Youtube videos have repeated/duplicate frames - is this normal?

[KDE_fan]

I was watchinng a video and I thought it looked odd, I didn't know what it was but something just seemed off. I downloaded the video in full resolution (1280 x 720 & 29.4 fps). I used a couple programs and they all downloaded files of the same size, so I'm sure I got the largest file that was on the server.

I started stepping through the video frame by frame and when there was a close up where it is basically just a person talking (nothing else moving excpet mouth, eyes, hair, facial features), the video will duplicate frames and run the same frame 2-4 times in a row. I looked at other videos that are the same basic setup and even when it is just a head shot, there are never EXACT duplicate frames. The video I was looking at had about 30-40% of the video as dupllicate frames.

I looked at VLC codec info and it was H264 and it did show 10 dropped frames, but I saw 100's of dupes.

This same poster, all their vids are the same with the repeated frames. Are there any codecs that do this when encoding or is there any reason for doing this? To me it looks like the video was highly edited ("air brushed") and it was easier to drop frames then to "clean" each individual frame as that would have been A LOT more work.

Anyone have any insight on this and have any ideas as to what might be going on?

[darkknight145]

Without knowing anything about the video it could possibly have been converted from PAL to NTSC before it was uploaded to YouTube.
PAL is 25 fps, NTSC is 29 fps. The conversion process will duplicate 4fps to make it up to the required 29 fps.

[KDE_fan]

Without knowing anything about the video it could possibly have been converted from PAL to NTSC before it was uploaded to YouTube.
PAL is 25 fps, NTSC is 29 fps. The conversion process will duplicate 4fps to make it up to the required 29 fps.

Thanks for the response! I don't think it was. I'm guessing that it was a webcam or cell phone from what I read in the description of the channel and most probably in the US.

I'm wondering if the porn industry uses this type of technique that I described. The way the video was recorded seems an awful lot like it was shot by someone who worked in that industry, the way they used the angles, where they focused and even the way the person talked and moved. I haven't seen any of "those" videos in a long time so I don't know how the current ones would look.

I just can't see a reason for editing the video like this, no benefit, unless it was to keep the # of frames down that needed editing/brushed.

I just counted 17 frames during one second, then 16 and in some others 13 and 14.
There were a number of frames where the blinking was off, one second open, next closed, next open while other videos with same rate, blinking is always at least 2 frames and I can always see motion.

[jagabo]

Give a link to the youtube video. But keep in mind... Youtube changes the frame rates if you upload something other than one of their accepted rates. And many people have no idea what they're doing.