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ruby-on-railsmp4rmagick

Generate 30FPS MP4 with Rmagick

I am using Imagemagick and Rmagick in Rails to generate MP4 videos. I am trying to change the frame rate and it keeps comming up at 25FPS.

I see in some examples that at a command line level you can use -delay 1x2, Nobody explains the 1x2, i'm guessing its ticks/second and tick/frame. but it doesn't seem to change the delay when using Rmagick.

I've also set the ticks_per_second to 600 and the delay to 30 on the Imagelist object. No joy.

Solution

  • Okay I made this work. if i do the math correctly:) 600/30=20FPS

    set ticks_per_second to 60 on the ImageList and delay to 2 on each image in the ImageList.

    animation=ImageList.new
animation.ticks_per_second=60
frames.each{ |frame|
   animation.push(frame)
   animation.cur_image.delay=2
}
animation.write('my file')

    I get an film at the right speed. But the film info window in Quicktime still shows 25FPS. That's probably a defect but easy to ignore.