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I have a SUSE linux machine running on the remote end which acts as tcp server.In the past this machine used to accept data over the serial port server, ie a piece of hardware that accepts serial data and converts it into TCP packets. I am trying to write an TCP/IP application to replace the port server.I am able to establish a connection between the linux machine but for some reason as soon as I send a Socket.Connect(remoteip), I am seeing SYN from my machine, SYN/ACK from linux, SYN/ACK from my machine and then SYN,FIN from linux machine and then ACK from my machine. I know that usually for a network communication, its supposed to be a three way handshake only. I see 5 channels of communication though instead of the 3. As soon as I send a packet, the linux machine sends a reset command.
I have something that can simulate what needs to be send to the remote linux machine. I compare my packats from the simulator and the packets I send , and the data packets are exactly the same. On the protocol level, there were some differences. The simulator had timestamps, so I added that using SocketOptions(....multicastdelay,1). The simulator was using a window size of 5480, so I set that using SocketOptions(..) also.
However still the linux machine is sending a reset packet as soon as I send data to it. I know that the linux machine server can accept TCP/IP communication in synchronous mode. I know the details of the what the data payload needs to be from a document and its maching the simulator . Thats all I know and I cannot get more information on it. The machine accepts data from a serial port server and works beatifully.
I am using socket programming and what i do can be summed up by the following three commands. Arguments are missing below but are correct in actual code.
socket.Connect()
socket.Send()
socket.Shutdown()
socket.Closet()
Another thing I noticed is that in Wireshark, when the simulator sends a Connect and when my machine sends a Connect, the TCP/IP options are in different order. The simultors protocol options are NOP,SACK PERMITTED, TIMESTAMP, NOP,WINDOW SCALE while mine are in a different order. I dont know to change the order, and I cant find much information about SACK PERMITTED. seems to be a default. I am programming with Visual Studio 2008 and a windows 7 computer. Any help will be appreciated.
What am I doing wrong? Please help.
Thanks
Jobin Thomas
-- Modified Tuesday, July 27, 2010 11:34 AM
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Are you sending your Data in Network Byte order? Don't know if that is the problem but always a good thing to check with network communications.
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I think I am sending it in the right order because I am matching the simulator. The linux machine is running on an intel i386, so should that matter?.
Thanks
Jobin Thomas
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It is very unlikely that the base protocol is causing your problems as these are tried and tested systems working all around the world every minute of every day. It is much more likely that the sequence of messages that you send to the server are incorrect, in the wrong order, or missing some vital piece of data. I notice in the above that you do a socket.Shutdown() immediately after your socket.Send() whereas I would expect some sort of input message to be received from the Linux server first. In general you would not close your socket until both ends have agreed that the conversation is complete.
It's time for a new signature.
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Thanks for the help. The issue was the stupid linux machine wasnt listening to my I.P address. We had to add some script to make it listen to my I.P.
I should make a point not to doubt TCP/IP again.
Thanks for the help.
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Hi every body,
I created C dll (Dynamic-link library) using .Net to use C function in C# application , I used DLL Export in the C project (when creating the dll) in order to export its function, then I used DLL Import In C# project to use the C function..
To make the C# project see the dll’s functions I just put it in the Debug folder of the C# project, and it works properly. Now after finishing making the C# application, you know that I have to make the setup of the application to install it in the client PC, and here is the problem! how to make the application see the dll in the client PC, When I installed the application in the client PC and tried to run it, it made an error showing that the application couldn’t see the dll functions at all!!
You know that in his PC there will not be a debug folder, on the other hand C dll can’t be added to the C# project as a reference!!
Also C dll can’t be registered in the operating system with the instruction:
regsvr32
I tried the following:
- Put the dll file in the installation folder of the client PC (it didn’t work)
- Put the dll file in the system32 folder of windows (it didn’t work)
- Put the dll in the setup ad a content file to be set in the installation folder (it didn’t work)
So anybody can help me please ! How to make the program see the dll to use its functions in the Client PC?
