Group of pictures
subsequence of video frames that a compression algorithm codes independently of other GOPs
In video coding, a group of pictures, or GOP structure, specifies the order in which intra- and inter-frames are arranged. The GOP is a collection of successive pictures within a coded video stream. Each coded video stream consists of successive GOPs, from which the visible frames are generated. Encountering a new GOP in a compressed video stream means that the decoder doesn't need any previous frames in order to decode the next ones, and allows fast seeking through the video.
Elements
A GOP can contain the following picture types:
I frame (intra coded picture) – a picture that is coded independently of all other pictures, each I frame can be decoded fully on its own. Each GOP begins (in decoding order) with this type of frame.
IDR frame (Instantaneous Decoder Refresh): I frame with a marking indicating that no subsequent P or B frames have references reaching further back than this I frame. Through the use of these IDR frames, closed GOPs are formed that can’t refer to frames outside the GOP. IDRs are the true keyframes together with clean random access frames (recovery points), CLA.
P frame (predictive coded picture) – contains motion-compensated difference information relative to previously decoded pictures. In older designs such as MPEG-1, H.262/MPEG-2 and H.263, each P frame can only reference one picture, and that picture must precede the P frame in display order as well as in decoding order, and the reference must be an I or P frame. These constraints do not apply in the newer standards H.264/MPEG-4 AVC and HEVC.
B frame (bipredictive coded picture) – contains motion-compensated difference information relative to previously decoded pictures.
“Group of pictures” enters the record as subsequence of video frames that a compression algorithm codes independently of other GOPs. Crown Archives preserves that source wording while asking what Group, pictures and subsequence can confirm, complicate or overturn.
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“Group of pictures” is worth following because a concise public description often conceals a longer documentary argument. Here, Group, pictures and subsequence provides the most credible route into that argument.
Vocabulary and entity names are the principal evidence signals here, because they determine the precision of every later search. The source revision retrieved here is dated Sep 22, 2026. The linked authority identifier is Q860741. None of the 0 selected statements returned an explicit reference.
The absence of detail may reflect summary conventions rather than a lack of surviving documentation. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
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This entry incorporates text from “Group of pictures” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.