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一分鐘快速搭建 rtmpd 服務器: https://blog.csdn.net/freeabc/article/details/102880984
軟件下載地址: http://www.qiyicc.com/download/rtmpd.zip
github 地址：https://github.com/superconvert/smart_rtmpd
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1. VP8 有兩證類型的幀 http://www.faqs.org/rfcs/rfc6386.html
There are only two types of frames in VP8.
Intraframes (also called key frames and, in MPEG terminology,
I-frames) are decoded without reference to any other frame in a
sequence; that is, the decompressor reconstructs such frames
beginning from its "default" state. Key frames provide random access
(or seeking) points in a video stream.
Interframes (also called prediction frames and, in MPEG terminology,
P-frames) are encoded with reference to prior frames, specifically
all prior frames up to and including the most recent key frame.
Generally speaking, the correct decoding of an interframe depends on
the correct decoding of the most recent key frame and all ensuing
frames. Consequently, the decoding algorithm is not tolerant of
dropped frames: In an environment in which frames may be dropped or
corrupted, correct decoding will not be possible until a key frame is
correctly received.
Intraframes 也叫 key frames ，類似於 h264 的 I 幀
Interframes 也叫 prediction frames， 類似於 h264 的 P 幀
2. Golden Frame 和 AltRef Frame
prediction frames, called golden frames and altref frames
(alternative reference frames). Blocks in an interframe may be
predicted using blocks in the immediately previous frame as well as
the most recent golden frame or altref frame. Every key frame is
automatically golden and altref, and any interframe may optionally
replace the most recent golden or altref frame.這兩個幀首先是 Key Frame ， Golden Frame 用於視頻背景的更新，可以用來克服幀丟失， 是可以顯示的。
AltRef Frame 只用於參考，不顯示，質量高於普通幀，主要提升幀間預測的一些信息參考。此外還有一個 Last Frame ，
這三種幀提供了幀間預測的功能，類似於 h264 的 B 幀功能。