Session description protocol (SDP) based signaling of camera calibration parameters
Various embodiments herein provide techniques for Session Description Protocol (SDP)-based signaling of camera calibration parameters for multiple video streams. In embodiments, a device may receive an SDP attribute to indicate that a bitstream included in a real-time transport protocol (RTP)-based media stream includes camera calibration parameters. The device may obtain the camera calibration parameters based on the SDP attribute, and process the RTP-based media stream based on the camera calibration parameters. In embodiments, the camera calibration parameters may be used to stitch together (e.g., align and/or synchronize) the multiple video streams. In embodiments, the stitched video streams may form an immersive video content (e.g., 360-degree video content). Other embodiments may be described and claimed.
1. One or more non-transitory computer-readable media (NTCRM) having instructions, stored thereon, that when executed by one or more processors cause a first device to:
receive, from a second device, a first session description protocol (SDP) attribute to indicate that a bitstream included in a real-time transport protocol (RTP)-based media stream includes camera calibration parameters;
obtain the camera calibration parameters based on the first SDP attribute;
transmit, to the second device, a second SDP attribute to acknowledge the first SDP attribute; and
process the RTP-based media stream based on the camera calibration parameters.
2. The one or more NTCRM of claim 1 , wherein the bitstream is an Advanced Video Coding (AVC) or High Efficiency Video Coding (HEVC) bitstream.
3. The one or more NTCRM of claim 1 , wherein the camera calibration parameters are included in one or more supplemental enhancement information (SEI) messages in the bitstream.
4. The one or more NTCRM of claim 1 , wherein the camera calibration parameters include one or more of: a number of cameras, or an angle, a radius, a resolution, a layout, or a position of one or more cameras.
5. The one or more NTCRM of claim 1 , wherein the camera calibration parameters include one or more intrinsic parameters.
6. The one or more NTCRM of claim 5 , wherein the intrinsic parameters include one or more of: a field of view, a principal point, an image and angular pixel resolution, a lens distortion (deviation from ideal perspective or fisheye), an image height, an image width, a center_x, a center_y, or a radius.
7. The one or more NTCRM of claim 1 , wherein the camera calibration parameters include one or more extrinsic parameters.
8. The one or more NTCRM of claim 7 , wherein the extrinsic parameters include one or more of: a rotation angle, a translation location, a center azimuth, a center elevation, a center tilt, an azimuth range, or an elevation_range.
9. The one or more NTCRM of claim 1 , wherein the instructions, when executed, are further to cause the device to:
receive a plurality of RTP streams that correspond to two-dimensional (2D) video bitstreams;
process the respective RTP streams based on corresponding camera calibration parameters; and
stitch the RTP streams to generate an immersive video production.
10. The one or more NTCRM of claim 1 , wherein the device is a media production system.
11. The one or more NTCRM of claim 10 , wherein the media production system is a teleconferencing system.
12. The one or more NTCRM of claim 1 , wherein the first SDP attribute indicates immersive media capabilities of the second device and wherein the second SDP attribute indicates an acknowledgement of receipt of the first SDP attribute by the first device.
13. The one or more NTCRM of claim 1 , wherein the RTP-based media stream is a first RTP-based media stream; and wherein the instructions are further to:
form a second RTP-based media stream based at least on the camera calibration parameters; and
transmit, to the second device, the second RTP-based media stream.