Forward error correction using source blocks with symbols from at least two datastreams with synchronized start symbol identifiers among the datastreams

• US 10,097,861 B2
• Filed: 07/10/2015
• Issued: 10/09/2018
• Est. Priority Date: 01/18/2013
• 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: Hellge, Cornelius, Schierl, Thomas, Sanchez, Yago, Hensel, Manuel
• Primary Examiner(s): Perungavoor, Sath V
• Assistant Examiner(s): Dang, Philip
• Application Number:
  US14/796,021
• Publication Number:
  US 20150319464A1
• Time in Patent Office: 1,187 Days
• CPC Class Codes: H03M 13/6522 Intended application, e.g. transmission or communication standard
• CPC Class Codes: H04L 1/004 by using forward error control H04L1/0618 takes precedence; coding, decoding or code conversion, for error detection or correction H03M13/00
• CPC Class Codes: H04L 1/0086 Unequal error protection H04L27/00 and H04L1/004 take precedence for layer 1/2 aspects, e.g. bit loading
• CPC Class Codes: H04L 7/0008 Synchronisation information channels, e.g. clock distribution lines
• CPC Class Codes: H04N 19/29 involving scalability at the object level, e.g. video object layer [VOL]
• CPC Class Codes: H04N 19/39 involving multiple description coding [MDC], i.e. with separate layers being structured as independently decodable descriptions of input picture data
• CPC Class Codes: H04N 19/46 Embedding additional information in the video signal during the compression process H04N19/517, H04N19/68, H04N19/70 take precedence
• CPC Class Codes: H04N 19/70 characterised by syntax aspects related to video coding, e.g. related to compression standards
• CPC Class Codes: H04N 19/89 involving methods or arrangements for detection of transmission errors at the decoder
• CPC Class Codes: H04N 21/234327 by decomposing into layers, e.g. base layer and one or more enhancement layers
• 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 21/4382 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
• CPC Class Codes: H04N 21/631 Multimode Transmission, e.g. transmitting basic layers and enhancement layers of the content over different transmission paths or transmitting with different error corrections, different keys or with different transmission protocols

Abstract

A forward error correction (FEC) data generator has an input for at least two datastreams for which FEC data shall be generated in a joint manner, each datastream having a plurality of symbols. A FEC data symbol is based on a FEC source block possibly having a subset of symbols of the at least two data streams. The FEC data generator further has a signaling information generator configured to generate signaling information for the FEC data symbol regarding which symbols within the at least two datastreams belong to the corresponding source block by determining pointers to start symbols within a first and a second datastream, respectively, of the at least two datastreams and a number of symbols within the first datastream and second datastreams, respectively, that belong to the corresponding source block.

Claims

1. A forward error correction data generator comprising an electronic circuit, a processor, or a computer, the forward error correction data generator comprising:

an input for an enhancement layer datastream and a base layer datastream for which forward error correction data shall be generated, wherein

each of the enhancement layer datastream and the base layer datastream includes a plurality of symbols, and

the electronic circuit or the processor is configured to, or the computer is programmed to;

group symbols in the base layer datastream and the enhancement layer datastream together to form forward error correction (FEC) source blocks, and to use Layer-Aware Forward Error Correction (LA-FEC) to generate a repair symbol based on a FEC source block, the symbols within the enhancement layer datastream and the base layer datastream including an incremental ID which is synchronized so as to start with a common symbol ID for each FEC source block, which is equal over the base layer datastream and the enhancement layer datastream;

generate signaling information for a repair symbol regarding which symbols within the enhancement layer datastream and the base layer datastream belong to the FEC source block based on which the repair symbol is generated, in a manner so that the signaling information is included into the repair symbol or linked therewith and so that the signaling information includes;

the common symbol ID of the FEC source block based on which the repair symbol is generated, the common symbol ID equally indicating a first start symbol within the enhancement layer datastream and a second start symbol within the base layer datastream,

a first length information for a number of symbols within the enhancement layer datastream, starting with the first start symbol, that belong to the FEC source block, and

a second length information for a number of symbols within the base layer datastream, starting with the second start symbol, that belong to the FEC source block.

