Convert WEBM to MP4 with audio

[cottage]

I have a WEBM file that I'd like to convert to MP4. (It's a long story but I produced the original video and converted it to webm for the web but have lost the original file. WEBM won't play on my local media server (WDTV) so I'd like to convert the webm file back to MP4).

I've tried Handbrake, VLC and AVIDEMUX. They all convert the file but I lose the audio in the conversion.

Is there a program (hopefully free) that will do the complete job?

[LigH.de]

More details please. What can MediaInfo and MKVtoolnixGUI tell about the content of your WebM file, especially the audio format? Is it Opus or Vorbis?

[cottage]

MediaInfo reports English, 48.0 kHz, 32 bits, 2 channels, Opus

After converting to MP4 with AVIDEMUX, MediaInfo reports the same audio format. The audio will play on the computer but will not play audio on my media server (WDTV).

[sneaker]

Convert Opus to (stereo LC-)AAC for best compatibility in mp4 container.

[cottage]

sneaker,

That did the trick!

Thank you so much for your help.