Glossary of video industry terms
A glossary of common terms and technology used in the video industry and for live streaming.
A glossary of common terms and technology used in the video industry and for live streaming.
Advanced Audio Coding is a digital audio codec that digitizes (encodes) analog audio and applies a small amount of compression to the original signal. AAC is a newer, lossy digital audio encoding standard that was designed to succeed MP3 and may provide better sound quality at a similar sample bitrate. Supported sampling bitrate values are: 16, 22, 44 and 48K kHz.
A noticeable video distortion that commonly affects filmed objects that have tight, repetitive patterns where the pattern appears to shift, causing a moiré effect. Motion can also appear to drag. The cause of aliasing is often a low sampling rate.
Refers to some visible distortion you see while watching a video, generally caused by a problem processing the signal but can also be caused by electromagnetic interference.
The aspect ratio describes the proportional relationship between the video output’s pixel width and height. For example, the resolution 1920×1080 is wider than it is tall. The ratio of its width to height is 16 to 9, which has an aspect ratio that is 16:9. Standard definition television has an aspect ratio of 4:3.
An audio codec is essentially a device or an algorithm capable of encoding and decoding a digital stream of audio. Common audio codecs include: AAC, MP3, and PCM. The audio codec selected determines the quality and amount of compression applied to the original signal during the conversion to digital.
A device that consolidates different audio sources and sends the combined audio output signal to devices like audio amplifiers and recording equipment. They typically offer controls for each source that let you set the volume, adjust tone, pan the signal L/R, and apply special effects to each source.
A portable HDMI to USB capture card.
A video codec developed for the Internet by Alliance for Open Media (AOMedia) as a successor for the High Efficiency Video Coding (HVAC)/H.265 codec.
Audio to video synchronization is a measure of how well the sound is synchronized with it’s source on video. One of the most common and obvious examples of an AV sync problem are lip synch issues, where the words heard don’t match the speaker’s moving lips.
Supplemental video footage that can be edited into a video for the purpose of providing extra details, act as a filler, aid in transitions, or add visual interest to the subject.
The maximum amount of data that a network can send over an Ethernet connection specified in Mbps or kbps is the maximum bandwidth of that link.
The number of bits per second (bps) transmitted over a digital network. Higher bit rates generally translate into higher quality video and audio.
Bonding (or cellular bonding) is when you associate different networks together that have Internet connectivity to create a redundant “back up” connection for your stream in case the primary link fails during the live broadcast. For example, a wired Ethernet connection and a cellular network.
A term describing a small, often semi-transparent image/logo that’s visible on the output of a broadcast stream (usually appearing on the lower corner) that is overlaid on the video using chroma keying, alpha channel, or even a transparent image overlay.
Capture card / capture device
An intermediary device that connects a video source to a computer so that the video with it’s associated audio can be viewed/processed on the computer. A capture card can be an external device, such as the AV.io 4K capture card or an internal capture card like the DVI2PCIe Duo.
A Content Delivery Network is a system of networked data servers that can store copies of original content (such as video) so that users can access the copy that’s closest to them on-demand, which makes it a fast delivery system.
Video and audio sources that are connected to the input ports of a Pearl device can be combined and added to channels, which you can then stream and record. A channel is essentially an encoding instance that produces an output such as a video recording or live stream.
A video editing feature that lets you choose a specific color in your video scene and replace everything of that color with a different image or video. The chroma key feature can be used to add special effects, lower thirds, or custom backgrounds to your video (often using a green screen).
clip or clipping (audio)
When the volume/decibel (dB) level of an audio source is too loud and electronically exceeds the maximum or “peak” voltage ceiling rated for an audio amplifier or audio processing software, the top of the sine wave is clipped off causing audible distortion.
A single shot, video sequence, or series of sequences that are filmed in one continuous session. The result is a single video file or “clip”.
A Content Management System is software that’s used to manage online content. WordPress is a common example of a CMS for websites, whereas Panopto or Kaltura are examples of common CMSs for corporate and educational video training. An out-of-the-box CMS application lets you start creating content right away.
codec (see audio codec and video codec)
A reference to the color wavelength of light in units of Kelvin (K). Light can fall within the range of cool (blue) to warm (red). Warm, incandescent light is around 2,700 K, florescent light is around 3,500 K, and daylight is around 5,500 K.
Video and audio compression takes an original signal and drops little bits of the original content to make the size of the file smaller.
