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  1. Member
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    I am thinking about making clips and merging them together in Virtualdub2. My question is, will be able to tell if the video merged or will they not? I know that there are very astute people who can pickup on details but will people able to tell if some video clips got merged into one video? Or is it all just one big "magic" trick that only all but the most eagle eyed individual can detect? How do make it so that the video appears to be one seamless transition to the next?
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  2. Originally Posted by Guernsey View Post
    I am thinking about making clips and merging them together in Virtualdub2. My question is, will be able to tell if the video merged or will they not? I know that there are very astute people who can pickup on details but will people able to tell if some video clips got merged into one video? Or is it all just one big "magic" trick that only all but the most eagle eyed individual can detect? How do make it so that the video appears to be one seamless transition to the next?
    It depends how similar the end of the 1st clip and start of the 2nd clip are .

    If you can choose points that are more similar, you can blend the clips over a certain number of frames to make the transition appear closer to "seamless"
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  3. Member
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    So there is a way to make the videos appear "seamless" I do not want any frame to appear out of place.
    Last edited by Guernsey; 26th Nov 2021 at 16:35.
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  4. Member Budman1's Avatar
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    Not sure exactly what you wish but thats probably just me. Are you wanting to create videoes from the same video and join them. Not sure how you would get the end of one video and the start of the other the same but if that is the case then just find the same frame in the second frame as the first and cut starting one frame beyond. Sort of like:
    1st videos end
    bbbpbbbpbbbP
    Pbbbpbbbpbbbp

    If you need to search the videos, make an image of the last frame you want in video one. Find similr image in video 2 using a script as:

    ffmpeg.exe -i video.mp4 -loop 1 -i image.jpg -an -filter_complex "blend=differencehortest=1,blackframe=99:32" -f null - 2> log.txt
    you will receive and output such as:

    frame= 123 fps=0.0 q=-0.0 size=N/A time=00:00:04.09 bitrate=N/A speed=7.73x
    frame= 255 fps=244 q=-0.0 size=N/A time=00:00:08.49 bitrate=N/A speed=8.13x
    [Parsed_blackframe_1 @ 06f29ec0] frame:300 pblack:99 pts:9999990 t:9.999990 type:B last_keyframe:250
    [Parsed_blackframe_1 @ 06f29ec0] frame:301 pblack:99 pts:10033323 t:10.033323 type:B last_keyframe:250
    [Parsed_blackframe_1 @ 06f29ec0] frame:302 pblack:99 pts:10066657 t:10.066657 type:P last_keyframe:250
    frame= 388 fps=249 q=-0.0 size=N/A time=00:00:12.93 bitrate=N/A speed=8.29x
    frame= 521 fps=251 q=-0.0 size=N/A time=00:00:17.36 bitrate=N/A speed=8.37x
    frame= 600 fps=240 q=-0.0 Lsize=N/A time=00:00:19.99 bitrate=N/A speed=8.01x
    video:239kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
    Notice frame 300 is almost 100 percent with 301 and 302 also 99 percent. Also notice the last keyframe was at 250 so the second video would have to be encoded in order to start with an 'I' frame. Yes you can join without a noticeable change.

    Now the bad news, video 1 cannot end on a b frame, especially if you are merging another video behind it. It would have to be a 'P' frame which it probably is if you created it. If you just cut it, then ending on a 'B' frame will cause many ecitors, especially those that are FFMPEG based, to double up the PTS time of the last several frames to account for this and that will be noticeable.

    Best to cut at a 'P' frame and rencode onlly the second video.
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