Video distribution system, edge server, and video distribution method

Abstract

To reduce delay in VR image distribution while keeping a quality bodily felt by a user with respect to a distributed VR image.SOLUTION: An image distribution system comprises: a server which processes an image from an image source into a virtual reality (VR) image, compression-codes the VR image with a plurality of qualities, and transmits the VR images; each edge server which from among the VR images compression-coded with the plurality of qualities and received from the server, distributes a VR image compression-coded with a quality selected according to a situation of viewing by a user; and each user device which transmits the situation of viewing by the user to the edge server and receives the VR image compression-coded with the selected quality from the edge server.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a technology that achieves low latency in video distribution while maintaining the user's quality of experience of VR video. [Background technology]

[0002] In recent years, there has been an increasing need for collaborative and remote work while being in different locations via a network. In order to provide users with a more realistic experience and a high level of immersion when performing collaborative and remote work, support for VR is required in addition to conventional 2D images. In a VR-compatible system, multiple users simultaneously share the same VR space via a network. Each user views a portion of the VR space through a wired or wireless VR headset.

[0003] As a method for delivering VR video, a technology has been proposed in which VR video is encoded according to the allowable bandwidth between a server and a user device (see, for example, Non-Patent Document 1). VR video is divided into multiple quality levels, compression-encoded according to the quality level, and the compressed and encoded VR video that matches the allowable bandwidth between the server and the user device is delivered.

[0004] One technique proposed for dividing VR video into tiles and distributing it involves using user gaze information to compress and encode the user's viewing area at high quality and the rest at low quality before distributing the tiled video (see, for example, non-patent document 2). [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] G. He, J. Hu, H. Jiang and Y. Li, “Scalable Video Coding Based on User′s View for Real-Time Virtual Reality Applications,” in IEEE Communications Letters, vol. 22, no. 1, pp. 25-28, Jan. 2018. [Non-patent document 2] Lungaro, Pietro, et al. “Gaze-aware streaming solutions for the next generation of mobile VR experiences,” IEEE transactions on visualization and computer graphics, vol. 24, no. 4, pp-1535-1544, 2018. Summary of the Invention [Problem to be solved by the invention]

[0006] However, the resolution of VR video is increasing year by year, which leads to an increase in network traffic even if the technologies in Non-Patent Documents 1 to 3 are applied, resulting in an increase in delay in VR video distribution and a deterioration in the quality of user experience of the distributed VR video.

[0007] Therefore, in order to solve the above problem, the present disclosure aims to reduce the delay in VR video distribution while maintaining the user's quality of experience for the distributed VR video. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems, the video distribution system of the present disclosure applies a layered architecture of servers and edge servers to distribute video from video sources.

[0009] Specifically, the present disclosure provides: A server processes video from a video source into VR (Virtual Reality) video, compresses and encodes it at multiple qualities, and transmits it. An edge server that distributes VR video compressed and encoded at a quality selected from the VR video compressed and encoded at multiple qualities received from the server according to the user's viewing situation; a user device that transmits the user's viewing status to the edge server and receives VR video compressed and encoded at the selected quality from the edge server; A video distribution system comprising: is.

[0010] The present disclosure also provides: The server further divides the VR video compressed and encoded at multiple qualities into tiles and transmits the tiles to the edge server; The edge server distributes to the user device VR video of a quality selected for each tile according to the user's viewing situation from the VR video compressed and encoded at multiple qualities and divided into tiles received from the server; The user device transmits to the edge server, as the user's viewing status, a high-priority tile number extracted based on the user's line of sight information regarding the VR video. It is characterized by:

[0011] The present disclosure also provides: The edge server divides the VR video compressed and encoded at multiple qualities from the server into tiles, and distributes the VR video at a quality selected for each tile according to the user's viewing situation to the user device; The user device transmits to the edge server, as the user's viewing status, a high-priority tile number extracted based on the user's line of sight information regarding the VR video. It is characterized by:

