Ambience extraction and modification for enhancement and upmix of audio signals
AssigneeCreative Technology Ltd
InventorsCarlos Avendano, Michael Goodwin, Ramkumar Sridharan, Martin Wolters, Jean-Marc Jot
Life of this patent
Estimating the term…
Abstract
Modifying an audio signal comprising a plurality of channel signals is disclosed. At least selected ones of the channel signals are transformed into a time-frequency domain. The at least selected ones of the channel signals are compared in the time-frequency domain to identify corresponding portions of the channel signals that are not correlated or are only weakly correlated across channels. The identified corresponding portions of said channel signals are modified.
Claims16
A method for modifying an audio signal comprising a plurality of channel signals, the method comprising:
- transforming at least selected ones of the channel signals into a time-frequency domain;
- comparing said at least selected ones of the channel signals in the time-frequency domain to identify corresponding portions of said channel signals that are not correlated or are only weakly correlated across channels;
- and
- modifying the identified corresponding portions of said channel signals, wherein the step of modifying comprises:
- determining for each channel an input ratio in which the numerator comprises a measure of said portions of the channel signal that are uncorrelated or weakly correlated and the denominator comprises a measure of the overall channel signal;
- receiving a user input indicating a desired output ratio of uncorrelated or weakly correlated portions to total signal;
- and
- applying to said portions of said channel signals that are uncorrelated or weakly correlated a modification factor calculated to modify the channel signals as required to achieve the desired output ratio indicated by the user.
A method for providing a generated signal to a playback channel of a multichannel playback system, the method comprising:
- receiving an input audio signal comprising a plurality of input channel signals;
- transforming at least selected ones of the input channel signals into a time-frequency domain;
- comparing said at least selected ones of the input channel signals in the time-frequency domain to identify corresponding portions of said input channel signals that are not correlated or are only weakly correlated;
- extracting from each of said input channel signals the identified corresponding portions of said input channel signals that are not correlated or are only weakly correlated;
- combining the extracted portions, including:
- determining the magnitude of the respective portions of said input channel signals that are not correlated or are only weakly correlated;
- taking the absolute difference of the magnitude values;
- and
- applying a phase to the result of the absolute difference;
- and
- providing to the playback channel a signal comprising at least in part said extracted and combined identified corresponding portions of said input channel signals that are not correlated or are only weakly correlated.
Dependencies are inferred from the claim text.