Create a video from an image and audio with ffmpeg:

ffmpeg -loop 1 -i <your_image.jpg> -i <your_audio.wav> -c:v libx264 -tune stillimage -c:a aac -b:a 192k -pix_fmt yuv420p -shortest <your_video.mp4>

• Replace <your_image.jpg> with the path of your image file
• Replace <your_audio.wav> with the path of your audio file
• Replace <your_video.mp4> with the path of your output video file