Abstract: Methods, systems, and devices for audio dejittering are described. The method may include determining a mean delay applied to packets in a packet voice communication system, calculating, from the mean delay, a standard deviation for at least a subset of packets in a talk spurt, determining a target delay for the talk spurt by applying a moving average to the standard deviation, and applying the target delay to a first packet from the talk spurt.

Abstract: An apparatus includes de-jitter buffer control circuitry configured to determine an arrival delay value based on previously received audio packets, to identify a receive time of a first audio packet of a talk spurt, to determine an offset value of the first audio packet based on the receive time and the arrival delay value, and to adjust a target delay value associated with a de-jitter buffer based on the offset value. The apparatus also includes a de-jitter buffer configured to buffer the first audio packet based on the adjusted target delay value.

Abstract: Certain aspects of the present disclosure generally relate to wireless communication. In some aspects, a wireless communication device may determine that a video frame was not properly received by the wireless communication device. The wireless communication device may determine whether a reference frame is stored in a buffer of the wireless communication device based at least in part on determining that the video frame was not properly received. The wireless communication device may selectively transmit a negative acknowledgement (NACK) indication based at least in part on determining whether the reference frame is stored in the buffer. Numerous other aspects are provided.

Abstract: An apparatus includes de-jitter buffer control circuitry configured to determine an arrival delay value based on previously received audio packets, to identify a receive time of a first audio packet of a talk spurt, to determine an offset value of the first audio packet based on the receive time and the arrival delay value, and to adjust a target delay value associated with a de-jitter buffer based on the offset value. The apparatus also includes a de-jitter buffer configured to buffer the first audio packet based on the adjusted target delay value.

Abstract: A system and method for performing video telephony (VT) is disclosed. In one example, there is provided an apparatus having a transceiver configured to receive VT data and information indicating a switch from a first display to a second display from a network. The apparatus also includes a decoder operatively coupled to the transceiver and configured to decode the VT data, a memory comprising a coded picture buffer (CPB) configured to store the decoded VT data, and a processor operatively coupled to the transceiver, the decoder, and the memory. The processor is configured to, in response to receiving the information indicating a switch from a first display to a second display, instruct the transceiver to transmit a request for an I-frame to the network.

Abstract: Techniques for setting up a packet-switched video telephony (PSVT) call are described. A mobile originated (MO) device may transmit an invitation for the PSVT call to a mobile terminated (MT) device. The invitation may initiate a process to reserve and identify video and audio resources to establish the PSVT call. The MO device may determine whether the video resources are available. If the video resources are not available but audio resources are available, the MO device may instead establish the PSVT call with only an audio stream call between the MO device and the MT device. If audio resources become available ahead of video resources, the PSVT call may be established with an audio stream first and a video stream is automatically added to the call when video resources are reserved later, or the PSVT call is downgraded to a VoIP call if the video resources cannot be reserved.

Abstract: A system and method for rate-adaptation of a video telephony (VT) session is disclosed. In one example, there is provided a method that includes receiving a first information set indicative of a start of a handover of a device from a first Radio Access Technology (RAT) to a second RAT. The method further includes receiving a second information set indicative of an end of the handover. The method further includes adjusting a rate-adaptation protocol for the VT session based at least in part on the first and second information sets.

Abstract: A system and method for rate-adaptation of a video telephony (VT) session is disclosed. In one example, there is provided a method that includes receiving a first information set indicative of a start of a handover of a device from a first Radio Access Technology (RAT) to a second RAT. The method further includes receiving a second information set indicative of an end of the handover. The method further includes adjusting a rate-adaptation protocol for the VT session based at least in part on the first and second information sets.

Abstract: A system and method for performing video telephony (VT) is disclosed. In one example, there is provided an apparatus having a transceiver configured to receive VT data and information indicating a switch from a first display to a second display from a network. The apparatus also includes a decoder operatively coupled to the transceiver and configured to decode the VT data, a memory comprising a coded picture buffer (CPB) configured to store the decoded VT data, and a processor operatively coupled to the transceiver, the decoder, and the memory. The processor is configured to, in response to receiving the information indicating a switch from a first display to a second display, instruct the transceiver to transmit a request for an I-frame to the network.

Abstract: A system and method for rate-adaptation of a video telephony (VT) session is disclosed. In one example, there is provided a method that includes receiving a first information set indicative of a start of a handover of a device from a first Radio Access Technology (RAT) to a second RAT. The method further includes receiving a second information set indicative of an end of the handover. The method further includes adjusting a rate-adaptation protocol for the VT session based at least in part on the first and second information sets.

Abstract: The disclosure relates to video telephony and, more particularly, to techniques for detecting a video pause in a video telephony application. In one example of the disclosure, a method for video telephony comprises detecting, at a receiving device, that video data packets associated with a video telephony call have stopped arriving from a sending device, and determining that the sending device has paused a video portion of the video telephony call based on information contained in video control packets.

Abstract: Methods, systems, and devices are described for media synchronization. Multi-stream media processes may include media streams captured with respect to different clock rates. Multi-processor implementations may involve separate clocks associated with different media streams, such as audio and video, respectively. The separate clocks may tend to drift from one another, becoming further out of sync as time passes. Selecting a reference time of one of the processors to function as a “wall clock,” recording frame capture times with respect to the reference time, accounting for propagation delays, and transmitting frame capture times in terms of the reference time may aid in AV synchronization at a device where audio and video streams are received.

Abstract: Techniques for setting up a packet-switched video telephony (PSVT) call are described. A mobile originated (MO) device may transmit an invitation for the PSVT call to a mobile terminated (MT) device. The invitation may initiate a process to reserve and identify video and audio resources to establish the PSVT call. The MO device may determine whether the video resources are available. If the video resources are not available but audio resources are available, the MO device may instead establish the PSVT call with only an audio stream call between the MO device and the MT device. If audio resources become available ahead of video resources, the PSVT call may be established with an audio stream first and a video stream is automatically added to the call when video resources are reserved later, or the PSVT call is downgraded to a VoIP call if the video resources cannot be reserved.

Abstract: Methods, systems, and devices are described for media synchronization. Multi-stream media processes may include media streams captured with respect to different clock rates. Multi-processor implementations may involve separate clocks associated with different media streams, such as audio and video, respectively. The separate clocks may tend to drift from one another, becoming further out of sync as time passes. Selecting a reference time of one of the processors to function as a “wall clock,” recording frame capture times with respect to the reference time, accounting for propagation delays, and transmitting frame capture times in terms of the reference time may aid in AV synchronization at a device where audio and video streams are received.

Abstract: The disclosure relates to video telephony and, more particularly, to techniques for detecting a video pause in a video telephony application. In one example of the disclosure, a method for video telephony comprises detecting, at a receiving device, that video data packets associated with a video telephony call have stopped arriving from a sending device, and determining that the sending device has paused a video portion of the video telephony call based on information contained in video control packets.