Audio

Bitgrain mixes music, voice and the sound from your video clips right in the browser. Each clip has its own volume, fades, speed and a 3-band equalizer, and the export renders the whole mix to stereo AAC or Opus.

Audio tracks

Audio clips live on audio tracks. New projects include one called "A1". Add more with Add Track and "Audio track" when you want to keep music, voice and effects apart.

All audio tracks play at the same time and are mixed together. There is no limit to how many you can stack. Each audio track header has two toggles:

Speaker: mutes the whole track.
Lock: protects the track. Its clips cannot be selected, moved, trimmed or deleted until you unlock it.

Video clips carry sound too. That sound plays from the video track unless you mute it or detach it to its own audio track.

Adding audio

Click Audio in the action bar. It opens a file picker for audio files and places what you pick at the playhead on the first audio track.
Or import through the media panel and click the tile, or drag it onto a specific audio track.

Supported formats are .mp3, .wav, .m4a, .ogg, .aac and .flac, as long as your browser can decode them. See adding media.

Waveforms

When you import audio or video, Bitgrain reads the sound and stores a compact waveform with the media. Audio and video clips then draw that waveform right on the timeline, trimmed to the part of the file the clip actually uses. It makes it easy to spot drum hits, pauses in speech, and where a song gets loud.

If an older project is missing waveforms, they are filled in automatically in the background when you open it.

The audio inspector

Select an audio clip to see:

Control	Range	Notes
Timing	Start, Duration, Speed (`0.25` to `4`x)	Speed changes length and pitch together
Mute	On or off	Silences just this clip
Volume	`0` to `100`%	Default is 100%
Fade in	`0` to `5` s	Ramps the volume up from silence
Fade out	`0` to `5` s	Ramps the volume down to silence
Equalizer	Low, Mid, High	See equalizer

You can also drag the amber fade handles at the top corners of the clip on the timeline, as with any clip.

Fades play the same everywhere: in the editor, in a WebM export and in an MP4 export.

Video clip sound

Select a video clip and scroll to its Audio section:

Mute clip audio silences the clip's own sound.
Volume from 0 to 100%.
The same Equalizer as audio clips.
Detach audio to track moves the sound onto a new audio track right below, as a linked clip you can trim and adjust on its own. Unlink audio appears once it is linked.

The video clip's Fade In and Fade Out also fade its sound, in playback and in both export formats.

Tip: To silence one video clip, use Mute clip audio. To silence a whole video track, use its speaker button. Either way the picture stays on screen.

Equalizer

Every audio clip, and the sound of every video clip, has a 3-band equalizer. Each band goes from -12 to +12 dB in 1 dB steps. At 0 the band does nothing.

Band	Filter	Centered on	Use it to
Low	Low shelf	200 Hz	Add weight to a kick or remove rumble and handling noise
Mid	Peaking	1 kHz	Push a voice forward or scoop out a boxy, crowded sound
High	High shelf	4 kHz	Add air and clarity, or tame hiss and harsh cymbals

A reset link appears next to "Equalizer" once any band is moved. It puts all three back to 0.

Tip: When music and voice fight, try cutting the music's Mid by 3 to 6 dB rather than turning the whole song down. The voice gets room and the music keeps its energy.

Mixing tips

Balance with volume first. Set the loudest part of the song where you want it, then bring voice and effects in around it.
Leave headroom. Clips add up. If a loud song and a loud voice both sit at 100%, the mix can clip in the export. Pull the music back to 60 to 80% under speech.
Fade everything. Even a 0.1 second fade in and fade out removes the click you sometimes hear at a hard cut.
Use separate tracks for music, voice and sound effects, so you can mute one while you work on another.
Hidden video still plays. Hiding a video track with the eye button removes its picture but keeps its sound in the mix.

How audio is exported

When you export an MP4, Bitgrain renders the full mix offline, faster than real time, before encoding the picture:

Every audible clip is gathered: audio clips on unmuted tracks, plus the sound of unmuted video clips on unmuted video tracks.
Each clip is placed at its start time with its speed, volume, fades and EQ applied. If you set an in and out range, only that stretch is rendered.
The mix is rendered at 48 kHz in stereo. Mono sources are copied to both channels.

A WebM export works differently: it records the mix live while the timeline plays, the same way you hear it in the editor.

Format	Audio codec	Settings
MP4	AAC (`mp4a.40.2`)	48 kHz, stereo, 128 kbps
WebM	Opus	Recorded from the live mix as it plays, fades included

If the timeline has no audible clips, the MP4 is written without an audio track. See exporting for the rest of the export settings.