question: Why, when watching a live TV program, is there a delay on a screen in the shot when it shows the same program as being broadcast
comment: Because there is a time delay in capturing video and displaying it. The live view is capturing a display of itself. At one frame in time, that light information from the camcorder gets converted to electrical signals, decoded, then sent to be displayed elsewhere. This will take several frames of time before it pops up on screen for the live view to see. This time difference is the delay you see. You can get the same effect by pointing a webcam to look at a screen with its own video feed, you'll get a repeating image of what you see but they will pop up one at a time due to the delay.
passages: Many modern digital television receivers, such as standalone TV sets and set-top boxes use sophisticated audio processing, which can create a delay between the time when the audio signal is received and the time when it is heard on the speakers. Since many of these TVs also cause delays in processing the video signal this can result in the two signals being sufficiently synchronized to be unnoticeable by the viewer. However, if the difference between the audio and video delay is significant, the effect can be disconcerting. Some TVs have a "lip sync" setting that allows the audio lag to be adjusted to synchronize with the video, and others may have advanced settings where some of the audio processing steps can be turned off.
   Tape delay may also refer to the process of broadcasting an event at a later scheduled time because a scheduling conflict prevents a live telecast, or a broadcaster seeks to maximize ratings by airing an event in a certain timeslot. That can also be done because of time constraints of certain portions, usually those that do not affect the outcome of the show, are edited out or the availability of hosts or other key production staff only at certain times of the day, and it is generally applicable for cable television programs.
   BULLET::::- A source of significant video delay is found in pixelated television displays (LCD, Plasma display, DLP) which utilize complex video signal processing to convert the resolution of the incoming video signal to the native resolution of the pixelated display, for example converting standard definition video to be displayed on a high definition display. "Lip-flap" may exceed 200 ms at times.
  
  BULLET::::- In broadcast television, it is not unusual for lip-sync error to vary by over 100 ms (several video frames) from time to time.
   Broadcasters across North America, particularly in the United States, regularly utilize a "west-coast delay" in which special events (including some award shows and several reality competition programs) broadcast live in the Eastern or Central Time Zones are then tape-delayed on the western half of the country, including California, which allows post-production staff to edit out any glitches that occurred during the live broadcast. In the U.S., however, this practice is now increasingly limited to live talent shows tape-delayed for West Coast viewers as major awards shows, beginning the 2010s, expanded to live global telecasts, including same-time continent-wide airings. Canada and Mexico, meanwhile, have multiple time zones but have routinely televised all live events simultaneously across both countries by the turn of the 21st century.
   Section::::Controversial Use.
   BULLET::::- December 20, 2015 – Miss Universe host Steve Harvey crowned the wrong winner by mistake then crowned the actual winner on live television.
  
  BULLET::::- January 8, 2016 – "The Late Show with Stephen Colbert" airs a live episode for the first time in the 23-year history of CBS's late-night franchise.
  
  BULLET::::- July 21, 2016 - Late Night with Seth Meyers airs a live episode for the first time in the 30-year history of NBC's late-night franchise.
   BULLET::::- There is extensive use of audio and video signal processing circuitry with significant (and often non-constant) delays in television systems. Particular video signal processing circuitry which is widely used and contributes significant video delays include frame synchronizers, digital video effects processors, video noise reduction, format converters and compression systems.
  
  BULLET::::- The video monitor processing circuit may delay the video stream. Pixelated displays require video format conversion and deinterlace processing which can add one or more frames of video delay.
   Section::::Regulation.
   Section::::History.
   TV viewers can be affected as well. If a home theater receiver with external speakers is used, then the display lag causes the audio to be heard earlier than the picture is seen. "Early" audio is more jarring than "late" audio. Many home-theater receivers have a manual audio-delay adjustment which can be set to compensate for display latency.
  
  Section::::Game mode.
   A short delay is often used to prevent profanity, bloopers, nudity, or other undesirable material from making it to air, including more mundane problems such as technical malfunctions (an anchor's lapel microphone goes dead). In that instance, it is often referred to as a 'seven-second delay' or 'profanity delay'. Longer delays, however, may also be introduced, often to allow a show to air at the same time for the local market as is sometimes done with nationally broadcast programs in countries with multiple time zones. Considered as time shifting, that is often achieved by a "tape delay," using a video tape recorder, modern digital video recorders, or other similar technology.
   Section::::Mechanism.
   This SCART feature had been used for connection to analogue decoding equipment by pay TV operators in Europe, and in the past was used for connection to teletext equipment before the decoders became built-in. The outgoing signal could be of the same nature as the incoming signal, or RGB component video, or even an "insert" over the original signal, due to the "fast switching" feature of SCART.
   BULLET::::- November 30, 1958 – Midway through transmission of the "Armchair Theatre" play "Underground" on the British ITV network, actor Gareth Jones died off-camera, forcing the cast to improvise the remainder of the broadcast.
  
