By setting the audio_codec to none (ac_none in URLs), you can strip the audio channel from the video, serving it without sound. You can also chain another audio file as an overlay to replace the video’s original audio.

The original video file (with audio) -

https://res.cloudinary.com/demo/video/upload/dog.mp4

The muted video -

https://res.cloudinary.com/demo/video/upload/ac_none/dog.mp4

The video with a different (and objectively better) audio.

https://res.cloudinary.com/demo/video/upload/e_volume:-100/l_video:sample_pnnlu7,eo_13,fl_layer_apply/dog.mp4

The song is actually larger, but we cut it to its first 13 seconds with the end_offset (eo_ in the URL) parameter to match the video’s length.