2. The forward error correction data generator according to claim 1, wherein the electronic circuit or the processor is configured to, or the computer is programmed to:

manage a common counter and determine for each FEC source block which datastream of the base layer datastream and the enhancement layer datastream includes the highest number of symbols, and to increment a common counter state by the determined highest number of symbols when passing on to a subsequent FEC source block.

3. A forward error correction decoder comprising:

an input configured to receive a repair stream including repair symbols relative to an enhancement layer datastream and a base layer datastream to be forward error corrected, wherein each of the enhancement layer datastream and the base layer datastream includes a plurality of symbols, and the symbols in the base layer datastream and the enhancement layer datastream are grouped together in order to form forward error correction (FEC) source blocks, wherein a repair symbol is generated based on a FEC source block using Layer-Aware Forward Error Correction, and wherein the symbols within the enhancement layer datastream and the base layer datastream have an incremental ID which is synchronized so that as to start with a common symbol ID for each FEC source block, which is equal over the base layer datastream and the enhancement layer datastream;

wherein

the forward error correction decoder includes an electronic circuit or a processor configured to, or a computer programmed to;

analyze a signaling information within a repair symbol or linked therewith, the signaling information including;

the common symbol ID of the FEC source block based on which the repair symbol is generated, the common symbol ID equally indicating a first start symbol within the enhancement layer datastream and a second start symbol within the base layer datastream,

a first length information for a number of symbols within the enhancement layer datastream, starting with the first start symbol, that belong to the FEC source block, and

a second length information for a number of symbols within the base layer datastream, starting with the second start symbol, that belong to the FEC source block; and

collect symbols within the base layer datastream and the enhancement layer datastream belonging to the FEC source block based on which the repair symbol is generated within which the signaling information is or with which the signaling information is linked, using the signaling information.

4. A method for generating forward error correction data, the method comprising:

receiving an enhancement layer datastream and a base layer datastream for which forward error correction data shall be generated, wherein each of the enhancement layer datastream and the base layer datastream includes a plurality of symbols;

grouping symbols in the base layer datastream and the enhancement layer datastream together in order to form forward error correction (FEC) source blocks;

using Layer-Aware Forward Error Correction (LA-FEC) to generate a repair symbol based on a FEC source block, wherein the symbols within the enhancement layer datastream and the base layer datastream have an incremental ID that is synchronized to start with a common symbol ID for each FEC source block, which is equal over the base layer datastream and the enhancement layer datastream; and

generating signaling information for a repair symbol regarding which symbols within the enhancement layer datastream and the base layer datastream belong to the FEC source block based on which the repair symbol is generated, so that the signaling information is included into the repair symbol or linked therewith and so that the signaling information includes;

the common symbol ID of the FEC source block based on which the repair symbol is generated, the common symbol ID equally indicating a first start symbol within the enhancement layer datastream and a second start symbol within the base layer datastream,

a first length information for a number of symbols within the enhancement layer datastream, starting with the first start symbol,that belong to the FEC source block, and

a second length information for a number of symbols within the base layer datastream, starting with the second start symbol, that belong to the FEC source block,

wherein at least one of the receiving, grouping, using and generating is implemented using an electronic circuit, a processor or a computer.

5. The method according to claim 4, further comprising:

providing a common counter that is valid for a plurality of source blocks or an entire forward error correction data generation process;

determining for each FEC source block which datastream of the enhancement layer datastream and the base layer datastream includes the highest number of symbols; and

incrementing a common counter state by the determined highest number of symbols when passing on to a subsequent FEC source block.

