how to convert output.mp3 to mp4 with ffmpeg?

Question

i use this command to merge many mp3 files in a directory:

ffmpeg -f concat -safe 0 -i <(for f in ./*.mp3; do echo "file '$PWD/$f'"; done) -c copy ./output.mp3

and now i want to convert output.mp3 to mp4 format. i want that my TV receiver read that mp4. what can i do?

Answer 1

Using an image

ffmpeg -loop 1 -i input.jpg -i input.mp3 -vf "scale=1920:1080:force_original_aspect_ratio=decrease,pad=1920:1080:-1:-1:color=black,setsar=1,format=yuv420p" -shortest -fflags +shortest output.mp4

This command uses the scale + pad filters to make image fit into 1920x1080, setsar filter to set a normal Sample Aspect Ratio, then the format filter sets the chroma subsampling to YUV 4:2:0 for playback compatibility.

See Resizing videos with ffmpeg to fit into specific size for more info and examples.

Generating a color background

If you want a plain color background use the color filter:

ffmpeg -f lavfi -i color=c=blue:s=1280x720 -i input.mp3 -shortest -fflags +shortest output.mp4

Adding text

You can add text with the drawtext filter:

ffmpeg -f lavfi -i color=c=blue:s=1280x720 -i input.mp3 -vf "drawtext=fontfile=/path/to/font.ttf:text='Your Text':fontcolor=white:fontsize=24:box=1:boxcolor=black@0.5:boxborderw=5:x=(w-text_w)/2:y=(h-text_h)/2" -shortest -fflags +shortest output.mp4

See Text on video using ffmpeg for many more examples.

Visualization (waveforms, etc)

See How do I turn audio into video (that is, show the waveforms in a video)?

Answer 2

Make a black image in some image editor, save it as image.jpg and use this one;

ffmpeg -loop 1 -i image.jpg -i audio.mp3 -c:a copy -c:v libx264 -shortest output.mp4

(see ffmpeg wiki)