remove ffmpeg dep and try to fix ffmpeg command

app.py

@@ -29,7 +29,7 @@ def audio_to_video_tab():
         output = os.path.join("out_video", output_file_name)
 
         # command = "ffmpeg -i \"{image}\" -i  \"{audio}\" \"{output}\"".format(image=image, audio=audio, output=output)
-        command = "ffmpeg -loglevel quiet -loop 1 -i \"{image}\" -i  \"{audio}\" -r 2 -c:v libx264 -tune stillimage -c:a aac -b:a 192k -pix_fmt yuv420p -shortest \"{output}\"".format(image=image, audio=audio, output=output)
+        command = "ffmpeg -loglevel quiet -loop 1 -i \"{audio}\" -i \"{image}\" -r 2 -c:v libx264 -tune stillimage -c:a aac -b:a 192k -pix_fmt yuv420p -shortest \"{output}\"".format(image=image, audio=audio, output=output)
         subprocess.call(command, shell=True)
 
         return output

packages.txt

@@ -1 +0,0 @@
-ffmpeg6