HDLC frame format
In HDLc, data and control packets are transmitted in the standard frame format. Frames in HDLC are similar to BSC character blocks, but the datagram and contr
to ensure the proper protocol is used, the router must be configured with the appropriate layer 2nd encapsulation.The choice of the protocol needs to be determined based on the WAN technology and communication equipment used. The router encapsulates the packet in two-layer frame format and then transmits it to the WAN link. Although there are several different WAN packages, most have the same principle. Thi
Prepare to crack the frame data format and open it with UE. It is obvious that the words serializer_v1.10 are written using the serializer class.
It should also be skeletonserializer. To verify the code, ue should look at the binary code. First, let's look at several file block enumerations of this class.
Enum skeletonchunkid {Skeleton_header = 0x1000,Skeleton_bone = 0x2000,
Skeleton_bone_parent = 0x3000,
S
Recently in the study of some of the web players, Videojs\ckplayer\jwplayer and other page players, found that in the video playback, some MP4 format video is not able to play on the side of the cache, read some information online, found that these MP4 format video, " metadata information is not in the first frame
A MP4 conversion tool was also found on one of t
1. MAC802.11 data frame format
The first thing to note is that the frame format of mac802.11 is very special. It is different from the TCP/IP protocol and its length is variable. The data frame lengths of different functions are different. This feature shows that mac802.11 d
bus frame period is not the same, but the SOF packet frame number increase speed is the same, because in the high-speed USB system, the SOF packet frame number is actually obtained is a high 11 bits of the counter, the lowest three bits as a micro-frame number is not used, Therefore, the
package shown in the figure shows two different forms of package format. The most commonly used encapsulation format is the format defined by the RFC894. Both frame formats use the destination address and source address of 48bit (6 byte).
The Ethernet frame
packaged (that is, the application data packet ), then, it is routed down to the transport layer. TCP is a stream-oriented protocol. The high-level protocol is not stream-oriented. You need to design the Message Size, start point, and end point. This is the message frame format.
In WCF, the message frame format is use
These days to complete a comparison of the Ethernet frame of the program (c), the teacher gave the Ethernet frame head and IP packet header structure, and the actual fetch to the packet format is the same.Data structure of Ethernet frame head:struct { char dest_mac[6]; Char src_mac[6]; Short
TCP/Socket learning --- Ethernet (RFC 894) frame format where the source address and destination address are the hardware address (also called MAC address) of the network card, and the length is 48 bits, it is fixed at the factory of the NIC. Run the ifconfig command to check that the "HWaddr 00: 15: F2: 14: 9E: 3F" part is the hardware address. The protocol field has three values, corresponding to IP, ARP,
The latest use of ffmpeg+x264 encoded video, before using the old version of FFmpeg encoded video files no problem, but after the latest version (FFmpeg version number 2.8.2), the encoded video frame rate is particularly large problem.
Looking for a long time, finally solved, here to record the exploration process.
First of all, I set the frame rate of the video is 25 frames/s, but the encoded video
routed down to the transport layer. TCP is a stream-oriented protocol. The high-level protocol is not stream-oriented. You need to design the Message Size, start point, and end point. This is the message frame format.
In WCF, the message frame format is used to support TCP transmission and soap messages. If WCF does
, this session is no longer allowed to send PPP services. The PAdT package does not require any labels, and its code field value is 0xa7
The session_id field value is the session ID number of the PPP session to be terminated. After sending or receiving PAdT, you do not have to send it even if the normal PPP terminates the group. The PPP peer end should use the PPP protocol itself to terminate the pppoe session. However, when the PPP cannot be used, the PAdT can be used. The above process can be
The size of each rgb24 frame is
Size = width × heigth × 3 bit
The size of each rgb32 frame is
Size = width × heigth × 4
Yuv420 the size of each frame is
Size = width × heigth × 1. 5 Bit
Differences between yv12 and i420 Space
Yv12, i420 is the surface format
Yv12: brightness (row x column) + U (row x column/4)
Ethernet frame format frames are a limited 0/1 series. It can be divided into three parts: Header, Data (Payload), and tail: Preamble sfd dst src Type Payload (Data) Pad FCS Extension frames are sent/received from start to end in the order above. We will further explain the regions below. The first seven bytes of the header frame are called the preface (preamble
1.FFMPEG cropping video
Command: Ffmpeg-ss start-t duration-i input-vcodec copy-acodec copy OUTPUT
The descriptions of each of these parameters are as follows:
Start: Starting time. As 00:01:20, indicates that the cropping section starts at 1 minutes and 20 seconds.
DURATION: Video length. As 00:02:30, a video that is 2 minutes and 30 seconds long to intercept.
Input: Enter. Represents the original video file
Output: Outputs.
-vcode copy and-acodec copy represent the encoding
Based on asp.net +easyui frame upload picture, judge format + realize instant browsing, the specific contents are as follows
Interface Effect Chart:
The above is the entire content of this article, I hope to help you learn, but also hope that we support the cloud habitat community.
NSLog (@ "%@", Nsstringfromcgrect (Pickerview.frame));OrCfshow (Nsstringfromcgrect (pickerview.frame));Print Cgsize:nslog (@ "%@", Nsstringfromcgsize (Somecg Size));The format of the NSLog is as follows:
%@ Object
%d,%i integer
%hi Short-integer
%lli Long Integral type
%u no-character shaping
%f floating point/double word
%0.2f Precision floating-point number with only two decimal places reserved
%x,%x binary integ
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