# Patent

## Title
Interactive zooming in video conferencing

## Abstract

In a video conferencing application, a user viewing a scene can performing zooming by selecting an area in the scene, then dynamically switching a video feed of the scene to the selected area of the scene. The hardware and software of the video conferencing application can limit the video transmitted to the user to include only the selected area of the scene. Transmitting only the selected area of the scene, and excluding the non-selected area of the scene from transmission, can more efficiently use the available bandwidth of the video conferencing application.

## Background
PRIORITY APPLICATION
This application claims the benefit of priority to U.S. Provisional Patent Application Ser. No. 61/816,662, filed Apr. 26, 2013, which is incorporated herein by reference in its entirety.


TECHNICAL FIELD
Embodiments pertain to operations and communications performed by electronic devices in wireless networks. Some embodiments relate to conversational video sessions occurring over wireless networks.
BACKGROUND
In typical videoconferencing applications, two users receive live video images of each other. In many cases, a user may wish to zoom in on a particular feature that appears in the live video image of the other user. Accordingly, there exists a need for interactive zooming in a videoconferencing application.



BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates an example of an architecture for a video conferencing application.
FIG. 2 illustrates an example of a signaling scheme for a video conferencing application.
FIG. 3 illustrates a flow chart of an example of a method of operation for a video conferencing application.
FIG. 4 illustrates an example of a mobile client device on which the configurations and techniques described herein can be deployed.
FIG. 5 illustrates an example computer system that can be used as a computing platform for the computing or networking devices described herein.



