Method and system for providing video stream of video conference
Provided is a method and system for providing a video stream for a video conference. A video stream providing method may include managing class information in which a resolution range for the video conference is classified into a plurality of classes; determining at least two classes in which a resolution providable from a source providing client that participates in the video conference is included among the plurality of classes, based on the class information; encoding a video stream for the video conference as a plurality of layers using a resolution set for each of the determined at least two classes; and controlling an electronic device of the source providing client to transmit the video stream encoded as the plurality of layers to a server for the video conference over a network.
1. A server for providing a video stream of a video conference over a network, the server comprising:
a memory having computer readable instructions stored thereon; and
at least one processor configured to execute the computer readable instructions to,
receive, from a source providing client connected to the video conference, an encoded video stream associated with the video conference from the source providing client, and video resolution available information including at least one layer of a plurality of layers associated with the encoded video stream of the video conference, the video resolution available information indicating a video resolution available for the source providing client to encode or decode the video stream associated with the video conference, the at least one layer of the plurality of layers corresponding to a selected video resolution being included within a video resolution range of the at least one layer,
receive, from at least one receiving client connected to the video conference, video resolution playable information associated with a video resolution playable by the at least one receiving client,
determine at least one layer of the encoded video stream to be transmitted to the at least one receiving client based on the received video resolution available information from the source providing client and the received video resolution playable information from the at least one receiving client, and
transmit the determined at least one layer of the encoded video stream to the at least one receiving client without transcoding the encoded video stream by the server.
2. The server of claim 1 , wherein the at least one layer of the plurality of layers includes:
a layer corresponding to a video resolution of the encoded video stream; and
at least one lower layer of the plurality of layers corresponding to a lower video resolution than the resolution of the encoded video stream.
3. The server of claim 1 , wherein
the encoded video stream is recorded by the source providing client based on managed class information for the video conference and hardware characteristics of the source providing client;
the class information includes the video resolution ranges for each layer of the plurality of layers; and
the selected video resolution of each of the plurality of layers includes,
a width of the video resolution of a layer n is a multiple of a width of the video resolution of a layer n−1, and
a height of the video resolution of the layer n is a multiple of a height of the video resolution of the layer n−1, wherein n denotes a natural number greater than or equal to 2.
4. The server of claim 1 , wherein the determining the at least one layer of the encoded video stream to be transmitted to the at least one receiving client includes:
parsing the encoded video stream based on the received video resolution playable information of the at least one receiving client, the parsing including identifying at least one layer of the plurality of layers of the encoded video stream that corresponds to the video resolution playable by the at least one receiving client; and
reconstructing the video stream based on the parsed video stream, the reconstructing including removing layers from the parsed video stream that are not playable by the at least one receiving client.
5. The server of claim 1 , wherein
the plurality of layers includes at least a first layer and a second layer, the second layer having a higher video resolution range than the first layer; and
the first layer and the second layer are generated based on a reference frame provided by the source providing client.
6. The server of claim 5 , wherein
the first layer and the second layer are generated using different encoding formats.
7. The server of claim 5 , wherein
the first layer is generated by downscaling the reference frame and encoding the downscaled reference frame.
8. The server of claim 5 , wherein
the second layer is generated based on encoding the reference frame and metadata associated with inter-layer prediction.
9. A non-transitory computer readable medium including computer readable instructions, which when executed by at least one processor of a server for providing a video stream of a video conference, causes the at least one processor to:
receive an encoded video stream associated with the video conference from a source providing client connected to the video conference, and video resolution available information including at least one layer of a plurality of layers associated with the encoded video stream of the video conference, the video resolution available information indicating a video resolution available for the source providing client to encode or decode the video stream associated with the video conference, the at least one layer of the plurality of layers corresponding to a selected video resolution being included within a video resolution range of the at least one layer;
receive video resolution playable information from at least one receiving client connected to the video conference, the video resolution playable information associated with a video resolution playable by the at least one receiving client;
determine at least one layer of the encoded video stream to be transmitted to the at least one receiving client based on the received video resolution available information from the source providing client and the received video resolution playable information from the at least one receiving client; and
transmit the determined at least one layer of the encoded video stream to the at least one receiving client without transcoding the encoded video stream.
10. The non-transitory computer readable medium of claim 9 , wherein the at least one layer of the plurality of layers includes:
a layer corresponding to a video resolution of the encoded video stream; and
at least one lower layer of the plurality of layers corresponding to a lower video resolution than the resolution of the encoded video stream.
11. The non-transitory computer readable medium of claim 9 , wherein
the encoded video stream is recorded by the source providing client based on managed class information for the video conference and hardware characteristics of the source providing client;
the class information includes the video resolution ranges for each layer of the plurality of layers; and
the selected video resolution of each of the plurality of layers includes,
a width of the video resolution of a layer n is a multiple of a width of the video resolution of a layer n−1, and
a height of the video resolution of the layer n is a multiple of a height of the video resolution of the layer n−1, and wherein n denotes a natural number greater than or equal to 2.
12. The non-transitory computer readable medium of claim 9 , wherein the determining the at least one layer of the encoded video stream to be transmitted to the at least one receiving client includes:
parsing the encoded video stream based on the received video resolution playable information of the plurality of layers of the encoded video stream that corresponds to the video resolution playable by the at least one receiving client; and
reconstructing the video stream based on the parsed video stream, the reconstructing including removing layers from the parsed video stream that are not playable by the at least one receiving client.
13. The non-transitory computer readable medium of claim 9 , wherein
the plurality of layers includes at least a first layer and a second layer, the second layer having a higher resolution range than the first layer; and
the first layer and the second layer are generated based on a reference frame provided by the source providing client.
14. The non-transitory computer readable medium of claim 13 , wherein
the first layer and the second layer are generated using different encoding formats.
15. The non-transitory computer readable medium of claim 13 , wherein
the first layer is generated by downscaling the reference frame and encoding the downscaled reference frame.
16. The non-transitory computer readable medium of claim 13 , wherein
the second layer is generated based on encoding the reference frame and metadata associated with inter-layer prediction.