OGG is an Ogg container carrying Vorbis audio, lossy, and free of the patents that hung over MP3 for twenty years. WMA is Windows Media Audio, lossy, and tied to a decade when Windows Media Player ripped everybody CDs. ffmpeg sits between the two, and this page says exactly what happens to an OGG file on the way to becoming a WMA one.
What runs when an OGG file becomes WMA
ffmpeg held to a single thread, on a machine we rent and watch. Your OGG file is uploaded once, ffmpeg runs once, the WMA comes back, and neither file is kept. OGG to WMA is one of the 3649 pairs that engine was probed on with a real file, which is why it has a page here and why the pairs the probe could not prove do not.
What survives from the OGG into the WMA
The running time and the channel layout. A stereo OGG comes back as a stereo WMA of the same length: this is a re-encode, not an edit, and nothing here normalises, trims or boosts the OGG.
Everything the OGG still had. ffmpeg decodes the OGG in full before it writes a single byte of WMA, so nothing is skipped on the way in, whatever was already missing.
What OGG to WMA costs you
Generation loss, and it is the whole story of this pair. OGG threw information away to be small, WMA throws more away on top of what is left, and neither pass can restore what the other removed. Converting the WMA back to OGG afterwards makes it worse a third time, not better.
Album art, where the OGG carried any. ffmpeg passes -vn on every audio target here, which counts an embedded cover as a video stream and drops it along with the film it was never part of. That is deliberate rather than careless: keeping it makes the mux fail outright on several audio containers, and hiding the choice would be lying by omission.
Any hope of WMA sounding better than the OGG. Nothing in this pass adds information, and a bitrate higher than the OGG deserved only makes a larger file of the same recording.
If a model is going to read the WMA
A WMA file is a waveform, and a language model reads text, so handing an assistant this WMA directly gets you nothing. The WMA becomes useful the moment somebody turns the sound into words, and that is a separate job with its own page here. OGG to WMA is the step before it: get the sound out of the OGG in a container the transcriber accepts, then hand the model a transcript instead of a file it cannot open.
Running OGG to WMA against the real engine with a real file, ffmpeg wrote 54,944 bytes of WMA in 0.2 seconds, machine otherwise idle. That is one OGG file on one day and not an average, which is why the number is given together with the file that produced it.
The OGG to WMA verdict was reached by ffprobe, meaning the container was actually demultiplexed, recognised under the right name, and carried at least one stream. Which check was used matters, because they do not all prove the same thing, and a status code of 200 proves nothing whatsoever about whether the WMA file has anything inside it.
The same OGG file, sent somewhere else
Other outputs the probe measured out of an OGG file, so the cost of choosing WMA can be read against something. Sizes do not compare across engines, because each family was probed with its own OGG witness file.
OGG to MP3: 24,468 bytes in 0.1 seconds, verified by ffprobe.
OGG to WAV: 264,678 bytes in 0.1 seconds, verified by ffprobe.
OGG to FLAC: 148,368 bytes in 0.1 seconds, verified by ffprobe.
OGG to M4A: 28,012 bytes in 0.1 seconds, verified by ffprobe.
OGG to OPUS: 30,214 bytes in 0.2 seconds, verified by ffprobe.
OGG to AAC: 27,598 bytes in 0.1 seconds, verified by ffprobe.
Other ways into WMA, and what they measured
Among the published routes into WMA, OGG is the number 14 largest output of the 16 measured. The witness files differ, so this ranks the probe run and not your document.
OPUS to WMA: 58,144 bytes in 0.1 seconds.
WAV to WMA: 54,944 bytes in 0.1 seconds.
WEBM to WMA: 58,144 bytes in 0.1 seconds.
WMV to WMA: 51,744 bytes in 0.1 seconds.
MP4 to WMA: 55,102 bytes in 0.1 seconds.
What we will not pretend about OGG to WMA
An OGG file over 150 MB is refused before the upload finishes rather than after it, so you do not wait for a rejection.
An OGG to WMA run that passes 240 seconds is killed, and the ffmpeg process is killed with it. A run left behind would sit on one of the machine's two cores until somebody noticed.
The OGG file behind the measurement on this page was a 3 second sine wave at 440 hertz, built by ffmpeg for the probe itself. That is why OGG to WMA came out at 0.2 seconds, and it is not what your file will do. The measurement proves the pair works and says almost nothing about how long yours will take.
OGG to WMA costs half a credit per conversion, whatever the length of the OGG. That is the same as an image or a document here, and it is a measurement rather than a gesture: an audio target on this engine is done in under two seconds, where a video target can take minutes.
An OGG longer than 60 minutes is refused before encoding. ffprobe measures the OGG first and answers with a refusal, rather than starting a job the 240 second guard would kill halfway to the WMA.
OGG to WMA waits at the audio door, which is 2 slots wide and gives up after 5 seconds rather than making you wait twenty times the length of the work. Until the 30th there was one door for everything, and a single video transcode starved every audio conversion for its whole duration: a WMA that needed less than a second was answered with a refusal after twenty.
Nothing here reads what is inside the OGG. No transcription, no scene detection, no summary: OGG to WMA is a container and codec operation, and the WMA says exactly what the OGG said, in a different wrapper. The sound is the whole payload.
One OGG file at a time, chosen in the browser. There is nothing else to set up and nothing else on offer.
OGG to WMA: what people ask
What actually converts my OGG file to WMA?
ffmpeg does it, held to a single thread, on a machine we rent and watch. Not a browser trick and not somebody else service: the OGG file is uploaded once, ffmpeg runs once, the WMA comes back, and neither file is kept afterwards.
How long does OGG to WMA take?
The probe measured 0.2 seconds for 54,944 bytes of WMA, on a 3 second file. An audio target scales far better than a video one: three minutes of source through this engine takes under a second, because only the sound is encoded. Past 240 seconds any run is stopped, and an audio one does not get close.
What do I lose going from OGG to WMA?
The one to know about first: Generation loss, and it is the whole story of this pair. OGG threw information away to be small, WMA throws more away on top of what is left, and neither pass can restore what the other removed. Converting the WMA back to OGG afterwards makes it worse a third time, not better.
Will the WMA sound better than the OGG?
No. Nothing in this pass adds information to the OGG, so the WMA is at best an exact carry of what you sent and at worst one more lossy pass over it. Asking for a higher bitrate than the OGG deserved just makes a bigger file of the same recording.
Is OGG to WMA free?
There is a free allowance every month, and one OGG to WMA conversion costs half a credit against it however long the OGG runs. An audio target is charged per conversion and not per minute, because the engine encodes three minutes of sound in well under a second.