[RESOLVED] Reliably identify video files. Was: Video file GUIDs?

[SomeYguy]

Hi everyone!

I use several of these in one of my projects in order to identify image files:

 Const ImageFormatBMP             As String = "{B96B3CAB-0728-11D3-9D7B-0000F81EF32E}"
    Const ImageFormatEMF             As String = "{B96B3CAC-0728-11D3-9D7B-0000F81EF32E}"

But I need same for mp4, mov, avi, wmv.

Not sure if exists or where to find? Thanks as always .

EDIT: What I really need is a reliable way to identify video files without using FSO etc.....I'm thinking open the file in binary mode & read applicable header bytes. Thoughts appreciated!

[SomeYguy]

Well, I decided to go simple and just read the file header. Here's what I came up with:

Dim d As Byte, s As Long, fI as long, st as string

fI = FreeFile

Open "C:\vids\ShakeItUp.mp4" For Binary As fI

For s = 5 To 8

Get fI, s, d

st = st & CStr(Hex(d))


Next s

Close fI

End Sub

'- mp4 = 5 to 8, 66747970
'- avi = 9 to 12, 41564920

This was just a quick throw together so not production code. Seems to work well!

[Niya]

GPT-4 gave me this:-

Private Sub IdentifyFileType(ByVal fileName As String)
    Dim fileNumber As Integer
    Dim header As String
    Dim buffer As String
    
    fileNumber = FreeFile ' Get a free file number
    
    On Error GoTo ErrorHandler ' Error handling if file can't be opened
    Open fileName For Binary As #fileNumber ' Open the file in binary mode
    
    ' Read the first 12 bytes from the file
    header = Space$(12)
    Get #fileNumber, , header
    Close #fileNumber ' Close the file
    
    ' Check for PNG
    If Left$(header, 8) = Chr$(137) & "PNG" & Chr$(13) & Chr$(10) & Chr$(26) & Chr$(10) Then
        MsgBox fileName & " is a PNG file."
    ' Check for JPEG
    ElseIf Left$(header, 3) = Chr$(255) & Chr$(216) & Chr$(255) Then
        MsgBox fileName & " is a JPEG file."
    ' Check for GIF
    ElseIf Left$(header, 3) = "GIF" Then
        MsgBox fileName & " is a GIF file."
    ' Check for BMP
    ElseIf Left$(header, 2) = "BM" Then
        MsgBox fileName & " is a BMP file."
    ' Check for AVI
    ElseIf Left$(header, 4) = "RIFF" And Mid$(header, 9, 4) = "AVI " Then
        MsgBox fileName & " is an AVI file."
    ' Check for MP4
    ElseIf Left$(header, 4) = Chr$(0) & Chr$(0) & Chr$(0) And _
           (Mid$(header, 5, 8) = "ftypisom" Or Mid$(header, 5, 8) = "ftypmp42") Then
        MsgBox fileName & " is an MP4 file."
    Else
        MsgBox "File type of " & fileName & " is unknown."
    End If

    Exit Sub

ErrorHandler:
    MsgBox "Error opening file. Please check if the file exists and is accessible."
    Close #fileNumber
End Sub

I'd recommend double checking that those header signatures as AIs tend to hallucinate. GPT-4 rarely screws up simple things like this but I'd double check it anyway.

I'd also recommend using ChrW instead of Chr. We live in a Unicode world now.

[SomeYguy]

Looks better than what I came up with as far as reading the needed bytes. I'll try it along with your recommendations, thanks