[0012] The present disclosure also provides: The edge server selects VR video compressed and encoded at high quality for tiles with many high priorities, and selects VR video compressed and encoded at low quality for tiles with few high priorities, according to the viewing status of users from a plurality of user devices, and unicasts the VR video of the selected quality to the plurality of user devices. It is characterized by:

[0013] The present disclosure also provides: The edge server selects VR video compressed and encoded at high quality for tiles with many high priorities, and selects VR video compressed and encoded at low quality for tiles with few high priorities, according to the viewing status of users from a plurality of user devices, and multicasts the VR video of the selected quality to the plurality of user devices. It is characterized by:

[0014] The present disclosure also provides: The edge server selects VR video compressed and encoded at high quality for tiles with many high priorities and selects VR video compressed and encoded at low quality for tiles with few high priorities according to the viewing status of users from a plurality of user devices, and broadcasts the VR video of the selected quality to the plurality of user devices. It is characterized by:

[0015] The present disclosure also provides: The edge server classifies the VR images into three or more levels according to the viewing status of users from a plurality of user devices, so as to select VR images compressed and encoded at higher quality for tiles with a larger number of high priorities and VR images compressed and encoded at lower quality for tiles with fewer high priorities, divides the VR images into two levels, and distributes tiles of VR images compressed and encoded at higher quality to each user device by multicast and distributes tiles of other VR images by unicast. It is characterized by:

[0016] The present disclosure also provides: The edge server selects tiles of VR video compressed and encoded with higher quality for tiles corresponding to high-priority tile numbers received from the user device, and unicasts the tiles to the user device that transmitted the high-priority tile numbers. It is characterized by:

[0017] The present disclosure also provides: The edge server classifies the VR video tiles into three or more levels according to the viewing status of users from a plurality of user devices so as to select tiles of VR video compressed and coded at higher quality for tiles with a higher priority and tiles of VR video compressed and coded at lower quality for tiles with a lower priority, divides the VR video tiles into thirds at any level, multicasts the tiles of VR video compressed and coded at higher quality, broadcasts the tiles of VR video compressed and coded at lower quality, and unicasts the remaining tiles of VR video compressed and coded at medium quality to each user device. It is characterized by:

[0018] The present disclosure also provides: The edge server selects tiles of VR video compressed and encoded with higher quality for tiles corresponding to high-priority tile numbers received from the user device, and unicasts the tiles to the user device that transmitted the high-priority tile numbers. It is characterized by:

[0019] The present disclosure also provides: An edge server that delivers VR video compressed and encoded at a quality selected from among VR video compressed and encoded at multiple qualities depending on the user's viewing situation. is.

[0020] The present disclosure also provides: A video distribution method for distributing VR video compressed and encoded at a quality selected from VR video compressed and encoded at multiple qualities according to a user's viewing situation. is.

[0021] The above-disclosed inventions can be combined as much as possible. [Effects of the Invention]

[0022] In this way, the present disclosure can achieve low latency in video distribution while maintaining the user's quality of experience for the distributed VR video. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a diagram illustrating a configuration of a video distribution system according to the present disclosure. [Figure 2] FIG. 2 is a diagram illustrating a tile structure of the video distribution system of the present disclosure. [Figure 3] FIG. 2 is a diagram illustrating a tile structure of the video distribution system of the present disclosure. [Figure 4] 1 is a diagram illustrating a configuration of a video distribution system according to the present disclosure. [Figure 5] 1 is a diagram illustrating a configuration of a video distribution system according to the present disclosure. [Figure 6] 1 is a diagram illustrating a configuration of a video distribution system according to the present disclosure. [Figure 7] 1 is a diagram illustrating a configuration of a video distribution system according to the present disclosure. [Figure 8] 1 is a diagram illustrating a configuration of a video distribution system according to the present disclosure. [Figure 9] 1 is a diagram illustrating a configuration of a video distribution system according to the present disclosure. [Figure 10] 1 is a diagram illustrating a configuration of a video distribution system according to the present disclosure. [Figure 11] 1 is a diagram illustrating a configuration of a video distribution system according to the present disclosure. [Figure 12] 1 is a diagram illustrating a configuration of a video distribution system according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the present disclosure is not limited to the embodiments shown below. These implementation examples are merely illustrative, and the present disclosure can be implemented in various forms with various modifications and improvements based on the knowledge of those skilled in the art. Note that components with the same reference numerals in this specification and drawings indicate the same components.

