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Hello all
I have the following two lines of code to play an avi file:
mciSendString("open Res\\test.avi type avivideo alias myfile", NULL, 0, NULL);
mciSendString("play myfile", NULL, 0, NULL);
The problem is that it plays the audio but no video is displayed.
I can play the video fine in any media player, but it wont show up in the program, but I know its getting to the file because I can hear the audio.
Any suggestions as to what the problem could be?
Thanks.
Chris
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I believe it might have something to do with not having a "window" to play the video in. It might be simpler to use the MCIWnd functions (I've used them and had no problem in playing videos) compared to sending command strings yourself.
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Yes! I tried that and it works. Once I set up a window to play it in with the MCIWnd functions the video plays in the window.
Thanks alot!
Chris
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Hi
I use coin3d(v2.2) for my project. it work on my desktop bit Ican't use it in my laptop.
I use vs6 and my project use matlab engine too.
the error that I receive is
error signature:
AppName:matlabversion.exe Appver .0.0.0 modname: coind2d.dll
modver .0.0.0 offset:001f29fd
my laptop cpu is AMD(turion64) and my desktop is Intel.
my software and windows are exactly the same.
my graphic card is not installed on my laptop(I only have it's driver in Vista not XP).
I use windows XP.
Regards
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You would probably get a better response on the coin3d support forum.
http://www.coin3d.org/support[^]
Btw... your pseudonym is saagh which is Irish or Scottish Gaelic på norsk skibet/båt == Boat/Ship in english. And the software library your inquiring about was written by a norwegian maritime companyKongsberg SIM[^]. Do you work in the marine industry?
Best Wishes,
-David Delaune
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Saagh is my nickname.
I try coin3d suport forum but I don't get response yet.
I would be glad if you could help me.
Regards
S.A.Ghazvini
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after file selecting from CFileDialog no new records added into log file.
Environment:
- Windows XP SP3, MSVC 6.0
- Dialog-based application
Logic:
- logging in file is Ok (file open+write+close)
- invoke DoModal()
- logging in file isn't performed
(running step by step in debug mode: open+write+close executed without errors and should be performed, but file hasn't new lines)
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Are you sure, the file open/write/close are success? Add err,hr to watch window and check the error code when you step through the code. Well, if you could post the relevant code snippet, it would be more easier to isolate the issue.
Well, how do you open your log file? By just passing the filename? In that case it could be also due to the effect of chdir pitfall[^]. Well, check out that possibility too by opening the file by passing fully qualified path.
Regards,
Jijo.
_____________________________________________________
http://weseetips.com[ ^] Visual C++ tips and tricks. Updated daily.
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Jijo, thanks for reply
For logging I'm using CTextFile class by Johan Rosengren, sorry don't remember url.
The code for write:
BOOL CTextFile::AppendFile( CString& filename, const CString& contents )
{
CFile file;
CFileException feError;
BOOL result = TRUE;
if( file.Open( filename, CFile::modeWrite | CFile::modeCreate, &feError ) ) { // Write the file
file.Write( contents, contents.GetLength() );
file.Close();
}
else { // Set error message
TCHAR errBuff[256];
feError.GetErrorMessage( errBuff, 256 );
m_error = errBuff;
result = FALSE;
}
}
err,hr while Open(): "0xb7 Cannot create a file when that file already exists" doesn't matter - appears in both cases before and after DoModal().
Besides this trouble I have one more. Before selecting file I mount linux partition and unmount it after this. Selected file is copied into windows folder. After that linux partition can't be unmounted.
On the other hand moun/unmount hasn't an influence on logging.
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Igor IP wrote: err,hr while Open(): "0xb7 Cannot create a file when that file already exists"...
What does this have to do with CFileDialog?
Igor IP wrote: ...appears in both cases before and after DoModal().
How is DoModal() relevant?
If the problem is with opening and/or creating the file, focus on that rather than all the other stuff.
"Love people and use things, not love things and use people." - Unknown
"The brick walls are there for a reason...to stop the people who don't want it badly enough." - Randy Pausch
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Igor IP wrote: if( file.Open( filename, CFile::modeWrite | CFile::modeCreate, &feError ) ) { // Write the file
If you open the file with just CFile::modeCreate, then it will truncate the content to zero - which can be a reason for your empty log file. Try adding the flag CFile::modeNoTruncate to the existing set of flags.
Regards,
Jijo.
_____________________________________________________
http://weseetips.com[ ^] Visual C++ tips and tricks. Updated daily.
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Sorry, I have got snippet from another function, in my case file used as follows
if( file.Open( filename, CFile::modeWrite | CFile::modeCreate | CFile::modeNoTruncate, &feError ) )
{
file.SeekToEnd();
file.Write( contents, contents.GetLength() );
file.Close();
}
and err,hr shows for
right before Open(): S_OK
Open(): 0xb7
SeekToEnd(): not changed
Write(): not changed
Close(): not changed
I see this in both cases: logging works good from starting program and after invoking CFileDialog::DoModal() no new line added into the file.
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Hello Genius
i want generate a random num with no duplication ,
i have some range,
example 1 to 10.
am using in flex as a fun math.random(); its generate a num with duplication,
how to eliminate the duplication in vc++,its posible.....
how to using the random function with range in vc++.
help me..... 
Regard's
Mathy's
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You can use rand()[^]. Well, check out this thread[^] too.
Regards,
Jijo.
_____________________________________________________
http://weseetips.com[ ^] Visual C++ tips and tricks. Updated daily.
