视频字节的解压缩在java中不起作用 [英] Decompressed of video bytes are not working in java

问题描述

以下代码无法重新生成压缩视频。你能不能请任何人帮助我吗？



atform，我正在努力解决这个问题。你能不能请任何人帮我这个。？

Below code is not working to re-generate my compressed video. Could you please any one help me on this ?

atform, i am struggling to resolve this problem. Could you please any one help me on this.?

public class CompressionTest
{
    public static void main(String[] args)
    {
        Compressor compressor = new Compressor();

        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        FileInputStream fis=null;
        File file=null;

        try
        {
            URL uri=CompressionTest.class.getResource("/Files/Video.mp4");
            file=new File(uri.getPath());
            fis = new FileInputStream(file);
        } 
        catch ( FileNotFoundException fnfe )
        {
            System.out.println( "Unable to open input file");
        }

        try 
        {

            byte[] videoBytes = getBytesFromFile(file);

            System.out.println("CompressionVideoToCompress is: '" +videoBytes + "'");

            byte[] bytesCompressed = compressor.compress(videoBytes);

            System.out.println("bytesCompressed is: '" +bytesCompressed+ "'");

            byte[] bytesDecompressed=compressor.decompress(bytesCompressed);

            System.out.println("bytesDecompressed is: '" +bytesDecompressed+ "'");

            FileOutputStream out = new FileOutputStream("A.mp4");
            out.write(bytesDecompressed,0,bytesDecompressed.length-1);
            out.close();

        } 
        catch (IOException e) 
        {
            // TODO Auto-generated catch block
            System.out.println("bytesCompressed is: '");
        }


    }

    public static byte[] getBytesFromFile(File file) throws IOException 
    {
        InputStream is = new FileInputStream(file);

        // Get the size of the file
        long length = file.length();

        // You cannot create an array using a long type.
        // It needs to be an int type.
        // Before converting to an int type, check
        // to ensure that file is not larger than Integer.MAX_VALUE.
        if (length > Integer.MAX_VALUE) {
            // File is too large
        }

        // Create the byte array to hold the data
        byte[] bytes = new byte[1064];

        // Read in the bytes
        int offset = 0;
        int numRead = 0;
        while (offset < bytes.length
               && (numRead=is.read(bytes, offset, bytes.length-offset)) >= 0)
        {
            offset += numRead;
        }

        // Ensure all the bytes have been read in
        if (offset < bytes.length) {
            throw new IOException("Could not completely read file "+file.getName());
        }

        // Close the input stream and return bytes
        is.close();
        return bytes;
    }
}

class Compressor
{
    public Compressor()
    {}

    public byte[] compress(byte[] bytesToCompress)
    {        
        Deflater deflater = new Deflater();
        deflater.setInput(bytesToCompress);
        deflater.finish();

        byte[] bytesCompressed = new byte[Short.MAX_VALUE];

        int numberOfBytesAfterCompression = deflater.deflate(bytesCompressed);

        byte[] returnValues = new byte[numberOfBytesAfterCompression];

        System.arraycopy
        (
            bytesCompressed,
            0,
            returnValues,
            0,
            numberOfBytesAfterCompression
        );

        return returnValues;
    }

    public byte[] decompress(byte[] bytesToDecompress)
    {
        Inflater inflater = new Inflater();

        int numberOfBytesToDecompress = bytesToDecompress.length;

        inflater.setInput
        (
            bytesToDecompress,
            0,
            numberOfBytesToDecompress
        );

        int compressionFactorMaxLikely = 3;

        int bufferSizeInBytes =
            numberOfBytesToDecompress
            * compressionFactorMaxLikely;

        byte[] bytesDecompressed = new byte[bufferSizeInBytes];

        byte[] returnValues = null;

        try
        {
            int numberOfBytesAfterDecompression = inflater.inflate(bytesDecompressed);

            returnValues = new byte[numberOfBytesAfterDecompression];

            System.arraycopy
            (
                bytesDecompressed,
                0,
                returnValues,
                0,
                numberOfBytesAfterDecompression
            );            
        }
        catch (DataFormatException dfe)
        {
            dfe.printStackTrace();
        }

        inflater.end();

        return returnValues;
    }
}

推荐答案

Deflater 和 Inflater 大概是用于zip文件处理而不是视频用途。尝试找一个用于视频处理的库。

Deflater and Inflater are presumably for zip file handling and not for video usage. Try finding a library for video handling instead.

请注意，java中的字符（不是字节）是宽字符 - 每个字符都是16位宽。一个字节是8位。在几乎所有其他语言中，字符默认为8位形式。

Be aware that characters (not bytes) in java are wide characters - each character is 16 bits wide. A byte is 8 bits. In almost every other language, a character defaults to 8 bit form.

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