KR102123070B1 - Video on Demand Steaming Server device and operating method thereof - Google Patents

Abstract

The present invention relates to a video on demand (VOD) content providing server device and its operation method. The VOD content providing server device according to the present invention includes a first communication circuit forming a communication channel with a transcoder providing a VOD content file, a second communication circuit forming a communication channel with a client terminal, a VOD content file, and VOD content Memory for storing Media Presentation Description (MPD) files and segment files generated according to DASH (Dynamic Adaptive Streaming over HTTP) processing of files, and a first communication circuit, a second communication circuit, and a processing unit electrically connected to the memory do. The processing unit is configured to provide a VOD list to the client, and transmit MPD files and segment files according to the client request to the client.

Description

VOD content providing server device and its operating method {Video on Demand Steaming Server device and operating method thereof}

The present invention relates to a VOD content providing server device related to content providing and a method for operating the same.

With the development of the Internet network, it is possible to transfer high-quality large-capacity media files. However, the quality of service (QoS) of the Internet network is not guaranteed for a service that provides a large amount of media content, and there is a limitation in bandwidth.

To solve this, development of various technologies capable of adaptively servicing the network environment was required, and standardization was carried out under the name of Dynamic Adaptive Streaming over HTTP (DASH) by the Moving Picture Experts Group (MPEG), an international standardization organization.

MPEG-DASH is a standard for seamlessly servicing media content to users according to the user environment (network and terminal performance, etc.).The standardized scope covered by MPEG-DASH is MPD (MPD) that describes consumption, combination, and other information of media content. Media Presentation Description) technology, Media Segmentation technology, time-based content segmentation technology, access location technology for downloading/streaming each time-divided file, file format technology supporting MPEG-DASH, MPD according to digital media consumption and storage format Profiling technology that can change the configuration is applicable.

Korean Registered Patent No. 10-1764317 (Registration on July 27, 2017)

On the other hand, even if the contents are provided based on the conventional MPEG-DASH, there is a problem in that it is difficult to provide seamless contents.

Accordingly, the present invention provides a VOD content providing server device capable of providing smooth, seamless or relatively low-delay VOD content and a method of operating the same.

According to an embodiment of the present invention, the VOD content providing server device of the present invention comprises a first communication circuit that forms a communication channel with a transcoder that provides a video on demand (VOD) content file, and a communication channel with a client terminal. 2 communication circuit, a memory for storing media presentation description (MPD) files and segment files generated according to DASH (Dynamic Adaptive Streaming over HTTP) processing of the VOD content file, the VOD content file, the first communication circuit, and the first And a processing unit electrically connected to the communication circuit and the memory, the processing unit may be configured to provide a VOD list to the client, and to transmit MPD files and segment files according to the client request to the client.

The processing unit may be configured to store the VOD content file received from the transcoder in a temporary directory, and delete the VOD content files stored in the temporary directory when DASH processing of the VOD content files is completed.

The processing unit may be configured to store pieces of media files DASH-processed for each name of the VOD content.

The processing unit may be configured to receive spatially segmented VOD content files of various resolutions that are HEVC tiled encoded from the transcoder.

The VOD content providing server device may further include an MPD cache in which the MPD file is stored, a media cache in which the segment file is stored, the DASH processed MPD file, and a VOD base directory in which the segment files are stored.

In addition, the method for operating a VOD content providing server device of the present invention includes forming a communication channel with a client terminal, providing a video on demand (VOD) list to the client, and a media presentation description (MPD) file according to the client request And transmitting segment files to the client based on a Moving Picture Experts Group-Dynamic Adaptive Streaming over HTTP (MPEG-DASH).

As described above, according to the VOD content providing server device of the present invention and an operation method thereof, the present invention can support a content providing service in a seamless or relatively low-delay manner.

1 is a view showing an example of a VOD content providing service system according to an embodiment of the present invention.
2 is a view showing an example of a VOD content providing server configuration according to an embodiment of the present invention.
3 is a view showing an example of the configuration of a receiving unit according to an embodiment of the present invention.
4 is a diagram showing an example of a VOD basic directory structure according to an embodiment of the present invention.
5 is a view showing an example of a streaming service unit according to an embodiment of the present invention.
6 is a diagram illustrating an example of an LRU cache structure according to an embodiment of the present invention.
7 is a diagram illustrating an example of a signal flow between a server and a client according to an embodiment of the present invention.

