Analyze my tennis post-game videos from a Mac

This holiday I got another tech toy – an M1 powered MacBook Pro 13”.   One of the reasons to justify my buying decision is I will be able to “produce” more tennis tracking videos using the Mac version of the SwingVision. In this post, I’d like to share my initial review of it, after using it for a couple of sessions.

In a normal situation, I would wait for a few more weeks to get a bit more hands-on experience. Unfortunately, the city I live in imposed a new lock-down measure, essentially blocking any indoor tennis over the winter. The plan is to keep updating this with more information available.

Key takeaways & recommendations

• SwingVision on Mac is a working version that can analyze video captured from any recording device with a minimum of 720p and 30fps.
• The convenience of viewing and editing the video on a bigger screen with a Mac provides a better user experience.
• The post-game editing feature is still limited since SwingVision doesn’t allow for exporting video in the Mac for now. However, it doesn’t limit any video edit by tools like iMovie to pre-process the imported video
• If you are an apple watch user to tag the game with real-time scoring, I don’t suggest you wait a bit. The current combination will result in losing the real-time scoring capabilities since the video and the watch stats isn’t talking to each other.

Let us start with “why”

With two years of exploration, I am getting more and more comfortable using SwingVision to track my tennis games ( See this original post about how I started this journey Tracking tennis using Apple Watch – My own takes after 18 month of usage). Despite occasional glitches on storage and battery, the app is generally reliable to record my tennis game, process the video with score and shots placement overlay, and then export the video for sharing purposes.

With that being said, the iPhone is a device designed for consuming instead of producing content. One of the biggest limitations is screen-size. Watching 1-2min highlight is fine on a 6 inches screen. Anything more than that became a less pleasant experience.

For example, if you want to do any of the following “PRO” tasks, it is better suited for a computer with a bigger screen and a more precise I/O device like a mouse.

• Adjust the timing of each rally points to improve the quality of the final video product
• Watch and analyze every point so that you can figure out the game plan (for the same opponent) like the legendary Tom Brady.
• Eliminate the unwanted sound (e.g. noise from the indoor bubble, curse word produced by player’s frustration)

The iPad should be able to do the trick. But it rarely works for me personally. I owned a 2017 iPad Pro, but I was never able to establish any habit of producing meaningful work out of it.

The Mac is a much better option. The newly launched M1 version of the Macbook has a 13 inches screen, a better processor(M1 is better than A14) and a larger starting SSD storage space at 256GB. All of them are tailored toward those advanced tasks.

What it can do

The app/experience in the Mac OS itself is similar to iOS: Download the app from the MacOS store, then log in using the same credential. The interface looks a bit rough – for example, the app’s title from the top left is still called “Swing” instead of “SwingVision.” Also, I wish it is better optimized in a Mac to leverage the landscaping view fully.

Put those complaints aside, the user experience is similar to the iOS version. The key feature in the Mac (also works with iOS version, but more practical in a Mac) is uploading an existing video recorded from any device, as long as it has a minimum 720p resolution with 30fps.

In my own test, I chose both 4k @ 30fps and 1080p @30fpsafter consulting the SwingVision support team. 1 hour of indoor tennis produced

• 4k video consumed 20GB space (6GB only for 1080p)
• It also used about 35% of my phone battery with the lowest brightness level in both resolutions. (That it should be fine with a 2hr standard match)

I was told the app currently doesn’t support 60fps yet. In retrospect, I wish I had recorded it in 1080p @ 60fps – Given storage space is no longer a limitation, it will at least allow me to store it at a higher frame rate. In the iPhone camera setting, you will need to turn off the “auto fps” feature, otherwise, the video might be recorded only at a lower fps even if you picked 60fps.

Higher FPS(frame per second) makes a big difference when reviewing the video. (see the following two video clips with 1 rally of 30fps and 60fps each). The smoother motion captured by 60fps is noticeable from the human eye, and it also works better when playing at the 0.5x speed.

On the flip side, the higher resolution only provides limited visual improvement. 4k export doesn’t work for now, and the 1080p and 720p (both at 30fps, see below two rallies) are barely noticeable.

Uploading the video is quite straightforward. The processing time (M1 chip) is only marginally better than iOS (A14): It takes roughly 10 minutes in my Mac, compared to 12 minutes in my iPhone for the same 1-hour video. My phone got a bit warm, actually, while the Mac completes it with flying colours.

Watch out for these steps, please

Instead of walking through the step-by-step instructions of “how” to use the Mac app, I believe it would be more valuable to share my own experience of using the Mac version. Hopefully, this can help you to get the most value out of this application.

• Pre-process the video in iMovie (or a more professional tool) before upload it to SwingVision. You can make voice adjustment, resolution and frame rate setting in iMovie, while these options are not available in SwingVision for now. For example, by cutting the warm-up portion of the video footage and reduce the resolution from 4k to 1080p, the video storage space has been reduced from 20GB to 6.7GB.
• Video upload will lose the real-time score tracking by apple watch. If you are using the apple watch to record the point by point score, the Mac upload version of the video can’t be synced with the score (for now). It will essentially show up as two sessions. One is recorded by your apple watch with scores and stats recorded by swing velocity—the other one recorded by the uploaded video. Not entirely a surprising move since this feature was mostly designed for Android users. To me, it is counter-intuitive to project GoPro/Android users will have an M1-chip Macbook.
• You can’t export video from the Mac (for now). Upon contact the support team, it looks like to be a feature coming soon. It is a little disappointing because the No.1 usage I would like to use with my Mac is to edit the video and then publish/share it. It is not possible yet, and I don’t understand why (behind resource limitations) since it is already available in the iOS app.