Scripting help to scene detect and split on many old avi files

ChuckMan wrote on 2/7/2026, 2:46 PM

I have hundreds of old hi8 avi files and would like to split them using scene detection. Then, I can import these clips into Lightroom for face detection searches.

I know how to write Vegas scripts but get stuck on how to execute the Split button in the detect scene fx. The google AI's answer is: not allowed due to security reasons.

There are the Detect Scenes and add to timeline and Detect Scense and add to subclips functions from the context menu when right click on a video file; however, I don't know the syntax to call these functions (I am using Vegas Prod v19).

I have also tried PySceneDetect tool. Althought it works; however, the output does not support the Video for Windows codec which I use to preserve the original video quality.

Any help is appreciated.

Thanks in advance.

Comments

jetdv wrote on 2/7/2026, 4:36 PM

This seemed to work for me. I manually added the "Scene Detection" effect (but the script could add it as well) to a clip I forced to have separate scenes and it was the only effect I added to I was sure it was the "first" effect.

            foreach (Effect eff in vEvent.Effects)
            {
                if (eff.IsOFX)
                {
                    OFXEffect ofx = eff.OFXEffect;

                    foreach(OFXParameter parm in ofx.Parameters)
                    {
                        if (parm.ParameterType.ToString() == "PushButton" && parm.Name == "Analysis")
                        {
                            parm.ParameterChanged();
                        }
                    }

                    myVegas.UpdateUI();

                    foreach (OFXParameter parm in ofx.Parameters)
                    {
                        if (parm.ParameterType.ToString() == "PushButton" && parm.Name == "SplitAction")
                        {
                            parm.ParameterChanged();
                        }
                    }
                }
            }

See this tutorial:

ChuckMan wrote on 2/7/2026, 11:21 PM

It works great. Thank you so much. If anyone is interested, I will share the code here.

snibchi1 wrote on 2/8/2026, 4:47 AM

Share it here:

VEGAS Pro Scripts Collections | SHARE YOUR SCRIPT HERE !!

Alex-Pitel wrote on 2/8/2026, 8:06 AM

The best and fastest for me worked "HandySaw DS" - it made an edl file (you can open it in Vegas).

ChuckMan wrote on 2/8/2026, 10:41 AM

Share it here:

VEGAS Pro Scripts Collections | SHARE YOUR SCRIPT HERE !!

Will do, after adding some comments to the code

ChuckMan wrote on 2/8/2026, 10:43 AM

The best and fastest for me worked "HandySaw DS" - it made an edl file (you can open it in Vegas).

Thanks for the suggestion. It is a commercial product that costs $65. Since I already purchased Vegas, I will stick with it although the scene detection is quite slow. I will just let it run overnight.

ChuckMan wrote on 2/8/2026, 11:38 AM

Another help - The custom preset for Scene Detection is not used. It is using the default preset instead. What did I do wrong? Please see code below:

vEvent.Effects.Add(sceneDetect);
// Setting presets via script requires the exact Preset Name string
vEvent.Effects[0].Preset = "High Sensitivity"; //Not using this preset. It uses the Default preset instead
//sceneDetect.Preset = "High Sensitivity"; //Not using this preset. It uses the Default preset instead

jetdv wrote on 2/8/2026, 3:50 PM

What if you just set the various parameters manually? What are the settings of the preset? There are no built-in presets so I'm not sure.

                    OFXEffect ofx = eff.OFXEffect;

                    OFXDoubleParameter p1 = (OFXDoubleParameter)ofx["SensitivityHardCuts"];
                    p1.Value = 1.0;

                    OFXDoubleParameter p2 = (OFXDoubleParameter)ofx["SensitivityFades"];
                    p2.Value = 1.0;

                    OFXDoubleParameter p3 = (OFXDoubleParameter)ofx["SensitivityDissolves"];
                    p3.Value = 1.0;


                    foreach (OFXParameter parm in ofx.Parameters)
                    {
                        if (parm.ParameterType.ToString() == "PushButton" && parm.Name == "Analysis")
                        {
                            parm.ParameterChanged();
                        }
                    }

                    myVegas.UpdateUI();

                    foreach (OFXParameter parm in ofx.Parameters)
                    {
                        if (parm.ParameterType.ToString() == "PushButton" && parm.Name == "SplitAction")
                        {
                            parm.ParameterChanged();
                        }
                    }

ChuckMan wrote on 2/8/2026, 6:49 PM

Thank you for the quick reply. After more testing, the preset actually works but behave differently. If working from the FX UI, 0.71 Hardcut sensitivity level will yield what I need; however, in the Script, I have to set it to 0.75 to get the same results.

Note this difference is only on SplitAction. The Analysis yields the same results in both UI/Script. Strange behavior.

jetdv wrote on 2/9/2026, 8:52 AM

That does seem odd as the "SplitAction" should use the results of "Analysis".

ChuckMan wrote on 2/9/2026, 8:40 PM

I was experimenting with the Scene Detection FX. What I found is that the Analyze function produces more cutting points than what are shown. For example, When I analyze with sensitivity set to 0.5, the cutting points are generated from sensitivity around 0.3 to 0.7. I know this because when I change the sensitivity to 0.7 or 0.3, the analyze function immediately shows the cutting points. When I change the sensitivity to 0.8, the analyze function will have to go through the long process of generating cutting points. So, there could be a bug in the SplitAction where it cutting points were not selected correctly.