What is CamTwist?

CamTwist is a software package that lets you add special effects to your video chats. It's also possible to stream your desktop and still images. With CamTwist, you can also use multiple video chat programs at the same time.

CamTwist is totally free and comes with no warranty or support. That being said, I welcome hearing about suggestions and problems you might have. I work on new features and bug fixes in my spare time and unfortunately some things don't get addressed. If CamTwist is useful to you, I'd enjoy hearing about it as well. Lastly, I've started accepting donations. Please feel free to donate whatever you feel is appropriate for CamTwist as it is. CamTwist is free because I enjoy working on it and because I don't have the resources to properly support it. If you decide to make a donation, I thank you, but please do it knowing that I'll still not be able to support you beyond what I already do.


System Requirements

CamTwist requires MacOS 10.4 and most of the interesting effects require hardware that supports Quartz Extreme. To find out more, and if your Mac supports Quartz Extreme, please see this article http://docs.info.apple.com/article.html?artnum=301347. CamTwist can be quite resource intensive, so the more CPU processing power, the better. I need help!

How does it work?

CamTwist comes with a few different pieces. At the lowest level, there is a QuickTime component that pretends to be a camera driver. What it does in reality is display the video frames that it collects from the CamTwist application. The CamTwist application is responsible for collecting the video frames, adding the special effects, and then feeding the images to the QuickTime component.

CamTwist Studio User Manual

CamTwist Studio is a television studio on your Mac. CamTwist Studio allows for multiple camera switching, DDR playback, CG insertion and more. Many of the terms and concepts in CamTwist Studio were pulled from existing television broadcast concepts. Since CamTwist Studio is all software based we were able to do even more than what a traditional television studio would be capable of.

The most important concept to take away from here is the basic workflow.

  1. Stage the next shot by selecting and deselecting on screen elements.
  2. Approve the shot and take it live.
  3. Repeat

You'll want to keep this workflow in mind as we describe the various parts of CamTwist Studio.

When you're operating in CamTwist Studio, you'll see the main CamTwist window react as you take elements in and out of program. The same is NOT true in reverse. Making changes in the main CamTwist window will not be seen by CamTwist Studio. By design, CamTwist Studio expects that it is the only thing that will be manipulating the live effects during your broadcast. You should resist the temptation of getting under the hood and adding/removing effects in the main window while CamTwist Studio is up otherwise you're likely to confuse things.


The CamTwist Studio interface is broken into 5 areas:

For those familiar with television broadcast studios it may look like a traditional video switcher at first glance. Upon closer inspection you'll notice that there is no program bus, no M/E busses and no EMEM as none of these items are needed in the all software view of CamTwist. If you're not familiar with a traditional television studio the interface should be very simple to use after you get used to what each section does.

Preview Monitor

The preview monitor is the large video window on the top left of the interface. As the name would suggest, the preview monitor lets you stage your next shot without effecting your live broadcast. Preview can only be seen by you and can not be broadcast. Whatever you see in preview is what you will see when you decide to go live with your shot. This serves two main purposes:

  1. By putting camera shots in to preview and not directly bringing them live it allows webcams a chance to warm up, white balance and stabilize.
  2. Minimize mistakes by getting to see what your next shot will look like before it goes live. If an incorrect button was pushed, the preview will show where the mistake is and allow a change before the shot is brought live.

Program Monitor

The program monitor is the large video monitor on the top right of the interface. By default the program monitor is off until it is clicked on. Program is the same as your live output and whatever you see in program is what you will be broadcasting. Enabling the program monitor does take additional CPU load so if you need to conserve system resources for broadcasting it is suggested that you turn the program monitor off. If you have enabled the program monitor you can very simply disable it by single clicking one again anywhere in the video.


The transitions section is directly between the program monitor and preview monitor. When activating a transition whatever is in your preview monitor will be brought to program and will then be live. The preview monitor will then go back to an empty state with color bars and the word 'preview'.

The most commonly used transition in television is the 'cut' or simply taking what is in preview and bringing it to program with no effect. The change take effect immediately upon pressing the cut button.

Below the cut button is the transition selection drop down. The default transition selected is the second most commonly used effect in television, the dissolve. You can click on this dropdown box to see a list of available transitions: Copy Machine, Dissolve, Flash, Mod, Ripple, Swipe and Dip.

