360 Video Part II The Stitch

Submitted by Mark Ferro on Tue, 06/20/2017 - 10:40
360 Video Part II The Stitch

Not only does a great 360 video have great content it also has a great stitch. The stitch is a very important step and how the final stitch comes out can make or break the video. We’ve seen great content with bad stitching that ruined the experience.

For a successful stitch, you need to start with having cameras that are synced up. For higher end cameras like the Nokia Ozo or GoPro Omni you don’t have to worry as those rigs ensure the cameras are synced but for other rigs especially custom rigs, this is where you need to pay attention. If you have a custom rig and the camera sync is even just a few frames off, things get bad really fast. For lower-end or custom rigs that don’t sync the cameras for you, there are two things you should do. First record at the highest frame rate you can. This will give you more flexibility in getting the correct sync point. Second thing to do is “clap” at the beginning of the recording. This will provide an audio cue and some stitching software can sync based on audible cues.

Stitching Software

With video footage captured the next step is stitching the footage from the cameras together. Depending on the 360 camera you’re using may determine what software you use to manually stitch the video. For example our lower end Kodak PixPro comes with some basic software which will stitch the video however it’s limited in its capabilities.

A very good step up in stitching software is AutoPano by Kolor. We use this software a lot and it’s very good but very good comes at a price of around $650. For this blog post 3 part series we used AutoPano to stitch the footage we captured from a GoPro Omni. We’ve used AutoPano to stitch footage from a few different rigs and like it a lot. Want the software to make all the decisions on the stitch? Simply drag and drop your source videos and AutoPano will automatically handle the stitching and we’ve found it to do a pretty good job. Want to do more fine tuning? AutoPano offers a lot tools to help produce a near seamless stitch.

Some 360 rigs have their own custom software like the Nokia Ozo. We really like using Nokia’s software. Similar to AutoPano it’s easy to use and offers a lot of tools to the user. There’s also rigs like the Orah 4i that does the stitching automatically in real-time and will even upload it directly to YouTube and other services.

Computer Requirements

The software you choose will determine the minimum computer requirements. We use AutoPano and run it on a custom-built PC that has a water-cooled Core i7 (w/ 10 cores) processor, 32GB of RAM, 512GB SSD, 4TB HDD, dual NVIDIA GTX1080 cards in SLI mode. We’ve found this to be a good system that might be overkill for a low-end camera but we’ve found it handles stitching from the GoPro Omni with ease. Do you need to rent a post-production PC like this? We rent post-production PCs and laptops with the stitching software pre-loaded.

OK so you have your captured footage, you have a computer with decent specs and stitching software installed. What’s next? For this part we’ll outline what we did using footage from a GoPro Omni and AutoPano Pro software.

  1. Transfer footage from SD cards (yes all 6 cameras in this case) to folders on the PC named according to camera number.
  2. Once the files are transferred and labeled properly, Autopano Pro allows you to drag and drop the video footage files directly into the interface.
  3. Once imported, AutoPano Pro will display all of the individual videos above the timeline in the interface.Kolor Autopano: File Import Results
  4. This is where the software gives you the option of syncing, either through an audio or motion cue. I find that syncing using audio produces the best results with very little or no frame-lag at all.Kolor Autopano: Syncing Window
  5. At this point, you can close the Synchronization & Input Video windows to make more room on your screen for the stitching preview window.
  6. Selecting the “Stitch” button at the top of the interface will open a window displaying the stitching options. Options include: Lens/Camera model, Stitch At, and Compute RMS Curve.Kolor Autopano: Stitching Window
  7. Once the desired options are selected, press the “Stitch” button in the “Stitch As” option set. This begins the automated stitching process which takes about 3 minutes of time to process 1 minute of footage.
  8. When that process has finished, the software will display the “Real-time Preview” window displaying the panoramic shot of the combined 6 shots. From here the user can adjust the starting/focal point as well as the horizon cohesion.
  9. Next, if desired, there are options for stabilization control, color correction and blending options to adjust the visual output.
  10. If satisfied, the video is ready to “Render” or process & export the file to your hard drive. Just select the “Render” or “Batch Render” from the top menu of the interface.Kolor Autopano: Render Window
  11. There are many options to choose from here such as the video dimensions, output file type, frames per second, video & audio bitrates, aspect ratio and audio sourcing. Select your preferred options & file output location and press the “Render” button at the bottom of the options window to begin the process of rendering. Don’t worry about that pesky metadata that YouTube requires to be embedded in the video for its 360 controls to be enabled because, Autopano Pro automatically includes them!
  12. This operation takes a while, depending on the quality options that were selected. So, get comfortable!

As you can see the stitching process is an involved process that requires software, hardware and time. Don’t have any of that to spare? No problem. Check out our Video Stitching Service and leave it to us. With all the resources at our disposal, we can provide you a premium stitched video in short order.

Here’s our finished project.

You want the easiest way ever? Simply rent a 360 camera from us, capture your footage, send it back and we’ll worry about the rest.