Method of transmitting omnidirectional video, method of receiving omnidirectional video, device for transmitting omnidirectional video, and device for receiving omnidirectional video

1. A method of transmitting omnidirectional video, the method comprising:

acquiring an image for the omnidirectional video;

projecting the image for the omnidirectional video onto a sphere;

packing the projected image;

encoding the packed image;

encapsulating the encoded image and metadata into a media file; and

transmitting the media file,

wherein the metadata includes information representing a center position of a sphere region, information representing a shape type of the sphere region, first range information and second range information for specifying the range through the center position, and interpolate information representing whether or not the information representing the center position is linearly interpolated,

wherein when the sphere region is represented based on four great circles, the shape type information has a first value,

wherein when the sphere region is represented based on two great circles and two small circles, the shape type information has a second value,

wherein a great circle is an intersection of the sphere and a plane that passes through the center point of the sphere, and a small circle is a circle on the sphere connecting all points with a same value from a center point of the sphere,

wherein the information representing a center position that applies to a media sample are linearly interpolated based on values of the information representing the center position in a current sample and a previous sample in response to the interpolate information corresponding to a specific value,

wherein a value of the interpolate information for a sync sample is set to zero (0), and

wherein the information representing a center position includes an integer value.

2. The method of claim 1 , wherein the sphere region corresponds to a viewport.

3. The method of claim 1 , wherein a small circle is different from a great circle.

4. The method of claim 1 , wherein the center position is represented by a first coordinate value and a second coordinate value,

wherein when the sphere region is represented based on two great circles and two small circles, a boundary of the sphere region is defined by:

the two great circles having two values associated with:

the first coordinate value+value of the first range information/2, and

the first coordinate value−value of the first range information/2,

and the two small circles having two values associated with:

the second coordinate value+value of the second range information/2, and

the second coordinate value+value of the second range information/2.

5. A transmitting device for transmitting omnidirectional video, the transmitting device comprising:

a processor configured to:

acquire an image for the omnidirectional video;

project the image for the omnidirectional video onto a sphere;

pack the projected image;

encode the packed image;

encapsulate the encoded image and metadata into a media file; and

a transmitter configured to transmit the media file,

wherein the metadata includes information representing a center position of a sphere region, information representing a shape type of the sphere region, first range information and second range information for specifying the range through the center position, and interpolate information representing whether or not the information representing the center position is linearly interpolated,

wherein when the sphere region is represented based on four great circles, the shape type information has a first value,

wherein when the sphere region is represented based on two great circles and two small circles, the shape type information has a second value,

wherein a great circle is an intersection of the sphere and a plane that passes through the center point of the sphere, and a small circle is a circle on the sphere connecting all points with a same value from a center point of the sphere,

wherein the information representing a center position that applies to a media sample are linearly interpolated based on values of the information representing the center position in a current sample and a previous sample in response to the interpolate information corresponding to a specific value,

wherein a value of the interpolate information for a sync sample is set to zero (0), and

wherein the information representing a center position includes an integer value.

6. The transmitting device of claim 5 , wherein the sphere region corresponds to a viewport.

7. The transmitting device of claim 5 , wherein a small circle is different from a great circle.

8. The transmitting device of claim 5 , wherein the center position is represented by a first coordinate value and a second coordinate value,

wherein when the sphere region is represented based on two great circles and two small circles, a boundary of the sphere region is defined by:

the two great circles having two values associated with:

the first coordinate value+value of the first range information/2, and

the first coordinate value−value of the first range information/2,

and the two small circles having two values associated with:

the second coordinate value+value of the second range information/2, and

the second coordinate value+value of the second range information/2.

9. A method of receiving omnidirectional video, the method comprising:

receiving a media file comprised of an encoded image for the omnidirectional video, and metadata,

wherein the metadata includes information representing a center position of a sphere region, information representing a shape type of the sphere region, first range information and second range information for specifying the range through the center position, and interpolate information representing whether or not the information representing the center position is linearly interpolated,

wherein when the sphere region is represented based on four great circles, the shape type information has a first value,

wherein when the sphere region is represented based on two great circles and two small circles, the shape type information has a second value,

wherein a great circle is an intersection of the sphere and a plane that passes through the center point of the sphere, and a small circle is a circle on the sphere connecting all points with a same value from a center point of the sphere,

wherein the information representing a center position that applies to a media sample are linearly interpolated based on values of the information representing the center position in a current sample and a previous sample in response to the interpolate information corresponding to a specific value,

wherein a value of the interpolate information for a sync sample is set to zero (0), and

wherein the information representing a center position includes an integer value.

10. The method of claim 9 , wherein the sphere region corresponds to a viewport.

11. The method of claim 9 , wherein a small circle is different from a great circle.

12. The method of claim 9 , wherein the center position is represented by a first coordinate value and a second coordinate value,

wherein when the sphere region is represented based on two great circles and two small circles, a boundary of the sphere region is defined by:

the two great circles having two values associated with:

the first coordinate value+value of the first range information/2, and

the first coordinate value−value of the first range information/2,

and the two small circles having two values associated with:

the second coordinate value+value of the second range information/2, and

the second coordinate value+value of the second range information/2.

13. A receiving device for receiving omnidirectional video, the receiving device comprising:

a receiver configured to receive a media file comprised of an encoded image for the omnidirectional video, and metadata,

wherein the metadata includes information representing a center position of a sphere region, information representing a shape type of the sphere region, first range information and second range information for specifying the range through the center position, and interpolate information representing whether or not the information representing the center position is linearly interpolated,

wherein when the sphere region is represented based on four great circles, the shape type information has a first value,

wherein when the sphere region is represented based on two great circles and two small circles, the shape type information has a second value,

wherein a great circle is an intersection of the sphere and a plane that passes through the center point of the sphere, and a small circle is a circle on the sphere connecting all points with a same value from a center point of the sphere,

wherein the information representing a center position that applies to a media sample are linearly interpolated based on values of the information representing the center position in a current sample and a previous sample in response to the interpolate information corresponding to a specific value,

wherein a value of the interpolate information for a sync sample is set to zero (0), and

wherein the information representing a center position includes an integer value.

14. The receiving device of claim 13 , wherein the sphere region corresponds to a viewport.

15. The receiving device of claim 13 , wherein a small circle is different from a great circle.

16. The receiving device of claim 13 , wherein the center position is represented by a first coordinate value and a second coordinate value,

wherein when the sphere region is represented based on two great circles and two small circles, a boundary of the sphere region is defined by:

the two great circles having two values associated with:

the first coordinate value+value of the first range information/2, and

the first coordinate value−value of the first range information/2,

and the two small circles having two values associated with:

the second coordinate value+value of the second range information/2, and

the second coordinate value+value of the second range information/2.