Techilles's Weblog

Error while building make

techilles — Thu, 23 Sep 2010 14:34:40 +0000

The other day I was building 2 different Qt projects – Qt4.6.3 and Qt4.7.0 using the same mingw.while doing so,the 4.6.3 one started giving build error such that make was being pointed to a wrong make file.when I checked the project view in qtcreator,the build settings was not pointing to mingw-make32.I tried correcting it but no go.

Solution: Used separate mingw directory for the 2 projects.Next I closed and reopened the QtCreator for the project giving error. Verified the build settings in Project view…all’s well,it’s mingw-make32.exe.It was happily building.

How to find the maximum size of an H263 or MPEG4 video frame?

techilles — Mon, 27 Apr 2009 04:45:43 +0000

The maximum size of H.263 encoded video frame is of (k*16384) bits where k=4,16,32.
The value of k varies w.r.t. the resolution .
QCIF and S-QCIF,k=4.
4CIF , k=16.
16CIF, k=32.

For more on Video Resolution: http://en.wikipedia.org/wiki/Common_Intermediate_Format

Critical Section in Windows Mobile.

techilles — Tue, 24 Mar 2009 19:52:45 +0000

When do we use Critical Section?
– To guarantee mutual exclusion to a certain designated piece of code across multiple threads.

Example Usage:
– In a typical real-time multimedia programming environment,there’ll be Codec interface which shall
throw or consume data at or from you respectively.The interaction between the user program(usually an app/UI) happens via callback function.Now mutual exclusion must be provided across the callback function which is being invoked to say write into/read from some buffers and the function used by the app to read/write from or to the same buffers.

INFO is that in Windows Mobile platform, if the same thread enters the same critical section handle without calling LeaveCriticalSection(),it does not block the calling thread.

Learning.

techilles — Tue, 24 Mar 2009 19:33:08 +0000

Today’s learning:

Priority is the key to a well-planned execution of a day’s work.

techilles — Mon, 23 Mar 2009 19:51:43 +0000

I’m back with conviction.

I have been really walking a tight rope w.r.t to my day job and hobby.It’s been really interesting to see through the tight schedules and to be able to squeeze a little while for myself.

I have made up mind – I shall be blogging more frequently.To be more precise,I shall blog everyday.

Windows Mobile 6 Browser Plugin

techilles — Mon, 07 Jul 2008 05:32:45 +0000

I have been trying to build browser plugins for the WM6 IE /PIE. The term “browser plugin” is not similarly applicable for IE as for Mozilla Firefox.There is more to IE: ActiveX , Asynchronous Pluggable Protocol Handlers,Browser Helper Objects are the prominent terms.

My requirement: Parse the HTML DOM tree of a downloaded webpage in IE browser.

After a week long searching in the WM6 documentation ,finally found out that there is some called Browser Helper Objects which will suffice my requirements not the other methods as above.

BHOs was not much of a problem as there are good examples in the WM6 SDK samples itself.Next came,how to parse the DOM tree.In the documentation iisnt mentioned.The only thing shows up is the XML DOM tree parsing.Mapping the IDispatch* obtained vis IWebBrowser2 interface pointer into the XMLDOMDocument interface failes during the latter’s load() method.

Then an extensive session of “googling” followed but with almost nothing.Some place I did find the IPIEHTMLDocument2 mentioned but since it didnt show in the WM6 documentation,i left that.

Later on when searching for “HTML” in webvw.h in the WM6 SDK,the interface declaration showed up.There we go…now I could successfully parse the HTML DOM tree.

How to find the maximum size of an H263 or MPEG4 video frame?

techilles — Tue, 30 Nov 1999 00:00:00 +0000

The maximum size of H.263 encoded video frame is of (k*16384) bits where k=4,16,32.
The value of k varies w.r.t. the resolution .
QCIF and S-QCIF,k=4.
4CIF , k=16.
16CIF, k=32.

For more on Video Resolution: http://en.wikipedia.org/wiki/Common_Intermediate_Format