Abstract: According to one embodiment, a signal correction apparatus includes a sound quality estimation module, a sound quality enhancement processing controller, and a sound quality enhancement processor. The sound quality estimation module is configured to generate channel importance information based on correlations of channels for signals input from one or more channels, and to generate frequency importance information based on noise levels. The sound quality enhancement processing controller is configured to decide valid channels and valid frequency components which are to undergo sound quality enhancement processing of the signals based on the channel importance information and the frequency importance information, and to generate valid channel information and valid processing frequency information.

Abstract: Activity is determined for each frequency band in a frame, and when it is determined that an activity-OFF state has not continued for a predetermined number of times for preceding frames, normal coding processing is performed for the frequency band. When it is determined that the activity-OFF state has continued for the predetermined number of times or more, DTX coding is performed for the frequency band. After this processing has been performed for all of the bands of one frame, a total power of the one entire frame and the power of the band or bands to which the DTX coding is applied are calculated. Subsequently, a new target bit value is calculated based on a ratio of the total power of the one entire frame and the power of the band or bands to which the DTX coding is applied.

Abstract: A signal processing apparatus is configured to change volume level or frequency characteristics of an input signal with a limited bandwidth in a first frequency range. The apparatus includes: an information extracting unit configured to extract second frequency characteristic information from a collection signal with a limited bandwidth in a second frequency range different from the first frequency range; a frequency characteristic information extending unit configured to estimate first frequency characteristic information from the second frequency characteristic information extracted by the information extracting unit, the first frequency characteristic information including the first frequency range; and a signal correcting unit configured to change volume level or frequency characteristics of the input signal according to the first frequency characteristic information obtained by the frequency characteristic information extending unit.

Abstract: A signal bandwidth expanding apparatus configured to expand a bandwidth of an input signal. The apparatus includes: a time acquiring section configured to acquire time information; a priority holding section configured to hold priority information of processes, each process divided from a process of bandwidth expansion; a controller configured to: sequentially perform the processes from a process having a higher priority using the priority information held by the priority holding section, calculate a time taken for the process using the time acquiring section when the process is ended, and control whether or not a next process having a secondary priority is performed according to the time taken for the process; and a frequency balance correcting section configured to change a frequency characteristic of a signal expanded in a bandwidth according to the process performed by the controller.

Abstract: A signal bandwidth extending apparatus including: a bandwidth extending section configured to extend a frequency bandwidth of a target signal, the target signal included in an input signal; a calculating section configured to calculate a degree of the target signal included in the input signal; and a controller configured to change a method of extending the frequency bandwidth by the bandwidth extending section according to a result of the calculating section.

Abstract: Masking thresholds are obtained for each frequency component of sound data and ambient noise. It is determined whether each frequency component of the sound data is masked by at least one of the other frequency components of the sound data. It is further determined whether each frequency component of the sound data is masked by ambient noise. Correction coefficients are set for each frequency component of the sound data according to whether the frequency component is masked by at least one of the other frequency components of the sound data and whether the frequency component is masked by the ambient noise. And each frequency component of the sound data is corrected by using the respective correction coefficients.

Abstract: A signal characteristic is detected from a block shape indicating a time/frequency conversion block length by a signal characteristic discrimination unit to discriminate whether the prediction precision in the time domain is high or the prediction precision in the frequency domain is high and, on the basis of a result of the discrimination, a signal correction unit corrects a quantization error in spectral information obtained by de-quantization.

Abstract: According to an aspect of the invention, there is provided an audio data processing apparatus including: a decoding unit configured to extract an encoding parameter from encoded audio data by decoding the encoded audio data; an acquisition unit configured to acquire a background noise signal; a correction gain calculating unit configured to calculate a correction gain for correcting frequency characteristics of the audio data by using the encoding parameter and the background noise signal; and a frequency characteristics correcting unit configured to correct the frequency characteristics of the audio data based on the correction gain.

Abstract: According to an aspect of the invention, there is provided an audio data processing apparatus including: a decoding unit configured to decode audio encoding data, while the decoding unit switches an M/S stereo application mode and an M/S stereo non-application mode, and thereby outputting frequency domain audio data; an inverse quantizing unit configured to inversely quantize and output the frequency domain audio data; an M/S stereo judgment unit configured to decide whether or not the M/S stereo application mode is applied to the scale factor band, and extract and output a frequency domain audio data of the S channel at a part of scale factor band to which the M/S stereo application mode is applied, and generate and output a frequency domain audio data of the S channel at a part of scale factor band to which the M/S stereo application mode is not applied.

Abstract: As adaptive convergence A, a global gain for operation of a quantization step size is obtained, a frequency spectrum is quantized on the basis of the obtained global gain, and a generated code amount of the quantized data is obtained by the quantization. If the generated code amount does not satisfy predetermined conditions as a result of comparison with a target code amount, the adaptive convergence A is executed again. At this time, generated code amount variation ? is obtained by varying the global gain by 1, the global gain is corrected with the adaptive convergence A of the previous time on the basis of the generated code amount variation ?, and the adaptive convergence A is executed with the corrected global gain.

Abstract: The present invention provides a packet stream receiving apparatus, comprising a packet separation section that extracts a presentation time from a packet, a discontinuity detection section that detects a discontinuity of the packet, a storage buffer that stores decoded frames after the discontinuity has been detected, and a presentation time comparison section that calculates a number of lost frames based on the actual number of frames received from a discontinuity point in which the discontinuity was detected until the presentation time is obtained in the case where the storage buffer has stored the decoded frames. By accurately comprehending the number of lost frames caused by packet losses, outputs without timing mismatch are enabled.

Abstract: Activity is determined for each frequency band in a frame, and when it is determined that an activity-OFF state has not continued for a predetermined number of times for preceding frames, normal coding processing is performed for the frequency band. When it is determined that the activity-OFF state has continued for the predetermined number of times or more, DTX coding is performed for the frequency band. After this processing has been performed for all of the bands of one frame, a total power of the one entire frame and the power of the band or bands to which the DTX coding is applied are calculated. Subsequently, a new target bit value is calculated based on a ratio of the total power of the one entire frame and the power of the band or bands to which the DTX coding is applied.