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| Unofficial VirtualDub Support Forums > Advanced Video Processing > Video Segmenting Issues |
| Posted by: czarmurphy Jun 24 2011, 10:56 PM |
| Hi guys, New to the forums here, mainly because I've never had problems with VirtualDub(Mod). I am having a problem splitting my videos, but before I get to my actual problem, I need to explain my situation. I record my video, and it generally ends up being about an hour in length (too big for YouTube), so I split the video up. I import the video into VDM via drag n drop, combine audio files with Audacity and add them to the VDM video project, and save the project through direct stream copy. This gives me a massive raw copy of recorded data (that plays fine). Now I compress my data, using XVid's codec (two passes of it, set at 720p). This takes a long time, but the product is a much smaller file, around three or four GB. Now I need to split my files into bitesize parts for uploading to YouTube. I take about ten minutes a piece using the selection tool in VDM (Home/End buttons, then the Save As.. command). I select Direct Stream Copy (since it's already compressed), and do this for each ~10 min piece until I reach the end. The Problem: Each video segment contains a number of seconds from the previous "segment" (oftentimes 8.5 seconds, strangely enough). I have NO IDEA why. I have tried cutting out those eight seconds from the segment product, but the result is the exact same video (same length, and audio is still synced)! I have tried reverting to the original compressed hour-long video file and segmenting again, but the result is the same (still eight extra seconds at the beginning). I have tried taking little selections out of the middle of my segment, and this sometimes works. However, if I move toward the beginning of the file ( first ~15 seconds) and save a selection from there, no matter how short the small selection is (e.g. under 8 seconds), my result still contains the first eight seconds from the segment. So I could grab seconds 10-15 from the beginning of the video, and the product would be an 8 second long (sometimes 15?) video of seconds 1-8 from the original segment. PLEASE tell me what is going on here. Help is much appreciated! |
| Posted by: dloneranger Jun 25 2011, 06:29 AM |
| In Direct stream copy mode Cuts can only start on key frames They are the only ones with a complete picture The rest of the frames are a sequence of changes to make to the previous frame If you start a selection on a frame that isn't a key frame, virtualdub has to include everything back to the previous keyframe So, you can end on any frame, but must start on a key frame Just set your selections to start on a key frame, using the two buttons with an image of a key on them (In the status area you should see [K] that lets you know if you're on a key frame) If you use virtualdub (not mod, that's very old and hasn't been updated) you could turn on 'smart rendering' in fast recompress mode instead Smart rendering lets you cut anywhere, and only recompresses the bits between cuts and keyframes (You have to use the same compression settings that you origionally used though, no mix'n'matching) |
| Posted by: ale5000 Jun 25 2011, 11:29 AM |
| Or you can simply divide video using "File => Save segmented AVI" in direct stream copy. |
| Posted by: dloneranger Jun 25 2011, 12:38 PM | ||
That works fine as well As long as you don't mind the segments being cut in the middle of words etc |
| Posted by: czarmurphy Jun 25 2011, 11:20 PM |
| Thanks, guys! It makes sense now. |
| Posted by: czarmurphy Jul 7 2011, 12:05 AM |
| Just as a note, I cannot get the "Save segmented AVI" to work after the video has already been compressed. |
| Posted by: ale5000 Jul 7 2011, 04:04 PM |
| Describe the exact steps that you do and the exact error. |
| Posted by: czarmurphy Jul 9 2011, 02:51 PM |
| It's similar to the same error I was having earlier. After the video is compressed, I am not able to segment my video file into bite-sized pieces. I am not able to use the command "Save segmented AVI" to cut at frames that are not keyframes. |