[技术讨论] PowerShell看RAR分割檔裡的mp4(缺檔)

#Requires -version 5.0
if ($host.Version.Major -lt 5){write-host '需要 PowerShell 5.0';pause;exit}


$dllfiles = @(gi pfmclr_183.dll , pfmshim16_183.dll )
if ( $dllfiles.length -lt 2 ){
	write-host '需要dll';pause;exit
}else{
	Add-Type  -literal  $dllfiles[0]
}



#分析RAR================================================================================
$rarGroup = dir *.part*.rar | sort |?{$_.name -match '(.*)\.part(\d+)\.rar$' } | 
			group -prop {$matches[1] + '/' + $matches[2].length}

for ($i = 0 ; $i -lt $rarGroup.length; $i++){
	if ($rarGroup[$i].group[0] -match 't0*1\.rar$'){
		$rar = $rarGroup[$i].group ; $nFiles = $rarGroup[$i].Count ; break}
}
if ($i -eq $rarGroup.lenth) {write-host '找不到第一檔';pause;exit}
if ($nFiles -eq 1) {write-host '只有一檔，不用處理了';pause;exit}


$fs = $rar[0].OpenRead()
$buffer = new-object byte[](2kb)


$n = $fs.read($buffer , 0 , 20)
if ( $n -ne 20 ) {$fs.close();write-host '第一檔太小了';pause;exit}
if ($buffer[10] -band 0x80){
	$fs.close();write-host '不能處理檔名加密的RAR檔';pause;exit
}

$findOK = $false
while ($fs.Position -lt $fs.length ){
	$n = $fs.read($buffer , 20 , 7)
	if ( $n -ne 7 ) {$fs.close();write-host '第一檔太小了';pause;stop-process -Id $PID}

	$n = [BitConverter]::ToUInt16($buffer , 25) -7
	if ( ($fs.Position + $n ) -gt $fs.length ){
		$fs.close();write-host '第一檔太小了';pause;stop-process -Id $PID
	}
	[void]$fs.read($buffer , 27 , $n)

	#如果是檔案區塊
	if ( $buffer[22] -eq 0x74 ) {
		#如果是mp4 -->  file continued in next volume
		if ( $buffer[23] -band 2 ) {
			#有沒有加密
			if ( $buffer[23] -band 4 ) { $encryption = $true} else { $encryption = $false}
			if ( $buffer[45] -ne 0x30) {
				$fs.close();write-host '壓縮方式不是僅儲存';pause
				stop-process -Id $PID
			}
			$HeaderSize = $n + 7
			$FirstSize = [BitConverter]::ToUInt32($buffer, 27 )
			$Mp4Size = [BitConverter]::ToUInt32($buffer, 31 )

			#如果檔案很大
			if  ($buffer[24] -band 1 ){
				$HighSize = [BitConverter]::ToUInt32($buffer, 52 )
				$FirstSize = ([long]$HighSize -shl 32 ) + $FirstSize

				$HighSize = [BitConverter]::ToUInt32($buffer, 56 )
				$Mp4Size = ([long]$HighSize -shl 32 ) + $Mp4Size
			}

			#取得檔名
			$nameSize = [BitConverter]::ToUInt16($buffer , 46 )
			if  ($buffer[24] -band 1 ){$namePos = 60 }else { $namePos = 52 }
			$mp4Name=[System.Text.Encoding]::Default.GetString($buffer,$namePos,$nameSize)
			$mp4Name = $mp4Name -replace '\x00.*',''  -replace '\?','_'
			$FirstOffset = $fs.Position
			$findOK = $true
			break

		}else{	#第一檔裡面的其他檔案
			$n = [BitConverter]::ToUInt32($buffer, 27)
			if  ($buffer[24] -band 1 ) {
				$HighSize = [BitConverter]::ToUInt32($buffer, 52 )
				$n += ([long]$HighSize -shl 32 )
			}
			if ( ($fs.Position + $n ) -gt $fs.length ){
				$fs.close();write-host '第一檔太小了';pause;stop-process -Id $PID
			}
			$fs.Position += $n
		}
	}else{#非檔案區塊
		if ($buffer[24] -band 0x80){
			$n = [BitConverter]::ToUInt32($buffer, 27)
				if ( ($fs.Position + $n ) -gt $fs.length ){
					$fs.close();write-host '第一檔太小了';pause;stop-process -Id $PID
				}
			$fs.Position += $n
		}
	}
}
$fs.close()
if ( !$findOK) {write-host '沒找到mp4';pause;exit}
#計算RAR資訊================================================================================
$MidOffset = $LastOffset = $HeaderSize + 20
$MidSize = $FirstSize + ( $FirstOffset - $MidOffset )
$FullPack = $Mp4Size
if ($encryption){
	if ( $Mp4Size % 16 ) {	$FullPack += 16 - ($Mp4Size % 16) }
}