[0025] (Embodiment 1) The video distribution system of this embodiment is shown in Fig. 1. The video distribution system of this embodiment includes a video source 11, a server 12, a communication network 13, an edge server 14, and a user device 15. The video distribution method will be described using Fig. 1.

[0026] The server 12 processes the video from the video source 11 into VR (Virtual Reality) video. Specifically, it performs a stitching process to join multiple videos together and a spherical mapping process. Furthermore, it compresses and encodes the VR video at multiple qualities and delivers the compressed and encoded VR video at all qualities to the edge server 14 via the communication network 13.

[0027] The edge server 14 distributes the VR video compressed and encoded at a quality selected from the VR video compressed and encoded at multiple qualities from the server 12 according to the user's viewing situation to the user device 15. The server 12 and the edge server 14 are connected via a communication network 13.

[0028] The user device 15 transmits the user's viewing status to the edge server 14, and receives the VR video compressed and encoded at the selected quality from the edge server 14. The user views the VR video via the user device 15.

[0029] In the video distribution system of this embodiment, a hierarchical architecture is applied to the distribution of VR video, in which a server 12 and an edge server 14 are provided between a video source 11 and a user device 15. This reduces the amount of data between the video source 11 and the server 12, thereby realizing low latency in video distribution. Furthermore, the user's quality of experience can be maintained even when the video is transmitted via the edge server 14.

[0030] (Embodiment 2) To enable low-latency video distribution according to the user's viewing situation, the video is divided into tiles. Figure 2 shows how 360-degree video is divided into tiles. 360-degree video (Figure 2(1)) can be divided into rows (Figure 2(2)), columns (Figure 2(3)), matrix blocks (Figure 2(4)), or a combination of these (Figure 2(5)). The tile division areas do not all have to be equal. For example, the size of the area can be changed depending on the VR video being distributed. If the viewing area is limited, the area can be made smaller.

[0031] In the following embodiments, 3 This will be explained using an example of a tile array divided into blocks of 4 rows and columns. 3 Here is an example of a tile array divided into blocks of 4 rows and columns. The tiles are assigned tile numbers t0 to t11. 。

[0032] The video distribution system of this embodiment is shown in Fig. 4. The video distribution system of this embodiment includes a video source 11, a server 12, a communication network 13, an edge server 14, and a user device 15.

[0033] The server 12 processes the video from the video source 11 into a VR (Virtual Reality) video and compresses and encodes it at a plurality of qualities. At this timeThe VR video compressed and encoded at multiple qualities is divided into tiles as shown in FIG. 3. Furthermore, the VR video divided into tiles at all qualities is transmitted to the edge server 14 via the communication network 13. In the example of FIG. 4, the VR video is compressed and encoded at, for example, five levels of quality. "5" is the highest quality and "1" is the lowest quality. The same applies to the following embodiments.

[0034] The edge server 14 distributes to the user device 15 the VR video compressed and encoded at a quality selected for each tile according to the user's viewing situation from the VR video compressed and encoded at multiple qualities received from the server 12 and divided into tiles.

[0035] The user device 15 transmits the high-priority tile number extracted based on the user's gaze information for the VR video as the viewing situation to the edge server 14. For example, a gaze detection device (not shown) extracts the tile number of the tile at which the user is looking from among the tiles of the VR video as the high-priority tile number, and the user device 15 transmits the extracted high-priority tile number to the edge server 14 as the viewing situation.

[0036] In the example of Figure 4, the edge server 14 receives high-priority tile numbers t0, t1, t4, t5 or t6, t7, t10, t11 from the user device 15, selects high-quality VR video of "5" for the tiles corresponding to the high-priority tile numbers, and selects low-quality VR video of "2" for the other tiles, and distributes them to each user device 15. The user device 15 receives VR video compressed and encoded at the quality selected for each tile. VR video encoded at low quality has a small data volume, allowing for video distribution with low delay.

