Method, Apparatus and Computer Program Product for Performing Stereo Adaptation for Audio Editing

• US 20080120114A1
• Filed: 11/20/2006
• Published: 05/22/2008
• Est. Priority Date: 11/20/2006
• Status: Abandoned Application

• Current Assignee: Nokia Corporation
• Original Assignee: Nokia Corporation
• Inventors: Ojanpera, Juha
• Application Number:
  US11/561,472
• Publication Number:
  US 20080120114A1
• Time in Patent Office: Days
• US Class Current: 704/278
• CPC Class Codes: G10L 19/008 Multichannel audio signal coding or decoding using interchannel correlation to reduce redundancy, e.g. joint-stereo, intensity-coding or matrixing
• CPC Class Codes: G10L 19/173 Transcoding, i.e. converting between two coded representations avoiding cascaded coding-decoding

Abstract

An apparatus for performing stereo adaptation for audio editing includes a stereo decorrelator configured to receive a stereo audio frame in a compressed domain. The stereo audio frame includes a first channel and a second channel. The stereo decorrelator includes a bandwidth limitation element configured to receive a user input defining a desired editing operation to be performed with respect to one of the first and second channels in the compressed domain, and to limit a bandwidth of the other of the first and second channels based on the user input.

Claims

1. A method comprising:

receiving a stereo audio frame in a compressed domain, the stereo audio frame comprising a first channel and a second channel;

receiving a user input defining a desired editing operation to be performed with respect to one of the first and second channels in the compressed domain; and

limiting a bandwidth of the other of the first and second channels based on the user input.

2. A method according to claim 1, wherein receiving the user input comprises receiving a stereo panning gain and wherein limiting the bandwidth is performed based on the stereo panning gain.

3. A method according to claim 1, further comprising performing a fast requantization on the other of the first and second channels in response to a determination that data associated with the other of the first and second channels has been encoded using M/S (Mid/Side) encoding after limiting the bandwidth.

4. A method according to claim 3, further comprising performing calculations associated with the fast requantization offline and storing results of the calculations for indexing.

5. A method according to claim 1, further comprising reducing selected quantized values in the other of the first and second channels based on the user input.

6. A method according to claim 5, further comprising performing an Intensity Stereo (IS) removal prior to reducing the selected quantized values.

7. A method according to claim 5, further comprising performing a smoothing of the selected quantized values.

8. A method according to claim 1, wherein limiting the bandwidth comprises:

determining a target bandwidth; and

mapping the target bandwidth to a selected number of spectral bands.

9. A computer program product comprising at least one computer-readable storage medium having computer-readable program code portions stored therein, the computer-readable program code portions comprising:

a first executable portion for receiving a stereo audio frame in a compressed domain, the stereo audio frame comprising a first channel and a second channel;

a second executable portion for receiving a user input defining a desired editing operation to be performed with respect to one of the first and second channels in the compressed domain; and

a third executable portion for limiting a bandwidth of the other of the first and second channels based on the user input.

10. A computer program product according to claim 9, wherein the second executable portion includes instructions for receiving a stereo panning gain and wherein limiting the bandwidth is performed based on the stereo panning gain.

11. A computer program product according to claim 9, further comprising a fourth executable portion for performing a fast requantization on the other of the first and second channels in response to a determination that data associated with the other of the first and second channels has been encoded using M/S (Mid/Side) encoding after limiting the bandwidth.

12. A computer program product according to claim 11, further comprising a fifth executable portion for performing calculations associated with the fast requantization offline and storing results of the calculations for indexing.

13. A computer program product according to claim 9, further comprising a fourth executable portion for reducing selected quantized values in the other of the first and second channels based on the user input.

14. A computer program product according to claim 13, further comprising a fifth executable portion for performing an Intensity Stereo (IS) removal prior to reducing the selected quantized values.

15. A computer program product according to claim 13, further comprising a fifth executable portion for performing a smoothing of the selected quantized values.

16. A computer program product according to claim 9, wherein the third executable portion includes instructions for:

determining a target bandwidth; and

mapping the target bandwidth to a selected number of spectral bands.

17. An apparatus comprising a stereo decorrelator configured to receive a stereo audio frame in a compressed domain, the stereo audio frame comprising a first channel and a second channel, the stereo decorrelator including a bandwidth limitation element configured to:

receive a user input defining a desired editing operation to be performed with respect to one of the first and second channels in the compressed domain; and

limit a bandwidth of the other of the first and second channels based on the user input.

18. An apparatus according to claim 17, wherein the bandwidth limitation element is configured to receive a stereo panning gain and limit the bandwidth based on the stereo panning gain.

19. An apparatus according to claim 17, wherein the decorrelator element further comprises a requantization element configured to perform a fast requantization on the other of the first and second channels in response to a determination that data associated with the other of the first and second channels has been encoded using M/S (Mid/Side) encoding.

20. An apparatus according to claim 19, wherein the requantization element is configured to perform calculations associated with the fast requantization offline and store results of the calculations for indexing.

21. An apparatus according to claim 17, wherein the decorrelator element further comprises a reducing element configured to reduce selected quantized values in the other of the first and second channels based on the user input.

22. An apparatus according to claim 21, wherein the decorrelator element further comprises an Intensity Stereo (IS) removal element configured to remove IS coding prior to reducing the selected quantized values.

23. An apparatus according to claim 21, wherein the decorrelator element further comprises a smoothing element configured to smooth the selected quantized values.

24. An apparatus according to claim 17, wherein the bandwidth limitation element is configured to:

determine a target bandwidth; and

map the target bandwidth to a selected number of spectral bands.

25. An apparatus according to claim 17, wherein the apparatus is embodied as a mobile terminal.

26. An apparatus comprising:

means for receiving a stereo audio frame in a compressed domain, the stereo audio frame comprising a first channel and a second channel;

means for receiving a user input defining a desired editing operation to be performed with respect to one of the first and second channels in the compressed domain; and

means for limiting a bandwidth of the other of the first and second channels based on the user input.