The Complete Online Video Streaming Glossary: Everything You Need to Know
We know that between encoders and RTMPs, the lingo of livestreaming can get a little confusing. Luckily we’ve broken down all the livestreaming terms and definitions you need to know from A to Z (or W for workflow, as the case may be).
4K Streaming: Similar to 720p or 1080p, 4K is a resolution for video content. There are over 7 million pixels in a 4K video display. Sample resolutions include: 4,096 x 2,160 and 3,840 x 2,160.
AAC: Advanced Audio Coding is a compression format, similar to MP3, that features increased sample frequency and offers a higher quality audio track for your live video.
Accepted Video Formats (In Livestream Studio): Most common formats that are accepted include (but are not limited to):
- .mp4, .m4v, .mov – Standard for MPEG-4 files
- .wmv – Windows Media Video
- .avi – AVI (Audio Video Interleaved)
- Full list of containers and codecs here.
Adaptive Streaming: A way to stream multiple resolutions of your live video to accommodate viewers with varying degrees of network bandwidth or internet speed. Adaptive streaming limits timeouts or buffering on the user side, giving them a smoother live video experience. Many of Livestream’s encoders include the option to stream at “multiple bitrates,” and the Livestream live player is adaptive as well.
Akamai: The world’s largest CDN (Content Delivery Network) with 90,000+ servers all over the world.
Anti-Lag: A tool in Livestream Producer and Livestream Studio that can be triggered when the encoder’s local Internet connection becomes slow. When enabled, it will build a cache of frames until it reaches a certain amount, and then clear that cache. This is in attempt to keep viewers at the most up-to-date live content. Having this feature disabled while Internet connection slows down will cause buffering and an endless cache of frames growing. While this will prevent choppy VODs, live viewers will be significantly behind the live content.
Aspect Ratio: The proportional relationship between an image’s or player’s width and its height. The standards for broadcast are 4:3 and 16:9. HD video is natively 16:9, which is what we recommend. 4:3 is typical for SD video.
Audio Mixer: A controller that takes in and combines various audio sources and allows the user to route each audio signal to a proper output and adjust each source’s levels. Can also be referred to as a sound mixer, mixing desk, or simply a mixer.
B-Roll: Additional footage that offers options for editors when cutting a live show. Having b-roll on hand is a great way to add dynamism to your live broadcast. Many editors will cut from a speaker or subject to crowd shots or wide shots for a smoother show.
Bounce Light: A softer way to light your subject. Instead of lighting a speaker with a single direct light, use a reflective surface like a bounce board to reflect direct lighting onto your subject. This will create a more natural, even look to your live video.
Bandwidth: Typically measured in bitrates, bandwidth refers to the amount of data that can be transferred from one location to another in a given amount of time.
Bitrate: The speed at which data is transferred over the Internet. The data is measured in bits, not to be confused with bytes.
- Kilo-bit per second (Kbps): A unit of data transfer rate equal to 1,000 bits per second.
- Mega-bit per second (Mbps): A unit of data transfer rate equal to 1,000,000 bits per seconds or 1,000 Kbps.
Blackmagic Design: Blackmagic Design is a company that creates several recording and encoding products that are compatible with Livestream’s technology including several capture cards and devices.
Bonding: Bonding allows you to combine multiple internet sources (ethernet, wifi, and/or 4G cellular data) to establish a redundant connection for your stream. It is a feature of the Livestream Studio software.
Broadcaster Pro: An ideal solution for single-camera streams, the Broadcaster Pro can stream any HDMI camera directly without the need for a computer. All you need is an event page to stream to and an Internet connection via Ethernet, WiFi, or 4G.
Buffering: Before a video can play, a certain amount of pre-loading data must be downloaded to stream.
Capture Cards/Devices: Hardware devices that convert the analog video signal coming from a camera into a digital format that a computer can read and understand. Different models connect to a computer through different means (PCIe, USB, Thunderbolt) and support different video signals (SDI, HDMI, Component, etc.).
Central Processing Unit (CPU): The brains of the computer that carries out instructions given by a computer program by performing calculations and operations.
Chroma Key: A special effects technique where a block of color (often blue or green) in a video frame is replaced by another color or image. The most common use is during the weather forecast segment of a news program. Chroma keying allows the forecaster to stand in front of a computer-generated map, when they are actually standing in front of a large green wall.