Hereinafter, various embodiments of the present invention will be described with reference to the accompanying drawings. However, this is not intended to limit the present invention to specific embodiments, and should be understood as including various modifications, equivalents, and/or alternatives of embodiments of the present invention. In connection with the description of the drawings, similar reference numerals may be used for similar elements.

1 is a view showing an example of a VOD content providing service system according to an embodiment of the present invention.

1, the VOD content providing service system 10 according to an embodiment includes a transcoder 12, a VOD content providing server 13 (or a VOD content providing server device, or a VOD content streaming server device), a client (14) (or a client terminal device).

The above-described VOD content providing service system 10 delivers the VOD content designated by the transcoder 12 to the VOD content providing server 13, and the VOD content providing server 13 performs DASHing on the received VOD content , VOD content designated according to the request of the client 14 may be provided to the client 14. In this operation, the VOD content providing server 13 may provide VOD content to the client 14 in a streaming form.

The transcoder 12 may divide the VOD media file into a plurality of spaces of the same resolution, or a plurality of spaces of different resolutions, or a specified time unit according to a specified policy and rule. The fragmented VOD media file pieces or data chunks (eg, high efficiency video coding (HEVC) tiled encoded data chunks) may be delivered to the VOD content providing server 13.

The VOD content providing server 13 performs MEPG-DASHing on the received media file fragments (or media data chunks) and provides the client 14 with designated VOD media file fragments in response to the client 14 request can do. DASH (Dynamic Adaptive Streaming over HTTP) processed (or Dashed) content may be divided into a sequence of segments based on HTTP.

As described above, the VOD content providing service system 10 processes data transmission through MPEG-DASH based on pieces of media files (or data chunks) divided according to a specified policy or rule, thereby loading data transmission. It can be reduced to support low-latency VOD content provision service or seamless VOD content provision service.

For example, the VOD content providing service system 10 may generate segmented media file fragments (MP4 Transport Segments (.m4s)) and MPD (Media Presentation Description) files by dashing the received video encoded in real time. have.

The transcoder 12 may transmit a specific VOD content to the VOD content providing server 13 by tiled encoding (HEVC) or encoding (HEVC). When performing the Tiled Encoding operation, the transcoder 12 creates the required Tiled information (MetaInfo) in the VOD content providing server 13, and transmits the created Tiled information (MetaInfo) to the media file fragments together with the VOD content providing server 13 ). The transcoder 12 may perform HEVC tiled encoding on a high quality image in real time or by VOD name. In this operation, the transcoder 12 may divide one image into specific time units and sequentially HEVC Tiled Encoding on the fragmented media file fragments and transmit it to the VOD content providing server 13. Alternatively, the transcoder 12 may divide one image into units of a predetermined size (or space), and sequentially perform HEVC tiled encoding on fragmented media file pieces to transmit to the VOD content providing server 13 . The pieces of media files that the transcoder 12 transmits to the VOD content providing server 13 include, for example, HQ (8K class HEVC Tiled Encoded High Quality Video), MQ (2K or 4K class HEVC Tiled Encoded Medium Quality Video) , FullMQ (2K or 4K class HEVC Encoded medium quality video). MetaInfo (or tiled information) may include meta information (Tile, Bitrate, FPS, bandwidth, etc.) for the HQ and MQ files described above.

The VOD content providing server 13 may perform a dashing operation on pieces of media files received from the transcoder 12. VOD content providing server 13 provides media file fragments (eg, segment files) for which dashing is performed through a VOD streaming service based on MPEG-DASH-SRD (Spatial Relationship Description) according to client 14 request can do.

The client 14 is connected to the VOD content providing server 13 based on MPEG-DASH, and may request the VOD content providing server 13 to select VOD content selected according to a user input. The client 14 may receive media file fragments (eg, MPD file and segment files) provided by the VOD content providing server 13 and output the received media file fragments.

2 is a view showing an example of a VOD content providing server configuration according to an embodiment of the present invention.

Referring to FIG. 2, the VOD content providing server 13 according to an embodiment includes a first communication circuit 110, a second communication circuit 120, a memory 140, and a processing unit 300 (eg, a controller, It may include at least one processor, or at least one processing module.

The first communication circuit 110 may form a communication channel capable of communicating with the transcoder 12. The first communication circuit 110 may include at least one of a wired communication interface or a wireless communication interface. The first communication circuit 110 may receive pieces of media files of various qualities transmitted by the transcoder 12. The first communication circuit 110 may receive MetaInfo of various quality media file pieces transmitted by the transcoder 12.

