Decoding data segments representing a time-domain data stream

• US 10,714,110 B2
• Filed: 05/15/2017
• Issued: 07/14/2020
• Est. Priority Date: 12/12/2006
• Status: Active Grant

• Current Assignee: Fraunhofer Gesellschaft Zur Foerderung Der Angewandten Forsching E.V.
• Original Assignee: Fraunhofer Gesellschaft Zur Foerderung Der Angewandten Forsching E.V.
• Inventors: Geiger, Ralf, Neuendorf, Max, Yokotani, Yoshikazu, Rettelbach, Nikolaus, Herre, Juergen, Geyersberger, Stefan
• Primary Examiner(s): Yen, Eric
• Application Number:
  US15/595,170
• Publication Number:
  US 20170249952A1
• Time in Patent Office: 1,156 Days
• CPC Class Codes: G10L 19/00 Speech or audio signals analysis-synthesis techniques for redundancy reduction, e.g. in vocoders; Coding or decoding of speech or audio signals, using source filter models or psychoacoustic analysis in musical instruments G10H
• CPC Class Codes: G10L 19/02 using spectral analysis, e.g. transform vocoders or subband vocoders
• CPC Class Codes: G10L 19/022 Blocking, i.e. grouping of samples in time; Choice of analysis windows; Overlap factoring
• CPC Class Codes: G10L 19/032 Quantisation or dequantisation of spectral components
• CPC Class Codes: G10L 19/18 Vocoders using multiple modes
• CPC Class Codes: G10L 19/265 Pre-filtering, e.g. high frequency emphasis prior to encoding
• CPC Class Codes: H04N 19/00 Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
• CPC Class Codes: H04N 21/2368 Multiplexing of audio and video streams
• CPC Class Codes: H04N 21/2383 Channel coding or modulation of digital bit-stream, e.g. QPSK modulation arrangements for detecting or preventing errors in the information received by adapting the channel coding H04L1/0009; analogue front ends or means for connecting modulators, demodulators or transceivers to a transmission line H04L27/0002
• CPC Class Codes: H04N 21/2662 Controlling the complexity of the video stream, e.g. by scaling the resolution or bitrate of the video stream based on the client capabilities
• CPC Class Codes: H04N 21/4341 Demultiplexing of audio and video streams
• CPC Class Codes: H04N 21/4382 Demodulation or channel decoding, e.g. QPSK demodulation analog front ends or means for connecting modulators, demodulators or transceivers to a transmission line H04L27/0002

Abstract

An apparatus for decoding data segments representing a time-domain data stream, a data segment being encoded in the time domain or in the frequency domain, a data segment being encoded in the frequency domain having successive blocks of data representing successive and overlapping blocks of time-domain data samples. The apparatus includes a time-domain decoder for decoding a data segment being encoded in the time domain and a processor for processing the data segment being encoded in the frequency domain and output data of the time-domain decoder to obtain overlapping time-domain data blocks. The apparatus further includes an overlap/add-combiner for combining the overlapping time-domain data blocks to obtain a decoded data segment of the time-domain data stream.

Claims

1. An apparatus for decoding data segments representing a time-domain data stream, a data segment encoded in a time domain, a data segment encoded in a frequency domain having successive blocks of data representing successive and overlapping blocks of time-domain data samples, the apparatus comprising:

a time-domain decoder for decoding the data segment encoded in the time domain;

a processor for processing the data segment encoded in the frequency domain and output data of the time-domain decoder to obtain overlapping time-domain data blocks; and

an overlap/add-combiner for combining the overlapping time-domain data blocks to obtain decoded data segments of a time-domain data stream.

2. The apparatus of claim 1, wherein the processor comprises a frequency-domain decoder for decoding the data segment encoded in the frequency domain to obtain one or more frequency-domain data segments.

3. The apparatus of claim 2, wherein the processor comprises a time-domain to frequency-domain converter for converting the output data of the time-domain decoder to obtain converted frequency-domain data segments.

4. The apparatus of claim 1, wherein the processor comprises a calculator for calculating the overlapping time-domain data blocks based on the output data of the time-domain decoder.

5. The apparatus of claim 4, wherein the calculator is adapted for reproducing an overlapping property of a frequency-domain to time-domain converter based on the output data of the time-domain decoder.

6. The apparatus of claim 5, wherein the calculator is adapted for reproducing a time-domain aliasing characteristic of the frequency-domain to time-domain converter based on the output data of the time-domain decoder.

7. The apparatus of claim 4, wherein the calculator is adapted for

segmenting the output data of the time-domain decoder in calculator segments comprising 2N sequential samples,

applying weights to the 2N sequential samples according to an analysis window function,

subtracting a first set of N/2 samples in reversed order from a second set of N/2 samples,

adding a fourth set of N/2 samples in reversed order to a third set of N/2 samples,

inverting the second and third sets of N/2 samples,

replacing the first set of N/2 samples with a time-reversed and inverted version of the second set of N/2 samples,

replacing the fourth set of N/2 samples with a time-reversed version of the third set of N/2 samples, and

applying weights to the 2N sequential samples according to a synthesis windowing function.

8. The apparatus of claim 4, wherein the calculator is adapted for applying weights to 2N samples according to an analysis windowing function being adapted to a size of an overlapping region of consecutive overlapping time-domain data blocks and wherein the calculator is adapted for applying weights to the 2N samples according to a synthesis windowing function being adapted to the size of the overlapping region.

9. The apparatus of claim 1, wherein the processor comprises a calculator, and wherein the calculator comprises a time-domain aliasing stage for time-aliasing the output data of the time-domain decoder to obtain the overlapping time-domain data blocks.

10. The apparatus of claim 1, wherein a size of an overlapping region of two consecutive time-domain data blocks which are encoded in the frequency domain is larger than a size of an overlapping region of two consecutive time-domain data blocks of which one being encoded in the frequency domain and one being encoded in the time domain.

11. Method for decoding data segments representing a time-domain data stream, a data segment encoded in the time domain, a data segment encoded in the frequency domain having successive blocks of data representing successive and overlapping blocks of time-domain data samples, comprising the steps of:

decoding the data segment encoded in the time domain to obtain time-domain output data;

processing the data segment encoded in the frequency domain and the time-domain output data to obtain overlapping time-domain data blocks; and

combining the overlapping time-domain data blocks to obtain decoded data segments of a time-domain data stream.

12. A non-transitory computer readable medium having code stored thereon, the code when executed by a processor, causing the processor to implement a method of claim 11.