$LastSize = ($FullPack - $FirstSize) % $MidSize
$nLastPart = ($FullPack - $FirstSize - $LastSize) / $MidSize +2

$Mp4offset = $nEmpty = 0
$mp4Info = & {
	if ($encryption){
		$buffer[10] = $buffer[10] -band 238
		$buffer[11] = $buffer[11] -band 254
		$buffer[23] = $buffer[23] -band 253

		$fpbyte = [BitConverter]::GetBytes([uint64]$FullPack)
		[array]::copy($fpbyte,0,$buffer,27,4)
		if  ($buffer[24] -band 1 ){
			[array]::copy($fpbyte,4,$buffer,52,4)
		}			

		@{fs = new-object IO.MemoryStream($buffer,0, (20 + $HeaderSize))
			Mp4offset = $Mp4offset	;offset = 0 ; length = 20 + $HeaderSize
		}
		$Mp4offset += 20 + $HeaderSize
	}
	if (  ($FirstOffset + $FirstSize) -gt $rar[0].length  ) {
		$nEmpty = $FirstOffset + $FirstSize - $rar[0].length
	}
	@{fs = $rar[0].OpenRead() ; Mp4offset = $Mp4offset
		offset = $FirstOffset ; length = $FirstSize - $nEmpty
	}

	$Mp4offset += $FirstSize - $nEmpty
	$nextN = 2

	#$rar[index]
	1.. ($nFiles - 1) | %{
		[int]$nPart = $rar[$_].basename -replace '.*part',''
		if ( $nPart -gt $nLastPart ) {
			@{fs = $null ; Mp4offset = $Mp4offset ; length = $FullPack - $Mp4offset}
			$nPart = $nLastPart ; return
		}

		if ( $nPart -gt $nextN  -or  $nEmpty -gt 0 ){
			@{fs = $null ; Mp4offset = $Mp4offset
				length = $MidSize * ( $nPart - $nextN ) +  $nEmpty
			}
			$Mp4offset += $MidSize * ( $nPart - $nextN ) +  $nEmpty
			$nEmpty = 0
		}

		#如果是最後一檔
		if ( $nPart -eq $nLastPart ){
			if (  ($LastOffset + $LastSize) -gt $rar[$_].length  ) {
				$nEmpty = $LastOffset + $LastSize - $rar[$_].length
			}
			@{fs = $rar[$_].OpenRead() ; Mp4offset = $Mp4offset
				offset = $LastOffset ; length = $LastSize - $nEmpty
			}

			if ( $nEmpty -gt 0 ){
				$Mp4offset += $LastSize - $nEmpty
				@{fs = $null ; Mp4offset = $Mp4offset ; length = $nEmpty}
			}
			return

		}else{#中間檔
			if (  ($MidOffset + $MidSize) -gt $rar[$_].length  ) {
				$nEmpty = $MidOffset + $MidSize - $rar[$_].length
			}
			@{fs = $rar[$_].OpenRead() ; Mp4offset = $Mp4offset
				offset = $MidOffset ; length = $MidSize - $nEmpty
			}
			$Mp4offset += $MidSize - $nEmpty
			$nextN = $nPart + 1		
		}
	}

	if ( $nPart -lt $nLastPart ){
		@{fs = $null ; Mp4offset = $Mp4offset ; length = $FullPack - $Mp4offset}
	}
}
#====================================================================================
$RarVolumeType=@'
#Learn from   Pismo File Mount Development Kit   samples\hellofs_cs\hellofs.cs
class RarVolume: Pfm+FormatterDispatch{
	$openRoot
	$openFile1
	$File1_name
	$File1_info
RarVolume(){
	$this.openRoot = new-object Pfm+OpenAttribs -prop @{
				openSequence = 1 ; accessLevel = [Pfm]::accessLevelReadData;
				attribs = new-object Pfm+Attribs -prop @{fileType = [Pfm]::fileTypeFolder ; fileId = 2 }}

	$this.openFile1 = new-object Pfm+OpenAttribs -prop @{
				openSequence = 1 ; accessLevel = [Pfm]::accessLevelReadData;
				attribs = new-object Pfm+Attribs -prop @{fileType = [Pfm]::fileTypeFile ; fileId = 3 }}
}

[void] Dispose(){}

[void] Open( [Pfm+MarshallerOpenOp]$op){
	$perr = 0
	$existed = $false
	$parentFileId = 0
	$endName = $null
	$openAttribs =  new-object Pfm+OpenAttribs
	if ($op.NameParts().Length -eq 0){
		if ($this.openRoot.openId -eq 0) {$this.openRoot.openId = $op.NewExistingOpenId() }
		$existed = $true
		$openAttribs = $this.openRoot

