Scalable audio coding

• US 20080004883A1
• Filed: 06/30/2006
• Published: 01/03/2008
• Est. Priority Date: 06/30/2006
• Status: Abandoned Application

• Current Assignee: Nokia Corporation
• Original Assignee: Nokia Corporation
• Inventors: Vilermo, Miikka, Tammi, Mikko
• Application Number:
  US11/479,994
• Publication Number:
  US 20080004883A1
• Time in Patent Office: Days
• US Class Current: 704/500
• 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

Abstract

A method and related apparatus for generating a scalable layered audio stream, whereby the method comprises: encoding an input audio signal with a low bitrate audio encoding technique to generate a base layer of a layered data stream representing the audio signal; and producing a plurality of enhancement layers into the layered data stream, at least one of the enhancement layers comprising a coded version of at least a part of the input audio signal rendering at least one of the lower layers comprising low bitrate audio encoded data redundant for decoding the audio signal.

Claims

1. A method comprising:

encoding an input audio signal with a low bitrate audio encoding technique to generate a base layer of a layered data stream representing said audio signal; and

producing a plurality of enhancement layers into said layered data stream, at least one of the enhancement layers comprising a coded version of at least a part of the input audio signal rendering at least one of the lower layers comprising low bitrate audio encoded data redundant for decoding the audio signal.

2. The method according to claim 1, further comprising:

encoding the base layer of the layered data stream as a mid channel downmix of a plurality of audio channels according to some low bitrate audio encoding technique.

3. The method according to claim 2, further comprising:

encoding at least one of the enhancement layers of the layered data stream as a side information related to said mid channel downnmix.

4. The method according to claim 2, wherein the parametric audio encoding technique is parametric stereo encoding or binaural cue coding encoding.

5. The method according to claim 1, further comprising:

encoding the base layer of the layered data stream according to a low bitrate waveform coding or a low bitrate transform coding scheme.

6. The method according to claim 1, further comprising:

encoding at least one of the enhancement layers of the layered data stream as a bandwidth extension to at least one of the lower layer signals having a bandwidth narrower than the input audio signal.

7. The method according to claim 1, further comprising:

encoding at least one of the enhancement layers comprising the coded version of at least a part of the input audio signal as a replacement for a low-frequency subband of a lower layer audio data.

8. The method according to claim 1, further comprising:

encoding at least one of the enhancement layers comprising the coded version of at least a part of the input audio signal as a replacement for the psychoacoustically most important subbands of a lower layer audio data.

9. The method according to claim 1, further comprising:

producing at least one enhancement layer into said layered data stream, which enhancement layer improves the decodable audio quality of the enhancement layer comprising the coded version of at least a part of the input audio signal.

27. An audio decoder arranged to decode at least one layer of a layered data stream encoded according to the method of claim 1.

10. An apparatus comprising:

a first encoder unit for encoding an input audio signal with a low bitrate audio encoding technique to generate a base layer of a layered data stream representing said audio signal; and

one or more second encoder units for producing a plurality of enhancement layers into said layered data stream, at least one of the enhancement layers comprising a coded version of at least a part of the input audio signal rendering at least one of the lower layers comprising low bitrate audio encoded data redundant for decoding the audio signal.

11. The apparatus according to claim 10, wherein:

the first encoder unit is configured to encode the base layer of the layered data stream as a mid channel downmix of a plurality of audio channels according to some parametric audio encoding technique.

12. The apparatus according to claim 11, further comprising:

a second encoder unit for encoding at least one of the enhancement layers of the layered data stream as a side information related to said mid channel downmix.

13. The apparatus according to claim 11, wherein the parametric audio encoding technique is parametric stereo encoding or binaural cue coding encoding.

14. The apparatus according to claim 10, wherein:

the first encoder unit is configured to encode the base layer of the layered data stream according to a low bitrate waveform coding or a low bitrate transform coding scheme.

15. The apparatus according to claim 10, further comprising:

a second encoder unit for encoding at least one of the enhancement layers of the layered data stream as a bandwidth extension to at least one of the lower layer signals having a bandwidth narrower than the input audio signal.

16. The apparatus according to claim 10, further comprising:

a second encoder unit for encoding at least one of the enhancement layers comprising the coded version of at least a part of the input audio signal as a replacement for a low-frequency subband of a lower layer audio data.

17. The apparatus according to claim 10, further comprising:

a second encoder unit for encoding at least one of the enhancement layers comprising the coded version of at least a part of the input audio signal as a replacement for the psychoacoustically most important subbands of a lower layer audio data.

18. The apparatus according to claim 10, further comprising:

a second encoder unit for producing at least one enhancement layer into said layered data stream, which enhancement layer is configured to improve the decodable audio quality of the enhancement layer comprising the coded version of at least a part of the input audio signal.

19. A computer program product, stored on a computer readable medium and executable in a data processing device, for generating a scalable layered audio stream, the computer program product comprising:

a computer program code section for encoding an input audio signal with a low bitrate audio encoding technique to generate a base layer of a layered data stream representing said audio signal; and

a computer program code section for producing a plurality of enhancement layers into said layered data stream, at least one of the enhancement layers comprising a coded version of at least a part of the input audio signal rendering at least one of the lower layers comprising low bitrate audio encoded data redundant for decoding the audio signal.

20. An audio encoder comprising:

a first encoder unit for encoding an input audio signal with a low bitrate audio encoding technique to generate a base layer of a layered data stream representing said audio signal; and

one or more second encoder units for producing a plurality of enhancement layers into said layered data stream, at least one of the enhancement layers comprising a coded version of at least a part of the input audio signal rendering at least one of the lower layers comprising low bitrate audio encoded data redundant for decoding the audio signal.

21. The audio encoder according to claim 20, wherein:

the first encoder unit is configured to encode the base layer of the layered data stream as a mid channel downmix of a plurality of audio channels according to some parametric audio encoding technique.

22. The audio encoder according to claim 21, further comprising:

a second encoder unit for encoding at least one of the enhancement layers of the layered data stream as a side information related to said mid channel downmix.

23. The audio encoder according to claim 21, wherein the parametric audio encoding technique is parametric stereo encoding or binaural cue coding encoding.

24. The audio encoder according to claim 20, wherein:

the first encoder unit is configured to encode the base layer of the layered data stream according to a low bitrate waveform coding or a low bitrate transform coding scheme.

25. A module, attachable to a data processing device and comprising an audio encoder, the audio encoder comprising:

a first encoder unit for encoding an input audio signal with a low bitrate audio encoding technique to generate a base layer of a layered data stream representing said audio signal; and

one or more second encoder units for producing a plurality of enhancement layers into said layered data stream, at least one of the enhancement layers comprising a coded version of at least a part of the input audio signal rendering at least one of the lower layers comprising low bitrate audio encoded data redundant for decoding the audio signal.

26. The module according to claim 25, wherein:

the module is implemented as a chipset.

28. An apparatus comprising:

means for encoding an input audio signal with a low bitrate audio encoding technique to generate a base layer of a layered data stream representing said audio signal; and

means for producing a plurality of enhancement layers into said layered data stream, at least one of the enhancement layers comprising a coded version of at least a part of the input audio signal rendering at least one of the lower layers comprising low bitrate audio encoded data redundant for decoding the audio signal.

29. The apparatus according to claim 28, wherein:

the means for encoding is configured to encode the base layer of the layered data stream as a mid channel downmix of a plurality of audio channels according to some parametric audio encoding technique.

30. The apparatus according to claim 29, further comprising:

means for encoding at least one of the enhancement layers of the layered data stream as a side information related to said mid channel downmix.