  BULLET::::- December 7, 1963 – Instant replay is used for the first time during the live transmission of the Army–Navy Game by its inventor, director Tony Verna.
   Section::::Television transmission synchronization.
  
  An example of a lip synchronization problem, also known as lip sync error is the case in which television video and audio signals are transported via different facilities ("e.g.," a geosynchronous satellite radio link and a landline) that have significantly different delay times. In such cases, it is necessary to delay the earlier of the two signals electronically.
   BULLET::::- During mixing of video clips normally either the audio or video needs to be delayed so they are synchronized. The AV-sync delay is static, but can vary with the individual clip.
  
  BULLET::::- Video editing effects.
  
  Examples of transmission (broadcasting), reception and playback that can get the AV-sync incorrectly synchronized:
   BULLET::::- March 16, 1971 – the first live broadcast of The Grammy Awards.
  
  BULLET::::- March 5, 1975 – Graham Kennedy mimicked a crow call ("faaaaaaark") remniscient of the word fuck during a hairspray ad on "The Graham Kennedy Show" on the Nine Network in Australia. He was banned from live TV indefinitely for the stunt. He quits the network on April 17 after the network took advantage of the pre-taping to delete a speech critical of Senator Doug McClelland (the then Minister for the Media).
  
  BULLET::::- October 11, 1975 – First episode of Saturday Night Live broadcast.
   On 12 January 2017, RT was accidentally broadcast for around 10 minutes on a web stream of U.S. public affairs service C-SPAN. RT stated that while it was testing its systems in preparation for the inauguration of Donald Trump, its signal was "mistakenly routed onto the primary encoder feeding C-SPAN1's signal to the internet, rather than to an unused backup."
   In this example, we will explore the signal flow of a hypothetical rock concert. For our example, this concert not only has a live audience, it is also being broadcast on live TV, and it is being recorded, with copies of the recording being sold to the public immediately after the concert is over. The signal from each microphone is therefore being sent to five places; the house sound system, the in-ear monitor system for the performers, the broadcast system, the recording system, and to the lobby, restrooms, and backstage areas so that people can hear the performance while outside the performance area.
   One of the main disadvantages of digital stage boxes, and digital audio systems in general, is their latency which is introduced in the analog-to-digital and digital-to-analog conversion processes. Latency is cumulative through all devices in the signal flow, so more complex networks, especially Ethernet-based ones, can experience latency significant enough to cause an audible delay. This was originally a major drawback of digital stage boxes, but recent systems have lowered latency to insignificant levelstypically 2–3 ms.
   BULLET::::- On occasion, an answer will have a different correct question when the show was recorded compared to the time the show airs. When that happens, the date of taping will appear on screen as the answer is read in order to comply with Standards and Practices. An example of this was during the second 2014 Jeopardy! Teen Tournament first round match: the answer in the $400 My Present Government Job category in the Jeopardy! round was, "Kathleen Sebelius, Insuring America, one person at a time." The correct response was "What is the Secretary of Health and Human Services?" However, she had resigned from that position in April 2014, between the taping of the match in March 2014 and the July 22, 2014 broadcast. The show posted a disclaimer, "Recorded in March 2014," as the category was being read.
   Section::::Technology.:Videoconferencing modes.
  
  Videoconferencing systems use two methods to determine which video feed or feeds to display.
  
  "Continuous Presence" simply displays all participants at the same time, usually with the exception that the viewer either does not see their own feed, or sees their own feed in miniature.
   Many shows of the program have a "fatal flaw," which invalidates the whole concept. For example, during one show it was unclear whether the show was live or prerecorded. Ken persuaded listeners the show was prerecorded and Andy persuaded the listeners the show was live. The fatal flaw was Ken kept quoting a live poll on the website to see whether listeners thought the show was live or not, thus proving it was live and leaving little material for the rest of the show.
   BULLET::::- Tennis: during the break after odd-numbered games when players change ends.
  
  BULLET::::- Volleyball and beach volleyball: in volleyball games governed by FIVB, television timeouts are referred to as technical time-outs and occur during each non-tie-breaking set.
  
  Section::::Use by other live events.
   However, since many live events became available via social media in the late 2000s, tape delays have become increasingly irrelevant because of live television's resurgence as a broadcast format. Since the mid-2010s, several high-profile entertainment programs with huge live global audiences like the Academy Awards, Primetime Emmy Awards and Grammy Awards, yearly specials like the Miss Universe and Miss World pageants, and major sporting events like the Olympic Games, FIFA World Cup and the National Football League's Super Bowl, air to totality live on both television and the internet virtually all across the world's time zones in and out of their countries of origin, with mandated prime time rebroadcasts (featuring edits as desired by broadcasters) for regions that previously and solely relied on delayed telecasts on prime time among these otherwise live events.
  
raw_presuppositions: A live view of a TV program should show the program in real time as it's broadcast.
raw_corrections: A live view of a TV program still has a delay in capturing video of a broadcast and displaying it.