In Pearl, a configuration preset is a predefined group of settings you can quickly apply to the system to reconfigure it on the fly for a consistent set up each time, leaving other important settings intact. They make it easy to manage multiple Pearl systems and to use Pearl in shared spaces, like a studio.
consumer level (audio)
A standardized audio input signal strength defined for consumer-grade equipment such as DVD/CD players and non-professional stereo equipment. Also called consumer line level, these inputs typically have unbalanced RCA, 1/4″, 3.5 mm and USB inputs. Consumer level audio signals are −10 dBV (loaded). See also line level.
custom layout editor
An application used in video production to modify a video source before it’s broadcast. For example, Pearl has a video editor that lets you easily combine multiple video sources into PiP or other configurations like side-by-side with text overlays and effects like transparent logos and lower thirds.
Video distortion can be seen as noticeable artifacts, jitter, or dropped frames and usually results from a problem processing the signal but can also be caused by electromagnetic interference. Audio distortion occurs when the volume/decibel (dB) level of an audio source is too loud and electronically exceeds the maximum or “peak” voltage ceiling rated for an audio amplifier or audio processing software, so that the top of the sine wave is clipped off causing audible distortion.
When watching a live stream, the download speed is the rate the data transfers from the live streaming service (like YouTube) to the person watching the live stream on their laptop or mobile device. The speed will be affected by things like bandwidth and network traffic.
Taking an original video source and changing the frame size to a smaller size. For example, downscaling a 4K Ultra High Definition (UHD) video source and changing it to 1920×1080.
downstream chroma keying
Downstream chroma keying applies the chroma key effect to all video sources you broadcast after they’re processed and switched.
The phenomena where video frames are not processed and get dropped from the video stream, causing the stream to look jerky and not smooth. A common cause is when processing very large video files that demand more processing power than the CPU can handle.
Digital Visual Interface defines a type of computer monitor/display interface developed by the Digital Display Working Group (DDWG). DVI is becoming less popular than newer HDMI interfaces.
How smooth the edges of a keyed out background appear next to the subject being filmed when using the chroma key feature. Other common terms are “spill” and “edge distance”. Edge blend is a setting that adjusts the amount of transparency/opacity of the edges where the keyed out background and the subject being filmed meet. See chroma key.
Encoding is the process of changing the format of digital content by applying a different set of standard parameters, such as the file type (AVI, MOV, MP4, etc), the codec (H.264, H.256), and the bitrate.
Epiphan Live is a web-based interface used to operate any of the Pearl family of video production systems from a computer or mobile device. Using the interface, you can do confidence monitoring of channels and sources, switching between layouts while recording and streaming, and to easily stop or start streaming and recording.
A Facebook feature that lets Facebook users live stream to their Facebook timeline, page, and groups.
Video frame rate specifies the number of images or video frames that are encoded per second and applies to encoded video recordings, like an AVI file or a live stream to YouTube. Common frame rates include: 24 fps (cinematic), 30 fps (television), and 60 fps (game play). The choice of frame rate depends on the motion effect you want, from a more natural looking motion blur (24 fps), to crisp fast moving sports (30 fps), and high definition game play (60 fps). Reducing the frame rate reduces the amount of bandwidth needed for live streaming since there are fewer video frames to stream.
Frame size (also know as video resolution or display mode) represents the number of pixels displayed horizontally and vertically. For example, the frame size of 1920×1080 produces an image that is 1920 pixels wide by 1080 pixels tall. The frame size of Standard Definition (SD) is 720×486 (NTSC) or 720×576 (PAL), High Definition (HD) is 1280×720, and Full HD is 1920×1080.
Refers to the width x height dimension of video or a monitor with a resolution of 1920×1080 pixels. Full HD is the standard resolution for Blu-Ray and digital television. Sometimes the term “HD” is used instead of “Full HD” to mean 1920×1080; however, “HD” is also the common term used to mean 1280×720.
Also called Advanced Video Coding (AVC), H.264 is a video compression codec standard used for recording video and for live streaming. It was developed by the International Telecommunications Union (ITU) and the International Organization for Standardization/International Electrotechnical Commission Moving Picture Experts Group. The newer and more efficient H.265 codec will succeed H.264 as it becomes more widely implemented.
The H.265 codec (also called High Efficiency Video Coding – HEVC) is a newer and more efficient video compression codec than H.264. Video content that’s compressed using H.265 is smaller and requires less bandwidth to stream than the same file compressed using H.264.
HandBrake is a free open-source video transcoder application that converts videos from one format to either MP4 or MKV format. It works with most common video files and formats created by video cameras, mobile phones, tablets, game consoles, computer screen captures, and non HDCP protected DVD and Blu-rays.
