mediaframe.mpeg1
Class DataBuffer

java.lang.Object
  |
  +--mediaframe.mpeg1.DataBuffer

public final class DataBuffer

extends java.lang.Object

A DataBuffer object represents a data stream (container of the information data blocks). It contains methods for storing and reading the information from the stream.

Author:

Konstantin Belous

Field Summary

private long	_start_time The start time of the reading side.
private long	_time_stamp The time stamp of the current frame to read.
private int	currentFrameIndex The frame index of the current frame in the vector of the frames to read the data.
private DataBlock	currentReadBlock The current data block to read the data.
private DataFrame	currentReadFrame The current frame to read the data.
private DataBlock	currentWriteBlock The current data block to write the data.
private DataFrame	currentWriteFrame The current frame to write the data.
private boolean	EOF True, if the end of the file has been reached.
private java.util.Vector	Frames The vector of the frames.
private int	lastSize The size the last information word (0-4).
private long	lastWord The last 0-4 information bytes (the last information word).
private MPEG_Reader	reader The MPEG_reader object (reader of the mpeg stream).
private int	type The type of the stream (video or audio).

Constructor Summary

DataBuffer(int type, MPEG_Reader reader)
Constructs a DataBuffer with the specified type and MPEG_reader.

Method Summary

void	addToStartTime(long wait) Adds the specified value to the start playing time.
int	getBufferPosition() Gets current position of the buffer.
DataFrame	getCurrentReadFrame() Gets the current frame to read.
long	getCurrentTime() Returns time in milliseconds callibrated from the start of the movie.
void	initReaderSide() Resets the reader's side to zero state.
boolean	isEOF() Returns end of file flag.
void	printPercent(int currentPercent) Prints the current "buffering" percent.
DataBlock	readNextBlock() Reads the next DataBlock from the movie's buffer.
void	registerNewFrame(DataFrame newFrame) Registers the new frame to read movie's data.
void	saveCurrentFrame() Saves the current frame into the buffer.
void	saveLastFrame() Saves the current frame into the buffer as a last frame in the movie file.
private void	setNewBlock() Adds the length of the block to the total amount of the readed bytes.
void	setStartTime(long time) Sets the start playing time to the specified value.
void	write(int Byte) Puts the next information byte into the buffer of movie's data.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

type

private int type

The type of the stream (video or audio).

See Also:

io_tool.TYPE_AUDIO, io_tool.TYPE_VIDEO

Frames

private java.util.Vector Frames

The vector of the frames.

currentFrameIndex

private int currentFrameIndex

The frame index of the current frame in the vector of the frames to read the data.

currentWriteBlock

private DataBlock currentWriteBlock

The current data block to write the data.

currentReadBlock

private DataBlock currentReadBlock

The current data block to read the data.

currentWriteFrame

private DataFrame currentWriteFrame

The current frame to write the data.

currentReadFrame

private DataFrame currentReadFrame

The current frame to read the data.

EOF

private boolean EOF

True, if the end of the file has been reached.

reader

private MPEG_Reader reader

The MPEG_reader object (reader of the mpeg stream).

_time_stamp

private long _time_stamp

The time stamp of the current frame to read.

_start_time

private long _start_time

The start time of the reading side.

lastWord

private long lastWord

The last 0-4 information bytes (the last information word).

lastSize

private int lastSize

The size the last information word (0-4).

Constructor Detail

DataBuffer

public DataBuffer(int type,
                  MPEG_Reader reader)

Constructs a DataBuffer with the specified type and MPEG_reader.

Parameters:

type - the type of the DataBuffer (video or audio).

reader - the MPEG_reader object (reader of the mpeg stream).

Method Detail

initReaderSide

public void initReaderSide()

Resets the reader's side to zero state.

readNextBlock

public final DataBlock readNextBlock()
                              throws java.io.EOFException,
                                     java.lang.InterruptedException

Reads the next DataBlock from the movie's buffer. If necessary waits for the writer process for the next block of data and calls the method that starts the "rebuffering" process of the applet after the free buffer size is less then the min buffer size. Sets EOF flag to true value if the end of the file has been reached.

Throws:

java.io.EOFException - if end of the file has been reached.

java.lang.InterruptedException - if another process interrupts the current process.

setNewBlock

private void setNewBlock()

Adds the length of the block to the total amount of the readed bytes. Starts the "rebuffering" process of the applet if the free buffer size is less then the min buffer size.

getCurrentReadFrame

public DataFrame getCurrentReadFrame()

Gets the current frame to read.

Returns:

the current frame to read.

write

public void write(int Byte)

Puts the next information byte into the buffer of movie's data.

Parameters:

Byte - the next information byte to put.

printPercent

public void printPercent(int currentPercent)

Prints the current "buffering" percent.

Parameters:

currentPercent - the current percent.

saveCurrentFrame

public void saveCurrentFrame()

Saves the current frame into the buffer. Gets the last 0-3 bytes from it and adds it to the list of frames.

saveLastFrame

public void saveLastFrame()

Saves the current frame into the buffer as a last frame in the movie file. Gets the last 0-3 bytes from it and adds it to the list of frames.

isEOF

public boolean isEOF()

Returns end of file flag.

Returns:

true, if the end of the file has been reached.

registerNewFrame

public void registerNewFrame(DataFrame newFrame)

Registers the new frame to read movie's data.

Parameters:

newFrame - the frame to register.

addToStartTime

public void addToStartTime(long wait)

Adds the specified value to the start playing time.

Parameters:

wait - the value to add.

setStartTime

public void setStartTime(long time)

Sets the start playing time to the specified value.

Parameters:

time - the start playing time value to set.

getCurrentTime

public long getCurrentTime()

Returns time in milliseconds callibrated from the start of the movie.

Returns:

current playing time in milliseconds.

getBufferPosition

public int getBufferPosition()

Gets current position of the buffer.

Returns:

current buffer position.