I want to merge an audio file (.wav or .au format) with a video file (.mp4 format).
Please suggest me a open-source utility to achieve this. I want to merge these file to new .mp4 video file. An ffmpeg command would be very welcome.
See this example, taken from this blog entry but updated for newer syntax. It should be something to the effect of:
You should transcode the audio in some way, since MP4s cannot have PCM audio streams. You can use a desired audio codec if you want. See the AAC Encoding Guide for more info.
If your input video already contains audio, and you want to replace it:
Try using mencoder (Yes it is ffmpeg based, but you never know). I use the
And, if you use Windows, Mediacoder (not open source anymore sadly) works... its basically a frontend for a lot of gnu encoders and a few non-free ones.