MP4 Tips & Tricks

Identifying Major Features of a MP4 Media Sound and Video File

Deciding which sounds to use to create a Haptic effect can be very subjective as different effect designers may think some aspects of the sound are more important than others.

There are, however, some key points to consider when deciding what sounds to use to create a Haptic effect:

• Sudden volume changes. For example, this can be a gun shot or a crack of thunder. Good effects for these types of sounds are usually very strong, abrupt vibrations, or jolts. Sudden periods of silence may also need to be set off by a conspicuous absence of vibration. For maximum effect, planning for time when the device remains still is just as important as determining when and how it vibrates.



• Gradual volume changes. Some sounds can swell or fade gradually. Haptic effects for this type of sound should follow the same general rhythm. Some sound effects are musical and have a definite rhythm and meter. You can also create effects that follow the rhythm of the melody, bass drum beats, cymbal crashes, or even riffs in the horn line.



• Prominent frequencies or pitches. The sound of tires squealing as a car rounds a corner is an example of a very high-pitch sound you can accent with a high speed vibration. A fog horn is a very low frequency noise, and a low speed rumble is suitable, however, you should not base the speed of the vibration solely on the pitch of the corresponding sound. Low- to mid-motor speeds on a haptic device often feel stronger than high motor speeds. So, a particularly loud, high-pitched sound may require a strong, medium speed vibration.



• Tonality. Some sounds have an eerie or dissonant quality that you can accentuate through haptics. High frequency vibrations that gradually swell can give a similar eerie effect. Other sounds may be peaceful or even happy. In these instances, short-duration, "bouncy" effects may be more appropriate.



• The physical action the sound represents. Many sounds represent some real-world actions that are being simulated in a virtual world. This includes gun shots, earthquakes, picking up items, opening doors, etc. Firing a gun produces a loud bang and strong kick, so a matching effect would be a very strong, abrupt vibration. If a silencer is added to a gun the sound will be muffled, but the jolt that is felt may be just as strong as before. Thus, a strong effect may be appropriate even though the sound is not strong.



• Visual cues lacking sound. If the MP4 media file has visual elements of physical action without sound, such as Superman leaping over a tall building (refer to MP4 Tutorial), you may want to add effects to these actions. When played within the Timeline window, these effects may not make sense because does not playback video elements; only sound elements. Therefore, you must use an external MP4 player to find the exact timing for the effect "launch event" for use within the Timeline. Only by loading the MP4 media file with effects onto your handset are you be able to verify that your timing is as you like it.