Updating ...

It has been a while since the last post, partly due to needing a little time to relax but primarily because of the updates needed to be made to my team's Dare To Be Digital 2008 entry - a winning entry if you can believe that. Extra work was needed to be done to it in preparation for the BAFTAs in March, however, now that is out the way I can get down to business again with this project.

With the final submission of my project proposal I narrowed down two main features to focus on that I felt were most neglected in current game audio tools. These features are time stretching and sample accurate looping.

Time Stretching

This is the method of lengthening or shortening an audio sample while preserving its pitch. During my research I have not found a single game specific application that supports this feature meaning that if any samples were to be layered together as part of one track they would have to be edited in another package first before they could be used together if their tempo's differed. In a review of the tool Wwise, Michael Henein stated that he would like to see time stretching implemented in these kind of tools to allow for more automated syncing with musical cues. I agree with his statement as tools are supposed to aid the developer - it's no use if you have one tool but are quite restricted in how you use it unless you have access to others.

In this project the time stretching will be implemented in a similar fashion to how Sony Acid has used it. With Acid, when you load in a sample you can make it fit with the rest of the project your working on by making its tempo match the projects tempo by either stretching or shortening it. This feature in a game specific tool would allow the audio designer/composer to just dump any suitable samples into their application without having to worry about their pacing as the tool will be able to make them all fit together.

Time stretching can have some adverse affects on certain types and lengths of samples such as the creation of artifacts ( clicks and pops ) and just making it sound unplesant. This is where the judgment of the user will be required to assess if more drastic measures are needed such as recording a new sample or changing the layout of the track.

Sample Accurate Looping

Unfortunatly with the audio APIs I have looked into I discovered ( through experience ) that when you set a sound to loop there is a slight delay from when it ends to when it loops round to the start. While this delay is inaudable it does pose an issue where multi-layered, different length sounds are concerned. The reasoning behind this was explained this previous post.

Why not just use samples that are the same length when layering them I hear you ask? Well, if you have ever taken a look at a complicated musical composition in any sequencer based program ( Cubase, Logic, Reason, Acid etc.) you'll notice that little variations, short phrases and contained loops can be found all over the place, seperated by blank spaces. If you were to create a single loop with samples of the same length then each sample would have to be as long as the longest sample. Not only would this take up huge amounts of unnecessary memory/CPU overhead in playing silent passages it also restricts how dynamic the composition can be. Individual phrases or loops could never be randomly played at any time unless an extra layer was added just for those bits - a layer that would again have to be the same length as the longest sample.

With using sample accurate looping, sections that have a lot of silence would simply not be played, reducing memory footprint as well as CPU overhead. Compositions could also be made more dynamic by allowing the composer to define sections that can have variations played in them, of which a certain variation could be picked in real time depending on the game state.