According to, VLC won’t play MP4 files that have AMR audio (usually from mobile phones). Even if the video codec is compatible, the audio codec may not work with VLC. MP4 is encoded with video codec plus audio codec (e.g. H.265 is not as common H.264 and has limited supply of supported hardware. The new encoder stores MP4 videos of the same quality while takes up less space (about increased by 25% to 50% better data compression than H.264). But video compression technology goes on, more and more MP4 files begin to use the H.265/HEVC codec. In the past, most MP4 files were encoded with H.264/MPEG-4 AVC. If your VLC won't open MP4 on Mac, go through reasons below and find corresponding solutions to solve the issue.
Cisdem Video Player is the best VLC alternative to play MP4 on Mac.
