final int	FLAG_SID Indicates that this Buffer contains only SID (silence information description) frames.
public static final int	FLAG_KEY_FRAME Indicates that this Buffer starts with a key frame.
public static final int	FLAG_NO_DROP Indicates that this Buffer will not be dropped even if the frame is behind the presentation schedule.
public static final int	FLAG_NO_WAIT Indicates that this Buffer will not be waited on even if the frame is ahead of the presentation schedule.
public static final int	FLAG_NO_SYNC Indicates that this Buffer is not to be presented in sync with the scheduled presentation time. In other words, the Buffer will not be dropped or waited on if it's behind or ahead of schedule.
public static final int	FLAG_SYSTEM_TIME Indicates that the Buffer carries a time stamp that's relative to the SystemTimeBase. This flag is generally set for data transferred from hardware capture DataSources that uses the system clock.
public static final int	FLAG_RELATIVE_TIME Indicates that the Buffer carries a time stamp that's in relative time units. This means that individual time stamps are not measured against any indentifiable absolute origin--only the difference between the time stamps of two consecutive buffers carries useful information. (This is the time difference between the two packets.)
public static final int	FLAG_FLUSH This is a marker bit used by the system. When this flag is set, it marks a zero-length Buffer generated by the system to flush the data path. Do not attempt to use or overwrite this flag.
public static final int	FLAG_SYSTEM_MARKER This is a marker bit used by the system. Do not attempt to use or overwrite this flag.
public static final int	FLAG_RTP_MARKER This is a marker bit for RTP. Indicates that the Buffer is the last packet of a video frame.
public static final int	FLAG_RTP_TIME Indicates that the Buffer carries a time stamp that's in RTP (NTP) time units.
public static final int	FLAG_BUF_OVERFLOWN Indicates that some buffer queue in the data flow path from where this buffer comes from is overflown. When such condition occurs, the processing element should attempt to speed up the procesing of this buffer object to reduce the overflow.
public static final int	FLAG_BUF_UNDERFLOWN Indicates that some buffer queue in the data flow path from where this buffer comes from is underflown. When such condition occurs, the processing element should attempt to speed up the procesing of this buffer object to reduce the underflow.
public static final int	FLAG_LIVE_DATA Indicates that the data is arriving from a live (real-time) source.
public static final long	TIME_UNKNOWN The getTimeStamp method return this value if the time stamp of the media is not known.
public static final long	SEQUENCE_UNKNOWN The getSequenceNumber method returns this value if the sequence number is not known.

Constructors Summary

Methods Summary
public java.lang.Object	clone() Clone a buffer. Buffer buf = new Buffer(); Object data = getData(); if (data != null) { if (data instanceof byte[]) buf.data = ((byte[])data).clone(); else if (data instanceof int[]) buf.data = ((int[])data).clone(); else if (data instanceof short[]) buf.data = ((short[])data).clone(); else buf.data = data; } if (header != null) { if (header instanceof byte[]) buf.header = ((byte[])header).clone(); else if (header instanceof int[]) buf.header = ((int[])header).clone(); else if (header instanceof short[]) buf.header = ((short[])header).clone(); else buf.header = header; } buf.format = format; buf.length = length; buf.offset = offset; buf.timeStamp = timeStamp; buf.duration = duration; buf.sequenceNumber = sequenceNumber; buf.flags = flags; return buf;
public void	copy(javax.media.Buffer buffer) Copy the attributes from the specified Buffer into this Buffer param buffer The input Buffer the copy the attributes from. copy(buffer, false);
public void	copy(javax.media.Buffer buffer, boolean swapData) Copy the attributes from the specified Buffer into this Buffer. If swapData is true, the data values are swapped between the buffers, otherwise the data value is copied. param buffer The input Buffer the copy the attributes from. param swapData Specifies whether the data objects are to be swapped. if (swapData) { Object temp = data; data = buffer.data; buffer.data = temp; } else { data = buffer.data; } header = buffer.header; format = buffer.format; length = buffer.length; offset = buffer.offset; timeStamp = buffer.timeStamp; duration = buffer.duration; sequenceNumber = buffer.sequenceNumber; flags = buffer.flags;
public java.lang.Object	getData() Gets the internal data object that holds the media chunk contained in this Buffer. return The data object that holds the media chunk for this Buffer. It can be an array type (such as byte[]) or any other type of object. Use instanceOf to determine what type it is. see #data return data;
public long	getDuration() Gets the duration of this Buffer. return The Buffer duration, in nanoseconds. see #duration return duration;