The second communication circuit 120 may form a communication channel through which the client 14 can communicate. The second communication circuit 120 may include at least one of a wired communication interface or a wireless communication interface. The second communication circuit 120 may allocate a channel according to the connection of the client 14 and receive a VOD content request signal from the client 14. The second communication circuit 120 may provide the client 14 with segmented file fragments (or segment files) and an MPD file corresponding to the VOD content request signal.

The memory 140 may store various programs or various commands necessary to operate the VOD content providing server 13. For example, the memory 140 may include at least one instruction set to receive media file fragments (eg, tiled encoded media file fragments) from the transcoder 12 based on the first communication circuit 110, transcoder. At least one instruction set to create MPD for media file fragments received from (12), at least one instruction set to perform segmentation on received media file fragments, and requesting VOD content of client 14 And at least one command set to transmit segmented file fragments in response to the received VOD content request.

The processing unit 300 may perform command processing and storage (eg, media file fragments or data chunks) related to operation of the VOD content providing server 13 and manage and transmit the data. In this regard, the processing unit 300 may include a receiving unit 301 and a streaming service unit 303. The reception unit 301 may receive media file fragments from the transcoder 12 through the first communication circuit 110 and store the received media file fragments. The streaming service unit 303 receives MPD generation and segmentation related to pieces of media files stored in the memory 140 by the receiving unit 301, and the specified MPD file and segmentation are generated in response to the request of the VOD content of the client 14 File fragments may be provided to the client 14.

At least one of the processing unit 300, the receiving unit 301, and the streaming service unit 303 may be implemented by at least one processor, or implemented by at least one software module and operated by a designated processor.

3 is a view showing an example of the configuration of a receiving unit according to an embodiment of the present invention.

Referring to FIG. 3, the receiving unit 301 according to an embodiment includes an encoding media file receiver 310 (EncodingMediaFileReceiver), a VOD handler 320 (VODHandler), a temporary directory 330 (Temp_Dir), and a dashing module 340 It may include a data manager 340 and the VOD base directory 350 (VOD_BASE_DIR).

The encoding media file receiver 310 may generate a channel related to receiving a tiled encoded media fragment file from the transcoder 12. For example, the encoding media file receiver 310 creates a socket for receiving a media fragment file from the transcoder 12, and when the socket is connected to the transcoder 12, calls a VOD handler thread, and VOD the socket. It can be delivered to the handler 320.

The VOD handler 320 may receive a media file (eg, a tile encoded file) from the transcoder 12 using a socket received from the encoding media file receiver 310. For example, the VOD handler 320 may receive MetaInfo, HQ, MQ, and FullMQ media files from the transcoder 12. The VOD handler 320 may store media files received from the transcoder 12 in a temporary directory 330. The VOD handler 320 may call the dessing module 340 of the data manager 340 when the reception of media files is completed.

When the VOD handler 320 receives the media files, the data manager 340 may generate the dashing module 340 according to the request. The desing module 340 may perform dessing processing on the received media files. The data manager 340 may store the dashed data (eg, MPD file and segment files) in the VOD base directory 350.

The VOD handler 320 may delete the original file stored in the temporary directory 330 when the desing process for the media files is completed.

The temporary directory 330 and the VOD basic directory 350 may be at least a part of the memory 140. The temporary directory 330 and the VOD base directory 350 may be resized according to the size of the received media files.

4 is a diagram illustrating an example of a structure of a desiring file system according to an embodiment of the present invention.

Referring to FIG. 4, the desinging file system structure may be a plurality of VOD_NAME directories as a sub-structure of the VOD base directory. Each VOD_NAME directory may correspond to one media file, for example. Each VOD_NAME directory may store MPD files and segment files according to the desing process.

5 is a diagram illustrating an example of a configuration of a streaming service unit of a VOD content providing server according to an embodiment of the present invention.

Referring to FIG. 5, the streaming service unit 303 may include a data manager 340, a VOD base directory 350, an MPD manager 360, a segment manager 370, and a servlet connector 380.