Cleeng: A Livestream partner that allows content creators and broadcasters to monetize their live events through pay-per-view.
Closed Captions: A text overlay of your subject’s dialogue, akin to a transcription, that appears on top of your live video to assist the hearing impaired. Could also include sound effects, in addition to dialogue.
Content Delivery Network (CDN): A distribution system on the Internet that accelerates the delivery of Web pages, audio, video, and other Internet-based content to users around the world.
Dedicated Bandwidth: Bandwidth that is reserved to a single purpose on a network. With a dedicated connection, it is possible to guarantee a certain amount of bandwidth for the duration of a stream. For example: A Network Administrator at a trade show, for a fee, is able to allocate a specific amount of bandwidth on a network to an exhibitor for the duration of a show. Dedicated bandwidth is always recommended for livestreaming and is required for events produced by the Livestream Production team.
Digital Zoom: Instead of a zoom created by an optical lens, digital zoom lets you create the effect of a “zoom in” or “zoom out” by expanding or cropping the size of your digital video frame. Livestream Studio software includes a 4K cropping tool that lets you seamlessly create new shots from a single video source.
Download Speed: The rate that data can be transferred from the Internet to a user’s computer or device. This is key for users looking to watch a stream.
Embedded Audio: The audio signal is sent to the output source through the video signal. This workflow is recommended to avoid audio/video sync issues. For example, a microphone is plugged into a camera, then a single HDMI cable connected to the camera carries both the video and the microphone’s audio to an encoder simultaneously. The opposite would be the microphone being plugged into the encoder directly, separate from the camera.
Embedded Video: A video player that can be seen on one website but is hosted on another website through HTML embed code.
Encoding (video): Encoding is the process of converting from a video source to a format that can be streamed over the Internet. Example: Procaster/Producer will convert a video source to H.264/AAC to be displayed on a Livestream player or mobile device.
Firewall: A security system that is designed to block unauthorized access while permitting authorized communications. This can cause issues when streaming if not configured properly. Livestream Studio, Producer, and Procaster use ports TCP 1935, 80, and 443.
Flash Player: A legacy software made by Adobe for viewing multimedia, Rich Internet Applications, and streaming video and audio, on a computer web browser. Capable of playing video in a variety of supported formats (most commonly H.264, H.263, VP6, VP7).
Geo-Blocking: The ability to restrict access based on the location of the individual attempting to see the content. This is typically determined by IP address.
Graphics: Logos, lower thirds, and text featured on screen during a stream or on-demand video.
H.264: Ideal for web videos and streaming, H.264 a compression format that lets you stream MPEG-4 video over the web without maxing out your bandwidth.
HDMI (High Definition Multimedia Interface): An audio/video interface for transferring video and audio data to and from HDMI-compliant source devices (cameras, receivers, etc.). A common standard for connecting HD devices at the consumer level.
HD Resolutions: High Definition video resolution, which contains more pixels than Standard Definition.
HDS: Adobe’s adaptive-bitrate streaming technology. “HTTP Dynamic streaming,” or HDS, is the process of efficiently delivering streaming video to users by dynamically switching among different streams of varying quality and size during playback. This gives viewers the best experience possible without overtaxing their computer.
HD SDI: High Definition Serial Digital Interface. It’s a video interface standard that allows for the transmission of high definition video over coaxial cable at faster speeds than other HD options, thus is recommended when longer cable runs are required.
HLS: Similar to Adobe HDS, HLS is Apple’s livestreaming adaptive bitrate solution. In this case, HLS breaks your video stream into MPEG2-TS files to allow for adaptive bitrate viewing.
HTML5 Video: An in-browser player format that is replacing Adobe Flash wherever video is streamed on the web. HTML5 requires less bandwidth overall, making it ideal for streaming video. For more information about Livestream’s HTML5 player, read our blog post here.
- 4G and LTE: A Mobile internet connection uses a 3G or 4G modem to transmit data and is part of a shared network. Since connection speed plays a large part in the success of a livestream, a mobile internet connection is not recommended. Networks with faster upload speeds than 3G as a result of limited user activity, improved technology, and reliability.
- Wi-Fi: A wireless connection that allows multiple devices to communicate on a shared network without cables. Should be used for streaming only in extreme cases when no other option is available.
