,nal_unit_unspecified_57,NAL_UNIT_UNSPECIFIED_58,nal_unit_unspecified_59,NAL_UNIT_UNSPECIFIED_60,Nal_unit_unspecified_61,NAL_UNIT_UNSPECIFIED_62,NAL_UNIT_UNSPECIFIED_63,Nal_unit_invalid,};Below receives the FU group packs the way, the FU packet header format is as follows:
Fus header contains two bytes of Payloadhdr, a byte of Fu Header,fu header and H264, the structure of the following figure, including the start bit (1b), stop bit (1b), Futype (6b)
PAYLODHDR two of its own assignment, in fact,
The payload type (Payload type) in the RTP packet has a column length of 7 bits, so RTP can support 128 types of payload that are not available. This field is used to indicate the type of encoding used by the sound or image, and is determined by the sending side, but of course the receiver has the ability to handle it. If the sender decides to change the encoding mode in the middle of the session or broadca
We used the RTP protocol in the previous issue and were configured to package the video data, which we reorganized and displayed on the receiving end of the data we sent. Finally, it is extended to support multi-client video sending, and display on the receiving end of the screen. Complete the remote monitoring simulation.Let's start with one.private bool Newrtppacket (Rtppacket packet) {if (! Clients.containskey (packet. SSRC)//If
Wireshark RTP parser DoS Vulnerability (CVE-2014-6421)
Release date:Updated on:
Affected Systems:Wireshark 1.12.0Description:Bugtraq id: 69855CVE (CAN) ID: CVE-2014-6421
Wireshark is the most popular network protocol parser.
Wireshark 1.12.0 has a denial of service vulnerability. Attackers can exploit this vulnerability to crash affected applications.
*>
Suggestion:Vendor patch:
Wireshark---------The vendor has released a patch to fix this secu
As the sender of multicast data, adding arm_linux to multicast groups is not required. You can add or not.
Arm_linux data sending program: (only functional functions are provided)
Void multicast_thread (){Rtpsession sess;Int portbase = 6000;Int status;// Int length;Int loop;Bool iscast;Unsigned long destip;Unsigned long localip;Char * buff = "multicasting test ";Int length = strlen (buff );Destip = inet_addr ("233.0.0.1 ");Localip = inet_addr ("172.29.26.101 ");If (destip = inaddr_none | localip
(1)(2)(3)-------------AUTHOR:PKF------------------time:2015-1-6Later discovered is that the server address of the connection is specified so that it can not play, and then with Wireshark capture a lot of UDP data came out, is not a port problem, and RTSP head problemIf it is an RTSP contract, the packet header will have a 4-byte symbol for a specific frame:Framingheader[0] = ' $ ';FRAMINGHEADER[1] = Streamchannelid;FRAMINGHEADER[2] = (u_int8_t) ((packetsize0xff00) >>8);FRAMINGHEADER[3] = (u_int8
After more than 20 days of sleep in a month (I really didn't take a nap), I finally completed the RTP/RTSP forwarding server (or proxy server )!!
New servermediasubsession, Demux, source, and sink classes are added based on the live555 architecture. (many classes use existing live555 classes as much as possible ). both VOD and real-time streams can be forwarded.
When Forwarding Real-time streams, we make full use of the existing data stream structur
H264.h Header File Contents:
#include
RTPSend.cpp File Contents:
#include
Save the following text as a RTPPARA.SDP file
M=video 1234 RTP/AVP 96a=rtpmap:96 H264A=framerate:30C=in IP4 192.168.0.25
Open the file with VLC and run the compiled send program.
Note that the IP of the header file and the SDP file should match the IP of the experimental machine.
The code modifies a memory bug based on the Naldecoder program. Thanks to the predecesso
RTP communication between PC and ARM-based JRTPLIB-general Linux technology-Linux technology and application information. For details, refer to the following section. In a cross-compiled library on linux, copy the library file to/usr/lib under nfs, compile it in WINDOWS, and test it in windows, however, communication between ARM and windows fails. I found some information on the Internet, saying that the PC side has a small byte order and the ARM side
RTCP RTP protocol format Analysis 5: RTCP protocol sending and receiving rules tp: the time when the RTCP package was last sent. Tc: current time. Tn: the time when the next RTCP package will be sent. Pmembers: Number of session members in the most recent calculation of tn. Members: current estimation of session members. Senders: estimate the number of senders in a session. Rtcp_bw: Target RTCP bandwidth. We_sent: this parameter is true if the applic
RTP jrtplib library programming, application compilation error -- Linux general technology-Linux technology and application information, the following is a detailed description. Hello everyone, please take a look at the reason for this. The programming method is based on what I said on the Internet, but I have reported these errors for a long time and I don't know why, could you please help me? Thank you.
[Root @ localhost C ++] # g ++-o send. C-I/usr
IX h264 RTP transmission details (1)
In the previous chapters, the introduction to the server has a very important issue that has not been carefully explored: how to open a file and obtain its SDP information. Let's start from here.
When the rtspserver receives a DESCRIBE request to a media set, it finds the corresponding servermediasession and calls servermediasession: generatesdpdescription (). In generatesdpdescription (), all servermediasubsessio
#include
Content of the h264.h header file:
Rtpsend. cpp file content:
# Include
Save the following text as the rtppara. SDP File
M = video 1234 RTP/AVP 96A = rtpmap: 96 h264A = framerate: 30C = in ip4 192.168.0.25
Open the file with VLC and run the compiled sending program.
Note that the header file and the IP address of the SDP file must be consistent with the IP address of the lab machine.
This code modifies a memory bug Based on the naldecoder
SDP protocol through the SIP protocol for media negotiations, the end of the main called media are used g.711u for media calls. During the call process, the negotiated g.711u media packaging time is 20ms,g.711u adoption rate of 8KHZ, namely: sampling 8,000 points per second.
The packet length of each packet during the call process is 20ms long, so the g.711u voice packet is fixed to 160 (160=8000*0.02) bytes in the payload of RTP g.711u.
The G.711U
FEC (Forward error Correction) forward error correction UDP\RTP used to improve wireless and other network packet loss problems
The algorithm is not introduced at this stage.
Idea: FEC ENCODE adds redundant packets, and when the wireless network drops packets, the receiver uses redundant packets to decode the lost packets.
Example: 10 packets, the code will add 2 packets, a total of 12 packets sent to the receiving end, the receiver lost the 5th an
UDP-based RTP transmission in the complex public network environment, especially 3G, 4G, WiFi network faced with packet loss, disorderly sequence, repetition, jitter and other issues, seriously affect the real-time audio and video interactive effect, even if it is a RTP packet lost, if the receiver does not do processing, will also lead to the appearance of video mosaic, This scheme uses a variety of method
When using RTP to transmit H264 data, when the length of the Nalu is too long to subcontract, here is an example, if you want to know more detailed protocol description can refer to the end of the connection.
Within live555, receive a piece of data at the beginning of each package as follows
7c Bayi E1 427c 1 D 8f7c 1 A7 C87c 1 2d。。。7c 1 6b FB7c 1 2b7c 3b
live555 the above data processing, the resulting data is returned to the user as follows
E1, 7f,
Because of the work exposure to a variety of different audio and video packaging formats, common national standard PS flow, onvif RTP stream and TS flow, and so on, all say good memory than rotten pen, the time to summarize, or in the future can be consulted, because of the level of problems, there may be omissions and problems, please advise one, PES flow
PES flow is the first layer of the original ES stream package, the basic unit of the PES stream
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