DETAILED DESCRIPTION
The following description and the drawings sufficiently illustrate specific embodiments to enable those skilled in the art to practice them. Other embodiments can incorporate structural, logical, electrical, process, and other changes. Portions and features of some embodiments can be included in, or substituted for, those of other embodiments. Embodiments set forth in the claims encompass all available equivalents of those claims.
In a video conferencing application, a user viewing a scene can performing zooming by selecting an area in the scene, then dynamically switching a video feed of the scene to the selected area of the scene. The hardware and software of the video conferencing application can limit the video transmitted to the user to include only the selected area of the scene. Transmitting only the selected area of the scene, and excluding the non-selected area of the scene from transmission, can more efficiently use the available bandwidth of the video conferencing application.
FIG. 1 illustrates an example of an architecture for a video conferencing application 100. The video conferencing application 100 performs two-way video conferencing between a local user 102 and a remote user 104.
The local user 102 runs the video conferencing application 100 on a local user equipment (local UE) 106, which can include a laptop computer, a cellular telephone, or another suitable device. The local UE 106 includes a camera, which captures video of the local user 102 during operation, and a display, which displays video of the remote user 104 to the local user 102 during operation.
The remote user 104 runs video conferencing application 100 on a remote user equipment (remote UE) 108. The remote UE 108 also includes a camera, which captures video of the remote user 104 during operation, and a display, which displays video of the local user 102 to the remote user 104 during operation. Both the local UE 106 and the remote UE 108 include circuitry configured to perform two-way video conferencing via the video conferencing application 100.
The local user 102 can zoom into a particular feature or location in the field of view of the remote camera. At the local UE 106, the local user 102 can define a region of interest (ROI) 110 within a field of view at the remote UE 108. In the example of FIG. 1, the field of view of the remote camera includes the head and upper torso of the remote user 104, while the ROI 110, defined by the local user 102, includes only the head of the remote user 104. This is but one example; the local user 102 can also define other suitable ROIs within the field of view of the remote camera.
Once an ROI 110 is defined, the video conferencing application 100 can direct the remote UE 108 to capture video within the ROI 110. In some examples, the remote UE 108 captures video that includes only the ROI 110 and excludes regions outside the ROI 110, and transmits the captured video to the local UE 106. In other examples, the remote UE 108 captures video that includes the full field of view of the remote camera 108, but transmits a video that includes only the ROI 110 and excludes regions outside the ROI.
The local UE 106 receives the video from the remote UE 108, where the received video includes regions within the ROI 110 and excludes regions outside the ROI 110. The local UE 106 displays the received video on the local display.
In some examples, the local user 102 can define an ROI 110 to have an arbitrary size and location within the field of view of the remote camera. In some examples, the remote UE 108 remains stationary when the ROI 110 is defined, so that selecting an ROI 110 does not move or change the field of view of the remote camera. In some examples, the local user 102 can select a new ROI 110 at will. In some examples, the remote user 104 can also select an analogous ROI to zoom in on the local user 102.
In the example of FIG. 1, the video conferencing application 100 operates over 3GPP-based multimedia telephony services, which connect the local UE 106 and the remote UE 108 to each other and to the telephone network. This is but one example; other suitable networks can also be used.
The local UE 106 connects to the core network through a radio access network 112, a serving GPRS support node (SGSN) 114, and/or a gateway GPRS support node (GGSN) 116. The local UE 106 sends and receives data through a proxy call session control function (P-CSCF) 118. The P-CSCF sends and receives data with a serving call session control function (S-CSCF) 120. In some examples, the S-CSCF 120 can send and receive data from an application server (AS) 122, which can provide supplementary services, such as call hold/resume, call forwarding and multi-party calls, and others. The S-CSCF 120 can send and receive data from other parts of the core network. The remote UE 108 communicates similarly with its own radio access network 124, SGSN 126, GGSN 128, P-CSCF 130, S-CSCF 132, and AS 134. The S-CSCFs 120, 132 can each communicate with an interrogating CSCF (I-CSCF) 134. The I-CSCF 134 can read and write to a home subscriber server (HSS) 136 and/or a subscriber location function (SLF) 136.
Specification document 3GPP TS 26.114 describes the multimedia telephony services over IMS (MTSI) that allows delivery of advanced multimedia conversational services and content over IMS-based networks. This includes specification of media handling and interaction, which includes media control, media codecs, as well as transport of media and control data. A MTSI call uses the Call Session Control Function (CSCF) mechanisms to route control-plane signalling between the UEs involved in the call. MTSI-based transmitter UE terminal captures and records video, and transfers it to the MTSI-based receiver UE terminal over the 3GPP network, which decodes and renders the video. In MTSI, the session initiation protocol (SIP) serves as the application-layer control protocol to establish, modify, and terminate conversational multimedia sessions, such as video conferences, Internet telephony calls, and others. Session description protocol (SDP) based signaling between the sending and receiving terminals allow for offer/answer considerations in the media-related capability negotiation, including codecs, bitrates, resolutions, and others. The transport of media in MTSI is based on the real-time transport protocol (RTP) (specified by IETF RFC 3550) over UDP/IP.