The data manager 340 may include a dessing module 340 and a data loader 342. Here, the desing module 340 of the data manager 340 operates as a configuration of the reception unit 301, and the data loader 342 of the data manager 340 may operate as a streaming service unit 303. The desing module 340 may perform dessing processing on the received media file fragments, and store the dashed data chunks (or media file fragments) in the VOD base directory 350. The data loader 342 may read data chunks stored in the VOD base directory 350 and transfer them to the MPD manager 360 and the segment manager 370. The VOD base directory 350 acts as a configuration of the receiving unit 301 while storing data (eg, MPD files and segment files) that have been shed during operation, and a streaming service while transmitting data to the client 14 It can operate as part 303.

The MPD manager 360 may serve to load and deliver MPD data requested from the connection handler 385 (ConnectionHandler) of the servlet connector 380. The MPD manager 360 primarily checks whether the corresponding MPD data is cached in the list of the MPD cache 361, and if there is no corresponding MPD data in the MPD cache 361, the MPD value in the VOD base directory 350 It can be read out and delivered to the servlet connector 380. After delivery of the MPD data, the MPD manager 360 may add the delivered MPD to the MPD cache 361. In this operation, the MPD manager 360 may call the data loader 342 of the data manager 340 to read the MPD data from the VOD base directory 350. The MPD cache 361 may be configured as a Key/Value type HashMap. For example, the key is {vod_name}{file_separator}{mpd file name}, and the value is the content of the MPD file and can be a Byte Array(byte[]). Here, file_separator is “\” in the Windows OS environment and “/” in the Unix or Linux environment.

The segment manager 370 may serve to load and transfer segment data (or segment file) requested from the connection handler 385 of the servlet connector 380. In this regard, the segment manager 370 primarily checks whether the corresponding segment data is cached in the cache list of the media cache 371, and if the corresponding segment data is not in the media cache 371, the VOD default directory 350 ) To read the segment value and deliver it to the servlet connector 380. The segment manager 370 reads and delivers the segment value, and then adds the segment value to the media cache 371. In this operation, the segment manager 370 may call the data loader 342 of the data manager 340 to read segment data from the VOD base directory 350. The segment cache 371 may be configured as a Key/Value type HashMap. Key is {vod_name}{file_separator}{segment file name}, Value is segment file content, and can be composed of byte array.

The servlet connector 380 may perform a role of receiving a request from the client 14 through the HTTP connection 390 and delivering a response corresponding to the request to the client 14. The servlet connector 380 may include a receiver 383 (Receiver), a transmitter 381 (Sender), and a connection handler 385 (ConnectionHandler (Thread)).

The receiver 383 and the transmitter 381 are modules that process messages received through the HTTP connection 390, such as HTTP Request and Response, and the connection handler 385 loads the desing data according to the RequestURI to sender 381 It can play a role to pass on.

Upon receiving the HTTP connection 390, the receiver 383 may generate a connection handler 385 corresponding to the connection handler thread, and deliver the HTTP Connection Servlet to the connection handler 385. After delivery of the HTTP Connection Servlet, the receiver 383 may wait to receive the next HTTP Connection.

The connection handler 385 may analyze the Request URI and request the requested MPD or segment file to the MPD manager 360 or the segment manager 370. The connection handler 385 may obtain MPD files or segment files from the MPD manager 360 or the segment manager 370, and deliver the obtained files to the transmitter 381.

The transmitter 381 may receive response information corresponding to a request from the connection handler 385 and an MPD or segment file. The transmitter 381 can deliver the received file to the client 14 that sent the request.

6 is a diagram illustrating an example of a Least Recently Used (LRU) cache structure according to an embodiment of the present invention

Referring to FIG. 6, the LRU cache structure of the MPD buffer or segment buffer may be composed of a hash map <key:String, value:byte[]>. In the MPD buffer or segment buffer, P1, P2, P3, P4, P5, and P6 corresponding to the MPD file or the segment file may be stored.

The data stored in the buffer is arranged in a LinkedList<key:String> structure in the LRU cache list, for example, according to the hashmap, P1 is N4, P2 is N2, P3 is N1, P4 is N3, and P5 is N6. , P6 may be mapped to N5. The order of mapping can be changed according to key values or value values.

7 is a diagram showing a signal flow between a VOD content providing server and a client according to an embodiment of the present invention.

Referring to FIG. 7, in connection with the signal flow between the VOD content providing server 13 and the client 14 according to an embodiment, in step 701, the client 14 sends a VOD List to the VOD content providing server 13 You can ask. For example, the client 14 may transmit the http://{ip_address}:{dash_vod_port}/GET_VOD_LIST message to the VOD content providing server 13. In response to this, the VOD content providing server 13 may generate a VOD List corresponding to the client 14 and transmit the VOD List to the client 14 in step 703. For example, the VOD content providing server 13 is {vod_name}{vod_name}… A VOD List such as {vod_name} can be delivered to the client 14.

