摘要:
Techniques for efficiently encoding an input signal are described. In one design, a generalized encoder encodes the input signal (e.g., an audio signal) based on at least one detector and multiple encoders. The at least one detector may include a signal activity detector, a noise-like signal detector, a sparseness detector, some other detector, or a combination thereof. The multiple encoders may include a silence encoder, a noise-like signal encoder, a time-domain encoder, a transform-domain encoder, some other encoder, or a combination thereof. The characteristics of the input signal may be determined based on the at least one detector. An encoder may be selected from among the multiple encoders based on the characteristics of the input signal. The input signal may be encoded based on the selected encoder. The input signal may include a sequence of frames, and detection and encoding may be performed for each frame.
摘要:
Techniques for efficiently encoding an input signal are described. In one design, a generalized encoder encodes the input signal (e.g., an audio signal) based on at least one detector and multiple encoders. The at least one detector may include a signal activity detector, a noise-like signal detector, a sparseness detector, some other detector, or a combination thereof. The multiple encoders may include a silence encoder, a noise-like signal encoder, a time-domain encoder, a transform-domain encoder, some other encoder, or a combination thereof. The characteristics of the input signal may be determined based on the at least one detector. An encoder may be selected from among the multiple encoders based on the characteristics of the input signal. The input signal may be encoded based on the selected encoder. The input signal may include a sequence of frames, and detection and encoding may be performed for each frame.
摘要:
A time shift calculated during a pitch-regularizing (PR) encoding of a frame of an audio signal is used to time-shift a segment of another frame during a non-PR encoding.
摘要:
The range of disclosed configurations includes methods in which subbands of a speech signal are separately encoded, with the excitation of a first subband being derived from a second subband. Gain factors are calculated to indicate a time-varying relation between envelopes of the original first subband and of the synthesized first subband. The gain factors are quantized, and quantized values that exceed the pre-quantized values are re-coded.
摘要:
The range of disclosed configurations includes methods in which subbands of a speech signal are separately encoded, with the excitation of a first subband being derived from a second subband. Gain factors are calculated to indicate a time-varying relation between envelopes of the original first subband and of the synthesized first subband. The gain factors are quantized, and quantized values that exceed the pre-quantized values are re-coded.
摘要:
A method for modifying a window with a frame associated with an audio signal is described. A signal is received. The signal is partitioned into a plurality of frames. A determination is made if a frame within the plurality of frames is associated with a non-speech signal. A modified discrete cosine transform (MDCT) window function is applied to the frame to generate a first zero pad region, where the region has a length of (M−L)/2, where L is an arbitrary value, and a second zero pad region if it was determined that the frame is associated with a non-speech signal. The frame is encoded. The decoder window is the same as the encoder window.
摘要:
A scheme for injecting noise at uncoded elements of a spectrum is controlled according to a measure of a distribution of energy of the original spectrum among the locations of the uncoded elements.
摘要:
A method of processing an audio signal is described. The method includes selecting one among a plurality of entries of a codebook based on information from the audio signal. The method also includes determining locations, in a frequency domain, of zero-valued elements of a first signal that is based on the selected codebook entry. The method further includes calculating energy of the audio signal at the determined frequency-domain locations. The method additionally includes calculating a value of a measure of a distribution of the energy of the audio signal among the determined frequency-domain locations. The method also includes calculating a noise injection gain factor based on the calculated energy and the calculated value.
摘要:
A method of bit allocation is described. The method includes, for each among a plurality of vectors, calculating a corresponding one of a plurality of gain factors. The method also includes, for each among the plurality of vectors, calculating a corresponding bit allocation that is based on the gain factor. The method further includes, for at least one among the plurality of vectors, determining that the corresponding bit allocation is not greater than a minimum allocation value. The method additionally includes, in response to the determining, for each of the at least one vector, changing the corresponding bit allocation.
摘要:
A dynamic bit allocation operation determines a bit allocation for each of a plurality of vectors, based on a corresponding plurality of gain factors, and compares each allocation to a threshold value that is based on a dimensionality of the vector.