VB6 - Simple Animated GIF Player (supports transparency) using WinRT / BitmapDecoder

[VanGoghGaming]

This project uses the BitmapDecoder WinRT class to decode a GIF file into its individual frames. These frames can then be rendered into any device context (Form, PictureBox, etc) using vanilla GDI functions.

A TypeLib with the required WinRT interface definitions is included in the ZIP archive, don't forget to set a reference to it.

Here's a classic GIF showing Commander Data losing his temper over the once ubiquitous blue screen of death:



The project also supports more complex GIFs (such as those with partial frames, as well as frames with transparency). Here's how you would play such an animated GIF in a loop on a form, simple and to the point:

frmGIFPlayer - This is all it takes:

Option Explicit

Private BitmapDecoder As cBitmapDecoder, lCurrentFrame As Long, bAdjustSize As Boolean

Private Sub Form_Load()
    Set BitmapDecoder = New cBitmapDecoder: AutoRedraw = True
    With BitmapDecoder
        .BackgroundBrush = CreateSolidBrush(GetBkColor(hDC))
        If .Decode(App.Path & "\Travolta.gif") Then tmrPlayGIF = True
    End With
End Sub

Private Sub tmrPlayGIF_Timer()
    With BitmapDecoder
        If .DecoderReady Then
            If Not bAdjustSize Then Width = ScaleX(.ContainerWidth, vbPixels, ScaleMode) + (Width - ScaleWidth): Height = ScaleY(.ContainerHeight, vbPixels, ScaleMode) + (Height - ScaleHeight): bAdjustSize = True
            If lCurrentFrame < .FrameCount Then
                With .GetFrame(lCurrentFrame + 1)
                    If .FrameReady Then
                        .RenderFrame hDC: tmrPlayGIF.Interval = .NextFrameDelay
                        lCurrentFrame = lCurrentFrame + 1: Set Picture = Image
                    End If
                End With
            Else
                lCurrentFrame = 0: Set Picture = LoadPicture: tmrPlayGIF_Timer ' Play the GIF in a loop
            End If
        End If
    End With
End Sub

Here is the demo project: GIFPlayer.zip (Updated!) - Download the GIFs above and place them in the project folder as they were too big to include in the attachment or provide your own GIFs for testing.

Requirements: Windows 10 ("Anniversary Update", July 2016) or later!