Picture in Picture requires two independent tuners or signal sources to supply the large and the small picture. Two-tuner PiP TVs have a second tuner built in, but a single-tuner PiP TV requires an external signal source, which may be an external tuner, VCR, DVD player, or a cable box with composite video outputs. Picture in Picture is often used to watch one program while waiting for another to start, or advertisements to finish.
Some manufacturers implement picture-in-picture in a very non-traditional manner. For example, and verified with their tech support group, Samsung redefines PiP on their LN-T4042H LCD television as the ability to switch between an analog and a digital source.
In 1980, NEC introduced its "Popvision" television (CV-20T74P) in Japan with a rudimentary picture-aside-picture feature: a separate 6" (15cm) CRT and tuner complemented the set's main 20" (50cm) screen. It was pricey: its ¥298,000 MSRP was equal to about $1,200 (at $1 = ¥250 ), and $1,200 in 1980 had the approximate buying power of $3,000 in 2007
An early consumer implementation of Picture-In-Picture was the Multivision set-top box; it was not a commercial success. Later PiP became available as a feature of advanced television receivers.
The Blu-ray Disc and HD DVD specifications included picture in picture, allowing viewers to see, say, the director's comment on a film they are watching. All of the Blu-ray Disc titles in 2006 and 2007 that had a PiP track used two separate HD encodings with one of the HD encodings including a hard coded PiP track. Starting in 2008 Blu-ray Disc titles started being released that use one HD and one SD video track which can be combined together with a Bonus View or BD-Live player. This method uses a less disc space allowing for PiP to be more easily added to a title. Several studios have released Bonus View PiP Blu-ray Disc titles in 2008 such as Aliens vs. Predator: Requiem, Resident Evil: Extinction, V for Vendetta, and War.