This topic describes the terms that are used in ApsaraVideo Live.
Stream ingest refers to the process of delivering the collected audio and video live streams to the live center of ApsaraVideo Live.
Stream pulling refers to the process of uploading third-party streaming URLs to the live center of ApsaraVideo Live for content delivery network (CDN) acceleration.
Streaming refers to the process of delivering live streams from the live center of ApsaraVideo Live to players for playback.
Edge ingest preferentially schedules streaming data to the optimal nodes that are nearest to users. The intelligent scheduling system of Alibaba Cloud is used to transmit the data to the live center of ApsaraVideo Live for content delivery. Supported by abundant CDN nodes with wide coverage, edge ingest ensures optimal link transmission and provides optimal uplink networks for user access. This resolves the issues of stuttering and slow stream pulling during uplink transmission.
Real-Time Streaming (RTS)
The RTS feature is developed based on ApsaraVideo Live. This feature monitors the latency during the complete live streaming process, reconstructs the CDN protocol, and optimizes the underlying technologies such as User Datagram Protocol (UDP). RTS SDK is integrated with player SDK of ApsaraVideo Live. RTS supports the playback of tens of millions of concurrent streams with a latency of milliseconds. You can use RTS to reduce latency and stuttering, and ensure instant loading and smooth playback for live streaming.
Live stream transcoding
Live streaming transcoding refers to the process of converting a video stream to another video stream. You can use transcoding to modify the parameters of original video streams, such as the encoding format, resolution, and bitrate. This enables you to play transcoded video streams on different terminals across different network environments. Transcoding enables you to adapt video streams to different network bandwidths and terminal processing capabilities. This enables you to satisfy the expectations of different users, such as low-latency playback.
The Narrowband HD™ technology optimizes video encoding based on video images, which improves the definition of videos without changing the network bandwidth. Developed based on the human vision model, the Narrowband HD™ technology reduces the bitrate of videos and delivers videos with higher definition. In addition, the Narrowband HD™ technology saves 20% to 40% of bandwidth without compromising the image quality.
Time shifting during live streaming
Time shifting during live streaming enables you to review the content of a live stream at a specific historical point in time. ApsaraVideo Live supports time shifting at a granularity accurate to the millisecond. The strong verification mode prevents a wrong timestamp of the live streaming signal source from causing dirty data and image discontinuity during time shifting.
Ingest domains are used to ingest live streams. To use ApsaraVideo Live, you must register an ingest domain, apply for an Internet Content Provider (ICP) filing, and configure the ingest domain. After you add a canonical name (CNAME) record for the ingest domain, associate the ingest domain with a streaming domain, and configure URL signing, you can use the URL generator provided by the ApsaraVideo Live console to obtain the ingest URL. The URL signing is optional.
Streaming domains are used to pull live streams. To use ApsaraVideo Live, you must register a streaming domain, apply for an ICP filing, and configure the streaming domain. After you add a CNAME record for the streaming domain, associate an ingest domain with the streaming domain, and configure URL signing, you can use the URL generator provided by the ApsaraVideo Live console to obtain the streaming URL. The URL signing is optional.
A CNAME is the domain that is assigned to you after you add a domain name for CDN in the Alibaba Cloud CDN console. The CNAME is in the format of
*.*kunlun*.com. You must add a CNAME record to the Domain Name System (DNS) server to map the domain name for CDN to
*.*kunlun*.com. After the CNAME record takes effect, ApsaraVideo Live is responsible for domain resolution. All requests that are sent to the domain name for CDN are redirected to the edge CDN nodes of ApsaraVideo Live. This way, content delivery is accelerated.
H.264, also referred to as MPEG-4 Part 10, is a video compression standard. H.264 is standardized by the Joint Video Team (JVT) that is jointly founded by the ITU-T Video Coding Experts Group (VCEG) and the ISO/IEC JTC1 Moving Picture Experts Group (MPEG). The advantages of videos in the H.264 format include low bitrates, high image quality, strong fault tolerance capability, and strong adaptability to networks.
H.265 is a video compression standard that is designed by the ITU-T VCEG as a successor to H.264. Based on H.264, H.265 retains specific technologies that are used for H.264 and adopts new technologies for improvement. The new technologies improve the relationship among streams, encoding quality, latency, and algorithm complexity, which optimizes video settings.
Live streaming URL
Live streaming URLs refer to ingest URLs or streaming URLs. A live streaming URL consists of a domain, an AppName parameter, a StreamName parameter, and an access token. The access token is optional. You can create multiple applications for a domain and create multiple live streams for an application. The ApsaraVideo Live console provides a URL generator to help you generate ingest URLs and streaming URLs with ease. You can use the generated ingest URLs in third-party stream ingest software, for example, Open Broadcaster Software (OBS), to ingest streams.
The AppName parameter indicates the name of the application in which live streaming is implemented. This parameter is used to distinguish the storage paths of the media files of live streams.
The StreamName parameter indicates the name of a live stream. This parameter is used together with a domain to identify a unique live stream.