Technology
Audio formats and file sizes
A listening file, project data and decoded audio in memory have different sizes. Choose a format for the job, not just the number of megabytes.
WAV, FLAC, MP3 and MIDI
| Format | What it stores | Useful for |
|---|---|---|
| PCM WAV | Uncompressed audio | Export and further audio processing. |
| FLAC | Losslessly compressed audio | Storing stems while preserving the PCM data. |
| MP3 | Lossy compressed audio | Lightweight previews and sharing recordings. |
| MIDI | Notes, timing and control events | Editing a musical performance. It does not contain the finished instrument sounds. |
Ordinary timeline audio import accepts WAV and MP3. Internal use of FLAC for stems does not mean every FLAC file can be imported through that same dialog. Use the formats explicitly listed by the upload control.
Why four stems can be large
A vocal may be silent for half a composition, but its WAV still covers the full timeline. Duration, channel count, sample rate and bit depth determine uncompressed PCM size. Silence takes space in a WAV too.
The example below is for three minutes, two channels and 44.1 kHz. It uses decimal megabytes; the WAV header is negligible at this rounding level.
| Bit depth | One WAV | Four WAVs |
|---|---|---|
| 16-bit | 31.8 MB | 127.0 MB |
| 24-bit | 47.6 MB | 190.5 MB |
| 32-bit | 63.5 MB | 254.0 MB |
Calculation: seconds × sample rate × channels × bytes per sample. A 24-bit sample uses three bytes. Keeping the original beside the four stems adds more space again.
How FLAC helps storage
FLAC reduces size without losing the original PCM data. The compression ratio depends on the signal: long quiet passages and dense, noisy music compress differently. No single size reduction can be promised for every track.
Oscivara stores separated stems losslessly and uses a lighter copy for previews. When you request a WAV download, the uncompressed file is prepared. This avoids keeping a permanent full WAV duplicate just for every potential future download.
Disk size is not memory use
Compressed audio must be decoded for processing. Three minutes of stereo 44.1 kHz audio in 32-bit numbers is roughly 63.5 MB for one complete buffer alone. Several parts and intermediate processing can use more memory than the FLAC or MP3 file sizes suggest.
A small file therefore does not guarantee inexpensive playback, and a bigger cache does not always help a slower computer. See the performance guide.
Bigger numbers do not restore lost detail
Converting MP3 to WAV cannot recover information removed by lossy compression. Increasing the sample rate also cannot recreate source information that was not present. Use the best available original for editing, and choose export settings that fit the intended use.