H264中的标题帧编号是什么意思?

时间:2014-08-13 18:47:12

标签: java video compression sequence h.264

我正在循环查看原始H264文件的H264 NAL标头切片列表。循环时,我打印出" slice_type" (iframe = I,pframe = P,或bframe = B)和" frame_num" (序列中帧的编号)。每个原始H264文件的顺序不同,但正如您在下面看到的,每个模式都会重置" frame_num"在某个" frame_num"之后计数。对于此序列,它在" frame_num"之后重置。 15然后" frame_num" 10然后15然后10等等。这个特定的H264的帧率是30.有44&0; 0' 0 "的frame_num"和659总" frame_num"约15' 0'对于其他类型的" frame_num"。

你们中的任何人都知道这个序列是什么" frame_num"意味着什么或重置?我假设每次重置都是视频帧的一半,但我不完全确定。

I,0,P,1,P,2,P,3,P,4,P,5,P,6,P,7,P,8,P,9,P,10,P,11 ,P,12,P,13,P,14,P,15,P,0,P,1,P,2,P,3,P,4,P,5,P,6,P,7,P ,8,P,9,P,10,I,0,P,1,P,2,P,3,P,4,P,5,P,6,P,7,P,8,P,9 ,P,10,P,11,P,12,P,13,P,14,P,15,P,0,P,1,P,2,P,3,P,4,P,5,P ,6,P,7,P,8,P,9,P,10,P,11,P,12,P,13,P,14,P,15,P,0,P,1,P,2 ,P,3,P,4,P,5,P,6,P,7,P,8,P,9,P,10,P,11,P,12,P,13,P,14,P ,15,P,0,P,1,P,2,P,3,P,4,P,5,P,6,P,7,P,8,P,9,P,10,P,11 ,I,0,P,1,P,2,P,3,P,4,P,5,P,6,P,7,P,8,P,9,P,10,P,11,P ,12,P,13,P,14,P,15,P,0,P,1,P,2,P,3,P,4,P,5,P,6,P,7,P,8 ,P,9,P,10,P,11,P,12,P,13,P,14,P,15,P,0,P,1,P,2,P,3,P,4,P ,5,P,6,P,7,P,8,P,9,P,10,P,11,P,12,P,13,P,14,P,15,P,0,P,1 ,P,2,P,3,P,4,P,5,P,6,P,7,P,8,P,9,P,10,P,11,I,0,P,1,P ,2,P,3,P,4,P,5,P,6,P,7,P,8,P,9,P,10,P,11,P,12,P,13,P,14 ,P,15,P,0,P,1,P,2,P,3,P,4,P,5,P,6,P,7,P,8,P,9,P,10,P ,11,P,12,P,13,P,14,P,15,P,0,P,1,P,2,P,3,P,4,P,5,P,6,P,7 ,P,8 ,P,9,P,10,P,11,P,12,P,13,P,14,P,15,P,0,P,1,P,2,P,3,P,4,P ,5,P,6,P,7,P,8,P,9,P,10,P,11,I,0,P,1,P,2,P,3,P,4,P,5 ,P,6,P,7,P,8,P,9,P,10,P,11,P,12,P,13,P,14,P,15,P,0,P,1,P ,2,P,3,P,4,P,5,P,6,P,7,P,8,P,9,P,10,P,11,P,12,P,13,P,14 ,P,15,P,0,P,1,P,2,P,3,P,4,P,5,P,6,P,7,P,8,P,9,P,10,P ,11,P,12,P,13,P,14,P,15,P,0,P,1,P,2,P,3,P,4,P,5,P,6,P,7 ,P,8,P,9,P,10,P,11,I,0,P,1,P,2,P,3,P,4,P,5,P,6,P,7,P ,8,P,9,P,10,P,11,P,12,P,13,P,14,P,15,P,0,P,1,P,2,P,3,P,4 ,P,5,P,6,P,7,P,8,P,9,P,10,P,11,P,12,P,13,P,14,P,15,P,0,P ,1,P,2,P,3,P,4,P,5,P,6,P,7,P,8,P,9,P,10,P,11,P,12,P,13 ,P,14,P,15,P,0,P,1,P,2,P,3,P,4,P,5,P,6,P,7,P,8,P,9,P ,10,P,11,I,0,P,1,P,2,P,3,P,4,P,5,P,6,P,7,P,8,P,9,P,10 ,P,11,P,12,P,13,P,14,P,15,P,0,P,1,P,2,P,3,P,4,P,5,P,6,P ,7,P,8,P,9,P,10,P,11,P,12,P,13,P,14,P,15,P,0,P,1,P,2,P,3 ,P,4,P,5,P,6,P,7,P,8,P,9,P,10,P,11,P,12,P,13,P,14,P,1 5,P,0,P,1,P,2,P,3,P,4,P,5,P,6,P,7,P,8,P,9,P,10,P,11, I,0,P,1,P,2,P,3,P,4,P,5,P,6,P,7,P,8,P,9,P,10,P,11,P, 12,P,13,P,14,P,15,P,0,P,1,P,2,P,3,P,4,P,5,P,6,P,7,P,8, P,9,P,10,P,11,P,12,P,13,P,14,P,15,P,0,P,1,P,2,P,3,P,4,P, 5,P,6,P,7,P,8,P,9,P,10,P,11,P,12,P,13,P,14,P,15,P,0,P,1, P,2,P,3,P,4,P,5,P,6,P,7,P,8,P,9,P,10,P,11,I,0,P,1,P, 2,P,3,P,4,P,5,P,6,P,7,P,8,P,9,P,10,P,11,P,12,P,13,P,14, P,15,P,0,P,1,P,2,P,3,P,4,P,5,P,6,P,7,P,8,P,9,P,10,P, 11,P,12,P,13,P,14,P,15,P,0,P,1,P,2,P,3,P,4,P,5,P,6,P,7, P,8,P,9,P,10,P,11,P,12,P,13,P,14,P,15,P,0,P,1,P,2,P,3,P, 4,P,5,P,6,P,7,P,8,P,9,P,10,P,11,I,0,P,1,P,2,P,3,P,4, P,5,P,6,P,7,P,8,P,9,P,10,P,11,P,12,P,13,P,14,P,15,P,0,P, 1,P,2,P,3,P,4,P,5,P,6,P,7,P,8,P,9,P,10,P,11,P,12,P,13, P,14,P,15,P,0,P,1,P,2,P,3,P,4,P,5,P,6,P,7,P,8,P,9,P, 10,P,11,P,12,P,13,P,14,P,15,P,0,P,1,P,2,P,3,P,4,P,5,P,6, P, 7,P,8,P,9,P,10,P,11,I,0,P,1,P,2,P,3,P,4,P,5,P,6,P,7, P,8,P,9,P,10,P,11,P,12,P,13,P,14,P,15,P,0,P,1,P,2,P,3,P, 4,P,5,P,6,P,7,P,8,P,9,P,10,P,11,P,12,P,13,P,14,P,15,P,0, P,1,P,2,P,3,P,4,P,5,P,6,P,7,P,8,P,9,P,10,P,11,P,12,P, 13,P,14,P,15,P,0,P,1,P,2,P,3,P,4,P,5,P,6,P,7,P,8,P,9, P,10,P,11,I,0,P,1,P,2,P,3,P,4,P,5,P,6,P,7,P,8,P,9,P, 10,P,11,P,12,P,13,P,14,P,15,P,0,P,1,P,2,P,3,P,4,P,5,P,6, P,7,P,8,P,9,P,10,P,11,P,12,P,13,P,14,P,15

1 个答案:

答案 0 :(得分:1)

对于具有重新排序的情况(例如使用B帧),该数字用于跟踪帧的相对顺序。它正在重置,因为它只有几位长,所以在你的情况下,它在15之后回绕到0.由于接收器知道它有多少位,它也可以知道0是15之后的下一帧,并且给出了一个短路框架窗口,例如13,14,15,0,1,2,它知道那些帧的正确顺序是什么。

此外,在IDR帧上,它也会从0重新开始,因为那些帧之后的帧不依赖于之前的帧。