摘要:
An apparatus for encoding comprises a first domain converter (510), a switchable bypass (50), a second domain converter (410), a first processor (420) and a second processor (520) to obtain an encoded audio signal having different signal portions represented by coded data in different domains, which have been coded by different coding algorithms. Corresponding decoding stages in the decoder together with a bypass for bypassing a domain converter allow the generation of a decoded audio signal with high quality and low bit rate.
摘要:
An audio encoder for encoding an audio signal comprises a first coding branch (400), the first coding branch comprising a first converter (410) for converting a signal from a time domain into a frequency domain. Furthermore, the audio encoder comprises a second coding branch (500) comprising a second time/frequency converter (523). Additionally, a signal analyzer (300/525) for analyzing the audio signal is provided. The signal analyzer, on the hand, determines whether an audio portion is effective in the encoder output signal as a first encoded signal from the first encoding branch or as a second encoded signal from a second encoding branch. On the other hand, the signal analyzer determines a time/frequency resolution to be applied by the converters (410, 523) when generating the encoded signals. An output interface includes, in addition to the first encoded signal and the second encoded signal, a resolution information identifying the resolution used by the first time/frequency converter and used by the second time/frequency converter.
摘要:
An audio encoder (10) adapted for encoding frames of a sampled audio signal to obtain encoded frames, wherein a frame comprises a number of time domain audio samples. The audio encoder (10) comprises a predictive coding analysis stage (12) for determining information on coefficients of a synthesis filter and an excitation frame based on a frame of audio samples, the excitation frame comprising samples of an excitation signal for the synthesis filter. The audio encoder (10) further comprises a time-aliasing introducing transformer (14) for transforming overlapping excitation frames to the frequency domain to obtain excitation frame spectra, wherein the time-aliasing introducing transformer (14) is adapted for transforming the overlapping excitation frames in a critically-sampled way. Moreover, the audio encoder (10) comprises a redundancy reducing encoder (16) for encoding the excitation frame spectra to obtain the encoded frames based on the coefficients and the encoded excitation frame spectra.
摘要:
An audio encoder comprises a first information sink oriented encoding branch such as a spectral domain encoding branch, a second information source or SNR oriented encoding branch such as an LPC-domain encoding branch, and a switch for switching between the first encoding branch and the second encoding branch, wherein the second encoding branch comprises a converter into a specific domain different from the spectral domain such as an LPC analysis stage generating an excitation signal, and wherein the second encoding branch furthermore comprises a specific domain coding branch such as LPC domain processing branch, and a specific spectral domain coding branch such as LPC spectral domain processing branch, and an additional switch for switching between the specific domain coding branch and the specific spectral domain coding branch. An audio decoder comprises a first domain decoder such as a spectral domain decoding branch, a second domain decoder such as an LPC domain decoding branch for decoding a signal such as an excitation signal in the second domain, and a third domain decoder such as an LPC-spectral decoder branch and two cascaded switches for switching between the decoders.
摘要:
An audio encoder (10) adapted for encoding frames of a sampled audio signal to obtain encoded frames, wherein a frame comprises a number of time domain audio samples. The audio encoder (10) comprises a predictive coding analysis stage (12) for determining information on coefficients of a synthesis filter and an excitation frame based on a frame of audio samples, the excitation frame comprising samples of an excitation signal for the synthesis filter. The audio encoder (10) further comprises a time-aliasing introducing transformer (14) for transforming overlapping excitation frames to the frequency domain to obtain excitation frame spectra, wherein the time-aliasing introducing transformer (14) is adapted for transforming the overlapping excitation frames in a critically-sampled way. Moreover, the audio encoder (10) comprises a redundancy reducing encoder (16) for encoding the excitation frame spectra to obtain the encoded frames based on the coefficients and the encoded excitation frame spectra.
摘要:
An audio encoder (100) for encoding audio samples, comprising a first time domain aliasing introducing encoder (110) for decoding audio samples in a first encoding domain, the first time domain aliasing introducing encoder (110) having a first framing rule, a start window and a stop window. The audio encoder (100) further comprises a second encoder (120) for encoding samples in a second encoding domain, the second encoder (120) having a predetermined frame size number of audio samples, and a coding warm-up period number of audio samples, the second encoder (120) having a different second framing rule, a frame of the second encoder (120) being an encoded representation of a number of timely subsequent audio samples, the number being equal to the predetermined frame size number of audio samples. The audio encoder (100) further comprises a controller (130) switching from the first encoder (110) to the second encoder (120) in response to characteristic of the audio samples, and for modifying the second framing rule in response to switching from the first encoder (110) to the second encoder (120) or for modifying the start window or the stop window of the first encoder (110), wherein the second framing rule remains unmodified.
摘要:
An apparatus for encoding comprises a first domain converter (510), a switchable bypass (50), a second domain converter (410), a first processor (420) and a second processor (520) to obtain an encoded audio signal having different signal portions represented by coded data in different domains, which have been coded by different coding algorithms. Corresponding decoding stages in the decoder together with a bypass for bypassing a domain converter allow the generation of a decoded audio signal with high quality and low bit rate.
摘要:
An audio encoder (100) for encoding audio samples, comprising a first time domain aliasing introducing encoder (110) for decoding audio samples in a first encoding domain, the first time domain aliasing introducing encoder (110) having a first framing rule, a start window and a stop window. The audio encoder (100) further comprises a second encoder (120) for encoding samples in a second encoding domain, the second encoder (120) having a predetermined frame size number of audio samples, and a coding warm-up period number of audio samples, the second encoder (120) having a different second framing rule, a frame of the second encoder (120) being an encoded representation of a number of timely subsequent audio samples, the number being equal to the predetermined frame size number of audio samples. The audio encoder (100) further comprises a controller (130) switching from the first encoder (110) to the second encoder (120) in response to characteristic of the audio samples, and for modifying the second framing rule in response to switching from the first encoder (110) to the second encoder (120) or for modifying the start window or the stop window of the first encoder (110), wherein the second framing rule remains unmodified.