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copied!<p>Replace it with e.g.</p> <pre><code>while(1) </code></pre> <p>or</p> <pre><code>for(;;) </code></pre> <p>or you can do (defining <code>c</code> before the loop):</p> <pre><code>while (c != 27) { //grab each frame sequentially IplImage* frame = cvQueryFrame( capture ); if (!frame) break; //show the retrieved frame in the window cvShowImage("BLINK", frame); //wait for 20 ms c = cvWaitKey(20); //exit the loop if user press "Esc" key } </code></pre> <p>or without <code>c</code> at all, but this will <em>start</em> the loop with a 20ms wait:</p> <pre><code>while (cvWaitKey(20) != 27) { //grab each frame sequentially IplImage* frame = cvQueryFrame( capture ); if (!frame) break; //show the retrieved frame in the window cvShowImage("BLINK", frame); } </code></pre> <p>And a third possibility:</p> <pre><code>for(;;) { //grab each frame sequentially IplImage* frame = cvQueryFrame( capture ); if (!frame) break; //show the retrieved frame in the window cvShowImage("BLINK", frame); if (cvWaitKey(20) == 27) break; } </code></pre> <p><em>UPDATE</em>: while wondering whether it would be more correct to define</p> <pre><code>#define true 1 #define false 0 </code></pre> <p>or</p> <pre><code>#define true 1 #define false (!true) </code></pre> <p>or again</p> <pre><code>#define false 0 #define true (!false) </code></pre> <p>because if I, say, did:</p> <pre><code>int a = 5; if (a == true) { // This is false. a is 5 and not 1. So a is not true } if (a == false){ // This too is false. So a is not false } </code></pre> <p>I would come up with a really weird result, I found <a href="http://markshroyer.com/2012/06/c-both-true-and-false/" rel="nofollow">this link</a> to a slightly weirder result.</p> <p>I suspect that to solve this in a safe way would require some macro such as</p> <pre><code>#define IS_FALSE(a) (0 == (a)) #define IS_TRUE(a) (!IS_FALSE(a)) </code></pre>

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