US 6,226,608 B1 · Data framing for adaptive-block-length coding system

Abstract

An audio encoder applies an adaptive block-encoding process to segments of audio information to generate frames of encoded information that are aligned with a reference signal conveying the alignment of a sequence of video information frames. The audio information is analyzed to determine various characteristics of the audio signal such as the occurrence and location of a transient, and a control signal is generated that causes the adaptive block-encoding process to encode segments of varying length. A complementary decoder applies an adaptive block-decoding process to recover the segments of audio information from the frames of encoded information. In embodiments that apply time-domain aliasing cancellation (TDAC) transforms, window functions and transforms are applied according to one of a plurality of segment patterns that define window functions and transform parameters for each segment in a sequence of segments. The segments in each frame of a sequence of overlapping frames may be recovered without aliasing artifacts independently from the recovery of segments in other frames. Window functions are adapted to provide preferred frequency-domain responses and time-domain gain profiles.

Claims32

Dependent claims

A method for audio encoding that comprises steps performing the acts of:

receiving a reference signal conveying alignment of video information frames in a sequence of video information frames in which adjacent frames are separated by a frame interval;
receiving an audio signal conveying audio information;
analyzing the audio signal to identify characteristics of the audio information;
generating a control signal in response to the characteristics of the audio information, wherein the control signal conveys segment lengths for segments of the audio information in a sequence of overlapping segments, a respective segment having a respective overlap interval with an adjacent segment and the sequence having a length equal to the frame interval plus a frame overlap interval;
applying an adaptive block encoding process to the overlapping segments in the sequence to generate a plurality of blocks of encoded information, wherein the block encoding process adapts in response to the control signal;
and
assembling the plurality of blocks of encoded information and control information conveying the segment lengths to form an encoded information frame that is aligned with the reference signal.

4 more elements

A method for audio decoding that comprises steps performing the acts of:

receiving a reference signal conveying alignment of video information frames in a sequence of video information frames in which adjacent frames are separated by a frame interval;
receiving encoded information frames that are aligned with the reference signal and each comprise control information and a plurality of blocks of encoded audio information;
generating a control signal in response to the control information, wherein the control signal conveys segment lengths for segments of audio information in a sequence of overlapping segments, a respective segment having a respective overlap interval with an adjacent segment and the sequence having a length equal to the frame interval plus a frame overlap interval;
applying an adaptive block decoding process to the plurality of blocks of encoded audio information in a respective encoded information frame, wherein the block decoding process adapts in response to the control signal to generate the sequence of overlapping segments of audio information.

1 more element

Dependencies are inferred from the claim text.

Data framing for adaptive-block-length coding system

Life of this patent

Data framing for adaptive-block-length coding system

Life of this patent

Abstract

Claims32