MOV Files

What is a .MOV file?

.MOV is a quicktime movie placed in a QuickTime File Format (QTFF), developed by Apple together with QuickTime in 1991; however, it does not necessarily identify any particular codec but rather indicates a multimedia container which is able to include one or more movie tracks with videos, audios, subtitle/text streams, Timecode, Chapters, thumbnails, edit lists, chapters, Colour Data, and metadata.

This file format occurs to be one of the common sources of multimedia streams for those, whose sources include smartphones with the iPhones and iPads' cameras; recordings on macOs; footage made with DSLRs or mirrorless cameras; exports with such codec as proRes; footage collected in various stock-footage sources; footage used in a professional post-production workchain. So, in a quicktime movie it can contain video stream, such as H.264, HEVCH265, Apple ProRes, Animation, CineForm, or DV and audiostream, including pcm, aac, alac, etc.

No widely used current containers unrelated to QuickTime are using extension ".MOV". If you suspect that the QuickTime movie under question is not video, check its MIME type, run "file", inspect it with MediaInfo, or open it in a hex viewer. A valid quicktime movie usually includes top-level atoms called ftyp/moov/mdat, free/wide or uuid, where ftyp atom, normally, can be found at offset 4 as 66 74 79 70.

Quicktime File format is related to the IsoBaseMediaFileFormat as well as the .MP4 container. It means that many MOV videos can be remuxed to MP4 format. The browser plays such quicktime videos as those encoded h.264/AAC, the others require a special decoder for proRes/anmination/pcm-based movies.

How to open a .MOV file

Technical details

MOV employs Apple's proprietary format which uses an internal storage in the form of QuickTime File Format. Each atom begins with a fixed header containing a 32-bit size parameter or even a 64-bit extended size field plus a four-byte string called "type" depending on the size and kind of an atom. The file is not in a plain text format and the format's structure involves boxes nested within boxes that comprise media and metadata content.

The standard top-level atoms are ftyp (identifying brand/file type of a format of a file being played), moov (containing metadata information), mdat (a container for data), free and skip atoms that serve padding roles in the layout, wide (for 64-bit alignment), and uuid - an atom containing a private data payload.

Anatomically standard MOV files are usually identified by the ASCII "ftyp" at byte offset 4. Old files, however, may use moov or even mdat (as well as the combination of atypical atoms) at the beginning of the file. The ftyp atom holds the information about brands in the format used, and QuickTime branding implies using "qt" followed by the necessary spacing. Some files combine this with the information about a set of formats used in ISO Media or BaseMedia (ISO 14496-12).

There are numerous versions of MOV format. The last one described by Apple's QuickTime File Format spec was published in 2012. The version is related to the family of formats developed later (ISO BMFF).

The MOV format supports both compressed and non-compressed streams including H.264/AVC, HEVC, ProRes, DNxHD/DNxHR, Animation (RLE), DV, JPEG images; AAC, ALAC and PCM audio streams; and timecode tracks.

In most cases playback requires reading of a moov atom first of all; otherwise streaming may not begin cleanly until the file is optimized. This problem can occur because moov atoms often locate at the end of the file and cannot start a playback process in case there is the need in optimization of the file. This atom plays a crucial role as its absence or any errors may trigger an error of "cannot open".

MOV files are quite large; they can weigh as little as mobile footage and reach many GB per minute when it comes to ProRes 4:4:4:4 or high resolution, uncompressed, etc. media. The file format's standard MIME type is "video/quicktime". However, some MOV files might have also different values ("application/quicktime") as well as alternative MPEG4 file types such as video/mp4 (also "application/octet-stream").

How to convert .MOV files

Use: ffmpeg -i input.mov -c:v libx264 -crf 20 -preset medium -c:a aac -b:a 160k -movflags +faststart output.mp4Copy If the streams are compatible with mp4 format, you do it lossless and quickly as possible: ffmpeg -i input.mov -c copy -movflags +faststart output.mp4Copy Note: it won’t help making ProRes / PCM / etc formats available by merely converting the container.

Camera Master or ProRes MOV files should use the .MOV file as the container, even though ProRes format. If the .mp4 container is suitable for delivery, but not for camera mastering since MP4/H.264 is usually a delivery format where .webm/VP9/OPUS and/or AV1/OPUS containers are preferred (note that ffmpeg supports output.webm but the compression takes much longer time and it might strip the QT metadata, time code, etc).

