Audio synchronization during handover

1. A method for wireless communications at a first wireless audio device, comprising:

identifying, based at least in part on communicating with a second wireless audio device, a link quality between the second wireless audio device and a host device;

initiating, based at least in part on the identified link quality, a handover interval comprising one or more extended synchronous connection-oriented (eSCO) windows;

buffering a set of one or more audio data packets during the handover interval based at least in part on the initiating;

discarding at least a first portion of the set of one or more audio data packets during the handover interval based at least in part on determining that the first portion of the set of one or more audio data packets has been transmitted to the host device by the second wireless audio device;

receiving, during an extended retransmission portion of a first eSCO window of the handover interval, a handover indication from the second wireless audio device; and

transmitting, to the host device based at least in part on the handover indication, at least a second portion of the set of one or more audio data packets during a second eSCO window that is subsequent to the handover interval.

2. The method of claim 1 , further comprising:

transmitting, based at least in part on receiving the handover indication, a handover indication response to the second wireless audio device during the extended retransmission portion of the first eSCO window, wherein transmitting the one or more audio data packets during the second eSCO window is based at least in part on the handover indication response.

3. The method of claim 1 , further comprising:

enabling microphone data for the first wireless audio device, based at least in part on initiating the handover interval, wherein buffering the set of one or more audio data packets is based at least in part on enabling the microphone data.

4. The method of claim 1 , wherein the communicating is performed over an eSCO link between the first wireless audio device and the second wireless audio device.

5. The method of claim 1 , further comprising:

timestamping, by an audio synchronization system of the first wireless audio device, each of the buffered set of one or more audio data packets;

identifying, based at least in part on the handover indication, a timestamp for a last audio data packet transmitted by the second wireless audio device to the host device; and

determining, based at least in part on the timestamping, whether one or more of the buffered set of one or more audio data packets is older than the timestamp for the last audio data packet transmitted by the second wireless audio device to the host device plus a maximum system latency.

6. The method of claim 5 , further comprising:

upon determining that one or more of the buffered set of one or more audio data packets is older than the timestamp for the last audio data packet transmitted by the second wireless audio device to the host device plus a maximum system latency, discarding the one or more of the buffered set of one or more audio data packets.

7. The method of claim 1 , further comprising:

monitoring, based at least in part on initiating the handover interval, for the handover indication during the extended retransmission portion of the first eSCO window of the handover interval, wherein receiving the handover indication is based at least in part on the monitoring.

8. The method of claim 1 , further comprising:

reverting to a default eSCO window duration that does not include an extended retransmission portion upon terminating the handover interval, wherein the default eSCO window duration is shorter than a duration of the one or more eSCO windows included in the handover interval.

9. The method of claim 1 , wherein the second eSCO window is consecutive to the first eSCO window.

10. The method of claim 1 , wherein the one or more audio data packets comprise one or more microphone data packets.

11. An apparatus for wireless communications at a first wireless audio device, comprising:

a processor,

memory in electronic communication with the processor; and

instructions stored in the memory and executable by the processor to cause the apparatus to:

identify, based at least in part on communicating with a second wireless audio device, a link quality between the second wireless audio device and a host device;

initiate, based at least in part on the identified link quality, a handover interval comprising one or more extended synchronous connection-oriented (eSCO) windows;

buffer a set of one or more audio data packets during the handover interval based at least in part on the initiating;

discard at least a first portion of the set of one or more audio data packets during the handover interval based at least in part on determining that the first portion of the set of one or more audio data packets has been transmitted to the host device by the second wireless audio device;

receive, during an extended retransmission portion of a first eSCO window of the handover interval, a handover indication from the second wireless audio device; and

transmit, to the host device based at least in part on the handover indication, at least a second portion of the set of one or more audio data packets during a second eSCO window that is subsequent to the handover interval.

12. The apparatus of claim 11 , wherein the instructions are further executable by the processor to cause the apparatus to:

transmit, based at least in part on receiving the handover indication, a handover indication response to the second wireless audio device during the extended retransmission portion of the first eSCO window, wherein transmitting the one or more audio data packets during the second eSCO window is based at least in part on the handover indication response.

13. The apparatus of claim 11 , wherein the instructions are further executable by the processor to cause the apparatus to:

enable microphone data for the first wireless audio device, based at least in part on initiating the handover interval, wherein buffering the set of one or more audio data packets is based at least in part on enabling the microphone data.

14. The apparatus of claim 11 , wherein the instructions are further executable by the processor to cause the apparatus to:

timestamp, by an audio synchronization system of the first wireless audio device, each of the buffered set of one or more audio data packets;

identify, based at least in part on the handover indication, a timestamp for a last audio data packet transmitted by the second wireless audio device to the host device; and

determine, based at least in part on the timestamping, whether one or more of the buffered set of one or more audio data packets is older than the timestamp for the last audio data packet transmitted by the second wireless audio device to the host device plus a maximum system latency.

15. The apparatus of claim 14 , wherein the instructions are further executable by the processor to cause the apparatus to:

upon determining that one or more of the buffered set of one or more audio data packets is older than the timestamp for the last audio data packet transmitted by the second wireless audio device to the host device plus a maximum system latency, discarding the one or more of the buffered set of one or more audio data packets.

16. The apparatus of claim 11 , wherein the instructions are further executable by the processor to cause the apparatus to:

monitor, based at least in part on initiating the handover interval, for the handover indication during the extended retransmission portion of the first eSCO window of the handover interval, wherein receiving the handover indication is based at least in part on the monitoring.

17. The apparatus of claim 11 , wherein the instructions are further executable by the processor to cause the apparatus to:

revert to a default eSCO window duration that does not include an extended retransmission portion upon terminating the handover interval, wherein the default eSCO window duration is shorter than a duration of the one or more eSCO windows included in the handover interval.

18. A non-transitory computer-readable medium storing code for wireless communications at a first wireless audio device, the code comprising instructions executable by a processor to:

identify, based at least in part on communicating with a second wireless audio device, a link quality between the second wireless audio device and a host device;

initiate, based at least in part on the identified link quality, a handover interval comprising one or more extended synchronous connection-oriented (eSCO) windows;

buffer a set of one or more audio data packets during the handover interval based at least in part on the initiating;

discard at least a first portion of the set of one or more audio data packets during the handover interval based at least in part on determining that the first portion of the set of one or more audio data packets has been transmitted to the host device by the second wireless audio device;

receive, during an extended retransmission portion of a first eSCO window of the handover interval, a handover indication from the second wireless audio device; and

transmit, to the host device based at least in part on the handover indication, at least a second portion of the set of one or more audio data packets during a second eSCO window that is subsequent to the handover interval.