Interestingly, FFmpeg converted the MP3 audio to AAC and muxed the file without so much as an informational message.

Then I tried this: ffmpeg -i video.mp4 -i audio.mp3 -c:v copy -c:a copy muxed.mp4 To explain, after designating the two input files, the script copies the existing video file as-is (c:v copy), converts the MP3 audio to aac (c:a aac), and muxes the two into muxed.mp4. ffmpeg -i video.mp4 -i audio.mp3 -c:v copy -c:a aac muxed.mp4 I tried the following command string which worked the first time.

Mux the H.264-encoded video and newly AAC-encoded audio into a single file.

Convert the MP3 file to AAC since MP4 files can’t include MP3 audio.

I quickly surmised that I had to accomplish two things. So I had to mux the two to input them into PowerPoint.Ī quick Google search led to a definitive StackExchange article here. Unfortunately, my download tool, wondershare’s excellent video converter, downloaded separate audio and video streams, the video in an MP4 wrapper and the audio as an MP3 file.

So, there I was downloading videos from YouTube to include in a PowerPoint for a training course I was producing.

Ffmpeg copy audio and video