However, Apple officially claimed that QuickTime does not support legacy or specifically-designed codecs and formats, and it only supports MP4 encoded with H.264, MPEG-4, and H.265/HEVC (since macOS 10.13). The video streams in MP4 files can be encoded in the MPEG-1, MPEG-2, MPEG-4, H.264/AVC, and H.265/HEVC standards. MP4 contains many sorts of video and audio codecs that may beyond the encoding and decoding capabilities of QuickTime. How the video was encoded determines whether it can be opened by a player. MP4 just refers to the format container or a video file with.

The MP4 video was encoded with older or specialized codecs. In QuickTime 10.0 or later versions, legacy media files will be converted automatically so that you can open MP4 files successfully.Īnd as the player was originally developed for macOS, there might be many bugs in Windows that result in MP4 playback errors in QuickTime. QuickTime Player 7 starts to support H.264 and newer versions in macOS High Sierra support HEVC/H.265. If you are using old versions of QuickTime, MP4 videos compressed with recent codecs will not be supported. The QuickTime Player stays in an old version. Before we dive into the solution, let's figure out what exactly causes the playback failure in your case. QuickTime Player can't play MP4 files for many reasons. To help users watch MP4 movies on Mac in QuickTime Player without errors, we are going to figure out why QuickTime can't play MP4 and how to fix it effectively. And what exactly makes Mac users upset is that sometimes QuickTime Player can't open MP4, the most commonly-used video format. However, it still can play only a handful of audio and video formats. With consistent updates over a decade, it has more playback controls and even is compacted with editing and screen recording utilities.

QuickTime is the default media player in macOS.

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