M4V Mimetype - video/mp4 or video/m4v?

Question

I am serving a video via the HTML5 video element. I'm finding conflicting information about the appropriate MIME type for m4v video. Most demos set the type attribute to video/mp4 in the source tag in the markup. Some articles I've read indicate video/m4v for the web server Mimetype, while others indicate video/mp4. Which is correct?

See for example, this article indicating video/m4v mimetype: http://html5center.sourceforge.net/make-your-html5-video-play-on-mobile-devices

And this article indicating video/mp4: http://www.coolestguyplanettech.com/use-html-5-video-on-all-browsers/

Answer 1

The standard media type is video/mp4.

The standard mp4 container format is commonly used for both AAC audio, and H.264 video + AAC audio. These have different media types, audio/mp4 and video/mp4, however often you want different applications for audio and video and on some systems it is only possible to associate a default application with a file extension. Therefore it has become popular in some circles to use the extensions .m4a and .m4v for audio and video(+audio), respectively, in an mp4 container. However this does not affect the media type, which already distinguishes these using the audio or video prefix.

A twist, however, is that Apple started using their own media type, video/x-m4v, for videos from their store, which are in an mp4 container and use a .m4v extension. This is set to open the video in iTunes by default. Sometimes that is necessary because the video uses DRM, AC-3 Dolby Digital audio, or other capabilities that are not commonly supported in an mp4 container, but which are supported by iTunes for files with a .m4v extension. If you rely on such capabilities then you may want to use this media type instead of the standard one.

Media types with no x- are standardized in an RFC and tracked by IANA. No media type with the name video/m4v has been standardized. Non-standard media types have a x- prefix.

Answer 2

I only write HTML5 for special projects, but I've had a problem which I was able to solve quite by accident. In my blocks, I was writing the video code like this:

        <source src="Videos/myvideo.mp4" type="video/mp4">
        <source src="Videos/myvideo.webm" type="video/webm">

Here was my problem: If I put the mp4 line first, Google Chrome would play the video part, but there would be no sound. If I put the webm line first, Google Chrome would play the video and sound correctly, but Apple Safari would not detect the video at all. Even if I added the codec information in the type= statement, it had no effect.

I was about to cave in and try to use Flash, but I happened on the solution, mostly by accident. In the line for mp4, I replaced the type="video/mp4" with type="video/m4v". It cured the problem completely! Note: I did not change the video file extentions from mp4 to m4v -- I only used m4v in the type= statement.

I couldn't find any documentation to tell me to do this, I just got interested in the difference between .mp4 and .m4v file extentions, and started playing around. I use Linux (Xubuntu) and I had created my videos as both webm and H.264 mp4 files, using Openshot Video Editor. Maybe the inner workings of Openshot caused this to be an issue, but anyway -- that's how I solved this problem. My mp4 videos play perfectly. I hope this helps somebody else -- MinnesotaJon

Answer 3

Answering this 8 years later with actual testing in Brave Version 1.22.70 Chromium: 89.0.4389.105 (Offizieller Build) (64-Bit) and Firefox 86.0.1 (64-Bit) on Linux.

<video controls="" controlslist="" preload="metadata">
    <source type="video/m4v" src="https://example.com/v.m4v">
</video>

Does NOT work.

But video/x-m4v and video/mp4 both work with the m4v file I am testing with. I guess it's best to use x-m4v based on the accepted answer.

Answer 4

Actually that totally depends on which video container you are using. Most browsers support the webm and/or mp4 file formats. Serving a combination of these two sourcefiles ensures browsers kan view the file. There's also the .ogg format if you wish to include it.

Not so sure about the m4v format, but it sounds like it's not one commonly used on the web. Anyway, I'd say serve m4v with a video/m4v MimeType and mp4 as a video/mp4 MimeType.