Sometimes called standard high definition, HD refers to the width x height dimensions of video or a monitor with a resolution of 1280×720. An HD video appears physically smaller than a video that’s full HD and needs less bandwidth to live stream because an HD signal contains fewer pixels. Sometimes the term “HD” is used instead of “Full HD” to mean 1920×1080, which can be confusing.
High-bandwidth Digital Content Protection (HDCP) is an anti-piracy copy-protection encryption commonly applied to DVDs and Bluerays to prevent illegal copying/playing of copyright protected video content. Only video players with the encryption key can properly decrypt the content.
High definition resolution
High definition resolution refers generally to the width x height dimensions of video or a monitor that’s bigger than 480 pixels (North America), such as: 1280×720 (HD), 1920×1080 (full HD), and 3840×2160 (UHD).
Impedance is a complex measure of the resistance that an electrical signal encounters in a circuit that has an AC voltage source. It takes in to account reactance, which is the combined effect of inductance and capacitance due to the frequency changes of alternating current. The unit is ohms, but because impedance takes in to account more than simple resistance, impedance uses Z instead of the Ω symbol.
Internet Protocol Television refers to a standard for delivering television content over the Internet as either a live broadcast, video on demand, or for interactive viewing using a Personal Video Recorder (PVR). However, the IPTV standard is also widely used in private networks for applications like corporate communications.
ISO video file
When recording a video program that has multiple video inputs arranged in different layouts that are switched live, it is the switched program that is recorded. An isolated (ISO) recording is when you record each video source on its own. Working with an ISO video file is usually better for post-production.
Intermittent distortion seen as jerky movements resulting from a problem processing video packets over an IP network where some packets are delayed en route to the destination. If there’s insufficient jitter buffer at the receiver, delayed packets can be dropped, which causes the video to intermittently jitter. A similar jerky looking video can be caused by down converting your video in uneven steps (such as down converting from 60 fps to 25 fps); however, the jerky effect in that case appears at a more regular interval and isn’t considered the same as jitter.
The color selected for keying out a background when using the chroma key feature. Used to replace the key colored parts of the video image with a different background image. Common key colors are green and blue. See chroma key.
A key frame is a specific frame of video chosen as the starting point (or the first frame) in a sequence of frames, usually for the purpose of manipulation by video editing software (for example, a key frame can mark the start of a transition). The beginning and the end of some video footage can be marked on the timeline with key frames to specify a concurrent range of frames to be manipulated.
How exact a color matches the selected key color when using the chroma key feature. A low threshold restricts the range of close color matches when using the chroma key feature. A high threshold will key on more colors that are close to the selected key color. See chroma key.
The delay between a request for data and when the data transfer actually starts.
line level (audio)
Describes the strength of an audio signal electrically in relation to a standard level where 1 Vrms equals 0 dBV. Consumer-grade equipment typically accept audio signals that are −10 dBV (loaded). Professional grade equipment typically accept signals that are +4 dBu (unloaded) where 0 dBu is the level at which approximately 0.7746 VRMS is applied across 600 Ω to produce 1 mW of power.
Is when you transmit live video over the Internet using a hardware video encoder such as the Webcaster X2 or a software encoder – usually to a video hosting platform such as YouTube or Facebook Live. Live streaming over private networks are used for more secure communications like internal training and corporate communications using video conferencing equipment and encoders like the Epiphan Pearl Mini and Pearl-2.
A Learning Management System is a software application for the purpose of creating, managing, and delivering online courses. Typical features include: managing course access, automated enrollment, progress tracking, managing exams, and a course creation editor. Most LMSs lack sophisticated analytics. A CMS can be integrated to provide better analytics.
A lower third refers to a graphic element that appears in the lower part of a video broadcast. It usually contains information like the name of someone being interviewed and is animated. Titling software in conjunction with chroma keying can be used to animate lower thirds (such as NewBlueFX); however, transparent images can also be used for lower thirds.
MP3 is a “lossy” audio codec that compresses the original audio signal into a much smaller file. The MP3 codec is most commonly used consumer audio codec for music and storage. For live streaming, MP3 is recommended because it uses less bandwidth.
Streaming to multiple destinations at the same time.
To multicast is when a single live stream is distributed to many viewers over a multicast-capable network.
NDI® (Network Device Interface) is a standard developed by NewTek that is used to transmit low-latency video content over Gigabit networks at broadcast quality with no audio compression. The quality of the video transported over the network is virtually lossless.
network file transfer protocol (SCP, FTP, SFTP, RSYNC or CIFS)
Allows computers to transfer and share large volumes of data across high-speed Ethernet connections.
Open Broadcast Software is a free and open source software for video recording and live streaming.