In step 705, the client 14 may request the MPD file from the VOD content providing server 13. In this regard, the client 14 may transmit a message including http://{ip_address}:{dash_vod_port}/{vod_name}/GET_MPD to the VOD content providing server 13.

In step 707, the VOD content providing server 13 may transmit the MPD file requested by the client 14 to the client 14.

In operation 709, the client 14 may request consecutive segment files from the VOD content providing server 13. In this regard, the client 14 may transmit a message including http://{ip_address}:{dash_vod_port}/vod_name/{segment_file_name} to the VOD content providing server 13.

When the VOD content providing server 13 receives a message requesting a segment file from the client 14, in step 711, the corresponding segment file may be transmitted to the client 14. Upon receiving the segment file, the client 14 may request the VOD content providing server 13 to request the last segment file (eg, (N) Segment file) among consecutive segment files in step 713. In step 715, the VOD content providing server 13 may transmit the corresponding segment file to the client 14.

When the reception of the segment files is completed, the client may branch to step 705 according to user input or according to a scheduled process to repeatedly perform the following operations.

The embodiments disclosed in the above-described document are provided for the description and understanding of the disclosed technical content, and do not limit the scope of the present invention. Therefore, the scope of this document should be construed to include all changes or various other embodiments based on the technical spirit of the present invention.

10: VOD content provision service system
12: transcoder
13: VOD content providing server
14: client
110: first communication circuit
120: second communication circuit
140: memory
300: processing unit
301: receiver
303: streaming service department

Claims (6)

A first communication circuit forming a communication channel with a transcoder that provides a video on demand (VOD) content file;
A second communication circuit forming a communication channel with the client terminal;
A memory for storing the VOD content file, a media presentation description (MPD) file and segment files generated according to DASH (Dynamic Adaptive Streaming over HTTP) processing of the VOD content file;
And a processing unit electrically connected to the first communication circuit, the second communication circuit, and the memory.
The processing unit
It is configured to provide a VOD list to the client terminal, and transmit MPD files and segment files according to the client terminal request to the client terminal,
It is set to receive HEVC Tiled Encoded VOD content files from the transcoder based on MPD files and segment files according to the client terminal request,
The VOD content files include space-divided VOD content file fragments, and the space-divided VOD content file fragments are each encoded in a plurality of different resolutions,
The MPD file and segment files are stored in an MPD buffer or a segment buffer,
The MPD buffer or segment buffer is formed of a Least Recently Used (LRU) cache structure, and MPD files and segment files corresponding to the MPD buffer and the segment buffer are mutually provided through a hash map <key:String, value:byte[]>. VOD content providing server device characterized in that it is connected and stored by a link. According to claim 1,
The processing unit
A VOD content providing server device configured to store VOD content files received from the transcoder in a temporary directory and delete VOD content files stored in the temporary directory when DASH processing of the VOD content files is completed. According to claim 1,
The processing unit
VOD content providing server device configured to store pieces of media files that are DASH-processed by name of the VOD content. delete According to claim 1,
An MPD cache in which the MPD file is stored;
A media cache in which the segment file is stored;
A VOD base directory in which the DASH processed MPD file and the segment files are stored;
VOD content providing server device further comprising. Forming a communication channel with the client terminal;
Providing a video on demand (VOD) list to the client terminal;
Including the step of transmitting MPD (Media Presentation Description) files and segment files according to the client terminal request to the client terminal based on a Moving Picture Experts Group-Dynamic Adaptive Streaming over HTTP (MPEG-DASH);
The step of transmitting to the client terminal is
Includes; receiving the HEVC Tiled Encoded VOD content files from the transcoder based on the MPD file and segment files according to the client terminal request;
The VOD content files include space-divided VOD content file fragments, and the space-divided VOD content file fragments are each encoded in a plurality of different resolutions,
The MPD file and segment files are stored in an MPD buffer or a segment buffer,
The MPD buffer or segment buffer is formed of a Least Recently Used (LRU) cache structure, and MPD files and segment files corresponding to the MPD buffer and the segment buffer are mutually provided through a hash map <key:String, value:byte[]>. A method of operating a VOD content providing server device, characterized in that it is connected and stored by a link.

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