files/en-us/web/api/mediatracksettings/samplesize/index.md
{{APIRef("Media Capture and Streams")}}
The {{domxref("MediaTrackSettings")}} dictionary's
sampleSize property is an integer indicating the linear
sample size (in bits per sample) the {{domxref("MediaStreamTrack")}} is currently
configured for. This lets you determine what value was selected to comply with your
specified constraints for this property's value as described in the
{{domxref("MediaTrackConstraints.sampleSize")}} property you provided when calling
either {{domxref("MediaDevices.getUserMedia", "getUserMedia()")}} or
{{domxref("MediaStreamTrack.applyConstraints()")}}.
If needed, you can determine whether or not this constraint is supported by checking the value of {{domxref("MediaTrackSupportedConstraints.sampleSize")}} as returned by a call to {{domxref("MediaDevices.getSupportedConstraints()")}}. However, typically this is unnecessary since browsers will ignore any constraints they're unfamiliar with.
An integer value indicating how many bits each audio sample is represented by. The most commonly used sample size for many years now is 16 bits per sample, which was used for CD audio among others. Other common sample sizes are 8 (for reduced bandwidth requirements) and 24 (for high-resolution professional audio).
Each audio channel on the track requires sampleSize bits.
That means that a given sample actually uses (sampleSize / 8) * {{domxref("MediaTrackSettings.channelCount","channelCount")}} bytes of data.
For example, 16-bit stereo audio requires (16/8)*2 or 4 bytes per sample.
See the Constraint exerciser example.
{{Specifications}}
{{Compat}}