	}elseif($op.NameParts().Length -eq 1){
		if($op.NameParts()[0].ToLowerInvariant() -ne $this.File1_name.ToLowerInvariant()){
			$perr = [Pfm]::errorNotFound
		}else{ 
			if ($this.openFile1.openId -eq 0) {$this.openFile1.openId = $op.NewExistingOpenId() }
			$existed = $true
			$endName = $this.File1_name
			$openAttribs = $this.openFile1
		}

	}else{  $perr = [Pfm]::errorParentNotFound }

	if($perr -eq [Pfm]::errorNotFound -and $op.CreateFileType() -ne 0)
	{	$perr = [Pfm]::errorAccessDenied          }

	$op.Complete( $perr, $existed, $openAttribs, $parentFileId, $endName, 0, $null, 0, $null)
}

[void] Replace( [Pfm+MarshallerReplaceOp]$op){
	$op.Complete( [Pfm]::errorAccessDenied, $null, $null)
}

[void] Move( [Pfm+MarshallerMoveOp] $op){
	$op.Complete( [Pfm]::errorAccessDenied, $false, $null, 0, $null, 0, $null, 0, $null)
}

[void] MoveReplace( [Pfm+MarshallerMoveReplaceOp] $op){
	$op.Complete( [Pfm]::errorAccessDenied)
}

[void] Delete( [Pfm+MarshallerDeleteOp] $op){
	$op.Complete( [Pfm]::errorAccessDenied)
}

[void] Close( [Pfm+MarshallerCloseOp] $op){
	$op.Complete( [Pfm]::errorSuccess)
}

[void] FlushFile( [Pfm+MarshallerFlushFileOp] $op){
	$perr = 0
	$openAttribs = new-object Pfm+OpenAttribs

	if ( $op.FileFlags() -ne [Pfm]::fileFlagsInvalid -or
        	 $op.Color() -ne [Pfm]::colorInvalid -or
         	$op.CreateTime() -ne [Pfm]::timeInvalid -or
         	$op.WriteTime() -ne [Pfm]::timeInvalid){

		$perr = [Pfm]::errorAccessDenied

	}elseif ($op.OpenId() -eq $this.openRoot.openId){

		$openAttribs = $this.openRoot

	}elseif ($op.OpenId() -eq $this.openFile1.openId){

		$openAttribs = $this.openFile1
	}else{
		$perr = [Pfm]::errorNotFound
	}

	$op.Complete( $perr, $openAttribs, $null)
}

[void] List( [Pfm+MarshallerListOp] $op){
	$perr = 0
	if ($op.OpenId() -ne $this.openRoot.openId){
		$perr = [Pfm]::errorAccessDenied
	}else{
		$op.Add( $this.openFile1.attribs, $this.File1_name)
	}

	$op.Complete( $perr, $true)
}

[void] ListEnd( [Pfm+MarshallerListEndOp] $op){
	$op.Complete( [Pfm]::errorSuccess)
}

[void] Read( [Pfm+MarshallerReadOp] $op){
	$data = $op.Data()
	$perr = 0
	$actualSize = 0

	if ($op.OpenId() -ne $this.openFile1.openId){
		$perr = [Pfm]::errorAccessDenied
	}else{
		$actualSize = $op.RequestedSize()
		if ($op.FileOffset() -ge $this.openFile1.attribs.fileSize){
			$actualSize = 0
		}elseif ( (  $op.FileOffset() + $op.RequestedSize()) -gt $this.openFile1.attribs.fileSize){
			$actualSize = $this.openFile1.attribs.fileSize - $op.FileOffset()
		}

		if ($actualSize -ne 0){
			for ( $i = 1 ; $i -lt $this.File1_info.length ; $i++ ){
				if ($op.FileOffset()  -lt $this.File1_info[$i].Mp4offset ){break}
			}					
			$i--

			if ($this.File1_info[$i].fs -ne $null ){
				$this.File1_info[$i].fs.Position = 
					$op.FileOffset() - $this.File1_info[$i].Mp4offset + $this.File1_info[$i].offset
			}

			$aaa = $this.File1_info[$i].length - ( $op.FileOffset() - $this.File1_info[$i].Mp4offset)

			$offset = 0
			$actualSize1 = $actualSize
			while ($actualSize1 -gt 0){
				if ($actualSize1 -gt $aaa ){
					if ($this.File1_info[$i].fs -ne $null ){
						$this.File1_info[$i].fs.read($data , $offset , $aaa)
					}else{
						[array]::Clear( $data , $offset , $aaa)
					}
					$actualSize1 -= $aaa
					$offset += $aaa

