Location Aware Music Player By Kevin West David Zhao

Basic Concept  A music player that knows where you are.  Play different music in different parts of your house.  Finish the song you are listening to right as you reach your destination.  Great for students traveling in between classes, who hate being interrupted.

Basic Scenario  People listen to different types of music when they are at different places.  A person may want to listen to heavy music when he’s working out at the gym.  He may want to listen to classical music when he’s studying in his room.

Basic Scenario (continued) Solution:  Detect the current location and play different types of music according to the location.

Basic Scenario (continued)  A student is listening to his mp3 player between classes. By the time he reaches his next class though, he still has over a minute to go on his favorite song. He’ll have to stop it to listen to the professor.  What if the song had already ended?

Basic Scenario (continued) Solution:  Figure out how much time until user reaches next destination. Alter the speed of music playback subtly to finish the track when the user arrives.

Architecture - Components  Music Player  Location-Detection: Placelab  Location analyzer  Sound speed adjuster

Expected Effort Pieces to be built:  Placelab Analyzer: Interpreting Placelab data to determine a location, and a velocity towards next location.  Audio Speed Adjuster: Speeding up and slowing down the audio stream without significant loss of quality.

Expected Effort (continued) Minimum Functionality:  Determining a location and playing the correct music.  Determining the velocity and adjusting the stream to finish as the user gets to his location.

Expected Effort (continued) Desired Functionality:  Fading in between different streams as you enter a new location.  Adjusting the audio speed in such a way that the change is invisible to the user.

Unknowns  How accurate is Placelab? Can we get a good velocity reading?  Can we change the audio speed without pitch shifting or losing significant quality?

Algorithmic Design  The Problem: Given a set of songs with specific lengths, minimize the speed changes in the audio.  Example: Song 1 = 3 min, Song 2 = 3 min, We will arrive in 5 min. We can adjust Song 1 to be 5 min, or adjust both to be 2.5 min.

Burning Questions  Will we be able to do speed adjustment of audio quickly enough to be unnoticed?  Can placelab provide accurate information on velocity?

Evaluation  Performance Tests Quality of speed-altered sound Accuracy of estimated arrival time  Usefulness How much does the user care for location-aware functionality?