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1. WO2007008008 - APPARATUS AND METHOD OF PROCESSING AN AUDIO SIGNAL

Note: Text based on automatic Optical Character Recognition processes. Please use the PDF version for legal matters

[CLAIMS]

1. A method of processing an audio signal, comprising:
subdividing at least one channel in a frame of the audio signal into a plurality of blocks, at least two of the blocks having different lengths, and a length of the frame being determined within a predetermined value; and
generating information indicating the subdivision of the channel into the blocks .

2. The method of claim 1, wherein the subdividing step
subdivides the channel according to a subdivision hierarchy, the subdivision hierarchy has more than one level, and each level is associated with a different block length.

3. The method of claim 2 , wherein a superordinate level of the subdivision hierarchy is associated with a block length double a block length associated with a subordinate level.

4. The method of claim 2, wherein the subdividing step
subdivides a block of the superordinate level to obtain two blocks at the subordinate level .

5. The method of claim 2, wherein if a channel has a length of N, then the subdividing step subdivides the channel into the plurality of blocks such that each block has a length of one of N/2, N/4, N/8, N/16 and N/32.

6. The method of claim 2, wherein the subdividing step
subdivides the channel into the plurality of blocks such that each block has a length equal to one of,

N/ (m1) for I = I, 2, ... p,

where N is the length of the channel, m is an integer greater than or equal to 2, and p represents a number of the levels in the subdivision hierarchy.

7. The method of claim 6, wherein m = 2 and p = 5.

8. The method of claim 2, wherein the generating step
generates the information such that a length of the
information depends on a number of levels in the subdivision hierarchy .

9. The method of claim 2, wherein the generating step
generates the information such that the information includes a number of information bits, and the information bits indicate the subdivision of the channel into the blocks.

10. The method of claim 9, wherein each information bit is associated with a level in the subdivision hierarchy and is associated with a block at the associated level, and each information bit indicates whether the associated block was subdivided.

11. The method of claim 10, wherein if the information bit has a value of 1, then the associated block is subdivided, and if the information bit has a value of 0, then the associated block is not subdivided.

12. The method of claim 1, further comprising:
sending the information.

13. The method of claim 1, further comprising:
predicting current data samples in the channel based on previous data samples, a number of the previous data samples used in the predicting step being the prediction order,- and obtaining a residual of the current data samples based on the predicted data samples .

14. The method of claim 13, wherein the predicting step progressively increases the prediction order to a desired prediction order as previous data samples become available.

15. The method of claim 14, wherein
the prediction order for an initial data sample having no previous data samples is zero, and the predicting step generates zero as the predicted initial data sample; and the obtaining step effectively does not change the
initial data sample as a result of the predicted initial data sample being zero.

16. The method of claim 14, further comprising:
determining the desired prediction order for each block based on a maximum permitted prediction order and a length of the block.

17. The method of claim 13, further comprising:
determining an optimum prediction order for each block based on a maximum permitted prediction order and a length of the block.

18. The method of claim 17, wherein the determining step comprises:
determining a global prediction order based on the maximum permitted prediction order;
determining a local prediction order based on the length of the block; and
selecting a minimum one of the global prediction order and the local prediction order as the optimum prediction order,

19. The method of claim 13, wherein if the frame is a random access frame, which is a frame to be encoded such that
previous frames are not necessary to decode the frame,
the predicting step progressively increases the
prediction order to a desired prediction order as
previous data samples from only the random access frame become available .

20. The method of claim 1, wherein the frame length is a user defined value represented by 16 bits.

21. The method of claim 1, further comprising:
adding the frame length to the audio signal as part of configuration information for the audio signal.

22. A method of encoding an audio signal, comprising:
subdividing at least one channel in a frame of the audio signal into a plurality of blocks, at least two of the blocks having different lengths and a length of the frame being determined within a predetermined value;
generating information indicating the subdivision of the channel into the blocks; and
encoding the plurality of blocks to produce a compressed bitstream that include the information.

23. A method of decoding an audio signal, comprising:
receiving an audio data frame having at least one
channel, the channel being subdivided into a plurality of blocks, at least two of the blocks having different lengths;
obtaining information from the audio signal indicating the subdivision of the channel into the blocks and a length of the frame; and
decoding the channel based on the obtained information.

24. An apparatus for encoding an audio signal, comprising:
an encoder configured to subdivide at least one channel in a frame of the audio signal into a plurality of blocks, at least two of the blocks having different lengths and a length of the frame being determined within a predetermined value, and the encoder configured to generate information indicating the subdivision of the channel into the blocks and encode the plurality of blocks to produce a compressed bitstream that include the information.

25. An apparatus for decoding an audio signal, comprising:
a decoder configured to receive an audio data frame having at least one channel, the channel being subdivided into a plurality of blocks, at least two of the blocks having different lengths, and the decoder configured to obtain information from the audio signal indicating the subdivision of the channel into the blocks and a length of the frame, and the decoder configured to decode the channel based on the obtained information.