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I have a couple hi-def movies, 1280x720, each is about 700mb, and all videos are of the same size, video codec and audio codec. All the movies can be played without any problem. I used mencoder from the mplayer package to merge them into one file. The command I used was:

mencoder *.wmv -oac copy -ovc copy -o video.wmv

But when I play video.wmv, the picture becomes lagged, it seems each frame will stay for 2-3sec. I tried to play with totem & vlc, both give the same results.

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Are you sure mencoder can easily merge videos with that command? Have you ever tried it before? As far as I'm concerned, you can't just "append" video like this and expect it to work. – slhck May 21 '12 at 14:53
^ at the least they may need to be fully the same type of video right down to framerate res , and audio type, or even if it could toss the data together, it wouldnt be correct. – Psycogeek May 21 '12 at 16:25
@slhck: I have used this method many times to merge my videos without any problem; – davidshen84 May 22 '12 at 9:21
up vote 0 down vote accepted


I think it is a compatibility issue with the wmv format and ffmpeg. ffmpeg cannot detect the fps of the video file correctly, and set it to 1. I think the default should be 25.

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