M4V files: an MP4 with an Apple extension, plus DRM
How M4V differs from MP4 (barely), why renaming often works, and which files will not convert. Convert M4V in your browser, no upload.
At a glance
- Type
- Video
- Container format
- Yes
- Extensions
- .m4v
- MIME type
- video/x-m4v
- Common codecs
- h264, aac
An M4V is an MP4. Structurally the file is the same container with the same H.264 or HEVC video and AAC audio; Apple adopted the different extension to mark iTunes video content. That is why converting M4V to MP4 is the fastest kind of conversion there is: the streams are copied into a file named .mp4 and nothing is decoded.
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It also explains why renaming the file by hand often works. The contents really are an MP4, so a player that refused the extension will usually accept it once relabelled. A proper repack does two extra things: it rewrites the index and sets the faststart flag, so the file can play while still downloading over a network.
The exception is DRM. Video bought or rented from the iTunes Store carries Apple's FairPlay encryption, and nothing that respects that encryption can read it — this converter included, so those files fail rather than convert. Home videos and exports from iMovie or Final Cut were never encrypted and convert normally, in seconds.
Convert M4V to other formats
FAQ
What is the difference between M4V and MP4?
Very little beyond the extension, which Apple used to mark iTunes content. Some M4V files also use Apple-specific flags, which a proper repack normalises.
Could I just rename the file to .mp4?
Often, yes — the contents really are an MP4. A repack additionally rewrites the index and sets the faststart flag, which matters for playing a file over a network while it downloads.
Why will my M4V not convert?
Almost certainly FairPlay DRM, which iTunes Store purchases and rentals carry. Encrypted files cannot be read by anything that respects the encryption.
Is quality lost converting to MP4?
None. The video and audio are copied without being decoded, so the result is identical to the source.
How long does it take?
Seconds, even for a feature-length file, because nothing is encoded.
Can I extract the audio instead?
Yes, and quickly — the video is discarded rather than decoded. The same DRM restriction applies to protected files.