# US 2014/0153431 A1 · Method and device for determining a jitter buffer level > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0153431 A1 - Document ID: US20140153431A1 - Status: Published application - Kind: A1 - Application number: 14/174,916 - Filed: 2014-02-07 - Published: 2014-06-05 - Earliest claimed: 2009-09-23 - Assignees: Google Inc. - Applicants: Google Inc. - Inventors: Henrik Fahlberg Lundin; Stefan Holmer - Web page: https://patentgrep.com/patent/US20140153431A1 ## CPC - H04L 43/087: Jitter - H04L 43/0852: Delays - H04L 43/106: using time related information in packets, e.g. by adding timestamps - H04L 49/9005: using dynamic buffer space allocation - H04L 49/9023: for implementing a jitter-buffer - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract A buffer level for jitter data buffer is determined. A frame payload size difference is determined for a plurality of video frames encoded into data packets sequentially received from a network. The difference is a difference in a payload size of a current frame and a previous frame. A frame network transit delay is determined as a difference in a transport time between the current frame and the previous frame and an expected transport time between the current frame and the previous frame. A slope and a variance of a linear relationship between the frame payload size difference and the frame network transit delay are determined for the plurality of video frames. Finally, a buffer level of a jitter data buffer is determined using a maximum frame payload size, an average frame payload size, the slope and the variance. ## Claims ### Claim 1 A method, comprising: determining, using a processing unit, a frame payload size difference for a plurality of video frames encoded into data packets sequentially received from a communications network, wherein a frame payload size difference is a difference in a payload size of a current frame and a payload size of a previous frame; determining, using the processing unit, a frame network transit delay for the plurality of video frames, wherein the frame network transit delay is a difference in a transport time between the current frame and the previous frame and an expected transport time between the current frame and the previous frame; determining, using the processing unit, a slope and a variance of a linear relationship between the frame payload size difference and the frame network transit delay for at least some of the plurality of video frames; and determining a buffer level of a jitter data buffer using a maximum frame payload size, an average frame payload size, the slope and the variance, the jitter data buffer located in memory associated with the processing unit. ### Claim 2 (depends on 1) The method of claim 1, further comprising: calculating the expected transport time between the current frame and the previous frame by comparing timestamp information of the previous frame with timestamp information of the current frame. ### Claim 3 (depends on 2) The method of claim 2, further comprising: calculating the transport time between the current frame and the previous frame by comparing a measured arrival time of the current frame with a measured arrival time of the previous frame. ### Claim 4 (depends on 1) The method of claim 1, further comprising: calculating the transport time between the current frame and the previous frame by comparing a measured arrival time of the current frame with a measured arrival time of the previous frame. ### Claim 5 (depends on 1) The method of claim 1 wherein determining the slope and the variance comprises: performing an adaptive filter algorithm updated upon arrival of each frame. ### Claim 6 (depends on 1) The method of claim 1, further comprising: before determining the slope and the variance, identifying whether a frame of the plurality of frames has an absolute value of a difference between its frame network transit delay and a portion of frame network transit delay attributable to payload size variation between previous frames that exceeds a threshold value. ### Claim 7 (depends on 6) The method of claim 6, further comprising: updating the linear relationship differently based on whether or not the absolute value exceeds the threshold. ### Claim 8 (depends on 1) The method of claim 1, further comprising: sensing a discontinuous change in a parameter of the communications network, the parameter being indicative of traffic conditions in the communications network; and adjusting at least one parameter used to determine the slope and the variance of the linear relationship based on the discontinuous change. ### Claim 9 (depends on 8) The method of claim 8 wherein adjusting at least one parameter comprises resetting the at least one parameter. ### Claim 10 (depends on 1) The method of claim 1, further comprising: determining whether the current frame was transmitted earlier than the previous frame with regards to a transmission order of the plurality of frames. ### Claim 11 (depends on 10) The method of claim 10, further comprising: omitting the current frame from determining the slope and the variance of the linear relationship when the current frame was transmitted earlier with regards to the transmission order. ### Claim 12 An apparatus, comprising: memory; and a processing unit configured to execute instructions stored in the memory to: determine a frame payload size difference for a plurality of video frames encoded into data packets sequentially received from a communications network, wherein a frame payload size difference is a difference in a payload size of a current frame and a payload size of a previous frame; determine a frame network transit delay for the plurality of video frames, wherein the frame network transit delay is a difference in a transport time between the current frame and the previous frame and an expected transport time between the current frame and the previous frame; determine a slope and a variance of a linear relationship between the frame payload size difference and the frame network transit delay for the plurality of video frames; and determine a buffer level of a jitter data buffer using a maximum frame payload size, an average frame payload size, the slope and the variance, the jitter data buffer located in the memory. ### Claim 13 (depends on 12) The apparatus of claim 12 wherein the processing unit is configured to: calculate the expected transport time between the current frame and the previous frame by comparing timestamp information of the previous frame with timestamp information of the current frame. ### Claim 14 (depends on 12) The apparatus of claim 12 wherein the processing unit is configured to: calculate the transport time between the current frame and the previous frame by comparing a measured arrival time of the current frame with a measured arrival time of the previous frame. ### Claim 15 (depends on 12) The apparatus of claim 12 wherein the processing unit is configured to determine the slope and the variance by: performing an adaptive filter algorithm updated upon arrival of each frame. ### Claim 16 (depends on 12) The apparatus of claim 12 wherein the processing unit is configured to, before determining the slope and the variance, identify whether a frame of the plurality of frames has an absolute value of a difference between its frame network transit delay and a portion of frame network transit delay attributable to payload size variation between previous frames that exceeds a threshold value. ### Claim 17 (depends on 16) The apparatus of claim 16 wherein the processing unit is configured to: update the linear relationship differently based on whether or not the absolute value exceeds the threshold. ### Claim 18 (depends on 12) The apparatus of claim 12 wherein the processing unit is configured to: sense a discontinuous change in a parameter of the communications network, the parameter being indicative of traffic conditions in the communications network; and reset at least one parameter used to determine the slope and the variance of the linear relationship based on the discontinuous change. ### Claim 19 (depends on 12) The apparatus of claim 12 wherein the processing unit is configured to: determine whether the current frame was transmitted earlier that the previous frame with regards to a transmission order of the plurality of frames. ### Claim 20 (depends on 19) The apparatus of claim 19 wherein the processing unit is configured to: omit the current frame from determining the slope and the variance of the linear relationship when the current frame was transmitted earlier with regards to the transmission order.