Chrome 52 has a bug where videos recorded vertically on mobile devices appear stretched when they are played back. The has been fixed in Chrome 53; however, it's not important enough of a bug for Chrome to hotfix it in 52. This project attempts to fix this issue in Chrome 52 by modifying the videos on the fly to display properly.
The underlying issue is caused by the display matrix in the mp4's track header box. Whenever a video is rotated 90° or 270° Chrome uses the display matrix to rotate the video properly; however, it's also stretching the video by interpreting the track header box's width and height incorrectly. This solution switches the height and width in the track header box when it detects a problematic rotation so that the video displays correctly.
This project has only been tested on Go 1.6 and assumes you have Go already installed.
go get github.com/kobelb/mp4-proxy
go build
There's also a build.sh that will statically build the app for Linux, which is currently used for the Docker image.
mp4-proxy or ./mp4-proxy depending on whether you installed the app after you built it.
Request the video using a URL like below http://localhost:5000?url=https%3A%2F%2Faddpipevideos.s3.amazonaws.com%2F29d9277c9b566c0e2322ce4540f36f5d%2Fmvs285869022.mp4
By default the app listens for requests on port 5000, and it's using port 5001 for a groupcache that keeps all the dimensions for the videos cached. You can change the ports by setting the PORT and the CACHE_PORT environment variables.