Preservation of local sound periodicity with variable-rate video

A method of allowing pitch preservation of sound with variable-rate video playback is suggested. This is an important factor in monitoring of audio content for cueing purposes. Methods of separately considering a signal's frequency and time representations are considered with a view to performing time-scale modification with preservation of local periodicity (pitch). Particular emphasis is placed upon granulation in time of a sampled source — a technique based upon Dennis Gabor's landmark papers in1946 and 1947 and developed in the field of computer music. This relatively simple method requires no prior signal analysis and is therefore a less computationally expensive method of achieving the goals stated above. This is an important point considering the need for real-time implementation. The process does however introduce some distortion, and investigation into how this may be minimised is necessary to produce acceptable results.