Minimizing speech delay in communication devices
View Patent ↗Methods and apparatus for coordinating audio data processing and network communication processing in a communication device are disclosed. An exemplary method begins with demodulating a series of received communication frames, using a network communication processing circuit, to produce received encoded audio frames. An event report for each of one or more of the received encoded audio frames is generated, the event report indicating a network communication circuit processing time associated with the corresponding received encoded audio frames. The received encoded audio frames are decoded, using an audio data processing circuit, and the decoded audio is output to an audio circuit. The timing of the outputting of the decoded audio is adjusted, based on the generated event reports.
1. A method, performed in a communication device operative in a communication network, for coordinating audio data processing and network communication processing within the communication device, the method comprising:
receiving a first communication frame from the network;
demodulating a the first received communication frame, using a network communication processing circuit in the communication device, to produce a first received encoded audio frame;
generating a first event report for the first received encoded audio frame, the event report indicating a network communication circuit processing time indicating a duration spent processing the first received encoded audio frame in the network communication processing circuit in the communication device;
decoding the first received encoded audio frame using an audio data processing circuit in the communication device, and outputting the decoded audio to an audio circuit in the communication device; and
adjusting a timing of the outputting of the decoded audio to the audio circuit based on the first generated event report.
2. The method of claim 1 , wherein the first event report for the first received encoded audio frame comprises all or a part of the encoded audio data for the corresponding encoded audio frame.
3. The method of claim 1 , further comprising receiving and processing a second a communication frame, and generating a second event report indicating the time spent processing the second received encoded audio frame in the network communication processing circuit in the communication device, wherein adjusting the timing of the outputting of the decoded audio comprises determining, based on the first and second generated event reports, that a timing drift has occurred, and adjusting the outputting of the decoded audio based on the timing drift to compensate for at least a portion of the timing drift.
4. The method of claim 1 , wherein said adjusting comprises calculating a start time for outputting the first frame of the decoded audio based on a frame duration, a maximum network communication circuit processing time, and a network communication circuit processing time corresponding to the first received encoded audio frame.
5. The method of claim 1 , wherein the first event report further indicates a maximum network communication circuit processing time indicating a maximum allowable time that the network communication processing circuit in the communication device should spend processing the first received encoded audio frame.
6. The method of claim 1 , wherein the first event report further indicates a network-related delivery delay relative to a reference delivery schedule having a constant intra-delivery interval, and wherein said adjusting the timing of the outputting of the decoded audio is further based on the network-related delivery delay.
7. The method of claim 6 , wherein the network-related delivery delay comprises a delay resulting from systematic variances in radio access network timing, or a delay resulting from one or more retransmissions of audio data, or both.
8. The method of claim 6 , wherein the first event report comprises a delay parameter indicating the sum of the network-related delivery delay and network communication circuit processing time.
9. The method of claim 6 , further comprising receiving and processing a second a communication frame, and generating a second event report indicating the time spent processing the second received encoded audio frame in the network communication processing circuit in the communication device, wherein said adjusting the timing of the outputting of the decoded audio comprises determining, based on the first and second generated event reports, that a timing drift has occurred, and adjusting the outputting of the decoded audio based on the timing drift.
10. The method of claim 6 wherein said adjusting comprises calculating a start time for outputting the first frame of the decoded audio based on a frame duration, a maximum delay parameter, and the delay parameter corresponding to a received encoded audio frame.
11. A communication device, comprising:
a network communication processing circuit configured to receive and demodulate a first communication frame to produce a first received encoded audio frame and to generate a first event report for the first received encoded audio frame, the first event report indicating a duration spent processing the first received encoded audio frame in the network communication processing circuit; and
an audio data processing circuit configured to decode the first received encoded audio frame and output the decoded audio to an audio circuit, and to adjust the timing of the output of the decoded audio to the audio circuit based on the first generated event report.
12. The communication device of claim 11 , wherein the first event report comprises all or a part of the encoded audio data for the corresponding frame.
13. The communication device of claim 11 , wherein the network communication processing circuit is further configured to receive and demodulate a second communication frame to produce a second received encoded audio frame and to generate a second event report indicating a duration spent processing the second received encoded audio frame in the network communication processing circuit, and wherein the audio data processing circuit is configured to adjust the timing of the outputting of the decoded audio by determining, based on the first and second generated event reports, that a timing drift has occurred, and adjusting the outputting of the decoded audio based on the timing drift to compensate for at least a portion of the timing drift.
14. The communication device of claim 11 , wherein the audio data processing circuit is configured to adjust timing of the outputting of the decoded audio by calculating a start time for outputting the first frame of the decoded audio based on a frame duration, a maximum network communication circuit processing time, and a network communication circuit processing time corresponding to the first received encoded audio frame.
15. The communication device of claim 11 , wherein the event report for the first received encoded audio frames further indicates a maximum allowable time that the network communication circuit processing circuit should spend processing the first received encoded audio frame.
16. The communication device of claim 11 , wherein the first event report further indicates a network-related delivery delay relative to a reference delivery schedule having a constant intra-delivery interval, and wherein the audio processing circuit is configured to adjust the timing of the outputting of the decoded audio based further on the network-related delivery delay.
17. The communication device of claim 16 , wherein the network-related delivery delay comprises a delay resulting from systematic variances in radio access network timing, or a delay resulting from one or more retransmissions of audio data, or both.
18. The communication device of claim 16 , wherein the first event report comprises a delay parameter indicating the sum of the network-related delivery delay and network communication circuit processing time.
19. The communication device of claim 16 , wherein the network communication processing circuit is further configured to receive and demodulate a second communication frame to produce a second received encoded audio frame and to generate a second event report indicating a duration spent processing the second received encoded audio frame in the network communication processing circuit, and wherein the audio processing circuit is configured to adjust the timing of the outputting of the decoded audio by determining, based on the first and second generated event reports, that a timing drift has occurred, and adjusting the outputting of the decoded audio based on the timing drift.
20. The communication device of claim 16 , wherein the audio processing circuit is configured to adjust the timing of the outputting of the decoded audio by calculating a start time for outputting the first frame of the decoded audio based on a frame duration, a maximum delay parameter, and the delay parameter corresponding to one or more of the received encoded audio frames.