# Audio Analysis --- ## What is Audio Analysis? During audio analysis, each file in your library is analyzed in order to extract information about their audio content. ## What is Audio Analysis used for? Data extracted during audio analysis is used for several purposes: ### Volume Leveling [[Volume Leveling]] automatically adjusts the the playback volume in order to maintain a consistent level regardless of the source material. Audio analysis extracts information about the loudness and peak values in the content. <img src='http://roon-kb.s3.amazonaws.com/5649432d-1e56-4b6f-8b8f-ae81d20ca753.png'/> ### Crossfade When fading between tracks, Roon skips over silence at the beginnings and ends of the tracks, in order to produce a more satisfying overlap. Audio Analysis measures these regions of silence in advance. <img src='http://roon-kb.s3.amazonaws.com/e0aea944-413c-48f6-b7d8-8b5eea187d00.png'/> ### Waveform displays Audio analysis captures the waveform data used to drive graphics like this: <img src='http://roon-kb.s3.amazonaws.com/3f14ed90-018c-4d2e-a25d-79760d17aeb4.png'/> ### Dynamic Range Audio Analysis captures information about the [[dynamic range|Dynamic Range]] of the content in your library: <img src='http://roon-kb.s3.amazonaws.com/f839d69c-7fad-4685-80d5-d0e0f30fb647.png'/> ### Detecting Corrupt media Because audio analysis touches every file in your library, it's in a great position to detect files with problems. <img src='http://roon-kb.s3.amazonaws.com/600907e0-cf4f-4dd4-becc-ce9721704593.png'/> ## Audio Analysis Settings Audio Analysis takes place automatically. The entire library is analyzed in the background, and when you start playback of an un-analyzed track, audio analysis is performed on demand. By default, Roon devotes roughly 30% of one CPU core to the task of background analysis, and uses 100% of one CPU core for on-demand analysis. While these defaults make the performance impact of audio analysis less visible, it also means that it can take a very long time. Analysis performance is almost totally dependent on the performance of the hardware that's serving as your [[Core|Architecture]]. In Settings->Library, there are two settings that allow you to control the tradeoff between "how long it takes" and "how hard it works the computer". These are located in Settings -> Library: <img src='http://roon-kb.s3.amazonaws.com/cd437e5a-ba54-44ad-a9b4-d1ce9307a47b.png'/> If you have just imported a large amount of content, are starting from scratch, or have just upgraded to Roon 1.3, and you are eager to have your library analyzed as quickly as possible, you might consider increasing the Background Audio analysis speed to something faster and letting it work hard overnight, like this: <img src='http://roon-kb.s3.amazonaws.com/69617f0e-e026-41db-acd4-91e498c71d88.png'/> Finally, if you have audio devices connected directly to the machine that's performing audio analysis, it's worth considering the recommendations in [[!Sound Quality In One Computer]] when choosing your analysis settings during listening sessions.
Page last changed Wed Feb 01 2017