In the time since my last post much progress has been made. The stereo mix is finished and the design for the subjective testing phase is well on the way. In this post I will reveal the video clips from Big Buck Bunny that I have chosen for testing, and the reasons behind certain decisions that have been made with regards to them and the test itself.
4 clips in total will be used for testing. Each clip is quite different in terms of action and it is hoped that this broad range of scene types will be able to effectively showcase the 3D audio capabilities of the Wave Arts Panorama plug-in. The clips will provide data for comparison at the analysis stage from which it is hoped conclusions can be made as to the type of scenes Panorama/Binaural audio can provide the most noticeable enhancement to the film soundtrack (if any), e.g. fast action or slower paced scenes. This comparison is additional to the main aim which is essentially Conventional stereo vs. Binaural.
Recommendation ITU-R BS.1534 – A technical standard for the subjective assessment of intermediate quality level of coding systems – states that the length of test sequences should not exceed 20 seconds in order to guard against listener fatigue and to reduce the overall length of the test. For this reason the duration of each clip was kept short (between 20-25 seconds long). It was my initial intention to strictly keep to the 20 second recommendation, however this proved difficult as it seemed chopping some sequences to 20 seconds spoiled the flow of the action: often cutting scenes short at points which seemed unnatural. It is believed 25 seconds is still short enough not to cause listeners too many problems. ITU-R B.S1534 has relevancy to this study as, like the differences in quality between audio coding systems, the differences between conventional stereo and binaural here are subtle, and in some cases very hard to perceive.
Below you will find each video clip which will be used for subjective testing. I had my reservations about posting them as I do not want to jeopardise my test in any way by potentially revealing test material which could void results. Here however I do not think there is any risk as the audio has been completely removed. Also Big Buck Bunny is a widely available and we known film which many people have seen before. Merely posting some muted clips shouldn’t harm the experiment, and there is the added comfort that no one actually reads this blog, at least the population from whom I will be taking test subjects from don’t!