The resolutions of capture devices and therefore compressed videos are rapidly increasing. For example, using the recent High Efficiency Video Coding (HEVC) standard, one can transport and store 4K content as part of an operational product. Cameras having 4 k-by-2 k resolution are now widely available. Live streaming video has been demonstrated with resolutions of 8 k-by-4 k. Resolutions, in terms of numbers of pixels, are likely to increase in the future. With these very high resolution contents, new usages in video streaming are now possible, like interactive zooming features.
The interactive zooming features enable dynamic adaptation of video in terms of bandwidth, spatial resolution, orientation, and so forth. In addition, the interactive zooming features can dynamically switch to a user-selected area in the video being streamed, and can optimize encodings for this purpose.
The device and method discussed herein proposes new media handling and session management features targeted for conversational video services toward enhancing resolutions delivered to the end user when using interactive zoom features. In particular, towards addressing the problem described above, we propose the capability to signal the information on the user's ROI from the receiving terminal to the sending terminal, e.g., as part of the RTCP feedback signaling or RTP header extension. This feature, named as ROI-based zooming (ROIZoom) can provide better image quality for the selected region than with a simple graphical zoom, since the sending device in this case can use all of the available bandwidth for encoding and transmitting the ROI, which can therefore deliver higher bitrates and quality to the receiving terminal.
FIG. 2 illustrates an example of a signaling scheme for a video conferencing application, such as the video conferencing application 100 of FIG. 1. A sending client 202 sends an offer, via session description protocol (SDP), to a receiving client 204 indicating ROI-based streaming. The receiving client 204 answers, via SDP, and accepts the ROI-based streaming. The receiving client 204 sends the ROI information to the sending client 202, such as in RTCP feedback messages or in RTP header extension for reverse-direction video streams. The sending client 202 encodes and transmits video based on the indicated ROI, potentially indicating an ROI in RTP header extension for forward-direction video streams. This is but one example; other suitable signaling schemes can also be used.
SDP-based signaling between the sending and receiving terminals allow for offer/answer considerations in the media-related capability negotiation for ROI-Zoom, e.g., 1) ability to indicate ROI in RTCP feedback and/or RTP header extension messages and 2) ability to understand/process ROI information and encode video accordingly.
An MTSI client supporting the ROI-Zoom feature can offer ROI-Zoom in SDP for all media streams containing video. ROIZoom can be offered by including the a=extmap attribute indicating the ROI-Zoom URN under the relevant media line scope. For instance, the ROI-Zoom URN can be set as:
urn:3gpp:roi-zoom.
An example of a media line that includes this URN is:
a=extmap:7 urn:3gpp:roi-zoom
In the above example of a media line, the number 7 can be replaced with any number between 1 and 14, inclusive.
The ROI-Zoom capability can be supported bi-directionally or uni-directionally depending on how clients negotiate to support the feature during SDP capability negotiations. For terminals with asymmetric capability (e.g. the ability to process ROI information but not detect/signal ROI information), the sendonly and recvonly attributes can be used. Terminals should express their capability in each direction sufficiently clearly such that signals are only sent in each direction to the extent that they both express useful information and can be processed by the recipient. ROI-Zoom includes signaling of the current ROI of the receiving user to the sender so that the sending UE can optimally encode and transmit the captured video. When ROI-Zoom is successfully negotiated, it can be signaled by the MTSI client. The signaling of the ROI-Zoom can use RTCP feedback reporting or RTP Header Extensions.
When using RTCP feedback reports, the receiving terminal includes the current ROI information of the user in the RTCP reports it is transmitting to the sending terminal. When using RTP header extensions, the receiving terminal includes the current ROI information of the user in the RTP packets it is transmitting to the sending terminal. These RTP packets carry video streams in the reverse direction, which can be used for bi-directional video communications in MTSI.
These different ROI signaling capabilities can be indicated in the SDP offer via different URNs. In some examples, one can pick one of these and use a single URN in the SDP capability negotiations. Since RTCP is not always used in video calls and can be turned off (this is also part of the SDP negotiation), it can be safest to deliver the ROI information as part of the RTP header extensions of the reverse-direction video streams for broadest support of the ROI-Zoom feature.
Two attributes can be used to define the ROI to be included in RTCP feedback reports or RTP header extensions. One attribute is position, which can specifies an upper left corner of the area covered in the original content, or can specify another suitable location. The other attribute is size, which can specify the size of the area covered in the original content in relative values. For instance, an example of position can be “0:0”, and an example of size can be “0.33:0.33”. Other suitable values can also be used.
The presence of ROI-Zoom should not impact the negotiated resolutions (based on SDP imageattr attribute) between the sending and receiving terminals. The only difference is that the sending terminal would encode only the ROI with the negotiated resolution rather than the whole captured frame, and this would lead to a higher overall resolution and better user experience than having the receiving terminal zoom in on the ROI and crop out the rest of the frame. The sending terminal can potentially indicate ROI as part of the RTP header extension in RTP packets for its forward-direction video streams.
Table 1 includes an example of an SDP offer indicating ROI-Zoom.









