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copied!<p>If you are working on OS X only I would stick with the QTKit APIs because they are much higher level and generally easier to work with.</p> <p>The general gist of what you want to do is:</p> <ol> <li>Step Through each frame in a movie</li> <li>Get a image representation for the current frame</li> <li>Save the current frame's image to a file on disk</li> </ol> <p>To step through the frames in a QuickTime movie, you can use the <a href="http://developer.apple.com/mac/library/documentation/QuickTime/Reference/QTKitFramework/Classes/QTMovie_Class/Reference/Reference.html" rel="nofollow noreferrer">QTMovie</a> class in QTKit to do this as follows:</p> <pre><code>- (void)dumpFramesWithMovie:(QTMovie*)movie toFolder:(NSString*)folderPath { [movie setIdling:NO]; // Don't idle the movie [movie gotoEnd]; QTTime endTime = [movie currentTime]; [movie gotoBeginning]; // Number of frames counted so far unsigned long numFrames = 0; // Turn off the Movie's looping so we are quaranteed to stop [movie setAttribute:[NSNumber numberWithBool:NO] forKey:QTMovieLoopsAttribute]; // Construct a Dictionary of to use when reading frames from a movie NSMutableDictionary *attributes = [NSMutableDictionary dictionary]; [attributes setObject:QTMovieFrameImageTypeNSImage forKey:QTMovieFrameImageType]; while (true) { QTTime curTime = [movie currentTime]; if (QTTimeCompare(curTime, endTime) == NSOrderedSame) { // Reached end of file break; } // Get the Current Frame as an NSImage NSImage* image = [movie frameImageAtTime:curTime withAttributes:attributes error:nil]; // Get the bitmap representation of this image // NOTE: This code assumes the first image representation is a NSBitmapImageRep, which is true // by default in OS X 10.5 and later. // Production code should do error checking here. NSBitmapImageRep *bitmap = [[image representations] objectAtIndex: 0]; // Construct a filename based upon the folder path and number of frames read so far NSString* fileName = [NSString stringWithFormat:@"%@/frame%d.png", folderPath, numFrames]; // Get an PNG representation of this file NSData *data = [bitmap representationUsingType: NSPNGFileType properties: nil]; // Write to disk [data writeToFile: fileName atomically: NO]; // Step to the next Frame [movie stepForward]; numFrames++; } [movie gotoBeginning]; } @end </code></pre> <p>This code compiles but has not been fully tested.</p> <p>One caveat with this approach is that MPEG-1 files will not decode properly on OS X 10.5 and earlier. This has been fixed as of 10.6 as far as I know. Also, if are writing a Windows application, you'll need to use the lower lever Quicktime-C APIs.</p> <p>Be sure to check the following reference pages while working on this:</p> <ul> <li><a href="http://developer.apple.com/mac/library/documentation/Cocoa/Conceptual/QTKitApplicationProgrammingGuide/Introduction/Introduction.html" rel="nofollow noreferrer">QTKit Application Programming Guide</a></li> <li><a href="http://developer.apple.com/mac/library/technotes/tn2005/tn2138.html#TNTAG11" rel="nofollow noreferrer">QTKit Frequently Asked Questions</a></li> <li><a href="http://developer.apple.com/mac/library/documentation/QuickTime/Reference/QTKitFramework/Classes/QTMovie_Class/Reference/Reference.html" rel="nofollow noreferrer">QTMovie Class Reference</a></li> <li><a href="http://borkware.com/quickies/one?topic=NSImage" rel="nofollow noreferrer">Quickies for NSImage</a></li> <li><a href="http://developer.apple.com/mac/library/documentation/cocoa/Reference/ApplicationKit/Classes/NSBitmapImageRep_Class/Reference/Reference.html" rel="nofollow noreferrer">NSBitmapImageRep Reference</a></li> <li><a href="http://developer.apple.com/mac/library/documentation/cocoa/Reference/ApplicationKit/Classes/NSImage_Class/Reference/Reference.html" rel="nofollow noreferrer">NSImage Reference</a></li> </ul>

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