C＃解码（解压缩）放气PDF文件的数据 [英] C# decode (decompress) Deflate data of PDF File

问题描述

我想解压缩在C＃中的一些DeflateCoded数据（PDF提取）。
不幸的是我每一次例外发现无效数据而解码。
，但数据是有效的。

I would like to decompress in C# some DeflateCoded data (PDF extracted). Unfortunately I got every time the exception "Found invalid data while decoding.". But the data are valid.

private void Decompress()
{
    FileStream fs = new FileStream(@"S:\Temp\myFile.bin", FileMode.Open);

    //First two bytes are irrelevant
    fs.ReadByte();
    fs.ReadByte();

    DeflateStream d_Stream = new DeflateStream(fs, CompressionMode.Decompress);

    StreamToFile(d_Stream, @"S:\Temp\myFile1.txt", FileMode.OpenOrCreate);

    d_Stream.Close();
    fs.Close();
}

private static void StreamToFile(Stream inputStream, string outputFile, FileMode fileMode)
{
    if (inputStream == null)
        throw new ArgumentNullException("inputStream");

    if (String.IsNullOrEmpty(outputFile))
        throw new ArgumentException("Argument null or empty.", "outputFile");

    using (FileStream outputStream = new FileStream(outputFile, fileMode, FileAccess.Write))
    {
        int cnt = 0;
        const int LEN = 4096;
        byte[] buffer = new byte[LEN];

        while ((cnt = inputStream.Read(buffer, 0, LEN)) != 0)
            outputStream.Write(buffer, 0, cnt);
    }
}

有没有人有一些想法？
谢谢

Does anyone has some ideas? Thanks.

推荐答案

我添加了这个测试数据： -

I added this for test data:-

private static void Compress()
{
  FileStream fs = new FileStream(@"C:\Temp\myFile.bin", FileMode.Create);

  DeflateStream d_Stream = new DeflateStream(fs, CompressionMode.Compress);
  for (byte n = 0; n < 255; n++)
    d_Stream.WriteByte(n);
  d_Stream.Close();
  fs.Close();
}

修改解压这样的： -

Modified Decompress like this:-

private static void Decompress()
{
  FileStream fs = new FileStream(@"C:\Temp\myFile.bin", FileMode.Open);

  //First two bytes are irrelevant
  //      fs.ReadByte();
  //      fs.ReadByte();

  DeflateStream d_Stream = new DeflateStream(fs, CompressionMode.Decompress);

  StreamToFile(d_Stream, @"C:\Temp\myFile1.txt", FileMode.OpenOrCreate);

  d_Stream.Close();
  fs.Close();
}

然这样的： -

Ran it like this:-

static void Main(string[] args)
{
  Compress();
  Decompress();
}

和有没有错误。

我的结论，无论是前两个字节是相关的（显然，他们是我的特别的测试数据。），或者你的数据有问题

I conclude that either the first two bytes are relevant (Obviously they are with my particular test data.) or that your data has a problem.

我们能有你的一些测试数据一起玩？

Can we have some of your test data to play with?

（显然不如果是大小写）

(Obviously don't if it's sensitive)

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