Win10 BUG会破坏FLAC音频文件 现已修复

如果你习惯从在线商城下载 FLAC（自由无损音频压缩编码）格式的音频文件，请不要使用 Windows 10 系统的资源管理器来编辑元数据。在 Windows 10 Version 2004 及更高版本中存在一个错误，如果使用资源管理器修改元数据，就有可能会损坏 FLAC 音频文件。

这个 BUG 影响 Windows 10 专业版、家庭版、企业版、工作站和其他 SKU 版本。根据本月早些时候发布的支持文件，Windows 10的文件资源管理器的错误将破坏某些FLAC文件，这些文件在FLAC头之前包含一个ID3框架。ID3是一个框架，它负责存储信息，如音乐标题、艺术家、专辑、曲目编号等。

在 Windows 10 系统，FLAC处理程序忽略了ID3框架，因为它认为FLAC文件在开头使用4字节的fLaC。当音乐文件被用户编辑时，ID3 框架被覆盖了，没有开始代码。因此，音乐播放器无法识别修改后的文件。如果音乐文件的标题、艺术家或其他元数据在文件资源管理器中被改变，音乐文件就不会播放或加载。

幸运的是，微软已经确定了根本原因，现在可以通过Windows Update进行修复。在 KB5003214 更新的更新日志中，微软确认该错误已被修复，如果你改变了他们的标题、艺术家或其他元数据，自由无损音频编解码器（FLAC）音乐文件将不再变得无法播放。

对于那些有损坏的音乐文件，微软已经发布了一个新的PowerShell脚本，你可以运行它来使文件再次播放。然而，它不能恢复存储在ID3框架中的丢失的元数据。为了避免FLAC音乐文件在未来出现问题，微软建议应用本月的可选累积更新。

解决方案

1. 打开记事本

2. 将以下脚本代码复制到记事本中

# Copyright 2021 Microsoft

# This script will repair a FLAC file that has been corrupted by Media Foundation in reference to KB5003430.

# Refer to KB5003430 for further information

param(

[parameter(Mandatory =$ true,

HelpMessage = "The path to the FLAC file that has been corrupted by Media Foundation",

ValueFromRemainingArguments =$ true)]

[ValidateScript({ -not [String]::IsNullOrEmpty( $_) -and (Test-Path $_) })]

[String] $ File

)

# We need to back up the current file incase we have any errors

$ FileDirectory = Split-Path -Resolve $ File

$ Filename = Split-Path -Leaf -Resolve $ File

$ FullPath = Join-Path -Resolve $ FileDirectory $ Filename

$ Filename = [String]::Format("Backup_{0:yyyyMMdd_hhmmss}_{1}", [DateTime]::Now, $ Filename)

$ BackupLocation = Join-Path $ FileDirectory $ Filename

Write-Output "Microsoft FLAC Repair Tool. This tool will repair a FLAC audio file that was corrupted when editing its details."

Write-Output "Affected File: $ FullPath"

Write-Output "A backup of the file will be made: $ BackupLocation"

Write-Output "Do you wish to continue?"

$ choice =$ host.ui.PromptForChoice("Fixing FLAC Script", "Do you wish to continue", ('&Yes', '&No'), 1)

function ParseStreamInfoMetADATABlock([System.IO.FileStream] $ stream)

{

$ blockType = $ stream.ReadByte()

$ lastBlock = ($ blockType -shr 7) -ne 0

$ blockType = $ blockType -band 0x7F

if ($ blockType -ne 0)

{

return $ false

}

$ blockSize = (($ stream.ReadByte() -shl 16) -bor ($ stream.ReadByte() -shl 8) -bor $ stream.ReadByte())

if ($ blockSize -lt 34)

{

return $ false

}

$ minAudioBlockSize = ($ stream.ReadByte() -shl 8) -bor $ stream.ReadByte()

$ maxAudioBlockSize = ($ stream.ReadByte() -shl 8) -bor $ stream.ReadByte()

if ($ minAudioBlockSize -lt 16 -or $ maxAudioBlockSize -lt 16)

