有没有办法用
java知道swf文件的原始宽度和高度？
int width,height;
// my stream contains an image or a swf file
InputStream stream = file.getInputStream();
// mediaType has been set with the help of file extension
switch (mediaType)
{
case IMAGE:
BufferedImage img = ImageIO.read(stream);
width = img.getWidth();
height = img.getHeight();
break;
case FLASH:
// what is the code here ?
break;
}
解决方法
我查看了brooksandrus来源,并且有点不知所措,所以我编写了自己的“一个顶级课程”解决方案.我意识到这是一个长篇大论,但不知道如何以其他方式发布它.
package resnbl.android.swfview;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.Arrays;
import java.util.zip.DataFormatException;
import java.util.zip.Inflater;
/**
* This class will read just enough of a SWF file's header to glean the essential
* meta-data about the animation.
*
* This is based on <a href="http://www.adobe.com/devnet/swf.html">
* SWF File Format Specification (version 10)</a>.
*
* @author Resnbl Software
* @since Mar 22,2011
*/
public class SWFInfo
{
static final int UNCOMP_HDR_LEN = 8; // portion of header that is never compressed
public boolean isCompressed;
public int version;
public long size;
public int width,height;
public float fps;
public int frameCount;
// Instantiate through getInfo() methods
private SWFInfo()
{ }
/**
* Get the header info for a (potential) SWF file specified by a file path String.
*
* @param path String containing path to file.
*
* @return {@link SWFinfo} object or null if file not found or not SWF.
*/
public static SWFInfo getInfo(String path)
{
return getInfo(new File(path));
}
/**
* Get the header info for a (potential) SWF file specified by a {@link File} object.
*
* @param path {@link File} pointing to the desired SWF file.
*
* @return {@link SWFinfo} object or null if file not found or not SWF.
*/
public static SWFInfo getInfo(File file)
{
SWFInfo info = new SWFInfo();
byte[] hdr = getBytes(file);
if (hdr == null)
return null;
info.isCompressed = hdr[0] == 'C';
info.version = hdr[3];
info.size = hdr[4]&0xFF | (hdr[5]&0xFF)<<8 | (hdr[6]&0xFF)<<16 | hdr[7]<<24;
BitReader rdr = new BitReader(hdr,UNCOMP_HDR_LEN);
int[] dims = decodeRect(rdr);
info.width = (dims[1] - dims[0]) / 20; // convert twips to pixels
info.height = (dims[3] - dims[2]) / 20;
info.fps = (float) rdr.uI16() / 256f; // 8.8 fixed-point format
info.frameCount = rdr.uI16();
return info;
}
/*
* Read just enough of the file for our purposes
*/
private static byte[] getBytes(File file)
{
if (file == null || !file.exists() || file.isDirectory())
return null;
byte[] bytes = new byte[128]; // should be enough...
FileInputStream fis = null;
try
{
fis = new FileInputStream(file);
if (fis.read(bytes) < bytes.length)
bytes = null; // too few bytes to be a SWF
else if (bytes[0] == 'C' && bytes[1] == 'W' && bytes[2] == 'S')
bytes = expand(bytes,UNCOMP_HDR_LEN); // compressed SWF
else if (bytes[0] != 'F' || bytes[1] != 'W' || bytes[2] != 'S')
bytes = null; // not a SWF
// else uncompressed SWF
}
catch (IOException e)
{ }
finally
{
if (fis != null)
try { fis.close(); }
catch (IOException ee) { }
}
return bytes;
}
/*
* All of the file past the initial {@link UNCOMP_HDR_LEN} bytes are compressed.
* Decompress as much as is in the buffer already read and return them,* overlaying the original uncompressed data.
