I followed this guide and successfully compiled vlc for android.
I added my own codec "my_codec" and installed vlc with
./gradlew installVanillaX86Debug
Now I want to force vlc to use my code. on pc the command is
./vlc --codec my_codec,none sample.mp4
for android I tried both
adb shell am start -n org.videolan.vlc.debug/org.videolan.vlc.gui.video.VideoPlayerActivity -d file:///sdcard/sample.mp4 --es --codec my_codec,none
adb shell am start -n org.videolan.vlc.debug/org.videolan.vlc.gui.video.VideoPlayerActivity -d file:///sdcard/sample.mp4 --es codec my_codec,none
but my codec wasn't used.