j2d.io.gif.stills
Class GifDecoder

java.lang.Object
  j2d.io.gif.stills.GifDecoder

public class GifDecoder
extends java.lang.Object

Class GifDecoder - Decodes a GIF file into one or more frames.

 Example:
    GifDecoder d = new GifDecoder();
    d.read("sample.gif");
    int n = d.getFrameCount();
    for (int i = 0; i < n; i++) {
       BufferedImage frame = d.getFrame(i);  // frame i
       int t = d.getDelay(i);  // display duration of frame in milliseconds
       // do something with frame
    }
 

No copyright asserted on the source code of this class. May be used for any purpose, however, refer to the Unisys LZW patent for any additional restrictions. Please forward any corrections to kweiner@fmsware.com.

Version:

1.01 July 2001

Author:

Kevin Weiner, FM Software; LZW decoder adapted from John Cristy's ImageMagick.

Nested Class Summary

static class

GifDecoder.GifFrame

Field Summary

static int	STATUS_FORMAT_ERROR File read status: Error decoding file (may be partially decoded)
static int	STATUS_OK File read status: No errors.
static int	STATUS_OPEN_ERROR File read status: Unable to open source.

Constructor Summary

GifDecoder()

Method Summary

java.awt.image.BufferedImage	getCurrentBufImg() Gets the first (or only) image read.
int	getDelay(int n) Gets display duration for specified frame.
java.awt.image.BufferedImage	getFrame(int n) Gets the image contents of frame n.
int	getFrameCount() Gets the number of frames read from file.
int	getLoopCount() Gets the "Netscape" iteration count, if any.
static void	main(java.lang.String[] args)
int	read(java.io.BufferedInputStream is)
int	read(java.lang.String name) Reads GIF file from specified source (file or URL string)

Methods inherited from class java.lang.Object

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

Field Detail

STATUS_OK

public static final int STATUS_OK

File read status: No errors.

See Also:

Constant Field Values

STATUS_FORMAT_ERROR

public static final int STATUS_FORMAT_ERROR

File read status: Error decoding file (may be partially decoded)

See Also:

Constant Field Values

STATUS_OPEN_ERROR

public static final int STATUS_OPEN_ERROR

File read status: Unable to open source.

See Also:

Constant Field Values

Constructor Detail

GifDecoder

public GifDecoder()

Method Detail

getDelay

public int getDelay(int n)

Gets display duration for specified frame.

Parameters:

n - int index of frame

Returns:

delay in milliseconds

getFrame

public java.awt.image.BufferedImage getFrame(int n)

Gets the image contents of frame n.

Returns:

BufferedImage representation of frame, or null if n is invalid.

getFrameCount

public int getFrameCount()

Gets the number of frames read from file.

Returns:

frame count

getCurrentBufImg

public java.awt.image.BufferedImage getCurrentBufImg()

Gets the first (or only) image read.

Returns:

BufferedImage containing first frame, or null if none.

getLoopCount

public int getLoopCount()

Gets the "Netscape" iteration count, if any. A count of 0 means repeat indefinitiely.

Returns:

iteration count if one was specified, else 1.

read

public int read(java.io.BufferedInputStream is)

Parameters:

is - An inputStream with gif animation

Returns:

status code (0=no error)

read

public int read(java.lang.String name)

Reads GIF file from specified source (file or URL string)

Parameters:

name - String containing source

Returns:

read status code (0 = no errors)

main

public static void main(java.lang.String[] args)