You want to Post an .mp3 file on a Media Site That Requires .mp4 files

What Bing AI tried to get me to do was just use a single command in this attempt making this video. so here is one command: ffmpeg -loop 1 -i thornhill.jpg -i thornhill.mp3 -r 1 -c:v libx264 -tune stillimage -c:a aac -b:a 40k -pix_fmt yuv420p -shortest thornout2.mp4
I did not need to input the time (-t) I also changed the audio to 40kb/s resulting in reducing the mp4 file size from 76 to 28 Mb.

Here is what Bing AI gave me:
To create an MP4 video from an MP3 file and a photo in Linux, you can use the ffmpeg command-line tool. Here are the steps:

Install ffmpeg if it is not already installed on your system. You can do this by running the following command in your terminal:

sudo apt-get install ffmpeg

Place the photo and MP3 file in the same directory.

Open your terminal and navigate to the directory where the files are located.

Run the following command to create the video:

ffmpeg -loop 1 -i photo.jpg -i audio.mp3 -c:v libx264 -tune stillimage -c:a aac -b:a 192k -pix_fmt yuv420p -shortest output.mp4

Here’s what each option does:

-loop 1: Loops the photo so that it appears throughout the entire video.
-i photo.jpg: Specifies the input photo file.
-i audio.mp3: Specifies the input audio file.
-c:v libx264: Sets the video codec to H.264.
-tune stillimage: Optimizes the video for still images.
-c:a aac: Sets the audio codec to AAC.
-b:a 192k: Sets the audio bitrate to 192 kbps.
-pix_fmt yuv420p: Sets the pixel format to yuv420p.
-shortest: Makes the output video the same length as the shortest input file.

Wait for the command to finish running. The output file will be saved in the same directory as the input files.

I hope this helps! Let me know if you have any other questions.