Learn how to stitch equirectangular 360 video with AutoPano Video Pro in this video tutorial.
Top image via Shutterstock.
The most intimidating factor for people new to 360° video is “how to stitch all of the footage together?” Just the term “stitching” sounds labor intensive. Luckily for us, this isn’t the case at all. Stitching software has come a long way in just a few short years, and companies like Kolor have really focused on streamlining the process. In this tutorial, we are going to learn how to stitch 360° video with AutoPano Video Pro and hopefully provide you with an understanding of the steps involved in the process.
A Quick Prologue for 360° Video
Once 360° is stitched, it is usually going to be in a format called equirectangular. (It is the same format as a world map, which is a sphere made to look flat.) You can see distortion at the top and bottom of the image, which would be the pole areas on a sphere.
The number of cameras it takes to create a 360° equirectangular image can differ. It could be anywhere from just one dual lens camera (like a Samsung Gear 360 or Ricoh Theta S) to multiple-camera system setups like the GoPro Omni that consists of six cameras. Other setups may include three, four, or really any number of cameras. Once you stitch them, no matter how many cameras you used, the footage will be in the same equirectangular format. In my case today, I am stitching footage from six GoPros.
AutoPano Video Pro
In this tutorial, I am going to be use AutoPano Video Pro 3.0 to stitch my 360° video. AutoPano Video Pro is the industry standard for stitching 360° footage and is popular among many VR filmmakers. Once the program launches, all we need to do is drag and drop our clips to get started.
One great aspect of AutoPano Video Pro is that it has all of the adjustment settings right at the top — in the order we will need to use them. So they act as an easy-to-follow guide for the stitching process.
Synchronizing 360 Footage
The first step is synchronizing your shot together. If you are using a DIY camera rig, or a rig that doesn’t start all of the cameras at the same time, then just click the Synchro button at the top. You will then get the option to synchronize your clips using audio or motion. (This will examine all of your clips and align them based on your preference.) I typically prefer audio synchronization, but if you didn’t record any audio, you can synchronize using motion. In my case, since I was using the GoPro Omni, all of the cameras synced by default.
Stitching 360 Video
The next step is the stitching, which you can select with the Stitch tab at the top. From there, you can select various camera options and if you would prefer the stitch analysis to take place at one position in time or analyze multiple positions (which is ideal for moving 360 shots). From there just click stitch, and AutoPano Video Pro will automatically stitch the clips. After the stitch is complete, you will see a real-time preview of the stitched 360° video, and you can level out the horizon line just by clicking and dragging on the image.
Now we can move on to stabilization by clicking the Stab tab on the top menu. Under the stabilization tab, settings include stabilization amount, which ranges from Fast Motions Only to Full Stabilization. Settings like Fast Motions Only will stabilize the 360° video while also allowing for some natural rotation and movement. Full Stabilization will try to get rid of all unwanted movement and keep the horizon level and static.
Quite often, the white balance and exposure will differ on the various cameras for 360 footage. This can lead to some areas of the video looking out of place. (In my example, the camera facing directly into the sun looks a bit washed out.) We can fix this under the Color tab, where you will see a variety of correction types.
The next settings tab we are going to look at is the Blend tab. This determines the type of blend between our stitched video clips. There are two main types: smooth and sharp. Smooth blending acts more like an opacity fade from one clip to the other. The clips overlay each other at the edges; however, this can often lead to ghosting on shots where the camera is moving (or if there is too much movement around the camera). If you’re pressed for time, smooth blending may be your best option. I personally prefer sharp blending, which acts more like a hard edge between clips. This setting can make a seamline more apparent, but it can also be cleaner when you use it with the next setting: D.WARP.
D.WARP is one of the newest settings integrated into AutoPano Video Pro. The D.WARP tab uses unique parallax compensation technology, which helps correct seamlines even more — particularly on shots that involve action close to the camera. D.WARP offers three settings options: Prioritize Space, Prioritize Time, and Still. The one we want to use is Prioritize Space, which will try to correct as many parallax artifacts as possible. The correction is automatic, so all we need to do is click “Compute D.WARP.” This process may take a bit of time depending on your clip and computer speed.
Render Settings for 360 Video
Finally, we can move to rendering out our 360° video by selecting the Render tab. For the output type, I recommend H.264 MP4 because Youtube and Facebook accept that 360 format. For Output Preset, select H.264 4K, which will allow you to output a 2:1 360° video that is 4096×2048. Below is a screen shot of my exact render settings. Once you have set those values, all we need to do is click “render.” This will launch the Batch Render, and we can see the real-time progress of the 360° video render.
If you are curious about how the final output for this 360° video turned out, you can watch it below.
Do you have any other tips for stitching 360° video? Let us know in the comments.