TABLE 1









m=video 49154 RTP/AVP 99



a=tcap:1 RTP/AVPF



a=pcfg:1 t=1



b=AS:315



b=RS:0



b=RR:2500



a=rtpmap:99 H264/90000



a=fmtp:99 packetization-mode=0; profile-level-



id=42e00c; \



sprop-parameter-sets=J0LgDJWgUH6Af1A=,KM46gA==



a=imageattr:99 send [x=320,y=240] [x=240,y=320]



recv [x=320,y=240] [x=240,y=320]



a=rtcp-fb:* trr-int 5000



a=rtcp-fb:* nack



a=rtcp-fb:* nack pli



a=rtcp-fb:* ccm fir



a=rtcp-fb:* ccm tmmbr



a=extmap:4 urn:3gpp:roi-zoom










Table 2 includes an example of an SDP answer accepting ROI-Zoom.









TABLE 2









m=video 49154 RTP/AVPF 99



a=acfg:1 t=1



b=AS:315



b=RS:0



b=RR:2500



a=rtpmap:99 H264/90000



a=fmtp:99 packetization-mode=0; profile-level-



id=42e00c; \



sprop-parameter-sets=J0LgDJWgUH6Af1A=,KM46gA==



a=imageattr:99 send [x=320,y=240] [x=240,y=320]



recv [x=320,y=240] [x=240,y=320]