Directly below the transition dropdown selection is the time box which is the duration of the transition. The default duration is 1 second. Depending on the frame rate of the broadcasting application you are using 1 second may or may not be enough time. Traditionally broadcasters use 7 to 13 frames for dissolves (or 1/3 to 1/2 of a second) but due to frame rate limitations of many flash streaming applications those times will probably not work online. Be aware that the lower your output framerate is the less impact your effect will have. At this time it is not possible to do fractions of a second in the timing window.

The final button is the 'Go' button which will activate the selected transition (other than cut) using the time specified. Objects in program will be removed and the objects in your preview monitor will replace what was in program using the transition selected.

At the bottom of the CamTwist Studio window are rows of buttons. Each button represents a Saved Setup from the main CamTwist window. The buttons on the bottom row are saved setups that contain video sources and the buttons above that row are saved setups without sources such as graphics or nameplates. By clicking on a button you select that object and change its state which is represented by a colored outline.

Outline colors:

Color What it means
Red In program (i.e. live)
Green In preview
Orange Indicates that the element is about to be removed from program
None Indicates that the source will remain unchanged

Bottom Row

The bottom row of buttons are your video sources. There is only one source row. This row is auto-populated from the main CamTwist application by any saved setup that had the 'Don't include video source' checkbox unchecked when it was saved. The name below each button is the name of the setup and they are organized from left to right alphabetically. Think of this row as your selection of cameras, video clips and full-screen images.

Unlike a traditional television studio in which one button can only be equal to one object, in CamTwist Studio a single button can be a slew of objects. It is possible to create a single button that has two cameras squeezed back, an animated background and graphics on top and have all of these object be available with one click on the bottom row.

While it is possible to hide the bottom row using the grey triangle directly to the left of the row it is not possible to have more than one row of sources in CamTwist Studio by design.

Top Rows

There can be many additional rows above the sources row. These rows are all automatically created by created a saved setup with the 'Don't include video source' button checked. Think of these rows as graphics or elements that go on top of the sources row. Things like RSS tickers, Logos (bugs), lower third nameplates, advertising graphics or anything that can go on top of a background source. It is possible to create additional rows by typing in how many rows you would like to see in the 'Rows' area of the effects list. By adding additional rows it is possible to layer graphics. The higher the row the higher up the graphic will be in the layer order. It is also possible to hide rows by clicking on the grey tiangle to the left of the row. This can be useful if you want to brand your show with a logo (bug), RSS ticker and ads but don't want to accidentally take these elements off the screen. Simply create a new row, select the object you want on the screen and take them live, then hide the row. It won't be possible to take the elements down and now you can go back and bring nameplates or animations on or off the screen without affecting the show branding.

Adding Icons

Each button can have a custom icon associated with it. The optimal size for the graphic is 64 pixels wide by 64 pixels high (64x64). If the image is not square or the proper size it will be scaled to fit. Alpha channels will be honored when using formats such as PSD or PNG.

To place an image on a button simply find the image on your hard drive and then drag and drop the image on top of the button you would like to change. If you would like to change the image simply drag a new image on top of the button. It is not possible to delete an icon at this time.

Source Controls

In between the video monitors and the button rows is some empty space that is used in situations when a video source needs extra control. One example of that is the Movie source and it it described below.


When moving between shots in your productions, you have the option of using graphical transitions. Most of the time you'll "Cut" from scene to scene but you can also pick from several other transitions such as dissolve, dip, copy machine, etc..

Movie Source in CamTwist Studio

When a movie source is selected, a controller will appear under either the preview or program monitor. This controller will affect the playback of the video clip. When the clip is in preview the controller will show up under that monitor. You can move the slider bar to the position of the video that you would like to start in. If you begin playing the video then transition to it in program the video will continue to play without restarting or hiccup. If you move the position bar partway through the video and have auto-play turned on in your saved setup then the video will automatically begin to play from the position selected in preview as soon as it is taken to program. On the left side of the controller is a play/pause button which will affect the playback of the video in either preview or program.


It is possible to automatically play the video when it is brought to program. When saving the setup in CamTwist ensure that the 'Autoplay' button is checked. The video will appear paused in preview but as soon as it is brought to program it will begin playback.

User menu/Keyboard controls

With the user menu, you can create shortcuts to commonly performed tasks and assign keyboard equivalents.

Useful tips

Keeping your cameras warm

When switching between cameras, it is usually necessary for the camera to warm up before the picture is stable. During a live production with a lot of switching, that warm up delay may be unacceptable. With the Keep Cameras Warm preference, once CamTwist has started using a camera, it will keep the camera ready even if you stop using it. That will make for instantaneous switches back to that camera but at a slight cost. Also note that no other application will be able to use that camera while CamTwist has it warmed.