For the edit use either wave FLAC for raw audio data or for distro use mp3/aac files stripping the video stream from file, chapters, timecodes, timecode info, and most of camera-generated information and parameters. You can utilize such pre-setting of HandBrake as the Fast 1080p30. The FFmpeg allows precise control through the map command and bitrates and subtitles etc as a commandline tools; the proxies are made in FCP and Premiere Pro and/or DaVinci resolve and later linked back into the media stream.

Common problems and fixes

“The document could not be opened.” on MacOS, and “QuickTime Player can’t open” usually denote problems with the used codec which prevents the player from decoding but not with wrong file extension MOV. Check whether your file is corrupt using stream info in MediaInfo. VLC 3 can also be employed as it uses own codecs and successfully opens movies which are inaccessible with QuickTime. Absence of Windows file preview, or inability to work with Media Player usually means lack of codec packages - HEVC, ProRes etc., and not corruption of the file structure itself.

“The moov atom not found”. FFmpeg throws it at you when there is no metadata or it is not accessible due to partial or corrupted nature of the source movie file caused by interrupting a record on the camera, partial file downloading from the Internet or copying files off SD card/mobile device. Solution in most cases is trying recovering a real file from the device you copied it from initially or fixing moov atom in it with specific utility for the camera manufacturer based on the other movie file or accompanying meta data file.

Videos that play with no audio most likely are encoded via PCM, AC-3 and timecode-only tracks or have multi channel audio that the player doesn’t recognize correctly. They should be transcoded to AAC audio so any device or software can use this kind of video. Black screens and green/black frames, stuttering of movie frames - probably, there is GPU decoder problem, problems of HEVC/H.265 encoding or data rate which is too high. Disable GPU acceleration, install new drivers and/or re-code your video into H.264. Sideways/upsidedown movie most likely is oriented by the rotation matrix ignored by some software.

Security considerations

It's important to understand that the MOV is a container and, as a rule, cannot contain scripts in style of macro office documents, which means playing these files is comparatively secure, but the parser surface is still large. Moreover, there have been exploits in codes and media files' containers for various software products, like QuickTime and FFmpeg, browser engine or media components of some mobile OSes. Stay up to date on your media software updates and system patches.

Play MOV videos with latest sand-boxed players such as VLC and not legacy player QuickTime for PC which, in fact, should not be used as a system-wide codec pack.

A file can contain private information in terms of embedded metadata - like GPS information, names and models of the devices where it was recorded, time of creation, application software versions used, reel identifiers and video snapshots or thumbnails. Remove all the metadata from MOV videos by choosing appropriate export options in your program or use ffmpeg and its parameters like ffmpeg -map_metadata -1.Copy

History and versions

QuickTime and the MOV container format were launched for classic Mac OS in 1991. By the late 1990s, QuickTime had become multi-platform, enabling authors to play their multimedia files on both PC and Apple platforms. MOV files were used for creating and playing content in CD-Roms, through the web, and in digital video applications. The specification of the MOV file format had been documented and published by Apple. The last major version of MOV's public documentation was archived in Apple's documentation site of the QuickTime File Format in 2012.

Because of the atom-based structure of the QuickTime file format, it has contributed considerably to MPEG-4 Part 14 as well as ISO base media file format standard; consequently, there exist many similarities between QuickTime files, MOVs, MP4, M4V, M4A and 3GP files' box-and-brand architecture. Final Cut Pro and iMovie as well as cameras with support to create MOV have made MOV popular when working with DVs, HDVs, ProRes as well as H.264 videos, recorded using a DSLR and even recently, HEVC videos along with HDR images.

Since then QuickTime 7 for Windows has been deprecated, so now OS frameworks or maintained third-party software such as VLC and FFmpeg-based tools can be responsible for QuickTime playback; nowadays MOV is popular mostly on Apple platform while for final delivery MP4 tends to be mostly used.

Related formats

The .MP4, or MPEG-4 Part 14/ISO Base Media File Format, usually proves a safer file format in the case of browsing, viewing videos in televisions or mobile phones. .MOV, on the other hand, is used widely in Final Cut Pro, iMovie, as well as camera-master workflows because its file formats support easily-editable meta data along with apple-friendly codecs. While the M4V file extension is an apple version MP4 like file format and often contains videos on iTunes and Apple TV where the purchased videos may also contain Digital Rights Management. On other hand .M4A is an audio version MPEG-4 file format that is usually AAC or ALAC.

In addition to multiple tracks handling capability with better subtitle support theMKV or Matroska is not as native in apple pro tools software. The old format like AVI is weak against metadata, B-frames or variable frame rate for new era. The MXF on the other hand works commonly in broadcast media along with WEBM used in case of royalty free web video that uses VP8, VP9, AV1, Opus, or Vorbis.