- Wired: A hard-wired connection that is established using an Ethernet cable. The cable is connected by the Ethernet port on a computer into an Ethernet outlet on a switcher/router or modem. A wired connection does not always mean the connection is dedicated. Other devices can pull bandwidth from a router that the Ethernet cable is connected to. For streaming, a wired connection is considered to be more reliable and is always recommended.
- Non-Dedicated Bandwidth: Bandwidth that is shared over multiple devices on a single network can be wireless or wired; with no restrictions on what devices are in use and how much bandwidth they are using causing a sometimes-unstable connection. For example: A WiFi network located in an airport terminal that is open to the public with multiple devices sharing bandwidth on the same network.
IP Camera: A digital camera that sends and receives video data over your network, rather than via a capture device.
ISO Recording: Abbreviation of ‘Isolated Recording.’ A recording of a single a camera source during a multi-camera production. Typically, multiple ISO recordings are done simultaneously and are edited together in post-production.
Key Frame Interval: A keyframe is a full frame of an image that provides a reference point within a video. They are typically used to detect changes in the video, such as movement of a talking head. The interval is how often keyframes are set within the video, which is configured in the encoder. If you are expecting lots of movement in your video, it’s best to have a shorter key frame interval, which can be data intensive and thus create a larger sized video.
Latency: The amount of time it takes for data to reach one point to another (e.g. the video from the event to be seen by the viewer). Synonymous with ‘lag’ and ‘delay.’ In livestreaming, lower latency is ideal. Livestream streams have about a 20-30 second latency to allow and facilitate DVR.
Livestream Producer Software: Livestream Producer Software is a free encoding software that works on both Mac and Windows computers. This is ideal for simple webcam or single-camera streams that can also screencapture your desktop.
Livestream Studio Cloud: With Studio Cloud, anyone can take advantage of the power of cloud computing to run a fully functional production switcher entirely from a browser through a dedicated server in the Amazon cloud.
Livestream Studio HD51: A powerful, rack-mountable computer with all the necessary software and hardware pre-installed to produce a professional multi-camera event. All you need to do is plug in your HD-SDI or HDMI cameras and launch Livestream Studio to get started with a live video stream.
Livestream Studio HD550: An all-in-one, portable multi-camera solution for producers who tend to travel or have limited space to work with. It includes all the necessary software and hardware pre-installed, so you can plug in your cameras and start streaming.
Livestream Studio Software: A powerful software that allows for switching between multiple cameras, graphic overlays, video playback, high-resolution recording, and multi-bitrate streaming. It will work on Windows 7 or higher.
Livestream Studio Surface: A control surface that connects to any Studio system via USB that gives you all of Studio’s broad functionality in an intuitive format. It includes controls to give you quick access to critical functions of a live production.
Livestream Studio Surface Go: A simple, light-weight control surface powered by USB that gives you only the essential controls needed to switch video in a production with Livestream Studio.
Livestreaming: The transmission of live video via a mobile or digital recording device that audiences can watch and interact with in real time.
Live Video Output: A physical output coming from your camera or switcher that allows your video source(s) to be seen in another source like a projector or monitor.
Lossless Compression: A compression format for video and audio that retains the original information of your audio and video sources. This method is best for maintaining the full quality of your sources while livestreaming, and is best suited for strong, fast network connections.
Lossy Compression: Unlike lossless compression, lossy compression removes some of the data of your audio and video sources in order to reduce the size when streaming.
Lower Thirds: A lower third is a graphic overlay placed in the lower area of the screen, but not taking up the entire area. Lower thirds are used to identify speakers, places, or events on screen not previously identified in the context of the video.
Media Bins: A module in video software where a producer or editor can import and organize their pre-recorded video files
Mevo: A small, live-editing and streaming camera from Livestream that allows you to record and stream live to Livestream or Facebook Live while editing the feed via an iPhone app in real time.
MPEG-DASH: An adaptive bitrate format that contains encoded audio and video. MPEG separates your video stream into smaller sequence files, allowing your content to stream seamlessly over the web.
MPEG-TS: A format designed for transmitting MPEG video and other streaming formats. Could also include separate streams for video, audio, and closed captions.