a=rtcp-fb:* trr-int 5000



a=rtcp-fb:* nack



a=rtcp-fb:* nack pli



a=rtcp-fb:* ccm fir



a=rtcp-fb:* ccm tmmbr



a=extmap:4 urn:3gpp:roi-zoom










Although the preceding examples of wireless network connections were provided with specific reference to 3GPP LTE/LTE-A, IEEE 802.11, and Bluetooth communication standards, it will be understood that a variety of other WWAN, WLAN, and WPAN protocols and standards can be used in connection with the techniques described herein. These standards include, but are not limited to, other standards from 3GPP (e.g., HSPA+, UMTS), IEEE 802.16 (e.g., 802.16p), or Bluetooth (e.g., Bluetooth 4.0, or like standards defined by the Bluetooth Special Interest Group) standards families. Other applicable network configurations can be included within the scope of the presently described communication networks. It will be understood that communications on such communication networks can be facilitated using any number of personal area networks, LANs, and WANs, using any combination of wired or wireless transmission mediums.
The embodiments described above can be implemented in one or a combination of hardware, firmware, and software. Various methods or techniques, or certain aspects or portions thereof, can take the form of program code (i.e., instructions) embodied in tangible media, such as flash memory, hard drives, portable storage devices, read-only memory (ROM), random-access memory (RAM), semiconductor memory devices (e.g., Electrically Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM)), magnetic disk storage media, optical storage media, and any other machine-readable storage medium or storage device wherein, when the program code is loaded into and executed by a machine, such as a computer or networking device, the machine becomes an apparatus for practicing the various techniques.
A machine-readable storage medium or other storage device can include any non-transitory mechanism for storing information in a form readable by a machine (e.g., a computer). In the case of program code executing on programmable computers, the computing device can include a processor, a storage medium readable by the processor (including volatile and non-volatile memory and/or storage elements), at least one input device, and at least one output device. One or more programs that can implement or utilize the various techniques described herein can use an application programming interface (API), reusable controls, and the like. Such programs can be implemented in a high level procedural or object oriented programming language to communicate with a computer system. However, the program(s) can be implemented in assembly or machine language, if desired. In any case, the language can be a compiled or interpreted language, and combined with hardware implementations.
FIG. 4 illustrates an example of a mobile device 400. The mobile device 400 can be a user equipment (UE), a mobile station (MS), a mobile wireless device, a mobile communication device, a tablet, a handset, or other type of mobile wireless computing device. The mobile device 400 can include one or more antennas 408 within housing 402 that are configured to communicate with a hotspot, base station (BS), an evolved NodeB (eNodeB), or other type of WLAN or WWAN access point. The mobile device 400 can be configured to communicate using multiple wireless communication standards, including standards selected from 3GPP LTE, WiMAX, High Speed Packet Access (HSPA), Bluetooth, and Wi-Fi standard definitions. The mobile device 400 can communicate using separate antennas for each wireless communication standard or shared antennas for multiple wireless communication standards. The mobile device 400 can communicate in a WLAN, a WPAN, and/or a WWAN.
FIG. 4 also shows a microphone 420 and one or more speakers 412 that can be used for audio input and output from the mobile device 400. A display screen 404 can be a liquid crystal display (LCD) screen, or other type of display screen such as an organic light emitting diode (OLED) display. The display screen 404 can be configured as a touch screen. The touch screen can use capacitive, resistive, or another type of touch screen technology. An application processor 414 and a graphics processor 418 can be coupled to internal memory 416 to provide processing and display capabilities. A non-volatile memory port 410 can also be used to provide data input/output options to a user. The non-volatile memory port 410 can also be used to expand the memory capabilities of the mobile device 400. A keyboard 406 can be integrated with the mobile device 400 or wirelessly connected to the mobile device 400 to provide additional user input. A virtual keyboard can also be provided using the touch screen. A camera 422 located on the front (display screen) side or the rear side of the mobile device 400 can also be integrated into the housing 402 of the mobile device 400.
FIG. 5 is a block diagram illustrating an example computer system machine 500 upon which any one or more of the methodologies herein discussed can be run. Computer system machine 500 can be embodied as the local UE 106, the remote UE 108, or any other computing platform described or referred to herein. In alternative embodiments, the machine operates as a standalone device or can be connected (e.g., networked) to other machines. In a networked deployment, the machine can operate in the capacity of either a server or a client machine in server-client network environments, or it can act as a peer machine in peer-to-peer (or distributed) network environments. The machine can be a personal computer (PC) that may or may not be portable (e.g., a notebook or a netbook), a tablet, a set-top box (STB), a gaming console, a Personal Digital Assistant (PDA), a mobile telephone or smartphone, a web appliance, a network router, switch or bridge, or any machine capable of executing instructions (sequential or otherwise) that specify actions to be taken by that machine. Further, while only a single machine is illustrated, the term “machine” shall also be taken to include any collection of machines that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein.