{

return $ false

}

$ minFrameSize = (($ stream.ReadByte() -shl 16) -bor ($ stream.ReadByte() -shl 8) -bor $ stream.ReadByte())

$ maxFrameSize = (($ stream.ReadByte() -shl 16) -bor ($ stream.ReadByte() -shl 8) -bor $ stream.ReadByte())

$ sampleInfo = (($ stream.ReadByte() -shl 24) -bor ($ stream.ReadByte() -shl 16) -bor ($ stream.ReadByte() -shl 8) -bor $ stream.ReadByte())

$ sampleRate = $ sampleInfo -shr 12

$ channelCount = (($ sampleInfo -shr 9) -band 0x7) + 1

$ bitsPerSample = (($ sampleInfo -shr 4) -band 0x1F) + 1

[UInt64] $ sampleCount = (($ stream.ReadByte() -shl 24) -bor ($ stream.ReadByte() -shl 16) -bor ($ stream.ReadByte() -shl 8) -bor $ stream.ReadByte())

$ sampleCount = (([UInt64] $ sampleInfo -band 0xF) -shl 32) -bor $ sampleCount

$ MD5HashBytes = New-Object byte[] 16

$ stream.Read( $ MD5HashBytes, 0, $ MD5HashBytes.Length)

$ MD5Hash = [Guid]( $ MD5HashBytes)

if ($ sampleRate -eq 0)

{

return $ false

}

# Passing these checks means that we likely have a stream info header and can rebuild the file

Write-Output "File Stream Information"

Write-Output "Sample Rate: $ sampleRate"

Write-Output "Audio Channels: $ channelCount"

Write-Output "Sample Depth: $ bitsPerSample"

Write-Output "MD5 Audio Sample Hash: $ MD5Hash"

return $ true

}

if ($ choice -eq 0)

{

Copy-Item $ FullPath -Destination $ BackupLocation -Force

$ stream = [System.IO.File]::Open( $ FullPath, [System.IO.FileMode]::Open)

$ stream.Seek(4, [System.IO.SeekOrigin]::Begin)

while ($ stream.ReadByte() -eq 0) {}

# We now need to figure out where a valid FLAC metadata frame begins

# We are likely pointing to the last byte of the size member so we'll seek back 4 bytes and retry

$ flacDataStartPosition = $ stream.Position - 4

$ stream.Seek( $ flacDataStartPosition, [System.IO.SeekOrigin]::Begin)

while (-not(ParseStreamInfoMetadataBlock( $ stream)))

{

$ flacDataStartPosition = $ flacDataStartPosition + 1

$ stream.Seek( $ flacDataStartPosition, [System.IO.SeekOrigin]::Begin)

}

# Insert the start code

$ stream.Seek( $ flacDataStartPosition, [System.IO.SeekOrigin]::Begin)

if (Test-Path "$ FullPath.tmp")

{

Remove-Item "$ FullPath.tmp"

}

$ fixedStream = [System.IO.File]::Open(" $ FullPath.tmp", [System.IO.FileMode]::CreateNew)

[byte[]] $ startCode = [char[]]('f', 'L', 'a', 'C');

$ fixedStream.Write( $ startCode, 0, $ startCode.Length)

$ stream.CopyTo( $ fixedStream)

$ stream.Close()

$ fixedStream.Close()

Move-Item -Force "$ FullPath.tmp" $ FullPath

}

3. 文件菜单上，点击保存。

4. 在 "另存为 "对话框中，找到你要保存PowerShell脚本的文件夹。

5. 在文件名框中，输入FixFlacFiles.ps1，将保存类型框改为文本文档（*.txt），然后点击保存。

6. 在Windows Explorer中，找到你保存的PowerShell脚本。

7. 右键单击该脚本，然后单击用PowerShell运行。

8. 当有提示时，输入无法播放的FLAC文件的文件名，然后按回车键。