Hello there I have a small NAS with various video files on it. Some AVI which work flawless but also some MOV which show but do not play audio. Other chromium based Browsers manage to do so without any problems therefore it should be possible somehow. Informations regarding the file: Filetype: MOV Codec: MP4 Base w/ AVC ext (ISO 144496-12:2005) Channels: 2 compressor: sowt Sample rate: 48khz Depth: 24bit Bit rate: 16 It was recorded with a Nikon D3200 camera. As I am hosting these Files for other people I always get requests on why it does not work in Firefox. I love Firefox and I want People to use it but such things just make in unnecessarly hard to do so. I have experienced great business support from the Mozilla team, hope this to be true for home users too. Thanks beforehand and have a nice evening.