Method and device for the generation of a scalable data stream and method and device for decoding a scalable data stream

• US 20040049376A1
• Filed: 06/10/2003
• Published: 03/11/2004
• Est. Priority Date: 01/18/2001
• 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: Grill, Bernhard, Sperschneider, Ralph, Lutzky, Manfred, Teichmann, Bodo
• Granted Patent: US 7,454,353 B2
• Time in Patent Office: Days
• US Class Current: 704/200.1
• CPC Class Codes: G10L 19/24 Variable rate codecs, e.g. for generating different qualities using a scalable representation such as hierarchical encoding or layered encoding
• CPC Class Codes: H04L 65/1101 Session protocols

Abstract

In a method of producing a scalable data stream of at least two blocks of output data of a first coder and a block of output data of a second coder, wherein the at least two blocks of output data of the first coder together represent a current section of an input signal in the first coder, and wherein the block of output data of the second coder represents the same current section of the input signal, a determination data block for the current section of the input signal is written. In addition, the block of output data of the second coder, in the direction of transfer from a coding device to a decoding device, is written after the determination data block for the current section of the input signal. In addition, at least one block of output data of the first coder, in the direction of transfer, is written in front of the determination data block of the current section of the input signal, whereupon offset information is written into the scalable data stream indicating that the at least one block of output data of the first coder, in the direction of transfer, is in front of the determination data block. Thus a low-delay transfer and decoding of only the first scaling layer can be obtained.

Claims

1. A method of producing a scalable data stream of at least two blocks of output data of a first coder and at least one block of output data of a second coder, wherein the at least two blocks of output data of the first coder together represent a number of sample values of the input signal for the first coder which form a current section of the input signal for the first coder, and wherein the at least one block of output data of the second coder represents a number of sample values of the input signal for the second coder, wherein the number of sample values for the second coder forms a current section of the input signal for the second coder, wherein the number of sample values for the first coder and the number of sample values for the second coder is the same, and wherein the current sections for the first and the second coder are identical or shifted compared to each other by a duration, the method comprising the following steps:

writing a determination data block for the current section of the input signal for the first or the second coder;

writing a block of output data of the second coder, in the direction of transfer from a coding device to a decoding device, after the determination data block;

writing at least one block of output data of the first coder, in the direction of transfer, in front of the determination data block; and

writing offset information into the scalable data stream, indicating that the at least one block of output data of the first coder, in the direction of transfer, is in front of the determination data block.

2. The method according to claim 1, wherein the blocks of output data of the first coder are written into the scalable data stream in such a way that they are arranged in equidistant intervals, or wherein the blocks of output data of the first coder have the same length.

3. The method according to claim 1,

wherein the block of output data of the second coder for equally long sections of the input signal has different lengths,

wherein a block of output data of the first coder for the current section of the input signal for the first coder is written directly after the determination data block,

wherein at least a part of a block of output data of the second coder for a previous section of the input signal is arranged after block of output data of the first coder, and

wherein buffer information is written into the bit stream, indicating how long the output data of the second coder for the previous section of the input signal for the second coder extends after the determination data block.

4. The method according to claim 3,

wherein the second coder comprises a bit savings bank function, wherein the size of the bit savings bank is given by the maximum buffer size information, and wherein the current situation of the bit savings bank function is given by current buffer information, and

wherein the buffer information corresponds to the current buffer information so that a decoder can determine by subtracting the current buffer information from the maximum buffer information and by exclusively considering output data of the second coder where in the scalable data stream after the determination data block in the current section the block of output data of the second coder for the current section begins.

5. The method according to claim 1,

wherein the step of writing the at least one block of output data of the first coder for the current section is directly performed when the at least one block is output by the first coder,

wherein the step of writing the determination data block for the current section is only performed when the block of output data of the second coder for the current section is output by the second coder, and

wherein the step of writing the output data of the second coder is only performed when, if necessary, existing output data of the second coder for a previous section of the input signal is written into the scalable data stream when the determination data block for the current section is written and when there is presently no block of output data of the first coder for writing.