[0037] A tile with a quality corresponding to a high priority selects a high-quality VR video of "5", and a tile with a quality corresponding to a low priority selects a low-quality VR video of "2". However, high quality and low quality are relative relationships; the idea is that high-priority tiles select VR video that has been compressed and encoded at a higher quality than tiles that are not high-priority.

[0038] In Figure 4, the quality of VR video is divided into five levels, but these values ​​are just an example. Also, the number of high priorities is divided into two levels, one with high priority and the other without, but it may be divided into three or more levels.

[0039] In the video distribution system of this embodiment, VR video is compressed and encoded at a quality selected from multiple qualities for each tile depending on the user's viewing situation, making it possible to deliver video with low latency while maintaining the quality of experience.

[0040] (Embodiment 3) The video distribution system of this embodiment is shown in Fig. 5. The video distribution system of this embodiment includes a video source 11, a server 12, a communication network 13, an edge server 14, and a user device 15.

[0041] The difference from the second embodiment is that it is the edge server 14, not the server 12, that divides the data into tiles.

[0042] The server 12 processes the video from the video source 11 into VR (Virtual Reality) video and compresses and encodes it at multiple levels of quality. Furthermore, the server 12 transmits all of the VR video compressed and encoded at multiple levels of quality to the edge server 14 via a communication network 13. In the example of Fig. 5, the VR video is compressed and encoded at, for example, five levels of quality.

[0043] The edge server 14 divides the VR video compressed and encoded at multiple qualities from the server 12 into tiles, and distributes the divided VR video compressed and encoded at a quality selected for each tile depending on the user's viewing situation to the user device 15.

[0044] The edge server 14 receives high-priority tile numbers t0, t1, t4, t5 or t6, t7, t10, t11 from the user device 15, selects high-quality VR video of "5" for tiles corresponding to the high-priority tile numbers, and selects low-quality VR video of "2" for other tiles, and distributes them to each user device 15. The user device 15 receives VR video compressed and encoded at the quality selected for each tile. VR video encoded at low quality has a small data volume, allowing video distribution with low delay.

[0045] 5, the edge server 14 receives high-priority tile numbers t0, t1, t4, t5 or t6, t7, t10, t11 from the user device 15, selects high-quality VR video of "5" for tiles corresponding to the high-priority tile numbers, and selects low-quality VR video for other tiles, and delivers them to each user device 15. Since the low-quality encoded VR video has a small data volume, video delivery can be performed with low delay.

[0046] A tile with a quality corresponding to a high priority selects a high-quality VR video of "5", and a tile with a quality corresponding to a low priority selects a low-quality VR video of "2". However, high quality and low quality are relative relationships; the idea is that high-priority tiles select VR video that has been compressed and encoded at a higher quality than tiles that are not high-priority.

[0047] In Figure 5, the quality of VR video is divided into five levels, but these values ​​are just an example. Also, the number of high priorities is divided into two levels, that is, whether or not there is a high priority, but it may be divided into three or more levels.

[0048] In the video distribution system of this embodiment, VR video is compressed and encoded at a quality selected from multiple qualities for each tile depending on the user's viewing situation, making it possible to deliver video with low latency while maintaining the quality of experience.

[0049] (Embodiment 4) The video distribution system of this embodiment is shown in Figures 6, 7, and 8. The video distribution system of this embodiment focuses on the edge server 14 and the user device 15 in embodiment 2 or 3, and describes the selection and distribution of tiles of VR video images consisting of multiple qualities by the edge server 14.

[0050] The multiple user devices 15 transmit high-priority tile numbers extracted based on the user's line-of-sight information to the edge server 14 as viewing situations. The edge server 14 classifies each tile into levels based on the number of high priorities, selects VR video compressed and encoded at high quality for tiles with many high priorities, and selects VR video compressed and encoded at low quality for tiles with few high priorities. The number that determines the high-priority level may be set in advance or may be changed arbitrarily.