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Hi,
native code DLLs need not and can not be registered; they are located using the Windows PATH mechanism, so any folder that is mentioned in the system environment variable "PATH" should be good. The folder holding your EXE itself should also be good.
Note1: on a 32-bit Windows system I expect C:\Windows\system32 to be in PATH
Note2: if your native DLL needs other DLLs, those too need to be accessible through PATH; if they aren't the error message will not be very specific! Example: if you are using say one of the C run-time DLLs, and your target system doesn't have Visual, it may be missing those DLL files. You could use DEPENDS.EXE to figure it out.
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Thank you Mr. Luc Pattyn for being helpful,
I tried the software you recommended (DEPENS.EXE) to know what is the dlls needed by my dll, then I copied all of them (they were about 5) and put them in system32 folder, but unfortunately the error happened !!
What do you think?
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what is the exact error message you are getting?
is it a C or a C++ native DLL?
did you have "extern C" in your source, preventing "C++ name mangling"?
is this a 32-bit Windows system? if it is a 64-bit Windows, did you build for x86 ot x64?
what is your PATH?
which DLL files did you have to copy?
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* The error message says:
System.DllNotFoundException: Unable to load DLL "Firas.dll": This application has failed to start because the application configuration is incorrect. Reinstall the application may fix this problem.(Exception from HRESULT: 0x800736B1)
at Template.CardInstruction.Open_USB()
and Open_USB() is one of the function in the dll file.
When creating the dll I used C++ project and make the project give dll as output, in the Code I use (extern “C”) then before each function I put the following:
_declspec(dllexport)
* What I want to inform you about is when running the project from the .Net (as a project) the application could see the dll (located in the debug folder) and use its functions without any problem, but when I setup the application in the Client PC the error occurred.
* The Client system is 32-bit Windows.
* The dll given by the software you had recommended is:
DCIC32.dll (which is the hardware library given by the manufacturer because my application is using Card reader and this is its library containing the function to read/write on the card)
MFC90UD.Dll (Idon’t know this one)
MSVCR90D.Dll (Idon’t know this one)
KERNAL32.Dll
OLEAUT32.Dll
USER32.Dll
ADVAPI32.Dll
Again thank you very much for being helpful !
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Hi,
I don't know the exact answer to your problem, but I do have two remarks:
1.
having to add/replace some of the files you mentioned is pretty strange; e.g. USER32.DLL should always be present on all kinds of Windows, it is an essential part of it. If you replaced it, your system may be unstable; if it was absent, I can't believe it.
2.
When an error message is entered verbatim into the Google search box (but excluding specific names), one normally gets good suggestions as to how to solve the problem. So try entering "This application has failed to start because the application configuration is incorrect" and look at them; not all will apply, but I have good hope something good will come out. In this case the general idea is: your target system is lacking some "VC++ redist" package, containing a lot of run-time library stuff that needs to be installed, not just copied. And an alternative may be to statically link your native coce.
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In general, when you make C dll and you use it in C# application, how do you make the application see it in the Client PC?
this is my problem !
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see my very first statement:
native code DLLs need not and can not be registered; they are located using the Windows PATH mechanism, so any folder that is mentioned in the system environment variable "PATH" should be good. The folder holding your EXE itself should also be good.
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I'm learning about the BinaryFormater. If I take a byte[] of length n and serialize it to a FileStream, then open the file as a byte[] with the BinaryReader ReadBytes method, the new byte array is always (n +28) bytes long. There is a 27 byte header that precedes my original byte and 1 final byte is added to the end.
It seems that, for a serialized byte[], the header is always: 0, 1, 0, 0, 0, 255, 255, 255, 255, 1, 0, 0, 0, 0, 0, 0, 0, 15, 1, 0, 0, 0, 169, 37, 0, 0, 2. The final byte is always 11.