public int	getFlags() Gets the mask of the flags set for this Buffer. The integer value of the mask is equal to the logical sum of the flags that are set. see #FLAG_EOM see #FLAG_DISCARD see #FLAG_SILENCE see #FLAG_SID see #FLAG_KEY_FRAME see #FLAG_NO_DROP see #FLAG_NO_WAIT see #FLAG_NO_SYNC see #FLAG_RELATIVE_TIME see #FLAG_FLUSH see #FLAG_SYSTEM_MARKER see #FLAG_RTP_MARKER return flags;
public javax.media.Format	getFormat() Get the Format of the data in this Buffer. return format;
public java.lang.Object	getHeader() Gets the header information for the media chunk contained in this Buffer. return The object that holds the header information. Use instanceOf to determine what type the header object is. see #header return header;
public int	getLength() Gets the length of the valid data in this Buffer if the data is held in an array. return The length of the valid data in the data array that holds the media chunk for this Buffer. see #length return length;
public int	getOffset() If the media chunk for this Buffer is held in an array, gets the offset into the data array where the valid data begins. return offset;
public long	getSequenceNumber() Gets the sequence number of this Buffer. return The sequence number of this Buffer. see #sequenceNumber return sequenceNumber;
public long	getTimeStamp() Gets the time stamp of this Buffer. return The Buffer time stamp, in nanoseconds. see #timeStamp return timeStamp;
public boolean	isDiscard() Checks whether or not this Buffer is to be discarded. This method provides a convenient alternative to using getFlags to check the DISCARD flag. return true if the DISCARD flag is enabled, false if it is not. see #getFlags see #FLAG_DISCARD return (flags & FLAG_DISCARD) != 0;
public boolean	isEOM() Checks whether or not this Buffer marks the end of the media stream. Even it isEOM returns true, the Buffer might still contain valid data--check the length of the Buffer. This method provides a convenient alternative to using getFlags to check the EOM flag. return true if the EOM flag is enabled, false if it is not. see #getFlags see #FLAG_EOM return (flags & FLAG_EOM) != 0;
public void	setData(java.lang.Object data) Sets the internal data object that holds the media chunk. param data The data object that holds the media data chunk for this Buffer. It can be an array type (such as byte[]) or any other type of object. see #data this.data = data;
public void	setDiscard(boolean discard) Sets the DISCARD flag for this Buffer. If the DISCARD flag is enabled, this Buffer is to be discarded. This method provides a convenient alternative to using setFlags to enable or disable the DISCARD flag. param discard A boolean value that contains the DISCARD status of the Buffer. Set to true to enable the EOM flag, false to disable the flag. see #setFlags see #FLAG_DISCARD if (discard) flags |= FLAG_DISCARD; else flags &= ~FLAG_DISCARD;
public void	setDuration(long duration) Sets the duration of this Buffer. param duration The duration for the Buffer, in nanoseconds. see #duration this.duration = duration;
public void	setEOM(boolean eom) Sets the EOM flag for this Buffer. If the EOM flag is enabled, this is the last Buffer in the media stream. This method provides a convenient alternative to using setFlags to enable or disable the EOM flag. param eom A boolean value that contains the EOM status of the Buffer. Set to true to enable the EOM flag, false to disable the flag. see #setFlags see #FLAG_EOM if (eom) flags |= FLAG_EOM; else flags &= ~FLAG_EOM;
public void	setFlags(int flags) Sets the flag mask for this Buffer. The integer value of the mask is equal to the logical sum of the flags that are set. see #FLAG_EOM see #FLAG_DISCARD see #FLAG_SILENCE see #FLAG_SID see #FLAG_KEY_FRAME see #FLAG_NO_DROP see #FLAG_NO_WAIT see #FLAG_NO_SYNC see #FLAG_RELATIVE_TIME see #FLAG_FLUSH see #FLAG_SYSTEM_MARKER see #FLAG_RTP_MARKER this.flags = flags;
public void	setFormat(javax.media.Format format) Sets the Format of the data in this Buffer. param format The Format of the data. this.format=format;
public void	setHeader(java.lang.Object header) Sets the header information for the media chunk. param header The header object that holds the media data chunk for this Buffer. see #header this.header = header;
public void	setLength(int length) Sets the length of the valid data stored in this Buffer if the data is held in an array. param length The length of the valid data in the data array that holds the media chunk for this Buffer. see #length this.length=length;
public void	setOffset(int offset) If the media chunk for this Buffer is held in an array, sets the offset into the array where the valid data begins. param offset The starting point for the valid data. see #offset this.offset = offset;
public void	setSequenceNumber(long number) Sets the sequence number of this Buffer. Sequence numbers increase or decrease by 1 for each sequential Buffer, indicating the order in which the data is to be processed. Can be used to identify lost samples of data. param number The sequence number for the Buffer. see #sequenceNumber sequenceNumber = number;
public void	setTimeStamp(long timeStamp) Sets the time stamp of this Buffer. param timeStamp The time stamp for the Buffer, in nanoseconds. see #timeStamp this.timeStamp = timeStamp;