[0051] In the examples of Figures 6, 7, and 8, tiles are divided into two levels: tiles with many high priorities and tiles with few high priorities. For tiles with many high priorities, VR video compressed and encoded at high quality at level "5" is selected, and for tiles with few high priorities, VR video compressed and encoded at low quality at level "2" is selected. As an example, the union of "high-priority tile numbers" from two user devices 15 is taken. For example, the union of high-priority tile numbers t0, t1, t4, t5 and high-priority tile numbers t4, t5, t8, t9 is t0, t1, t4, t5, t8, t9. In other words, for tiles that one of the user devices 15 has set as high priority, VR video compressed and encoded at high quality at level "5" is selected, and for tiles that neither user device 15 has set as high priority, VR video compressed and encoded at low quality at level "2" is selected.

[0052] In the examples of Figures 6, 7, and 8, the quality of VR video is divided into five levels, but these values ​​are merely examples. Also, the number of high priorities is divided into two levels, depending on whether or not there is a high priority, but it may be divided into three or more levels.

[0053] 6, the edge server 14 unicasts VR video images made up of tiles with commonly selected quality to each user device 15. Unicast distribution enables highly reliable video distribution.

[0054] Therefore, in the video distribution system of this embodiment, highly reliable, low-latency video distribution is possible by unicasting VR video of a quality selected according to the user's viewing situation.

[0055] 7, the edge server 14 multicasts VR video images made up of tiles with commonly selected quality to each user device 15. Multicast distribution reduces the amount of data, enabling low-delay video distribution.

[0056] Therefore, in the video distribution system of this embodiment, by multicasting VR video of a quality selected according to the user's viewing situation, it is possible to achieve highly reliable video distribution with less delay.

[0057] 8, the edge server 14 broadcasts VR video images made up of tiles of commonly selected quality to each user device 15. Broadcast distribution involves a small amount of data and, since there is no two-way negotiation, there is little delay.

[0058] Therefore, in the video distribution system of this embodiment, by broadcasting VR video of a quality selected according to the user's viewing situation, it is possible to achieve video distribution with even lower delay.

[0059] (Embodiment 5) The video distribution system of this embodiment is shown in Figures 9 to 12. The video distribution system of this embodiment focuses on the edge server 14 and the user device 15 in embodiment 2 or embodiment 3, and describes the selection and distribution of tiles of VR video from multiple qualities of the edge server 14.

[0060] The user device 15 transmits the high-priority tile numbers extracted based on the user's line of sight information to the edge server 14 as viewing conditions. The edge server 14 classifies each tile into levels based on the number of high priorities, and classifies them into three or more levels so that tiles with more high priorities select VR video compressed and encoded at higher quality, and tiles with fewer high priorities select VR video compressed and encoded at lower quality. The number that determines the high-priority level may be set in advance or may be changed arbitrarily.

[0061] The number of high priorities is a relative relationship, and the intention is to classify into three or more levels according to the number of high priorities. High quality or low quality is a relative relationship, and the intention is to select VR video compressed and encoded at a higher quality for tiles with a higher number of high priorities than for tiles with a lower number of high priorities. For example, when classifying into three levels according to the number of high priorities, VR video compressed and encoded at a medium quality is selected for tiles with a medium number of high priorities, VR video compressed and encoded at a higher quality than tiles with a medium number of high priorities is selected for tiles with a higher number of high priorities, and VR video compressed and encoded at a lower quality than tiles with a medium number of high priorities is selected for tiles with a lower number of high priorities.

[0062] In addition, for tiles corresponding to high-priority tile numbers received from user device 15, edge server 14 may select VR video compressed and encoded at a higher quality for user device 15 that sent the high-priority tile number, just as with tiles with a larger number of high priorities.