Open Broadcasting Software: Open Broadcaster Software is free and open source software for video recording and live streaming.
Password Protection: Restricting access to streaming content via a password that is given out only to those who should see it.
Picture in Picture (PiP): The ability to see multiple video sources simultaneously.
Ping: Tests the reachability of an IP network or a server. It measures the round-trip time for messages sent from the originating host to a destination computer and then back to the source, typically in milliseconds.
Progressive Video: A video track with complete frames, as opposed to interlaced fields. Progressive video can be paused at any time, and would still display the paused frame as a complete image. Streaming videos are progressive by nature.
RTMP (Realtime Messaging Protocol): A protocol used for streaming audio, video and data over the Internet between a Flash player and a server. Commonly used by Adobe Flash Media Encoder, NewTek Tricaster, and Telestream Wirecast.
RTP (Realtime Transport Protocol): A network protocol for delivering audio and video over IP networks. Commonly used with video teleconference systems and web-based push-to-talk features.
RTSP (Realtime Streaming Protocol): A commonly used streaming protocol designed for entertainment and communications systems to control streaming media servers. Clients of media servers issue VCR-style commands, such as play, record and pause to facilitate real-time control of the media streaming from the server to a client (Video On Demand) or from a client to the server (Voice Recording).
Satellite Uplink/Downlink: When you do not have access to a dedicated 4G or Ethernet network, for example in a broadcast truck, a broadcaster can beam the livestream signal to a satellite and route it back to an office or dedicated line for encoding.
SD (Standard Definition) Resolutions: Any video resolution below 1280×720 is considered SD. Common SD resolutions include 1024×576 pixels and 720×480 pixels.
SD-CDN (aka Software-Defined CDN): A content delivery network that uses multiple CDNs to improve your viewer’s experience.
Streaming Video: Video content that is played directly over the internet. Can be live, or pre-recorded, but does not need to be downloaded in order to view.
Switcher: Traditionally a large device that is used to select and switch between several different video sources, control graphics overlays, and perform keying operations and general color signals. In recent years, switchers have become available as software installed on PC’s like Livestream Studio, Newtek Tricaster, etc.
Teradek: A company that builds video encoders, decoders, and transmitters, among other products. Teradek manufactures wireless video devices for remote video capture, camera control, real-time monitoring, color correction and webcasting. The Livestream platform supports the Teradek VidiU and the Teradek Cube.
Transcoding: The process of converting data from one form of coded representation to another. The process by which video files are converted to a reduced bit rate while still maintaining the original video format. This enables users to fit specific media into a much smaller storage space or deliver video files more efficiently using reduced bandwidth.
Transmission Control Protocol (TCP): TCP is a communications protocol which enables two hosts to establish a connection and exchange streams of data. Guarantees not only the delivery of data but also that packets will be delivered in the same order in which they were sent.
UDP: User Datagram Protocol is another way to transmit or receive audio and video via a network card or modem. Real Time Media Flow Protocol (RTMFP) is based on UDP, whereas Real Time Messaging Protocol (RTMP) is based on TCP (Transmission Control Protocol).
Upload Speed: The rate that data can be transferred from a user’s computer or device to the Internet. This is key for users looking to broadcast an event.
User Datagram Protocol (UDP): A communications protocol used primarily for establishing low latency and lost-tolerating connections between applications on the Internet. Ideal protocol for network applications in which perceived latency is critical such as streaming or gaming.
- H.264: Is a standard for video compression, and is currently one of the most commonly used formats for the recording, compression, and distribution of high definition video.
- AAC: Advanced Audio Coding is the default or standard audio format across all media platforms, including YouTube, iPhone, iPod, and iPad.
Video on Demand (VOD): The ability for viewers to watch or listen to content when they choose to rather than having to watch at a specific time.
WebVTT: Web Video Text Tracks, or VTT (Video Text Tracks) is a text format that seamlessly integrates with video, allowing for closed captions or subtitles. It contains a timestamp, which syncs with your video timecode.
White Labeling: The practice of a product or service being provided by one company but rebranded by another to make it appear as if the latter made it.
Workflow: A sequence of equipment or processes through which a piece of work passes from initiation to completion. In video production, it typically refers to the process in which your video and audio reach your audience: what camera, cables, capture device, encoding software/hardware, Internet connection, etc. is being used.
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