Question

使用zlib.net在vb.net上压缩字节后，具有相同长度的2个文件是否正常？

这是我使用zlib.net引用的压缩模块，2个文件是相同的，有juste小于100个字节使它们之间有区别

Imports System.IO
Imports zlib

Module zlib_compression

    Public Sub CopyStream(ByRef input As System.IO.Stream, ByRef output As         System.IO.Stream)

        Dim num1 As Integer
        Dim buffer1 As Byte() = New Byte(2000 - 1) {}
        num1 = input.Read(buffer1, 0, 2000)
        Do While (num1 > 0)
            output.Write(buffer1, 0, num1)
            num1 = input.Read(buffer1, 0, 2000)
        Loop
        output.Flush()

    End Sub


    Public Function Compress(ByVal InputBytes As Byte()) As Byte()

        Using output As New MemoryStream
            Dim outZStream As Stream = New ZOutputStream(output,         zlib.zlibConst.Z_BEST_SPEED)
            Using input As Stream = New MemoryStream(InputBytes)
                CopyStream(input, outZStream)
                outZStream.Close()               'do not remove
                Return output.ToArray()
            End Using
        End Using

    End Function

    Public Function Decompress(ByVal InputBytes As Byte()) As Byte()

        Using output As New MemoryStream
            Using outZStream As Stream = New ZOutputStream(output)
                Using input As Stream = New MemoryStream(InputBytes)
                    CopyStream(input, outZStream)
                    Return output.ToArray()
                End Using
            End Using
        End Using

    End Function


End Module

Answer 1

当然，是的。事实上它必然是真的。不可能将所有相同长度的文件无损压缩到较小的大小，因为较小的大小中没有足够的位来标识所有原始文件。如果有些是压缩的，那么必须扩展一些。

zlib.net具有相同lengt的2个文件在压缩后产生2个不同的最终长度

1 个答案: