Abstract: A method and apparatus for limiting the absolute magnitude of an audio signal. The method may include firstly variable-gain reducing the gain of an audio signal, and then secondly variable-gain reducing the gain of the audio signal faster than the first variable-gain reduction, thereby limiting the absolute magnitude of the audio signal to a threshold. The first variable-gain reduction may include variable-gain reducing the gain of the audio signal in a first stage, and the second variable-gain reduction may include variable-gain reducing the gain of the audio signal in a second stage that reduces the gain faster than the first stage. The second variable-gain reduction may include delaying the audio signal, finding a peak among the delayed audio signal, calculating a fast gain from a found peak, and modifying the delayed audio signal with the calculated fast gain.

Abstract: In one aspect, the invention divides an audio signal into auditory events, each of which tends to be perceived as separate and distinct, by calculating the spectral content of successive time blocks of the audio signal, calculating the difference in spectral content between successive time blocks of the audio signal, and identifying an auditory event boundary as the boundary between successive time blocks when the difference in the spectral content between such successive time blocks exceeds a threshold. In another aspect, the invention generates a reduced-information representation of an audio signal by dividing an audio signal into auditory events, each of which tends to be perceived as separate and distinct, and formatting and storing information relating to the auditory events. Optionally, the invention may also assign a characteristic to one or more of the auditory events. Auditory events may be determined according to the first aspect of the invention or by another method.

Abstract: One or a combination of two or more specific loudness model functions selected from a group of two or more of such functions are employed in calculating the perceptual loudness of an audio signal. The function or functions may be selected, for example, by a measure of the degree to which the audio signal is narrowband or wideband. Alternatively or with such a selection from a group of functions, a gain value G[t] is calculated, which gain, when applied to the audio signal, results in a perceived loudness substantially the same as a reference loudness. The gain calculating employs an iterative processing loop that includes the perceptual loudness calculation.

Abstract: In one disclosed aspect, dynamic gain modifications are applied to an audio signal at least partly in response to auditory events. In another aspect, an input channel is divided into auditory events by detecting changes in a measurable characteristic of the input signal with respect to time.

Abstract: In one disclosed aspect, dynamic gain modifications are applied to an audio signal at least partly in response to auditory events. In another aspect, an input channel is divided into auditory events by detecting changes in a measurable characteristic of the input signal with respect to time.

Abstract: Measuring the loudness of audio encoded in a bitstream that includes data from which an approximation of the power spectrum of the audio can be derived without fully decoding the audio is performed by deriving the approximation of the power spectrum of the audio from said bitstream without fully decoding the audio, and determining an approximate loudness of the audio in response to the approximation of the power spectrum of the audio. The data may include coarse representations of the audio and associated finer representations of the audio, the approximation of the power spectrum of the audio being derived from the coarse representations of the audio. In the case of subband encoded audio, the coarse representations of the audio may comprise scale factors and the associated finer representations of the audio may comprise sample data associated with each scale factor.

Abstract: In one disclosed aspect, dynamic gain modification s are applied to an audio signal at least partly in response to auditory events and/or the degree of change in signal characteristics associated with said auditory event boundaries. In another aspect, an audio signal is divided into auditory events by comparing the difference in specific loudness between successive time blocks of the audio signal.

Abstract: In one alternative, an audio signal is analyzed using multiple psychoacoustic criteria to identify a region of the signal in which time scaling and/or pitch shifting processing would be inaudible or minimally audible, and the signal is time scaled and/or pitch shifted within that region. In another alternative, the signal is divided into auditory events, and the signal is time scaled and/or pitch shifted within an auditory event. In a further alternative, the signal is divided into auditory events, and the auditory events are analyzed using a psychoacoustic criterion to identify those auditory events in which the time scaling and/or pitch shifting processing of the signal would be inaudible or minimally audible. Further alternatives provide for multiple channels of audio.

Abstract: In one disclosed aspect, dynamic gain modifications are applied to an audio signal at least partly in response to auditory events and/or the degree of change in signal characteristics associated with said auditory event boundaries. In another aspect, an audio signal is divided into auditory events by comparing the difference in specific loudness between successive time blocks of the audio signal.

Abstract: Apparatuses for and methods of carrying out dynamic equalization processing of an audio signal, and apparatuses for and methods of controlling such equalization processing of the audio signal to dynamically adjust the time-varying spectrum of an audio signal to more closely match a user specified target time-invariant perceived audio signal spectrum while preserving the original dynamic range of the audio signal. The dynamic equalization is carried out according to a user-defined spectral profile specified by a control interface that allows a user to define, create, modify and/or apply the user-defined spectral profile.

Abstract: A coded signal conveys encoded audio information and metadata that may be used to control the loudness of the audio information during its playback. If the values for these metadata parameters are set incorrectly, annoying fluctuations in loudness during playback can result. The present invention overcomes this problem by detecting incorrect metadata parameter values in the signal and replacing the incorrect values with corrected values.

Abstract: Methods and apparatuses for media data communication for improved bandwidth utilization are provided. A client device communicates profile information to a server. The server maintains media content data and first metadata category information associated with the media content data. Based upon the profile information, a determination is made as to whether the client device is to utilize the first metadata category information. If to be utilized, media content data as well as the first metadata category information is provided to the client device. If a non-utilization determination is made, media content data is provided without the first metadata category information. In exemplary embodiments, first metadata category information can relate to any of the following: closed captioning, speaker virtualization, three dimensional rendering, global positioning, audio and/or video codecs, volume control, and the like.

Abstract: A process for the production of a tinted polymer, which comprises co-polymerising a compound of the general formula I or a salt thereof with a polymerisable monomer containing a vinyl group, formula I being: in which R represents a hydrogen atom or an —SO3H group; A represents a direct bond, -alkylene-O—, or a -phenylene-NH— or -phenylene-NH-phenylene-NH— group in which the or each phenylene ring may be optionally substituted by one or more of the same or different groups selected from —SO3H, —(CH2)mSO3H, —SO2(CH2)mSO3H, —SO2NH(CH2)mSO3H, —SO2C1-2alkyl, —SO2C1-2haloalkyl, —SO2NHC1-2alkyl, —SO2NHC1-2haloakyl, —C1-2alkyl, or C1-2haloalkyl, in which m represents 1 or 2; R1 represents a hydrogen or halogen atom or a C1-4 alkyl group; and each of R2 and R3, which may be the same or different, represents a hydrogen atom or a C1-4 alkyl or alkoxy group; with the proviso that, if R1 represents a hydrogen or a C1-4alkyl group and simultaneously R represents a hydrogen atom, A must represent a -phenylene-NH— or -ph

Abstract: A coded signal conveys encoded audio information and metadata that may be used to control the loudness of the audio information during its playback. If the values for these metadata parameters are set incorrectly, annoying fluctuations in loudness during playback can result. The present invention overcomes this problem by detecting incorrect metadata parameter values in the signal and replacing the incorrect values with corrected values.

Abstract: In one alternative, an audio signal is analyzed using multiple psychoacoustic criteria to identify a region of the signal in which time scaling and/or pitch shifting processing would be inaudible or minimally audible, and the signal is time scaled and/or pitch shifted within that region. In another alternative, the signal is divided into auditory events, and the signal is time scaled and/or pitch shifted within an auditory event. In a further alternative, the signal is divided into auditory events, and the auditory events are analyzed using a psychoacoustic criterion to identify those auditory events in which the time scaling and/or pitch shifting processing of the signal would be inaudible or minimally audible. Further alternatives provide for multiple channels of audio.

Abstract: A system for securing user created Web resources that includes a data store and a URI security engine. The data store can store digitally encoded content comprising a set of user created, URI identified resources. The URI security engine can provide declarative instance based URI access control to the user created URI identified resources. The URI security engine can apply semantics of user/group control for accessing the URI identified resource. These controls can be group controlled based upon deployer (creator) established privileges rather than being based upon an explicit developer established privileges, which may not be possible since the resources can be deployer (end-user) created resources not existing at development time.

Abstract: Processing an audio signal represented by the Modified Discrete Cosine Transform (MDCT) of a time-sampled real signal is disclosed in which the loudness of the transformed audio signal is measured, and at least in part in response to the measuring, the loudness of the transformed audio signal is modified. When gain modifying more than one frequency band, the variation or variations in gain from frequency band to frequency band, is smooth. The loudness measurement employs a smoothing time constant commensurate with the integration time of human loudness perception or slower.

Abstract: A coded signal conveys encoded audio information and metadata that may be used to control the loudness and dynamic range of the audio information during its playback. If the values for these metadata parameters are set incorrectly, annoying fluctuations in loudness during playback can result. The present invention overcomes this problem by detecting incorrect metadata parameter values in the signal and replacing the incorrect values with corrected values.

Abstract: A method and apparatus for limiting the absolute magnitude of an audio signal. The method may include firstly variable-gain reducing the gain of an audio signal, and then secondly variable-gain reducing the gain of the audio signal faster than the first variable-gain reduction, thereby limiting the absolute magnitude of the audio signal to a threshold. The first variable-gain reduction may include variable-gain reducing the gain of the audio signal in a first stage, and the second variable-gain reduction may include variable-gain reducing the gain of the audio signal in a second stage that reduces the gain faster than the first stage. The second variable-gain reduction may include delaying the audio signal, finding a peak among the delayed audio signal, calculating a fast gain from a found peak, and modifying the delayed audio signal with the calculated fast gain.

Abstract: In one alternative, an audio signal is analyzed using multiple psychoacoustic criteria to identify a region of the signal in which time scaling and/or pitch shifting processing would be inaudible or minimally audible, and the signal is time scaled and/or pitch shifted within that region. In another alternative, the signal is divided into auditory events, and the signal is time scaled and/or pitch shifted within an auditory event. In a further alternative, the signal is divided into auditory events, and the auditory events are analyzed using a psychoacoustic criterion to identify those auditory events in which the time scaling and/or pitch shifting procession of the signal would be inaudible or minimally audible. Further alternatives provide for multiple channels of audio.