Some Random Stuff

I got a chance to work on a video encoding application that decodes series of jpeg files and convert them into ogg theora video file. I used the infamous libavcodec library that is used in FFMPEG . I decided to write blog posts explaining how I decode jpeg images and convert them into ogg video file. This is the first part and in this I will explain how to decode jpeg images using libavcodec. To learn how to write decoded images as a ogg video file please read http://random-stuff-mine.blogspot.com/2017/07/encoding-raw-images-to-ogg-theora-video.html Before reading this blog post you must be aware of using and setting up libavcodec. I highly recommend this tutorial to get basics of using libavcodec http://www.ffmpeg.org/doxygen/0.6/api-example_8c-source.html Allocating input format context We will first allocate input format for reading the file. We will use avformat_open_input function that will allocate AVFormatContext structure passed to it , the function detects input typ

Pointers are one of the most difficult concepts in C language to grasp. Many programmers get confused in pointers.I am one of them. I decided to write series of blog posts covering basic to advance concepts of pointers. This is the first part to understand very basic of pointer that what pointer actually is and how we can store/access data through pointers. Put simply A pointer is a variable that contains the address of a variable Lets try to understand pointers using some code. int x=3; int *ptrToX; ptrToX=&x;  In above code we simply took a variable x of type int . Then we define a pointer ( * denotes that variable is a pointer and it is known as indirection or dereferencing operator ) ptrToX  of type int and assigned address of x to ptrToX . Now ptrToX points to x . Note that ptrToX do not contain value of x ( i.e 3 ) instead it contains memory address of x . Now we can access and manipulate value of x using ptrToX . Accessing value of a variable that is p

Changing Blackberry 10 wallpaper through code is a fairly easy task. In this blog post we will cover two methods of changing wallpaper of Blackberry 10 programatically. Using Cascades In cascades we can use HomeScreen class defined inside bb::platform namespace. To link against this class you must have following line in your .pro file LIBS += -lbbplatform HomeScreen class has a function setWallpaper which accept object of type QUrl as argument. This function sets the wallpaper to the image pointed by url passed. It returns a bool as status of call. Now we can write code to change the wallpaper. For simplicity, code will set image as wallpaper from assets directory. bb::platform::HomeScreen homeScr; bool wallpaperResult=homeScr.setWallpaper(QUrl("asset:///mywallpaper.png")); Blackberry notes for setWallpaper method The image will be scaled to fit the screen. If the wallpaper image is deleted while it is set as the current wallpaper (say, because the image