I have assumed that the purpose of this header is to indicate the stream's type in subsequent de-serializations and that the final byte is simply a terminator.
Do I have this right?
For a serialized byte[], will the header always be the same sequence within .NET applications?
Is there any logic behind the specific header byte sequence that I am seeing?
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If you are using a default formatter, the deserialization process needs to know what to desearialize it into - which means there's information in there telling it how to deserialize. When you get to large streams, the default binary formatter is an absolute nightmare to work with because it uses reflection on each row of data to work out how to fill the structures back up.
"WPF has many lovers. It's a veritable porn star!" - Josh Smith As Braveheart once said, "You can take our freedom but you'll never take our Hobnobs!" - Martin Hughes.
My blog | My articles | MoXAML PowerToys | Onyx
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Hi,
I have Live GPS data streaming over a serial port and live video feed on a capture device. Both are related in time. I wish to log (in a text file) incoming GPS data (whether valid or not) synchronized with live video feed recording. And then be able to playback both of them, same thing as in movie subtitles.
Need some help how on:
1 - What pattern to adopt while logging data with the live video recording file in a text file.
2 - Pattern on how to playback the logged data and video file in a synchronized manner.
Least amount of CPU resources are to be used as i intend to run multiple playback simultaneously.
Thank you in advance...
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"To enable a decoder to present synchronized content, such as audio tracks matching the associated video, at least once each 100 ms a Program Clock Reference, or PCR is transmitted in the adaptation field of an MPEG-2 transport stream packet. The PID with the PCR for an MPEG-2 program is identified by the pcr_pid value in the associated Program Map Table. The value of the PCR, when properly used, is employed to generate a system_timing_clock in the decoder. The STC decoder, when properly implemented, provides a highly accurate time base that is used to synchronize audio and video elementary streams. Timing in MPEG2 references this clock, for example the presentation time stamp (PTS) is intended to be relative to the PCR. The first 33 bits are based on a 90 kHz clock. The last 9 are based on a 27 MHz clock. The maximum jitter permitted for the PCR is +/- 500 ns." --Stolen from the wiki on the subject.
If you an read the PCR you should be able to create an overly with your GPS data as a static image with transparencies. I do not know if DirectX supports programmatic access to the PCR information, however.
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hi thankyou for ure deep insight.
but i must define my problems a bit more.
customized gps data coming from a remote data is not to be overlaid on thr video stream rather on maps and several gauges providing also virtual fieldview from above. data is cming around at 3-4hz not at fixed time intervals as its ota. i donot need perfect synchronization just efficent logging and playback techniques to take toll from cpu. as user front end manages multiple live connections each with video feeds maps gauges blah blah and sinultaneously i wish to ablle to playback multiple logged data. so just need some kind of cpu efficent algorithm to playback data and video feed simultaneously or independently and a pattern to log data.
thanks in advance.
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hi ,
Thanks you faheemnadeem, this is the Great topic.
i was searching the information of "mapping with GPS file and Video file using C#.net" from 3 days. currently i am working with sync the GPS data and Video file. give me some more example to sync those file using C#.net , it will be helpfull
Vijaya Raghavendran R
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Hi,
Sorry i am a bit late replying to your question. Anyways there were many ways to implement the syncing of GPS data with a video file. I completed my project sometime ago. In my case i had to implement a very precise synchronization because I had an airborne stabilized articulated camera which has to lock on a certain location and the data was simultaneously play backed with the video and it was very easy to spot sync discrepancies.
Solutions:
1. In real-time while recording one can take the time-stamp from the video when GPS data arrived, store it in a hash-table and while playing it back just search for the closest time stamp from the hash-table matching with current video time after some fixed interval (200ms). This method introduced some time delay as the data display event is to be fired after fixed time interval. (Works well nonetheless).