[0063] 9 and 10 , tiles are divided into three levels: tiles with a larger number of high priorities, tiles with a medium number of high priorities, and tiles with a smaller number of high priorities. VR video compressed and encoded at level "5" is selected for tiles with a larger number of high priorities, VR video compressed and encoded at medium quality at level "3" is selected for tiles with a medium number of high priorities, and VR video compressed and encoded at low quality at level "2" is selected for tiles with a smaller number of high priorities. As an example, the intersection and union of "high-priority tile numbers" from two user devices 15 are taken. For example, the intersection of high-priority tile numbers t0, t1, t4, t5 and high-priority tile numbers t5, t6, t9, t10 is t5, and the union of high-priority tile numbers t0, t1, t4, t5 and high-priority tile numbers t5, t6, t9, t10 is t0, t1, t4, t5, t6, t9, t10. In other words, for tile t5, which all user devices 15 have set as high priority, they select VR video compressed and encoded at high quality level "5", for tiles t0, t1, t4, t6, t9, and t10, which all user devices 15 have set as high priority, they select VR video compressed and encoded at medium quality level "3", and for the remaining tiles, which none of user devices 15 have set as high priority, they select VR video compressed and encoded at low quality level "2".

[0064] Also, as shown in FIG. 11, for tiles corresponding to high-priority tile numbers t0, t1, and t4 received from user device 15, edge server 14 may select VR video compressed and encoded at high quality for the user device that transmitted those high-priority tile numbers, and for tiles corresponding to tile numbers t6, t9, and t10, edge server 14 may select VR video compressed and encoded at high quality for the user device that transmitted those high-priority tile numbers.

[0065] In the examples of FIGS. 9 to 12, the quality of compression encoding is divided into five levels from "1" to "5", but it may also be divided into three or more levels.

[0066] In the example of Figure 9, the edge server 14 divides the selected VR video tiles into tiles of VR video compressed and coded at high quality, tiles of VR video compressed and coded at medium quality, and tiles of VR video compressed and coded at low quality, and distributes the tiles of VR video compressed and coded at high quality to the user device 15 by multicast, and distributes the other tiles, i.e., tiles of VR video compressed and coded at medium quality and tiles of VR video compressed and coded at low quality, by unicast to the user device 15. Unicast distribution enables highly reliable video distribution. Multicast distribution uses a small amount of data, enabling video distribution with low latency.

[0067] 11, for tiles of VR video corresponding to high-priority tile numbers t0, t1, and t4 received from user device 15, edge server 14 may select VR video compressed and encoded at high quality and unicast the VR video to user device 15 that transmitted the high-priority tile numbers. Similarly, for tiles of VR video corresponding to high-priority tile numbers t6, t9, and t10 received from user device 15, edge server 14 may select VR video compressed and encoded at high quality and unicast the VR video to user device 15 that transmitted the high-priority tile numbers.

[0068] Therefore, in the video distribution system of this embodiment, highly reliable, low-latency video distribution is possible by combining multicast distribution and unicast distribution with the distribution of VR video of a quality selected according to the user's viewing situation.

[0069] In the example of Figure 10, the edge server 14 divides the selected VR video tiles into three groups: tiles of VR video compressed and coded at high quality, tiles of VR video compressed and coded at medium quality, and tiles of VR video compressed and coded at low quality. The edge server 14 distributes the tiles of VR video compressed and coded at high quality to the user device 15 by multicast, distributes the tiles of VR video compressed and coded at medium quality to the user device 15 by unicast, and distributes the tiles of VR video compressed and coded at low quality to the user device 15 by broadcast. Unicast distribution enables highly reliable video distribution. Multicast distribution enables video distribution with a small amount of data and low latency. Broadcast distribution reduces the amount of data and has a small latency because there is no two-way negotiation.

[0070] 12, the edge server 14 may select high-quality compressed and encoded VR video for tiles of VR video corresponding to high-priority tile numbers t0, t1, and t4 received from the user device 15, and unicast the selected VR video to the user device 15 that transmitted the high-priority tile numbers. Similarly, the edge server 14 may select high-quality compressed and encoded VR video for tiles of VR video corresponding to high-priority tile numbers t6, t9, and t10 received from the user device 15, and unicast the selected VR video to the user device 15 that transmitted the high-priority tile numbers.

[0071] Therefore, in the video distribution system of this embodiment, VR video compressed and encoded at various qualities depending on the user's viewing conditions is selected for each tile, and by combining multicast distribution, unicast distribution, and broadcast distribution, highly reliable, low-latency video distribution is possible.

