Method and apparatus for audio normalization

Abstract

A request is received to play an audio file. A determination is made regarding whether volume normalization parameters associated with the audio file are stored in a media library. If the volume normalization parameters associated with the audio file are stored in the media library, the volume normalization parameters are retrieved from the media library. If the volume normalization parameters associated with the audio file are not stored in the media library, retrieving the volume normalization parameters from the audio file. The volume normalization parameters are applied while playing the audio file. The volume normalization process can be applied across multiple audio files during playback.

1 . An apparatus comprising:
 a volume normalization parameter calculator to analyze an audio file and calculate at least one volume normalization parameter;   a media library coupled to the volume normalization parameter calculator, the media library to store volume normalization parameters associated with audio files; and   a volume normalizer coupled to the media library, the volume normalizer to apply volume normalization parameters to normalize playback volumes of audio files.   
     
     
         2 . An apparatus as recited in  claim 1 , wherein the volume normalization parameter calculator calculates a mapping function. 
     
     
         3 . An apparatus as recited in  claim 2 , wherein a first portion of the mapping function is applied to audio data in the audio file when the amplitude of the audio data exceeds a threshold value, and a second portion of the mapping function is applied to audio data in the audio file when the amplitude of the audio data does not exceed the threshold value. 
     
     
         4 . An apparatus as recited in  claim 1 , wherein the volume normalizer is to retrieve volume normalization parameters from an associated audio file. 
     
     
         5 . An apparatus as recited in  claim 1 , wherein the volume normalizer is to retrieve volume normalization parameters from the media library. 
     
     
         6 . An apparatus as recited in  claim 1 , wherein the volume normalization parameter calculator is to analyze the audio file and calculate the at least one volume normalization parameter in response to a request to copy the audio file. 
     
     
         7 . An apparatus as recited in  claim 6 , wherein the volume normalization parameter calculator is to calculate the at least one volume normalization parameter based on volume levels in the audio file. 
     
     
         8 . An apparatus as recited in  claim 6 , wherein the volume normalization parameter calculator is to save a copy of the audio file in the media library and to save the at least one volume normalization parameter with the copy of the audio file. 
     
     
         9 . An apparatus as recited in  claim 6 , wherein the volume normalization parameter calculator is to save a copy of the audio file in the media library and to store the at least one volume normalization parameter in the copy of the audio file. 
     
     
         10 . An apparatus as recited in  claim 1 , wherein the volume normalization parameter calculator is further to:
 identify a plurality of audio files on the apparatus;   analyze the content of each identified audio file;   calculate the at least one volume normalization parameter associated with each identified audio file, wherein the volume normalization parameters associated with a particular audio file are calculated based on volume levels in the particular audio file; and   store the at least one volume normalization parameter associated with each identified audio file in the media library.   
     
     
         11 . An apparatus as recited in  claim 10 , wherein to store the at least one volume normalization parameter is to store the at least one volume normalization parameter associated with each associated audio file. 
     
     
         12 . An apparatus as recited in  claim 10 , wherein to store the at least one volume normalization parameter associated with each associated audio file is to store the at least one volume normalization parameter in a header of the associated audio file. 
     
     
         13 . An apparatus as recited in  claim 10 , wherein the volume normalization parameter calculator is part of a media player application. 
     
     
         14 . One or more computer storage devices having stored thereon a computer program that, when executed by one or more processors, causes the one or more processors to:
 receive a request to play an audio file;   identify a first volume normalization parameter associated with the audio file, wherein the first volume normalization parameter includes a peak volume level associated with the audio file;   identify a second volume normalization parameter associated with the audio file, wherein the second volume normalization parameter includes an average volume level associated with the audio file; and   play the audio file while applying the first volume normalization parameter and the second volume normalization parameter.   
     
     
         15 . One or more computer storage devices as recited in  claim 14 , wherein the first volume normalization parameter and the second volume normalization parameter are stored in the audio file. 
     
     
         16 . One or more computer storage devices as recited in  claim 14 , wherein the first volume normalization parameter and the second volume normalization parameter are stored in a media library. 
     
     
         17 . One or more computer storage devices as recited in  claim 14 , the computer program further causing the one or more processors to:
 receive a request to copy an additional audio file;   identify a third volume normalization parameter associated with the additional audio file, wherein the third volume normalization parameter includes a peak volume level associated with the additional audio file;   identify a fourth volume normalization parameter associated with the additional audio file, wherein the fourth volume normalization parameter includes an average volume level associated with the additional audio file;   store the third volume normalization parameter and the fourth volume normalization parameter in a media library; and   save a copy of the additional audio file to a storage device.   
     
     
         18 . One or more computer storage devices as recited in  claim 17 , wherein to save a copy of the additional audio file to a storage device is to store the third volume normalization parameter and the fourth volume normalization parameter in the copy of the audio file. 
     
     
         19 . One or more computer storage devices as recited in  claim 14 , the computer program further causing the one or more processors to:
 identify a plurality of additional audio files on a computer system;   for each of the plurality of additional audio files:
 identify volume normalization parameters associated with the additional audio file, wherein the volume normalization parameters associated with the additional audio file include a peak volume level associated with the additional audio file and an average volume level associated with the additional audio file; and 
 store the volume normalization parameters associated with the additional audio file in a media library. 
   
     
     
         20 . One or more computer storage devices as recited in  claim 14 , the computer program comprising a media player application.