Audiokinetic Wwise Knowledge Base

Seeking times

Whenever a music segment should start playing in the middle of an audio clip, the underlying stream will be opened, read (for header parsing), then seeked to the appropriate place, then buffered normally. Playback that involves seeking at the beginning can also occur if a clip is trimmed within a track (with the blue handles).

Look-ahead time and source starvation

With interactive music, the streams are opened and start buffering some time before playback starts. This time is specified in the UI (look-ahead time, in the track properties). When playback starts, some data should be ready in the stream manager, otherwise source starvation will occur. If source starvation occurs in the Interactive Music hierarchy, playback of audio clips will be late compared to the high-level music engine. This is corrected when the next segment is played, however the transition to the next segment might sound weird (not sample accurate). Also, tracks of the same segment can become out-of-sync because of source starvation.

Audio clip looping

As soon as you stretch an audio clip beyond the end of the underlying file, a blue triangle appears in the upper part of the clip. When that happens, the sound represented by the clip is tagged as "looping". This is explained here. This may have consequences on I/O if the track is streaming: the Stream Manager fetches buffers at the beginning of the loop slightly before playback reaches the end of the loop. So, if the clip is looping, make sure that you really mean it, that it was not over-stretched accidentally, otherwise this may waste some I/O bandwidth.