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mathy wrote: i want generate a random num
Technically, this is not possible with a computer. If you would be satisifed with a pseudo-random number, check out rand().
"Love people and use things, not love things and use people." - Unknown
"The brick walls are there for a reason...to stop the people who don't want it badly enough." - Randy Pausch
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Hi,
random and pseudo-random numbers will have some duplication, that's part of the game.
Without duplication, what would you want rand() to return once all possible values have been returned?
if you want to avoid duplication, you have to add some code to take care of that; here are two possible
approaches:
1.
keep track of earlier values, of the new number already is in that collection, create a new random number; as soon as you accept a new number, add it to the collection.
2.
beforehand, create a collection of all acceptable values; use rand() to generate an index into that
collection, return the number it points at, and remove the number from the collection.
Obviously, both these methods will fails once all acceptable numbers have been picked. But that is
what you asked for.
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The following recipe correnspond to the (pseudo) extraction of numbers from a bag:
<ol>
<li>Create an array containig all the candidate numbers, for instance <code>int value[]={1,2,3,4,5,6,7,8,9,10};</code>,
initialize a variable that will keep track of the sequence length, for instance <code>len=10;</code></li>
<li>make an loop for how many numbers you wish to extract, at each cycle</li><ol>
<li>select an index number via <code>index = (int)( (double)rand() * len / RAND_MAX);</code></li>
<li>keep the number corrensponding to the index, for instance <code>num = value[index];</code> that is you extracted one.</li>
<li>swap the index selected with the one at the (the current) bottom of the array, i.e. <code>swap(value[index], value[len-1]);</code></li>
<li>decrement <code>len</code>;</li>
</ol>
</ol>
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke
[My articles]
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My TCP/IP server(a dialog based MFC/VC app developed using CAsyncSocket class) is supposed to send 76800 bytes of data to the client which is a gsm modem(baud set at 57600 bps) which receives the data via gprs. i split it up into 240 packets of 320 bytes each.
The problem i am facing is loss of data at the client. I tried introducing delay(1s to 5s) at the server after sending each packet. Still the whole set of 76800 bytes never reach the client.
If i introduce an ACK from the client after receiving each paket and make the server to send the next packet only after RXing the ACK, then there is NO loss of data but it takes a long time(8to13 minutes) for the whole data transfer. My afordable time space is 40secs.
I am looking for a solution where the server can make sure when each packet(of 320 bytes) has reached the destination so that the next packet can be sent.
It would be extremely kind of you if you could help me up solve the issue. Pls let me know if any part is unclear.
(Note: The bytes are pixel data of a 240 x 320 resolution image, 8 bits per pixel.)
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Don't know why you get data loss, you shouldn't need to send your own ACK-s back since TCP should handle that by itself, don't know the GPRS protocol. Anyways, you could try sending less but bigger packets, so for example try sending the pixel data in 4 or maybe 2 packets instead of 240. That should lessen the time needed for the transfer. You could also consider using compression instead of sending uncompressed pixel data over.
> The problem with computers is that they do what you tell them to do and not what you want them to do. <
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If you look at the TCP section in the IBM TCP/IP redbook[^] (warning - it's a 6MB PDF, but well worth the download), you'll see that the TCP layer should handle all the ACKs and stuff for you. You'll also see that it's a stream oriented protocol - which means that it's probably best if you send all 76800 bytes in one go - the TCP layer should ensure that the data gets split into packets, each packet transmitted and received and the data reconstructed correctly. It sends a set of packets, assuming successful transmission, and doesn't expect an ACK immediately (as you've seen, the ACKs aren't immediate!) - it sets a timeout for each packet, and expects the ACK before the timeout occurs.
Splitting your data up into bits stops TCP doing its job so easily, and is probably better suited to a datagram oriented protocol like UDP.
As I said before, the IBM redbook is a very good resource that helps you understand networking technology better, which should help you design networking apps better.
One last thing - there may be some options that need be set using setsockopt to optimise your TCP/IP stack for your transport layer (the GSM modem), as it's quite slow?
HTH!
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As suggested by you frends, i made it a single packet of 76.8 kB instead of 240. It works perfectly. Just that the time taken depends on the gprs speed and connectivity (31 secs to 2 mins in 10 trials).
Thanks a lot:
Randor
Sturat Dootson &
Cod-o-mat
for the help and support.
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Shameer E.A. wrote: As suggested by you frends, i made it a single packet of 76.8 kB instead of 240
Happy to hear that it worked for you. Did you enable RFC 1323?
You should know that you are actually sending more than 1 packet if you are using the default TCP window size.
Best Wishes,
-David Delaune
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No David, I didnt enable RFC 1323.
I just sent it using CAsyncSocket::Send() command once.
i see that the TCP/IP protocol breaks it up into packets when using the default TCP window size.
ThanQ David.
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Hi Shameer,
I have done some marine industry related GPRS socket programming and have battled the same problem. You may want to check if your modem and upstream provider supports TCP Window Scaling[^] as defined in RFC 1323[^]. This will allow you to send packets larger than 64K. In fact you could send all of your data in a single packet. Or is there a reason that you need to send 240 packets at 320 bytes each?
Light travels at a maximum of 299792458 meters per second to the satellite, actually slightly slower in the Earth atmosphere. Sending only 320 bytes each packet in a high-loss environment will increase the SYN-ACK/RESEND cross-talk. This will probably result an increased transmission time. Sending larger packets may be your answer.
Best Wishes,
-David Delaune
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