Typical Group of Pictures (GOP) Structure
The typical Group Of Pictures (GOP) structure is IBBPBBP... The I-frame is used to predict the first P-frame and these two frames are also used to predict the first and the second B-frame. The second P-frame is predicted using the first P-frame and they join to predict the third and fourth B-frames. The scheme is shown in the next picture:
This structure suggests a problem because the fourth frame (a P-frame) is needed in order to predict the second and the third (B-frames). So we need to transmit the P-frame before the B-frames and it will delay the transmission (it will be necessary to keep the P-frame).
This structure has strong points:
- It minimizes the problem of possible uncovered areas.
- P-frames and B-frames need less data than I-frames, so less data is transmitted.
But it has weak points:
- It increases the complexity of the decoder, which can mean more memory is needed to rearrange the frames.
- The interpolated frames (namely B-frames) require more motion vectors which means an increased bit rate.
Read more about this topic: Inter Frame
Famous quotes containing the words typical, group, pictures and/or structure:
“The books may say that nine-month-olds crawl, say their first words, and are afraid of strangers. Your exuberantly concrete and special nine-month-old hasn’t read them. She may be walking already, not saying a word and smiling gleefully at every stranger she sees. . . . You can support her best by helping her learn what she’s trying to learn, not what the books say a typical child ought to be learning.”
—Amy Laura Dombro (20th century)
“[The Republicans] offer ... a detailed agenda for national renewal.... [On] reducing illegitimacy ... the state will use ... funds for programs to reduce out-of-wedlock pregnancies, to promote adoption, to establish and operate children’s group homes, to establish and operate residential group homes for unwed mothers, or for any purpose the state deems appropriate. None of the taxpayer funds may be used for abortion services or abortion counseling.”
—Newt Gingrich (b. 1943)
“Then my verse I dishonour, my pictures despise,
My person degrade & my temper chastise;
And the pen is my terror, the pencil my shame;
And my talents I bury, and dead is my fame.”
—William Blake (1757–1827)
“Just as a new scientific discovery manifests something that was already latent in the order of nature, and at the same time is logically related to the total structure of the existing science, so the new poem manifests something that was already latent in the order of words.”
—Northrop Frye (b. 1912)