Inter-channel phase difference parameter modification

1. A device comprising:

a receiver configured to receive an encoded bitstream that includes an encoded mid channel and stereo parameters, the stereo parameters including inter-channel phase difference (IPD) parameter values and a mismatch value indicative of an amount of temporal misalignment between an encoder-side reference channel and an encoder-side target channel;

a stereo parameter adjustment unit configured to modify at least a portion of the IPD parameter values based on the mismatch value to generate modified IPD parameter values; and

an up-mixer configured to perform an up-mix operation on a decoded frequency-domain mid channel to generate a frequency-domain left channel and a frequency-domain right channel, the modified IPD parameter values applied to the decoded frequency-domain mid channel during the up-mix operation, and the decoded frequency-domain mid channel corresponding to a decoded version of the encoded mid channel.

2. The device of claim 1 , further comprising:

a mid channel decoder configured to decode the encoded mid channel to generate a decoded mid channel; and

a transform unit configured to perform a transform operation on the decoded mid channel to generate the decoded frequency-domain mid channel.

3. The device of claim 1 , further comprising:

a first inverse transform unit configured to perform a first inverse transform operation on the frequency-domain left channel to generate a time-domain left channel; and

a second inverse transform unit configured to perform a second inverse transform operation on the frequency-domain right channel to generate a time-domain right channel.

4. The device of claim 3 , further comprising:

one or more speakers configured to output at least one of a left channel or a right channel, the left channel associated with the time-domain left channel, and the right channel associated with the time-domain right channel.

5. The device of claim 4 , wherein the stereo parameters include an inter-channel time difference (ITD) parameter value as the mismatch value, and further comprising:

an inter-channel alignment unit configured to:

adjust the time-domain right channel based on the ITD parameter value to generate the right channel; or

adjust the time-domain left channel based on the ITD parameter value to generate the left channel.

6. The device of claim 5 , wherein the inter-channel alignment unit is included in the up-mixer.

7. The device of claim 1 , wherein the stereo parameter adjuster unit is configured to:

compare an absolute value of the mismatch value to a threshold; and

modify at least the portion of the IPD parameter values in response to a determination that the absolute value of the mismatch value satisfies the threshold.

8. The device of claim 1 , further comprising:

a side channel decoder configured to decode an encoded side channel to generate a decoded side channel, the encoded side channel included in the encoded bitstream; and

a second transform unit configured to perform a second transform operation on the decoded side channel to generate a decoded frequency-domain side channel.

9. The device of claim 8 , wherein the stereo parameter adjustment unit is further configured to modify the IPD parameter values based on an availability of the encoded side channel.

10. The device of claim 1 , wherein the stereo parameter adjustment unit is further configured to modify the IPD parameter values based on a bit rate associated with the encoded bitstream.

11. The device of claim 1 , wherein the stereo parameter adjustment unit is further configured to modify the IPD parameter values based on a voicing parameter, a packet loss determination associated with a previous frame, a speech/music classification, or another parameter.

12. The device of claim 1 , wherein the mismatch value indicates one of the amount of temporal misalignment in a frequency domain or the amount of temporal misalignment in a time domain.

13. The device of claim 1 , wherein the stereo parameter adjustment unit is integrated into a mobile device or a base station.

14. A method of decoding audio channels, the method comprising:

receiving, at a decoder, an encoded bitstream that includes an encoded mid channel and stereo parameters, the stereo parameters including inter-channel phase difference (IPD) parameter values and a mismatch value indicative of an amount of temporal misalignment between an encoder-side reference channel and an encoder-side target channel;

modifying at least a portion of the IPD parameter values based on the mismatch value to generate modified IPD parameter values; and

performing an up-mix operation on a decoded frequency-domain mid channel to generate a frequency-domain left channel and a frequency-domain right channel, the modified IPD parameter values applied to the decoded frequency-domain mid channel during the up-mix operation, and the decoded frequency-domain mid channel corresponding to a decoded version of the encoded mid channel.

15. The method of claim 14 , further comprising:

decoding the encoded mid channel to generate a decoded mid channel; and

performing a transform operation on the decoded mid channel to generate the decoded frequency-domain mid channel.

16. The method of claim 14 , further comprising:

performing a first inverse transform operation on the frequency-domain left channel to generate a time-domain left channel; and

performing a second inverse transform operation on the frequency-domain right channel to generate a time-domain right channel.

17. The method of claim 14 , wherein modifying at least the portion of the IPD parameter values comprises:

comparing an absolute value of the mismatch value to a threshold; and

modifying at least the portion of the IPD parameter values in response to a determination that the absolute value of the mismatch value satisfies the threshold.

18. An apparatus comprising:

means for receiving an encoded bitstream that includes an encoded mid channel and stereo parameters, the stereo parameters including inter-channel phase difference (IPD) parameter values and a mismatch value indicative of an amount of temporal misalignment between an encoder-side reference channel and an encoder-side target channel;

means for modifying at least a portion of the IPD parameter values based on the mismatch value to generate modified IPD parameter values; and

means for performing an up-mix operation on a decoded frequency-domain mid channel to generate a frequency-domain left channel and a frequency-domain right channel, the modified IPD parameter values applied to the decoded frequency-domain mid channel during the up-mix operation, and the decoded frequency-domain mid channel corresponding to a decoded version of the encoded mid channel.

19. The apparatus of claim 18 , further comprising:

means for decoding the encoded mid channel to generate a decoded mid channel; and

means for performing a transform operation on the decoded mid channel to generate the decoded frequency-domain mid channel.

20. The apparatus of claim 18 , further comprising:

means for performing a first inverse transform operation on the frequency-domain left channel to generate a time-domain left channel; and

means for performing a second inverse transform operation on the frequency-domain right channel to generate a time-domain right channel.