[Qt-interest] x32 and x64 process : QSharedMemory

[Pavel Koshevoy]

On 07/05/2010 02:23 AM, justine loke wrote:
> I wants to port my application from Windows x32 to x64. I need to use quicktime
> lib to playback some movies. There is no x64 quicktime lib so I can't compile my
> application in x64. Is it possible to use QSharedMemory to do the trick :
>     - launch a process to decode quicktime movie using x32.
>     - launch my main application compile in x64.
>     - use QSharedMemory to grab new frame from the decode process.
>
> Is it possible? will it be efficient ?


Yes.  This is in fact how QuickTime X supports legacy QuickTime 7 components on 
the Mac.  Although, I imagine they don't use QSharedMemory to achieve this.  I 
would consider using Boost shared memory APIs as well.

As always, when adding another layer there is a performance penalty.  However, 
if it's good enough for QT X it will probably be good enough for you.  If I 
recall the numbers correctly from a developer conference video the penalty is 
about 5%.

	Pavel.