6. A method for forward error correction decoding, the method comprising:

receiving a repair stream including repair symbols relative to an enhancement layer datastream and a base layer datastream to be forward error corrected, wherein each of the enhancement layer datastream and the base layer datastream includes a plurality of symbols, and the symbols in the base layer datastream and the enhancement layer datastream are grouped together in order to form forward error correction (FEC) source blocks, wherein a repair symbol is generated based on a FEC source block using Layer-Aware Forward Error Correction, and wherein the symbols within the enhancement layer datastream and the base layer datastream have an incremental ID which is synchronized so that as to start with a common symbol ID for each FEC source block, which is equal over the base layer datastream and the enhancement layer datastream;

analyzing a signaling information within a repair symbol or linked therewith, the signaling information including;

the common symbol ID of the FEC source block based on which the repair symbol is generated, the common symbol ID equally indicating a first start symbol within the enhancement layer datastream and a second start symbol within the base layer datastream,

a first length information for a number of symbols within the enhancement layer datastream, starting with the first start symbol, that belong to the FEC source block, and

a second length information for a number of symbols within the base layer datastream, starting with the second start symbol, that belong to the FEC source block; and

collecting symbols within the base layer datastream and the enhancement layer datastream belonging to the FEC source block based on which the repair symbol is generated within which the signaling information is or with which the signaling information is linked, using the signaling information, wherein

at least one of the receiving, analyzing and collecting is implemented using an electronic circuit, a processor or a computer.

7. A non-transitory computer readable medium including a computer program for implementing a method for generating forward error correction data when being executed on a computer or signal processor, the method comprising:

receiving an enhancement layer datastream and a base layer datastream for which forward error correction data shall be generated, wherein each of the enhancement layer datastream and the base layer datastream includes a plurality of symbols;

grouping symbols in the base layer datastream and the enhancement layer datastream together in order to form forward error correction (FEC) source blocks;

using Layer-Aware Forward Error Correction (LA-FEC) to generate a repair symbol based on a FEC source block, wherein the symbols within the enhancement layer datastream and the base layer datastream have an incremental ID that is synchronized to start with a common symbol ID for each FEC source block, which is equal over the base layer datastream and the enhancement layer datastream; and

generating signaling information for a repair symbol regarding which symbols within the enhancement layer datastream and the base layer datastream belong to the FEC source block based on which the repair symbol is generated, so that the signaling information is included into the repair symbol or linked therewith and so that the signaling information includes;

the common symbol ID of the FEC source block based on which the repair symbol is generated, the common symbol ID equally indicating a first start symbol within the enhancement layer datastream and a second start symbol within the base layer datastream,

a first length information for a number of symbols within the enhancement layer datastream, starting with the first start symbol, that belong to the FEC source block, and

a second length information for a number of symbols within the base layer datastream, starting with the second start symbol, that belong to the FEC source block.

8. A non-transitory computer readable medium including a computer program for implementing a method of forward error correction decoding when being executed on a computer or signal processor, the method comprising:

receiving a repair stream including repair symbols relative to an enhancement laver datastream and a base layer datastream to be forward error corrected, wherein each of the enhancement layer datastream and the base layer datastream includes a plurality of symbols, and the symbols in the base layer datastream and the enhancement layer datastream are grouped together in order to form forward error correction (FEC) source blocks, wherein a repair symbol is generated based on a FEC source block using Layer-Aware Forward Error Correction, and wherein the symbols within the enhancement layer datastream and the base layer datastream have an incremental ID which is synchronized so that as to start with a common symbol ID for each FEC source block, which is equal over the base layer datastream and the enhancement layer datastream;

analyzing a signaling information within a repair symbol or linked therewith, the signaling information including;

the common symbol ID of the FEC source block based on which the repair symbol is generated, the common symbol ID equally indicating a first start symbol within the enhancement layer datastream and a second start symbol within the base layer datastream,

a first length information for a number of symbols within the enhancement layer datastream, starting with the first start symbol, that belong to the FEC source block, and

a second length information for a number of symbols within the base layer datastream, starting with the second start symbol, that belong to the FEC source block; and

collecting symbols within the base layer datastream and the enhancement layer datastream belonging to the FEC source block based on which the repair symbol is generated within which the signaling information is or with which the signaling information is linked, using the signaling information.