2. See the basic algorithm to sync subtitle (.srt) files on video. It can be used as well with some modifications.
3. In my case i had to be able to playback recording in a video only, Video + Data and Data only modes with varying playback speeds. No problem for video only mode. For data only mode I used two timers. At start or zero time I read the first NMEA string from the recorded text file. Note: Time stamps are attached with each NMEA string like in .srt file (a unique time not a range). i also read the the second string time and saved a copy of it. Parsed and displayed the first NMEA strings data, took the difference of two time stamps and set the second timer to fire at the next time interval which took the second line and did the same things and sets the first timer as in the previous case. Thus providing synchronization's with minimal delay. Playing it varying speeds is also easy as you have to just divide or multiply the timer value with playback speed. Same procedure follows with video and NMEA data synchronization.
The last case is difficult to implement if you are using a seek bar as well but provides the best synchronization with least processing.
I hope you got some clue to the solution.
Bye...
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hi,
Thanks for your reply i got some idea. currently my recuirement is matching with third point.
I have two Gps file (ground details and player details) and one video file(its contains the game video).I was doing with two timer control, one timer will be keep redraw the 2d graph in form1 and second form contains media player control and its playing the videos.
how can i validate, this is the gps file for the video or this is the videos for the gps file.
Because, i am keeping drawing the 2D graph from gps file using timer1_tick event and video is playing seperatly but its showing as sync formate.
for example,
my system will allow the all the video, if the user is uploading any film(Mummy film) video and click the play button
Then my output will be,
FORM1 it shows the 2d graph from the gps data
FORM2 it plays the Mummy film in the media player control
how i can resolve it
Thanks
Vijay r
Vijaya Raghavendran R
modified on Tuesday, November 16, 2010 1:16 AM
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If i am guessing right then your question was how i can associate multiple GPX files to a video or single GPX files to multiple videos.
The solution is simple.
I was using the name of the files to identify them. e.g i was using a label like this:
<ddmmyy-hhmmss-imei-partno>Both video and gpx files are in the same directory and have the same label for the same job. As the recording for both was started at the same time, so time + date stamp is unique, you can always use a unique ID in front to identify as well. i used the IMEI to identify individual remote clients internally and the part no to identify the number of GPX files or video files associated with each other.
Usually i used a single GPX file to record data as while recording i forced the OS file stream buffer to write the stream to text file immediately once arrived so that data won't be lost or the GPX text file corrupted in case of power loss. Usually you have to make multiple clips of the recorded videos to avoid much data loss incase of power loss. I used to make a new clip after 10 minutes.
I hope i got your question right.
Get back to me if there is anything else you require
Bye.
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Exactly right. but its only from "multiple GPX files to a video".
here
1)Ground details ground1.xml file
2)Player details player1.xml and player2.xml
3)one video file.
I did the master for adding the details of game info and holding the game id for the entire project
Game Name : Test football game
Ground details :Ground1.xml
Adding Player for the game.
Player Name :Vijayr
Player gps data :vijayr.xml
and etc.
Steps i am followed
1)loading the ground in 2D while selecting the game info.
2)having the array with player info based on the game info.
2)Using the timer control i am drawing the player in the ground with using gps player data from the array loop. but it's not
properly sync with video.
As per the above my application is running but its not sync properly with vidoe file.
give me some idea to make it work
Thanks
Vijay r
Vijaya Raghavendran R
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hi!!
m back... this time i thinks its a very basic problem...
i'm trying to copy all the contents of a file(a txt file of 700 lines)
when i write it in another file, it writes 75% of text....
it leaves the rest...
y???
i dont understand...
i'm using stream reader n writer... is it the way to do it..
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ayandelhi wrote: i dont understand...
Without seeing any code I doubt anyone else will either. 
Why not just use File.Copy()? (If there was some code it might explain why you cannot use it. )
Regards
David R
---------------------------------------------------------------
"Every program eventually becomes rococo, and then rubble." - Alan Perlis
The only valid measurement of code quality: WTFs/minute.
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