MJPEG to OGV Converter

MJPEG to OGV Converter

A raw .mjpeg file is not really a video file. It is a run of complete JPEG images written end to end with nothing wrapping them — no duration, no index, no frame rate and no audio track. .ogv is the opposite kind of object: the Xiph.Org Foundation's Ogg container, designed from the start to multiplex timed streams and carry the metadata a player needs to seek through them.

That mismatch produces two results people do not expect, and both are worth knowing before you press Convert: the output is silent, because there was never an audio track to carry over, and the video codec is VP8, not Theora, because VP8 is what this page's Video Codec list opens on. Everything below is about those two facts and the settings that follow from them.

What a Raw .mjpeg File Actually Carries

The frame-rate point is the one that bites. We built a two-second clip at 10 fps and wrote it out as a raw .mjpeg: 20 frames went in, but because the file has no rate header a decoder reads them at its assumed 25 fps and hands back a 0.8-second clip. If your camera recorded at anything other than 25 fps, the .ogv will run at the wrong speed — that is the source file's limitation, not the conversion's, and no setting on this page repairs it.

What Goes Into the Ogg Container

Ogg/Theora playback is effectively finished in mainstream browsers: caniuse's Ogg/Theora entry puts global support at 5.76%, with Chrome disabling it by default from version 120, Opera from 106, Firefox from 126, and Safari never having shipped it at all. VP8 inside Ogg is rarer still — browsers that decode VP8 expect to find it in WebM. If a browser is your destination, MJPEG to WebM is the royalty-free target that still works and MJPEG to MP4 is the one that works everywhere.

How to Convert MJPEG to OGV

1. Upload Your MJPEG File: Drag the .mjpeg onto the page or click "+ Add Files". Several captures can be queued and all of them run with the same settings.
2. Leave Video Codec on VP8, or Switch to Theora: VP8 is the value the Video Codec list opens on and the better encoder of the two. Pick Theora only when a legacy consumer names Theora specifically — choosing it re-ranges the Constant Quality field onto Theora's own scale and removes Constraint Quality from the panel.
3. Set File Compression and Video resolution: File Compression opens on Quality Preset at "Very High (Recommended)"; Specific file size, Constant Bitrate, Variable Bitrate, Constant Quality and Constraint Quality are the alternatives. Under Video resolution, "Keep original" holds the capture's frame size, and Preset Resolutions sets height with width following the source aspect. Trim takes a Start time and Duration.
4. Convert and Download: Click Convert and save the .ogv. Files upload over an encrypted connection, are converted on our servers and are deleted automatically after a few hours — no sign-up, no watermark, never shared or made public.

Rate Control When the Source Declares No Bitrate

VP8 has no CRF mode, so Quality Preset works by multiplying the source video bitrate. A raw .mjpeg does not report one — so instead of scaling your capture's real rate, the pipeline scales a stand-in figure of 2.56 Mbit/s. The presets still change the output, they just are not measuring your file:

Those numbers are fixed regardless of whether you uploaded a 320x240 webcam capture or a 4K machine-vision sequence, which makes them a poor fit for either extreme. Constant Bitrate or Specific file size are the honest controls on this page: type the number you want and the encoder aims at it. Constant Quality is the one mode to avoid outright — on VP8 neither a quality value nor a rate reaches the encoder, so libvpx falls back to its own internal default and every value in the box produces the same file.

Frequently Asked Questions

Why does my OGV have no sound?

Because the source had none. A raw .mjpeg is a bare run of JPEG frames with no container around them, and a container is the only place an audio track could live — so cameras and capture cards that write MJPEG either record no audio at all or store it as a separate file beside the video. The Audio Codec list still appears on this page, because Ogg genuinely can carry audio, but with no track in the input there is nothing to encode. If your capture rig saved a companion .wav or .mp3, you need a desktop tool to mux the two together after conversion.

Does this page output Theora, the codec OGV is named for?

Not unless you ask for it. The Video Codec list opens on VP8, with Theora as the alternative. That is a deliberate engineering choice: both are royalty-free, but VP8 is a later design and holds detail at bitrates where Theora visibly falls apart. Pick Theora only when the software or archive consuming the file names Theora explicitly, which a surprising number of .ogv consumers written in the 2008-2012 era do. Be aware that choosing it reshapes the panel — the Constant Quality field moves onto Theora's own narrow scale and Constraint Quality disappears.

Will the OGV play in a browser?

Realistically, no, on two counts. Ogg/Theora support sits at 5.76% globally on caniuse and is disabled by default in Chrome from version 120, in Opera from 106 and in Firefox from 126, with Safari never having implemented it. And this page's default codec is VP8, which browsers only expect to find inside WebM — VP8 in an Ogg wrapper is a pairing nothing was built to handle. Convert to MJPEG to WebM if a browser is the destination; it is the same royalty-free philosophy in a container that is still shipping.

Why is my OGV bigger than the MJPEG I uploaded?

Two reasons stack up. First, the preset the page opens on aims at roughly 3.4 Mbit/s regardless of your source, which is generous for a low-rate webcam capture. Second, MJPEG is intra-only — every frame is a full JPEG — so a static scene that MJPEG stores cheaply gets re-encoded at whatever rate the preset asked for. Switch File Compression to Constant Bitrate and type a figure that matches the material, or use Specific file size and name a byte budget.

Does the conversion fix the wrong playback speed my MJPEG has?

No. The speed problem is baked into the source: a raw MJPEG stores no frame rate, so a decoder assumes 25 fps and a capture made at 15 or 30 fps plays back stretched or hurried. There is no frame-rate control on this page to correct it, so the .ogv inherits the same assumption. To fix it you need a tool that lets you declare the input rate explicitly when the file is read — then convert the corrected file here.

Which audio codec should I choose in the dropdown?

For this conversion it makes no practical difference, because there is no audio in the source to encode. If you are reading this page as background for a different, sound-carrying conversion: Vorbis is the pick anything expecting an .ogv will decode; Opus is technically better per bit but a legacy Vorbis-only player will not read it; Speex is an older speech codec that Opus superseded; and FLAC is lossless at the cost of a much larger track.

Can I convert only part of a long camera recording?

Yes — set Trim to "Time Range" and enter a Start time and a Duration, in plain seconds or as HH:MM:SS.sss. It is worth doing on surveillance-length captures, because MJPEG files are large in proportion to their picture quality and upload time is usually the slow part of the job. The video cutter accepts .mjpeg directly if you would rather choose in and out points visually first.

Is OGV or WebM the right open format to standardise on?

WebM, for anything new. Both come from the same royalty-free tradition, but WebM is the container VP8, VP9 and AV1 were designed to travel in, and it is decoded by current browsers, phones and TVs. OGV's remaining value is backward compatibility with systems, scripts and archives written when Theora-in-Ogg was the open option and which reject anything not named .ogv. If that is your situation, this page is right. If it is not, MJPEG to WebM gives you a smaller file more things can open.

What happens to my file after the conversion?

It is uploaded over an encrypted connection, converted on our servers, and both the upload and the finished .ogv are deleted automatically after a few hours. There is no sign-up, no watermark, and nothing is shared or made public. Because the encoding runs on our side, the practical constraint is upload size and connection speed rather than anything on your own machine — and raw MJPEG is bulky, so a long capture can take a while to send.