Made SetVideo discard keyframe data if every frame in the video is a keyframe. Fixes #547.

Originally committed to SVN as r1699.

aegisub/changelog.txt

@@ -30,6 +30,7 @@ Please visit http://aegisub.net to download latest version
   o CSRI support for subtitles on all platforms. (equinox/AMZ)
   o Framegrabs from the video now also includes framenumber in the filename. (jfs)
   o Added a toggleable overscan mask to show which areas might get cropped by televisions. (AMZ)
+  o Keyframe data will no longer be loaded for video files which are all keyframes (i.e. most lossless AVI files) since it was meaningless. (TheFluff)
 - Visual Typesetting functionality implemented, which should make typesetting much easier and faster. It supports: (AMZ)
   o Dragging, including support for \move;
   o Rotation on Z axis;

aegisub/video_context.cpp

@@ -297,7 +297,23 @@ void VideoContext::SetVideo(const wxString &filename) {
 #endif
 				keyFramesLoaded = true;
 			}
+			
+			// Check if the file is all keyframes
+			bool isAllKeyFrames = true;
+			for (unsigned int i=1; i<KeyFrames.GetCount(); i++) {
+				// Is the last keyframe not this keyframe -1?
+				if (KeyFrames[i-1] != (i-1)) {
+					// It's not all keyframes, go ahead
+					isAllKeyFrames = false;
+					break;
+				}
+			}
 
+			// If it is all keyframes, discard the keyframe info as it is useless
+			if (isAllKeyFrames) {
+				KeyFrames.Clear();
+				keyFramesLoaded = false;
+			}
 
 			// Set GL context
 #ifdef __WXMAC__