写回解码文件后出现异常字符添加

Question

我正在使用 ZXing.Net 库使用 RS 编码器对我的视频文件进行编码和解码。它通过在编码和解码之后分别添加和删除奇偶校验来很好地工作。但是当写回解码文件时，它会添加“？”文件中不同位置的字符不是原始文件的一部分。我不明白为什么在写回文件时会出现此问题。这是我的代码

using ZXing.Common.ReedSolomon;

namespace zxingtest
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
            string inputFileName = @"D:\JM\bin\baseline_30.264";
            string outputFileName = @"D:\JM\bin\baseline_encoded.264";
            string Content = File.ReadAllText(inputFileName, ASCIIEncoding.Default);
            //File.WriteAllText(outputFileName, Content, ASCIIEncoding.Default);
            ReedSolomonEncoder enc = new ReedSolomonEncoder(GenericGF.AZTEC_DATA_12);
            ReedSolomonDecoder dec = new ReedSolomonDecoder(GenericGF.AZTEC_DATA_12);
            //string s = "1,2,4,6,1,7,4,0,0";
            //int[] array = s.Split(',').Select(str => int.Parse(str)).ToArray();
            int parity = 10;
            List<byte> toBytes = ASCIIEncoding.Default.GetBytes(Content.Substring(0, 500)).ToList();

            for (int index = 0; index < parity; index++)
            {
                toBytes.Add(0);
            }
            int[] bytesAsInts = Array.ConvertAll(toBytes.ToArray(), c => (int)c);

            enc.encode(bytesAsInts, parity);
            bytesAsInts[1] = 3;
            dec.decode(bytesAsInts, parity);
            string st = new string(Array.ConvertAll(bytesAsInts.ToArray(), z => (char)z));
            File.WriteAllText(outputFileName, st, ASCIIEncoding.Default);
        }
    }
}

这里是H.264码流的Hex文件视图

Answer 1

问题是您正在处理二进制格式，就好像它是带有编码的文本文件一样。但是根据你正在做的事情，你似乎只对读取一些字节感兴趣，处理它们（编码，解码）然后将字节写回文件。

如果这是您的需要，那么请为您的文件使用正确的 reader 和编写器，在本例中为 BinaryReader and BinaryWriter。使用您的代码作为起点，这是我使用前面提到的 readers/writers 的版本。我的输入文件和输出文件读取和写入的字节数相似。

string inputFileName = @"input.264";
string outputFileName = @"output.264";

ReedSolomonEncoder enc = new ReedSolomonEncoder(GenericGF.AZTEC_DATA_12);
ReedSolomonDecoder dec = new ReedSolomonDecoder(GenericGF.AZTEC_DATA_12);

const int parity = 10;

// open a file as stream for reading
using (var input = File.OpenRead(inputFileName))
{
    const int max_ints = 256;
    int[] bytesAsInts = new int[max_ints];
    // use a binary reader
    using (var binary = new BinaryReader(input))
    {
        for (int i = 0; i < max_ints - parity; i++)
        {
            //read a single byte, store them in the array of ints
            bytesAsInts[i] = binary.ReadByte();
        }
        // parity
        for (int i = max_ints - parity; i < max_ints; i++)
        {
            bytesAsInts[i] = 0;
        }

        enc.encode(bytesAsInts, parity);

        bytesAsInts[1] = 3;

        dec.decode(bytesAsInts, parity);

        // create a stream for writing
        using(var output = File.Create(outputFileName))
        {
            // write bytes back
            using(var writer = new BinaryWriter(output))
            {
                foreach(var value in bytesAsInts)
                {
                    // we need to write back a byte
                    // not an int so cast it
                    writer.Write((byte)value);
                }
            }
        }
    }
}

写回解码文件后出现异常字符添加

Unusual Character addition after writing back decoded file

c#

file

zxing