To change Aspect Ration of an MP4 file, I know this easy way of doing it :
(1) Download latest FFMPEG static version from:
http://ffmpeg.zeranoe.com/builds/(2) Extract all only that is inside this folder "ffmpeg-xxx-git-xxx-winxx-static" to this new folder "c:/ffmpeg/" that you need to create on drive c:/
(3) Create new Environment Variable through the following steps:
Start Menu > PC > Properties > Advanced system Settings > Environment Variables > New:
Put in "path" in Variable name box, without the quotation marks
Put in "c:\ffmpeg\bin" in variable value box, without the quotation marks
(4) Run cmd.exe from Start Menu and check if it works by Typing in: "ffmpeg -version" and Press Enter.
(5) Now to start conversion from your default PC Videos Folder location, Copy and Paste this command into cmd.exe,
ffmpeg -i C:\Users\yourpcusername\Videos\inputname.mp4 -vcodec copy -acodec copy -aspect x:y C:\Users\pcusername\Videos\outputname.mp4Replacing "inputname & outputname" with your actual mp4 video name moved to PC default video folder to be converted, Replacing x:y with desired aspect ration, ex. 16:10 , 16:9 etc.. and finally "yourpcusername" the actual pc user name :
for example, if you have a corrupted Proxypaige.mp4 with wrong aspect ratio, then move it to PC default video folder and paste this command in cmd.exe :
*Set your inputname different from the outputname so that you don't have to overwrite the original one.
ffmpeg -i C:\Users\John\Videos\Proxypaige.mp4 -vcodec copy -acodec copy -aspect 16:9 C:\Users\John\Videos\Proxypaige2.mp4and Press Enter, and wait for the process to terminate ...
6) Finally enjoy your new MP4 Copy with the correct aspect ration 16:9
I guess there more things that you can change than just aspect ratio, like resol, bitrates etc ... you can change almost any video attributes, just google about it to find out more.
The Fixed Copy is an Exact Identical Original copy with just the basic attributes changed.
It's a bit sad that you have to go through this little long process ...
CHANGING RESOLUTION TO 1280 X 720 :Simply use this command, replacing "input & output" with the file location name of the mp4 to be converted, but it is recommended you rename your long mp4 name to just a one-word name, for ex. Huge Butt Bella Diamond.mp4 changed it to Huge.mp4 temporarily to ensure you won't get any error during process ...
ffmpeg -i input.mp4 -vf scale=1280:720 output.mp4I recommended you use only this command that changes Resolution instead of Aspect Ratio, because changing Resolution seems to automatically fixed the Aspect Ratio along. But this time this process uses pc resources and do real encoding it looks so. If you have better suggestions you are welcomed*Recommended to Play Video File with Free Best Player like :
https://potplayer.daum.net/https://www.videolan.org/vlc/index.html