Example computer system machine 500 includes a processor 502 (e.g., a central processing unit (CPU), a graphics processing unit (GPU) or both), a main memory 504 and a static memory 506, which communicate with each other via an interconnect 508 (e.g., a link, a bus, etc.). The computer system machine 500 can further include a video display unit 510, an alphanumeric input device 512 (e.g., a keyboard), and a user interface (UI) navigation device 514 (e.g., a mouse). In one embodiment, the video display unit 510, input device 512 and UI navigation device 514 are a touch screen display. The computer system machine 500 can additionally include a storage device 516 (e.g., a drive unit), a signal generation device 518 (e.g., a speaker), an output controller 532, a power management controller 534, and a network interface device 520 (which can include or operably communicate with one or more antennas 530, transceivers, or other wireless communications hardware), and one or more sensors 528, such as a Global Positioning Sensor (GPS) sensor, compass, location sensor, accelerometer, or other sensor.
The storage device 516 includes a machine-readable medium 522 on which is stored one or more sets of data structures and instructions 524 (e.g., software) embodying or utilized by any one or more of the methodologies or functions described herein. The instructions 524 can also reside, completely or at least partially, within the main memory 504, static memory 506, and/or within the processor 502 during execution thereof by the computer system machine 500, with the main memory 504, static memory 506, and the processor 502 also constituting machine-readable media.
While the machine-readable medium 522 is illustrated in an example embodiment to be a single medium, the term “machine-readable medium” can include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) that store the one or more instructions 524. The term “machine-readable medium” shall also be taken to include any tangible medium that is capable of storing, encoding or carrying instructions for execution by the machine and that cause the machine to perform any one or more of the methodologies of the present disclosure or that is capable of storing, encoding or carrying data structures utilized by or associated with such instructions.
The instructions 524 can further be transmitted or received over a communications network 526 using a transmission medium via the network interface device 520 utilizing any one of a number of well-known transfer protocols (e.g., HTTP). The term “transmission medium” shall be taken to include any intangible medium that is capable of storing, encoding, or carrying instructions for execution by the machine, and includes digital or analog communications signals or other intangible medium to facilitate communication of such software.
It should be understood that the functional units or capabilities described in this specification can have been referred to or labeled as components or modules, in order to more particularly emphasize their implementation independence. For example, a component or module can be implemented as a hardware circuit comprising custom very-large-scale integration (VLSI) circuits or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components. A component or module can also be implemented in programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices, or the like. Components or modules can also be implemented in software for execution by various types of processors. An identified component or module of executable code can, for instance, comprise one or more physical or logical blocks of computer instructions, which can, for instance, be organized as an object, procedure, or function. Nevertheless, the executables of an identified component or module need not be physically located together, but can comprise disparate instructions stored in different locations which, when joined logically together, comprise the component or module and achieve the stated purpose for the component or module.
Indeed, a component or module of executable code can be a single instruction, or many instructions, and can even be distributed over several different code segments, among different programs, and across several memory devices. Similarly, operational data can be identified and illustrated herein within components or modules, and can be embodied in any suitable form and organized within any suitable type of data structure. The operational data can be collected as a single data set, or can be distributed over different locations including over different storage devices, and can exist, at least partially, merely as electronic signals on a system or network. The components or modules can be passive or active, including agents operable to perform desired functions.
Additional examples of the presently described method, system, and device embodiments include the following, non-limiting configurations. Each of the following non-limiting examples can stand on its own, or can be combined in any permutation or combination with any one or more of the other examples provided below or throughout the present disclosure.
Example 1 includes the subject matter embodied by a method performed by a local user equipment (local UE) for zooming within a video conferencing application that provides two-way video communication between the local UE and a remote user equipment (remote UE), the method including: defining, at the local UE, a user-defined region of interest (ROI) within a field of view at the remote UE; directing the remote UE to capture video within the ROI; receiving, at the local UE, the captured video from the remote UE, the received video including regions within the ROI and excluding regions outside the ROI; and displaying, at the local UE, the received video.
In Example 2, the subject matter of Example 1 can optionally include the method of example 1, wherein directing the remote UE to capture video within the ROI includes indicating the ROI in RTCP feedback reports; and sending the RTCP feedback reports to the remote UE.