6. The method according to claim 1,

wherein more than one block of output data of the first coder for the current section of the input data is written in front of the determination data block, and

wherein the offset information indicates how many blocks of output data of the first coder for the current section of the input signal are arranged in front of the determination data block for the current section of the input signal.

7. The method according to claim 1, wherein the at least one block of output data of the second coder and the at least two blocks of output data of the first coder are the payload data in a superframe, wherein the ratio of the number of blocks of output data of the second coder and the number of blocks of output data of the first coder is smaller than one and, in particular, is one of the following ratios:

2/3, 1/2, 1/3, 1/4, 1/6, 1/12, 3/4.

8. A method of decoding a scalable data stream of at least two blocks of output data of a first coder and at least one block of output data of a second coder, wherein the at least two blocks of output data of the first coder together represent a number of sample values of the input signal for the first coder forming a current section of the input signal for the first coder, wherein the at least one block of output data of the second coder represents a number of sample values of the input signal for the second coder, wherein the number of sample values for the second coder forms a current section of the input signal for the second coder, wherein the number of sample values for the first coder and the number of sample values for the second coder is equal, and wherein the current sections for the first and second coders are identical or shifted regarding each other by a duration, wherein the scalable data stream further comprises a determination data block for the current section of the first coder or the second coder, a block of output data of the second coder after the determination data block, at least one block of output data of the first coder in front of the determination data block and offset information indicating that the at least one block of output data of the first coder, in the direction of transfer from a coding device to a decoding device, is in front of the determination data block, the method comprising the following steps:

reading the at least one block of output data of the first coder;

reading the output data of the second coder;

reading the offset information;

determining that the at least one block of output data of the first coder belongs to the output data of the second coder although the at least one block is in front of the determination data block in the data stream; and

decoding the output data of the second coder and the output data of the first coder to obtain a decoded signal.

9. A device for producing a scalable data stream of at least two blocks of output data of a first coder and at least one block of output data of a second coder, wherein the at least two blocks of output data of the first coder together represent a number of sample values of the input signal for the first coder forming a current section of the input signal for the first coder, wherein the at least one block of output data of the second coder represents a number of sample values of the input signal for the second coder, wherein the number of sample values for the second coder forms a current section of the input signal for the second coder, wherein the number of sample values for the first coder and the number of sample values for the second coder is equal, and wherein the current sections for the first and second coders are identical or shifted regarding each other by a duration, the device comprising:

data stream writing means formed to be able to perform the following steps;

writing a determination data block for the current section of the input signal for the first or the second coder;

writing a block of output data of the second coder, in the direction of transfer from a coding device to a decoding device, after the determination data block;

writing at least one block of output data of the first coder, in the direction of transfer, in front of the determination data block; and

writing offset information in the scalable data stream indicating that the at least one block of output data of the first coder, in the direction of transfer, is in front of the determination data block.

10. A device for decoding a scalable data stream of at least two blocks of output data of a first coder and at least one block of output data of a second coder, wherein the at least two blocks of output data of the first coder together represent a number of sample values of the input signal for the first coder forming a current section of the input signal for the first coder, wherein the at least one block of output data of the second coder represents a number of sample values of the input signal for the second coder, wherein the number of sample values for the second coder forms a current section of the input signal for the second coder, wherein the number of sample values for the first coder and the number of sample values for the second coder is equal, wherein the current sections for the first and second coders are identical or shifted, regarding each other, by a duration, wherein the scalable data stream further comprises a determination data block for the current section of the first coder or the second coder, a block of output data of the second coder after the determination data block, at least one block of output data of the first coder in front of the determination data block and offset information indicating that the at least one block of output data of the first coder, in the direction of transfer from a coding device to a decoding device, is in front of the determination data block, the device comprising:

data stream demultiplexing means formed in order to be able to perform the following steps;

reading the at least one block of output data of the first coder;

reading the output data of the second coder;

reading the offset information;

determining that the at least one block of output data of the first coder belongs to the output data of the second coder although the at least one block is in front of the determination data block in the data stream; and

means for decoding the output data of the second coder and the output data of the first coder to obtain a decoded signal.