It makes movies out of Google Street View images!

You provide point A and point B. It uses the Google Roads API to get directions from A to B, then repeatedly looks for Street View images along that path, and converts them into a movie.

E.g., here is a video taken along the Copacabana beach in Rio, with a little snippet of Senor Coconut's "Neon Lights (Cha Cha Cha)" added for fun:

To run this code yourself takes some fussing around:

1. Make sure FFMPEG is installed and callable from the command line. I brew-installed it.
2. pip-install this project's python requirements. The only packages you may not have are googlemaps and polyline. Note: this project is written for Python 2.
3. Lastly, and trickiest of all: the code requires API keys for Google Map's Street View and Directions APIs. Note: setting up the Street View API now requires a billing account! it tends to be free for small amounts of traffic, but you have to set it up anyway.

When using Google Maps to plan a route I haven't driven or walked before, I always though it would be nifty to be able to preview the directions as a video. Obviously, you can check out the route by looking at Street View at random points, or navigating in Street View mode itself. But these options are tedious!

Other people have had the same idea; at least two have created web services to do it:

• Streetview Player
• Route View

In each case, the user gives points A and B, the site fetches directions, picks a set of waypoints about 150m apart, and shows you the image at each waypoint. But the sites don't download the images and compile them into a movie; they just repeatedly reload Google Street View at each waypoint. I wanted to obtain a simulated video preview.

Also, both services are basically defunct now that using the Street View API requires billing. (I last checked the functional sites in 2017.)

Step 1 was downloading an image. I started with the Street View API documentation, but to get it working in Python, I used this blog post as a reference.

Step 2 was computing the route and selecting GPS points along that route. Using the Directions API was straightforward with the Python Client for Google Maps Services.

Step 3 was computing the correct heading (compass direction) from A to B, which is really tricky! I ultimately found someone else's code to do this.

But there were lots of failed hacks in between. The math for computing distances and angles on spheres is very cool---the Haversine formula, but I probably would have enjoyed learning about it more in high school. The best among them used the GeoPy package, but was ugly: with GeoPy, I couldn't compute the heading from A to B. But, given point A, a bearing, and a distance, I could compute a destination C. I could also compute the distance between any two points. So, I computed 360 potential destinations, each a degree apart and a fixed distance from A, and then found the one that was nearest to C, which gave the approximate heading.

Step 4 was concatenating the images into a movie, for which FFMPEG is indispensible!