Dan Scholnik wrote: > I recently took some really unsteady video (walking on sand, partially > zoomed in; we're talking the bridge of the Enterprise after a direct > hit shaky) and decided to test the limits of y4mstabilizer. It seems > to be up to the task in theory (if one doesn't mind much of a given > frame being off-screen), but I have run into some bugs related to the > large offsets. I'm working on 640x480 progressive video in this case, > and the required motion compensation can easily exceed 200 pixels in > any direction. If I use a small radius with y4mstabilizer (say the 15 > pixel default) then it tends to segfault as soon as the motion is > greater than that, which is to say right away. I can keep things going > longer by increasing the radius a lot, but sometimes in the 200-235 > pixel range I get immediate segfaults anyway. Then if I use a radius of > 236 or more, y4mstabilizer no longer operates correctly, but after the > first few frames just shows a fixed corner of the video.
A pixel adjustment of greater than 200? Wow!! I never anticipated anything THAT shaky! Are you following the recommended filter sequence? (progressive, 444 input?) > > The first type of segfault (from too large a motion) is the most > important, and I've narrowed it down to the motion estimation code, > specifically gmotion() or motion(). I'll track it down myself > eventually, but I thought I'd throw it out there in case someone more > familiar with the code wanted to take a crack at it. I can provide > example video sequences. It sure seems to be a bug. It should be easy to isolate, since it should only need a couple of input frames. If you make them available, then I will see what I can do. Please provide some y4m sequences that illustrate the two problems, along with your calling parameters. The shorter the sequences that illustrate the problems, the better. I must tell you that in two weeks, I will be taking a one-month business trip. I will try to work on it while I am out, but time will be limited. Thanks. Jim Macropol ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ Mjpeg-users mailing list Mjpeg-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mjpeg-users
