[Ffmpeg-devel] FFMPEG RTSP for Windows

[Ben Lear]

Fran?ois wrote:
>> On Wed, Mar 29, 2006 at 03:52:20PM -0600, Michael A. Kohn wrote:
>>> 
>>>>> I don't know anything about Winsock, but go ahead and send
>>>>> patches for any improvements you make. Send unified diffs: 'diff
>>>>> -Naur' or 'cvs
>>> diff
>>>>> -u'. If they're good changes then the patches ought to be
>>>>> considered.
>>> 
>>> One important thing is kinda missing from this.  The Winsock library
>>> has to be intialized before it can be used.  At the top of my test
>>> program I have something like this:
>>> 
>>> WSADATA wsaData;
>>> WORD wVersionRequested=MAKEWORD(1,1); int Win32isStupid;
>>> 
>>>   Win32isStupid=WSAStartup(wVersionRequested, &wsaData);
>>>   if (Win32isStupid) return -1;
>> 
>> This code does not give me much confidence in your knowledge of the C
>> language. The above can be done without useless temp vars:
>> 
>> WSADATA dummy;
>> if (WSAStartup(MAKEWORD(1,1), &dummy)) return 1;
>> 
>> and I assume MAKEWORD(1,1) is just 0x0101..
>> 
>> BTW your variable name is misleading. It suggests that the function
>> should always return -1... :)
> 
> Hmm is it reentrant or can must it only be called once ?

The function must be called at least once per process using sockets, though
may be called multiple times without problem.

MSDN "man" page:
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/winsock/win
sock/wsastartup_2.asp

> How can an app using libav* possibly know it has to init winsock ?

It shouldn?t need too. And as such the init function should be transparently
called by the underlying library unconditionally on startup or when any
network operations will occur.

> That sucks :) Just get a real OS :p

That?s the prefered option.

Cheers,

Ben.