In Example 3, the subject matter of Example 1 can optionally include wherein directing the remote UE to capture video within the ROI includes capturing local video at the local UE; embedding the ROI in at least one RTP header extension in the captured local video; and sending the captured local video, with the embedded at least one RTP header extension, to the remote UE.
In Example 4, the subject matter of Example 3 can optionally include the at least one RTP header extension including a position and a size, the position and the size defining the ROI.
In Example 5, the subject matter of Example 4 can optionally include wherein the position includes two position values indicative of a corner position of the ROI within the field of view at the remote UE.
In Example 6, the subject matter of Example 5 can optionally include wherein the two position values are normalized to indicate relative position in two dimensions.
In Example 7, the subject matter of one or any combination of Examples 4-6 can optionally include wherein the size includes two size values indicative of a size of the ROI within the field of view at the remote UE.
In Example 8, the subject matter of Example 7 can optionally include wherein the two size values are normalized to indicate relative size in two dimensions.
In Example 9, the subject matter of one or any combination of Examples 1-8 can optionally include wherein the ROI includes a variable number of pixels; and wherein the received video has a variable refresh rate that is inversely proportional to the number of pixels in the ROI.
In Example 10, the subject matter of one or any combination of Examples 1-9 can optionally include wherein the ROI includes a fixed number of pixels; and wherein the received video has a constant refresh rate.
Example 11 includes the subject matter embodied by a user equipment (UE), including circuitry configured to perform two-way video conferencing between the UE and a remote user equipment (remote UE), the circuitry arranged to: define, at the UE, a user-defined region of interest (ROI) within a field of view at the remote UE; direct the remote UE to capture video within the ROI; receive, at the UE, the captured video from the remote UE, the received video including regions within the ROI and excluding regions outside the ROI; and display, at the UE, the received video.
In Example 12, the subject matter of Example 11 can optionally include the method of example 1, wherein directing the remote UE to capture video within the ROI includes indicating the ROI in RTCP feedback reports; and sending the RTCP feedback reports to the remote UE.
In Example 13, the subject matter of Example 11 can optionally include wherein directing the remote UE to capture video within the ROI includes capturing local video at the local UE; embedding the ROI in at least one RTP header extension in the captured local video; and sending the captured local video, with the embedded at least one RTP header extension, to the remote UE.
In Example 14, the subject matter of Example 13 can optionally include wherein the at least one RTP header extension includes a position and a size, the position and the size defining the ROI.
In Example 15, the subject matter of Example 14 can optionally include wherein the position includes two position values indicative of a corner position of the ROI within the field of view at the remote UE.
In Example 16, the subject matter of Example 15 can optionally include wherein the two position values are normalized to indicate relative position in two dimensions.
In Example 17, the subject matter of one or any combination of Examples 14-16 can optionally include wherein the size includes two size values indicative of a size of the ROI within the field of view at the remote UE.
In Example 18, the subject matter of Example 17 can optionally include wherein the two size values are normalized to indicate relative size in two dimensions.
In Example 19, the subject matter of one or any combination of Examples 11-18 can optionally include wherein the ROI includes a variable number of pixels; and wherein the received video has a variable refresh rate that is inversely proportional to the number of pixels in the ROI.
In Example 20, the subject matter of one or any combination of Examples 11-19 can optionally include wherein the ROI includes a fixed number of pixels; and wherein the received video has a constant refresh rate.
Example 21 includes the subject matter embodied by a method performed by a local user equipment (local UE) for zooming within a video conferencing application that provides two-way video communication between the local UE and a remote user equipment (remote UE), the method including defining, at the local UE, a user-defined region of interest (ROI) within a field of view at the remote UE; capturing local video at the local UE; embedding the ROI in at least one RTP header extension in the captured local video; and sending the captured local video, with the embedded at least one RTP header extension, to the remote UE, the at least one RTP header extension including a position and a size, the position and the size defining the ROI, the position including two position values indicative of a corner position of the ROI within the field of view at the remote UE, the size including two size values indicative of a size of the ROI within the field of view at the remote UE; directing the remote UE to capture video within the ROI; receiving, at the local UE, the captured video from the remote UE, the received video including regions within the ROI and excluding regions outside the ROI; and displaying, at the local UE, the received video.
The Abstract is provided to allow the reader to ascertain the nature and gist of the technical disclosure. It is submitted with the understanding that it will not be used to limit or interpret the scope or meaning of the claims. The following claims are hereby incorporated into the detailed description, with each claim standing on its own as a separate embodiment.