					$i++
					if ($this.File1_info[$i].fs -ne $null ){
						$this.File1_info[$i].fs.Position = $this.File1_info[$i].offset
					}
					$aaa = $this.File1_info[$i].length
				}else{
					if ($this.File1_info[$i].fs -ne $null ){
						$this.File1_info[$i].fs.read($data , $offset , $actualSize1)
					}else{
						[array]::Clear( $data , $offset , $actualSize1)
					}
					$actualSize1 = 0
				}
			}

		}
	}

	$op.Complete( $perr, $actualSize)
}

[void] Write( [Pfm+MarshallerWriteOp] $op){
	$op.Complete( [Pfm]::errorAccessDenied, 0)
}

[void] SetSize( [Pfm+MarshallerSetSizeOp] $op){
	$op.Complete( [Pfm]::errorAccessDenied)
}

[void] Capacity( [Pfm+MarshallerCapacityOp] $op){
	$op.Complete( [Pfm]::errorSuccess, 10TB, 9TB)
}

[void] FlushMedia( [Pfm+MarshallerFlushMediaOp] $op){
	$op.Complete( [Pfm]::errorSuccess, -1)
}

[void] Control( [Pfm+MarshallerControlOp] $op){
	$op.Complete( [Pfm]::errorInvalid, 0)
}

[void] MediaInfo( [Pfm+MarshallerMediaInfoOp] $op){
	$mediaInfo = new-object Pfm+MediaInfo
	$op.Complete( [Pfm]::errorSuccess, $mediaInfo, "RarMp4")
}

[void] Access( [Pfm+MarshallerAccessOp] $op){
	$perr = 0
	$openAttribs =  new-object Pfm+OpenAttribs

	if ($op.OpenId() -eq $this.openRoot.openId){
		$openAttribs = $this.openRoot

	}elseif($op.OpenId() -eq $this.openFile1.openId){
		$openAttribs = $this.openFile1

	}else{
		$perr = [Pfm]::errorNotFound
	}

	$op.Complete( $perr, $openAttribs, $null)
}

[void] ReadXattr( [Pfm+MarshallerReadXattrOp] $op){
	$op.Complete( [Pfm]::errorNotFound, 0, 0)
}

[void] WriteXattr( [Pfm+MarshallerWriteXattrOp] $op){
	$op.Complete( [Pfm]::errorAccessDenied, 0)
}


}

'@

Invoke-Expression $RarVolumeType
#開始掛載==================================================================================
$mcp = new-object Pfm+MountCreateParams -prop @{
	mountFlags = 1
	driveLetter = "Z"
	mountSourceName = "感謝大大無私分享"  }

$msp = new-object Pfm+MarshallerServeParams  -prop @{
	volumeFlags = 1
	dispatch = new-object RarVolume
	formatterName = "RarMp4Fs"  }


$msp.dispatch.File1_name = split-path  $mp4Name  -leaf
$msp.dispatch.openFile1.attribs.fileSize = $Mp4Size
$msp.dispatch.File1_info = $mp4Info

if ($encryption){
	$msp.dispatch.File1_name = $msp.dispatch.File1_name +".rar"
	$msp.dispatch.openFile1.attribs.fileSize = $FullPack + 20 + $HeaderSize

}

$n1 = $n2 = -1
$err = [Pfm]::SystemCreatePipe( [ref] $n1, [ref]$n2 )
$msp.toFormatterRead = $n1
$mcp.toFormatterWrite = $n2
      

$n1 = $n2 = -1
$err = [Pfm]::SystemCreatePipe( [ref] $n1, [ref]$n2 )
$mcp.fromFormatterRead = $n1
$msp.fromFormatterWrite = $n2        



$pfmApi = $null 
$err = [Pfm]::ApiFactory( [ref] $pfmApi)
if($err -ne 0){  Write-Host "ERROR: $err Unable to open PFM API.`n" ; pause ; exit }

$mount = $null
$err = $pfmApi.MountCreate( $mcp, [ref] $mount)
if ($err -ne 0){ Write-Host "ERROR: $err Unable to create mount.`n"  }


[Pfm]::SystemCloseFd( $mcp.toFormatterWrite)
[Pfm]::SystemCloseFd( $mcp.fromFormatterRead)


Write-Host "Press CTRL+C to exit.`n"
$marshaller = $null
$err = [Pfm]::MarshallerFactory( [ref]$marshaller )
if($err -ne 0){  Write-Host "ERROR: $err Unable to create marshaller.`n" ; pause ; exit }
$marshaller.ServeDispatch( $msp)


[Pfm]::SystemCloseFd( $msp.toFormatterRead)
[Pfm]::SystemCloseFd( $msp.fromFormatterWrite)


$pfmApi.Dispose()
$mount.Dispose()
$marshaller.Dispose()
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