Convert MOV to OGG

This page has a different reader from most conversion pages. You are not trying to open a file somebody sent you; you made it, you hold the rights to it, and you want to give it to a collection that will keep it — Wikimedia Commons, an institutional repository, an oral history archive, a wiki that documents something you filmed.

Those places have codec policies, and the policies are about freedom rather than quality. A format encumbered by patents cannot be redistributed by everyone under every licence, so the accepted list is short and open: Ogg, WebM, FLAC, WAV. Your MOV, carrying H.264 or HEVC, is not on it, and that is the entire reason you are here.

Ogg was published by Xiph.Org and standardised as RFC 3533. It can carry Vorbis, Opus, FLAC, Speex and a couple of things nobody uses any more, which means "an Ogg file" describes a wrapper and says nothing about the audio in it.

This conversion writes Opus. That is the modern choice and the right default: Opus is an IETF standard, RFC 6716, royalty-free by design, and better than Vorbis at every bitrate that matters. It is also not Vorbis, and if the thing you are depositing to names Vorbis explicitly then this file does not meet the letter of the requirement even though it meets the spirit of it.

Converting to either target on this site produces Ogg-encapsulated Opus. The only thing that differs is the four characters on the end of the filename, and there is no version of this file in which the contents disagree with each other.

That is convenient and it is also a trap, because deposit forms and validators do care about extensions. Some accept .ogg and reject .opus on the grounds that they have never heard of it; a few prefer .opus so that a player knows what it is getting without reading the header. If one is refused, rename it to the other — you are not misrepresenting anything, because the file genuinely is both.

What comes out is a re-encode. If the MOV holds AAC — which is what a phone writes — the audio has now been through two lossy codecs, and the ceiling is whatever the first one left. If the MOV holds uncompressed PCM, which many cameras record, this is the first lossy pass and Opus is very good at it.

For spoken material, which is most of what gets deposited, neither case is audible at 64 kilobits. Where it shows is music with a lot of high-frequency texture — applause, cymbals, a room full of people — recorded by a camera microphone and then compressed twice. If the recording is musically important, deposit FLAC as well, which most of these archives accept and which gives nothing away.

The three bands resolve to roughly 38, 64 and 128 kilobits a second. That puts an hour of audio at about 17 MB, 29 MB or 58 MB, against a video that may well have been several hundred megabytes a minute.

Opus is unusually good at the low end, which is why 38 kilobits is offered at all — for a single speaker in a quiet room it is genuinely usable, where MP3 at the same rate is not. Balanced is the right choice for almost everything; the high band is for music and costs little enough that there is no reason to hesitate over it.

Title, description, artist and creation date are copied out of the MOV and written into the Ogg as Vorbis comments. A camera fills in the creation date and rarely anything more, and QuickTime metadata has no licence field to copy from at all, so an archive that hands the file to somebody later is usually handing them something close to anonymous.

The deposit form is where the metadata belongs and where it will be indexed, so fill it in properly. But it is worth filling in the remaining Vorbis comments as well, with a tool that writes them, because files outlive the pages that describe them and a recording of a person talking in 1998 is much more useful when it says so inside itself.

The video track is dropped, which is the intention. So is most of what else the QuickTime container carried: the location a phone recorded, the timecode track a camera wrote, and any subtitles.

That last one is worth a thought before depositing. If the recording is speech and the archive wants it accessible, a transcript or a caption file is a separate deposit and a much more valuable one than the audio alone. It cannot be extracted from this file and it is not lost either — it simply never existed in the MOV.

The limit is on the video you hand over. Camera footage is large — around 170 MB a minute for 4K at 30 frames a second — so a long recording will not pass, even though the Ogg that would come out of it is tiny.

The route for a long deposit is to export audio from whatever software already holds the footage and convert that, or to trim the video first. It is worth noting that many archives would rather have the video as well, in WebM; if that is on offer, deposit both and let the Ogg be the lightweight listening copy.

The conversion happens in this browser tab, on your own machine, using codecs it already has. Nothing carrying the recording is sent anywhere, which you can watch in the network tab.

For a deposit that is the correct sequence of events. The file is going to be public, deliberately, at a moment you choose and under a licence you choose — and there is no reason for it to have been on an unrelated server first, under nobody’s terms in particular, on the way there.