## Claims

1. A method performed by a local user equipment (local UE) for zooming within a video conferencing application that provides two-way video communication between the local UE and a remote user equipment (remote UE), the method comprising:
defining, at the local UE, a user-defined region of interest (ROI) within a field of view at the remote UE, without changing the field of view of the remote UE;
directing the remote UE to capture video within the ROI, without changing the field of view of the remote UE;
receiving, at the local UE, the captured video from the remote UE, the received video including regions within the ROI and excluding regions outside the ROI; and
displaying, at the local UE, the received video.

2. The method of claim 1, wherein directing the remote UE to capture video within the ROI comprises:
indicating the ROI in RTCP feedback reports; and
sending the RTCP feedback reports to the remote UE.

3. The method of claim 1, wherein directing the remote UE to capture video within the ROI comprises:
capturing local video at the local UE;
embedding the ROI in at least one RTP header extension in the captured local video; and
sending the captured local video, with the embedded at least one RTP header extension, to the remote UE.

4. The method of claim 3, wherein the at least one RTP header extension includes a position and a size, the position and the size defining the ROI.

5. The method of claim 4, wherein the position comprises two position values indicative of a corner position of the ROI within the field of view at the remote UE.

6. The method of claim 5, wherein the two position values are normalized to indicate relative position in two dimensions.

7. The method of claim 4, wherein the size comprises two size values indicative of a size of the ROI within the field of view at the remote UE.

8. The method of claim 7, wherein the two size values are normalized to indicate relative size in two dimensions.

9. The method of claim 1,
wherein the ROI includes a variable number of pixels; and
wherein the received video has a variable refresh rate that is inversely proportional to the number of pixels in the ROI.

10. The method of claim 1,
wherein the ROI includes a fixed number of pixels; and
wherein the received video has a constant refresh rate.

11. A user equipment (UE), comprising:
circuitry configured to perform two-way video conferencing between the UE and a remote user equipment (remote UE), the circuitry arranged to:
define, at the UE, a user-defined region of interest (ROI) within a field of view at the remote UE, without changing the field of view of the remote UE;
direct the remote UE to capture video within the ROI, without changing the field of view of the remote UE;
receive, at the UE, the captured video from the remote UE, the received video including regions within the ROI and excluding regions outside the ROI; and
display, at the UE, the received video.

12. The UE of claim 11, wherein directing the remote UE to capture video within the ROI comprises:
indicating the ROI in RTCP feedback reports; and
sending the RTCP feedback reports to the remote UE.

13. The UE of claim 11, wherein directing the remote UE to capture video within the ROI comprises:
capturing local video at the local UE;
embedding the ROI in at least one RTP header extension in the captured local video; and
sending the captured local video, with the embedded at least one RTP header extension, to the remote UE.

14. The UE of claim 13, wherein the at least one RTP header extension includes a position and a size, the position and the size defining the ROI.

15. The UE of claim 14, wherein the position comprises two position values indicative of a corner position of the ROI within the field of view at the remote UE.

16. The UE of claim 15, wherein the two position values are normalized to indicate relative position in two dimensions.

17. The UE of claim 14, wherein the size comprises two size values indicative of a size of the ROI within the field of view at the remote UE.

18. The UE of claim 17, wherein the two size values are normalized to indicate relative size in two dimensions.

19. The UE of claim 11,
wherein the ROI includes a variable number of pixels; and
wherein the received video has a variable refresh rate that is inversely proportional to the number of pixels in the ROI.

20. The UE of claim 11,
wherein the ROI includes a fixed number of pixels; and
wherein the received video has a constant refresh rate.

21. A method performed by a local user equipment (local UE) for zooming within a video conferencing application that provides two-way video communication between the local UE and a remote user equipment (remote UE), the method comprising:
defining, at the local UE, a user-defined region of interest (ROI) within a field of view at the remote UE;
capturing local video at the local UE;
embedding the ROI in at least one RTP header extension in the captured local video; and
sending the captured local video, with the embedded at least one RTP header extension, to the remote UE, the at least one RTP header extension including a position and a size, the position and the size defining the ROI, the position including two position values indicative of a corner position of the ROI within the field of view at the remote UE, the size including two size values indicative of a size of the ROI within the field of view at the remote UE;
directing the remote UE to capture video within the ROI;
receiving, at the local UE, the captured video from the remote UE, the received video including regions within the ROI and excluding regions outside the ROI; and

displaying, at the local UE, the received video.