*
* Fortunately,the compression algorithm used by Flash is the ZLIB standard,* i.e.,the same algorithms used to compress .jar files
*/
private static byte[] expand(byte[] bytes,int skip)
{
byte[] newBytes = new byte[bytes.length - skip];
Inflater inflater = new Inflater();
inflater.setInput(bytes,skip,newBytes.length);
try
{
int outCount = inflater.inflate(newBytes);
System.arraycopy(newBytes,bytes,outCount);
Arrays.fill(bytes,skip + outCount,bytes.length,(byte) 0);
return bytes;
}
catch (DataFormatException e)
{ }
return null;
}
/**
* Return Stage frame rectangle as 4 <code>int</code>s: LRTB
*
* Note the values are in TWIPS (= 1/20th of a pixel)
*
* I do this to avoid a loading the <code>Rect</code> class which is an
* <code>android.graphics</code> class,and not available if you want to
* test this with desktop Java.
*
* @param rdr
* @return
*/
public static int[] decodeRect(BitReader rdr)
{
int[] dims = new int[4];
int nBits = rdr.uBits(5);
dims[0] = rdr.sBits(nBits); // X min = left always 0
dims[1] = rdr.sBits(nBits); // X max = right
dims[2] = rdr.sBits(nBits); // Y min = top always 0
dims[3] = rdr.sBits(nBits); // Y max = bottom
return dims;
}
/**
* This can be run from a desktop command line sitting at the .../bin directory as:
*
* java resnbl.android.swfview.SWFInfo swf_file
*
* @param args path to swf_file to parse
*/
// commented out to prevent Eclipse from thinkg this is a standard Java app when used for Android!
// public static void main(String[] args)
// {
// if (args.length == 0)
// throw new IllegalArgumentException("No swf_file parameter given");
//
// File file = new File(args[0]);
// SWFInfo info = SWFInfo.getInfo(file);
//
// if (info != null)
// {
// System.out.println("File: " + file);
// System.out.println("Flash ver: " + info.version + " FPS: " + info.fps + " Frames: " + info.frameCount);
// System.out.println("File size: " + file.length() + " Compressed: " + info.isCompressed + " Uncompressed size: " + info.size);
// System.out.println("Dimensions: " + info.width + "x" + info.height);
// }
// else
// System.out.println("File not a .SWF: " + file);
// }
/**
* Read an arbitrary number of bits from a byte[].
*
* This should be turned into a full-featured independant class (someday...).
*/
static class BitReader
{
private byte[] bytes;
private int byteIdx;
private int bitIdx = 0;
/**
* Start reading from the beginning of the supplied array.
* @param bytes byte[] to process
*/
public BitReader(byte[] bytes)
{
this(bytes,0);
}
/**
* Start reading from an arbitrary index into the array.
* @param bytes byte[] to process
* @param startIndex byte # to start at
*/
public BitReader(byte[] bytes,int startIndex)
{
this.bytes = bytes;
byteIdx = startIndex;
}
/**
* Fetch the next <code>bitCount</code> bits as an unsigned int.
* @param bitCount # bits to read
* @return int
*/
public int uBits(int bitCount)
{
int value = 0;
while (--bitCount >= 0)
value = value << 1 | getBit();
return value;
}
/**
* Fetch the next <code>bitCount</code> bits as a <em>signed</em> int.
* @param bitCount # bits to read
* @return int
*/
public int sBits(int bitCount)
{
// First bit is the "sign" bit
int value = getBit() == 0 ? 0 : -1;
--bitCount;
while (--bitCount >= 0)
value = value << 1 | getBit();
return value;
}
// Get the next bit in the array
private int getBit()
{
int value = (bytes[byteIdx] >> (7 - bitIdx)) & 0x01;
if (++bitIdx == 8)
{
bitIdx = 0;
++byteIdx;
}
return value;
}
/**
* Fetch the next 2 "whole" bytes as an unsigned int (little-endian).
* @return int
*/
public int uI16()
{
sync(); // back to "byte-aligned" mode
return (bytes[byteIdx++] & 0xff) | (bytes[byteIdx++] & 0xff) << 8;
}
/**
* Bump indexes to the next byte boundary.
*/
public void sync()
{
if (bitIdx > 0)
{
++byteIdx;
bitIdx = 0;
}
}
}
}
注意：我用它们的HTML等价物全局替换了尖括号,以使其正确显示.如果你剪切并粘贴它,希望你不必恢复那个改变.
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