[0072] As described above, according to the present disclosure, it is possible to achieve low latency in video distribution while maintaining the user's quality of experience for the distributed VR video.

[0073] The edge server of the present disclosure can also be realized by a computer and a program, and the program can be recorded on a recording medium or provided via a communication network. [Explanation of symbols]

[0074] 11:Video source 12: Server 13: Communication Network 14: Edge server 15: User device

Claims

1. A server that processes video from a video source into VR (Virtual Reality) video, compresses and encodes the video at multiple qualities, and transmits the video; an edge server that distributes VR video compressed and encoded at a quality selected from the VR video compressed and encoded at multiple qualities received from the server according to a user's viewing situation; a user device that transmits the user's viewing status to the edge server and receives VR video compressed and encoded at a selected quality from the edge server; A video distribution system comprising:

2. The VR image transmitted from the server is divided into tiles, The edge server receives the VR video compressed and encoded at multiple qualities from the server, and distributes the VR video corresponding to the tile number received from the user device from among the received VR video to the user device; The user device transmits to the edge server, as the user's viewing status, a high-priority tile number extracted based on the user's line of sight information regarding the VR video.

2. The video distribution system according to claim 1.

3. The edge server receives VR video compressed and encoded at multiple qualities from the server, divides the received VR video into tiles, and distributes the VR video of the tile number received from the user device to the user device; The user device transmits to the edge server, as the user's viewing status, a high-priority tile number extracted based on the user's line of sight information regarding the VR video.

2. The video distribution system according to claim 1.

4. The edge server selects VR video compressed and encoded at high quality for tiles with many high priorities according to the viewing status of users from a plurality of user devices, and selects VR video compressed and encoded at low quality for tiles with few high priorities, and unicasts the VR video of the selected quality to the plurality of user devices.

4. The video distribution system according to claim 2 or 3.

5. The edge server selects VR video compressed and encoded at high quality for tiles with many high priorities according to the viewing status of users from a plurality of user devices, and selects VR video compressed and encoded at low quality for tiles with few high priorities, and multicasts the VR video of the selected quality to the plurality of user devices.

4. The video distribution system according to claim 2 or 3.

6. The edge server selects VR video compressed and encoded at high quality for tiles with many high priorities according to the viewing status of users from a plurality of user devices, and selects VR video compressed and encoded at low quality for tiles with few high priorities, and broadcasts the VR video of the selected quality to the plurality of user devices.

4. The video distribution system according to claim 2 or 3.

7. The edge server classifies the VR images into three or more levels according to the viewing status of users from a plurality of user devices, selecting VR images compressed and encoded at higher quality for tiles with a larger number of high priorities and VR images compressed and encoded at lower quality for tiles with fewer high priorities, dividing the VR images into two levels, and multicasting and distributing tiles of VR images compressed and encoded at higher quality to each user device and unicasting tiles of other VR images.

4. The video distribution system according to claim 2 or 3.

8. The edge server selects tiles of VR video compressed and encoded with higher quality for tiles corresponding to high-priority tile numbers received from the user device, and unicasts the tiles to the user device that transmitted the high-priority tile numbers.

8. The video distribution system according to claim 7.

9. The edge server classifies the VR video tiles into three or more levels according to the viewing status of users from a plurality of user devices, so as to select tiles of VR video compressed and coded at higher quality for tiles with a higher priority and tiles of VR video compressed and coded at lower quality for tiles with a lower priority, divides the tiles into thirds at any level, and distributes the tiles of VR video compressed and coded at higher quality by multicast, distributes the tiles of VR video compressed and coded at lower quality by broadcast, and distributes the remaining tiles of VR video compressed and coded at medium quality by unicast to each user device.

4. The video distribution system according to claim 2 or 3.

10. The edge server selects tiles of VR video compressed and encoded with higher quality for tiles corresponding to high-priority tile numbers received from the user device, and unicasts the tiles to the user device that transmitted the high-priority tile numbers.

10. The video distribution system according to claim 9.

Images