How to set custom aspect ratio (32:9)?

[hireegy]

Hi,
I wanted to test the ability of a cheap android-based VR headset (like google cardboard, durovis dive, zeiss vr one...) to play a 3D movie.
The solution I retained was using a side by side video (where each 1920x1080 frame in the file actually contains two 960x1080 images together, for the left and right eye - this is a common format for 3D files), which I then want to play on my android phone.
Problem is, I have to "squeeze" the format vertically, by a factor of 2, so that the video would play at 1920x540, thus making for two 960x540 images in each frame, which would then be imaged by the lensing system of the android-based VR headset.

To play a 1920x1080 video file in 1920x540 on desktop (Windows) VLC, it is easy: you just launch it from command line:

C:\my_video_folder>vlc "my_3D_test_file.mkv" --aspect-ratio="32:9"

here I added VLC to my windows PATH so that it works. And it did work.

But now, as I am a complete newbie to android, I don't know how to do the same on my phone. So how can I do the following:

1) how to even start VLC from command line DIRECTLY from the android device itself? i.e. no adb involved, I want to type that directly in a shell terminal that would run and be displayed on the android phone, with the phone not connected to any computer? (I know I insist with a very elementary formulation, but I want to be clear about that!). I tried downloading and installing a command prompt like the Terminal Emulator, but "vlc --help" does nothing there...

2) I do not want to root my phone, I want my warranty intact

3) once I have all this, will the windows-based option ("--aspect-ratio X:Y") work in the android shell, or do I have to do something different?

Just as additional information, I also tried vlc direct to stream the video directly from the PC to the android phone, problem is, the only way I found to open a video located on my laptop, and view it on the phone, was by browsing my hard drives in the app and clicking on a video. i.e. it just starts playback with default options. In other words, no action that I could find on the desktop VLC player could lead to a video image appearing on my phone. As a result, I did not find a way to push my forced 32:9 anamorphosed video to the phone.

Thank you very much for your help!

[Jean-Baptiste Kempf]

1) you cannot. You need to recompile.
2) see 1.
3) see 1.