Pulse Code Modulation (PCM) is a “lossless” digital audio codec commonly used in computers, compact disks, and digital phones. PCM is the most basic form of encoding and is usually just the raw output from the analog-to-digital conversion process. Because it’s a simple digital replication of the audio signal without added compression, PCM provides a more accurate representation of the original audio signal when converted back into audio. It also produces a larger digital audio file than a “lossy” codec that applies some compression during the analog-to-digital conversion.
Real Time Messaging Protocol (RTMP) is an efficient live streaming protocol standard used to stream (i.e. push) content over the Internet to CDNs, servers, and online video platforms like YouTube. Real Time Messaging Protocol Secure (RTMPS) encrypts the RTMP content before it is sent over the network for secure streaming. The destination CDN or server must support RTMPS to decrypt the stream.
Real Time Streaming Protocol (RTSP) is an older media streaming protocol that enables a media viewer to access an independent unicast media stream over the network using the URL of the RTSP stream. Another older streaming protocol called RTSP Announce can push the media stream to a CDN or server (as opposed to a viewer retrieving the stream). RTSP Announce is not commonly in use anymore by modern CDNs.
Video scaling means converting the video’s original resolution to either a higher resolution (i.e. scaling up from 1280×720 to 1920×1080) or to a lower resolution (i.e. scaling down from 3840×2160 to 1920×1080), as well as changing aspect ratios (i.e. from 4:3 to 16:9).
Single Touch streaming and recording
Single Touch streaming and recording is a convenient feature of the Epiphan Pearl family of all-in-one video switching, recording, and streaming devices that lets users start streaming to multiple destinations and recording multiple channels with just a single tap of Pearl’s touch screen.
Skype is a free instant messaging app used for Internet voice or video calls between computers, tablets, game stations like the Xbox One, and mobile devices. Skype is popular for remote interviews due to the relatively low latency and quality of video calls.
When some of the light coming from video or photography studio lighting is cast where it’s not wanted.
A solid state drive (SSD) is a digital media storage chip that stores data in nonvolatile flash memory so that the data is persistent and can be retrieved after it is powered down.
Standard definition resolution
Standard Definition (SD) resolution refers to the width x height dimension of video or a monitor with a resolution of 640×480 pixels and a 4:3 aspect ratio, which is more square in appearance than a wide-angle 16:9 aspect ratio.
Transcoding video is the process of converting video from one format to another. For example, HandBrake is a free tool that can be used to convert video from nearly any format (such as MP4 , MOV, MPEG, AVI, WMV etc.) to MP4 or MKV format.
Ultra HD (also called UHD or 4K) is on the upper end of the resolution spectrum that is 3840 x 2160. The resolution produces a larger, crisper, and clearer video than lower resolutions.
Is the rate at which you can upload data such as live video to CDN server (such as YouTube) over the network. The speed will be affected by things like upload bandwidth and network traffic. Your Internet Service Provider can tell you what the theoretical upload speed is for your connection. However, running speed tests at different times of the day is a smart idea to know the actual amount of available upload bandwidth before live streaming.
upstream chroma keying
Upstream chroma keying applies the chroma key effect to a specific video source before it’s processed, switched, and broadcast.
The video codec determines the type of compression and decompression, and also affects the video quality. Common video codecs are MP4, H.264, and Motion JPEG.
Video resolution (also know as frame size or display mode) represents the number of pixels displayed horizontally and vertically. For example, the resolution 1920×1080 produces an image that is 1920 pixels wide by 1080 pixels tall. Standard Definition (SD) resolution is 720×486 (NTSC) or 720×576 (PAL), High Definition (HD) is 1280×720, and Full HD is 1920×1080.
A streaming platform with up to 1080p HD capabilities, allowing Vimeo Premium account owners to live stream and simulcast to Vimeo.
Software application used to record, stream, or display video content using a personal computer and supports features like switching and lower thirds.
The Epiphan Webcaster X2™ is a dedicated social media live streaming encoder used to stream video from HDMI and USB sources to platforms like YouTube, Facebook Live, and Twitch using API integrations, as well as a growing list of third-party streaming services like Switchboard Live, ChurchStreaming.tv, and more.
WebRTC is a free Real-Time Communications (RTC) API specification that enables browsers and mobile applications to provide two-way video and audio communication directly from the browser web page without needing to download a plugin or use a separate app. The project is supported by Apple, Google, Mozilla, and notable others.
YouTube is an Online Video Platform (OVP) headquartered in San Bruno (CA) that offers free video uploading/sharing and live streaming services to its website. Paid “premium” options that are ad free are also available.