This topic describes the common terms that are used in ApsaraVideo Live.
Stream ingest refers to the process of delivering collected audio and video streams to a live center of ApsaraVideo Live.
Stream pulling refers to the process of uploading third-party streaming URLs to a live center of ApsaraVideo Live for accelerated content delivery.
Streaming refers to the process of delivering live streams from a live center of ApsaraVideo Live to a player for playback.
Edge ingest preferentially schedules streaming data to the optimal points-of-presence (POPs) that are nearest to users. The intelligent scheduling system of Alibaba Cloud is used to transmit the data to a live center of ApsaraVideo Live for content delivery. Supported by abundant POPs with wide coverage, edge ingest ensures optimal link transmission and uses 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 entire live streaming process, reconstructs the CDN transmission protocol, and optimizes underlying technologies such as User Datagram Protocol (UDP). RTS SDK is integrated with ApsaraVideo Player SDK. RTS supports tens of millions of concurrent playback requests at a low latency of milliseconds. You can use RTS to reduce the latency and video stuttering, and ensure instant loading and smooth playback for live streaming.
Live stream transcoding
Live stream transcoding refers to the process of converting a video stream to another video stream. You can use the transcoding feature to modify the parameters of original video streams, such as the encoding format, resolution, and bitrate. This allows you to play transcoded video streams on different devices in different network conditions. You can satisfy the requirements of different users, such as users that have different bandwidths, whose devices have different processing capabilities, and who require different latency levels.
The Narrowband HD™ technology applies different encoding optimization policies to different images to allow a vivid video experience. This technology is developed based on the human vision model and reduces the bitrate of videos while maintaining the same level of quality. High-definition streams can be delivered with 20 to 40% less bandwidth consumption.
The time shifting feature allows 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 milliseconds. The strong verification mode prevents an incorrect 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 and apply for an Internet Content Provider (ICP) filing for the ingest domain. After you add a CNAME record for the ingest domain, associate the ingest domain with a streaming domain, and configure URL signing if necessary, you can use the URL generator in the ApsaraVideo Live console to generate the ingest URL.
Streaming domains are used to pull live streams. To use ApsaraVideo Live, you must register a streaming domain and apply for an ICP filing for 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 if necessary, you can use the URL generator in the ApsaraVideo Live console to generate the streaming URL.
A CNAME is a domain name that is assigned to you after you add an accelerated domain name in the Alibaba Cloud Management Console. The CNAME is in the format of
*.*kunlun*.com. You must add a CNAME record to your Domain Name System (DNS) server to map the accelerated domain name to
*.*kunlun*.com. After the CNAME record takes effect, ApsaraVideo Live is responsible for domain resolution. All requests that are sent to the accelerated domain name are redirected to the POPs of ApsaraVideo Live. This way, content delivery is accelerated.
H.264, also referred to as MPEG-4 Part 10, is a video compression standard that is designed by the Joint Video Team (JVT). JVT 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 relationships among streams, encoding quality, latency level, and algorithm complexity, which optimizes video settings.
Live streaming URL
Live streaming URLs are divided into ingest URLs and streaming URLs. A live streaming URL consists of a domain name, an AppName parameter, a StreamName parameter, and an access token. The access token is optional. You can create multiple applications for a domain name and create multiple live streams for an application. The ApsaraVideo Live console provides the 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, such as Open Broadcaster Software (OBS), to ingest streams.
The AppName parameter indicates the name of an 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 name to identify a unique live stream.