FPS Help

[Sakuya]

The AVI I'm converting is 23.976fps. What difference will it make if I convert it to 29.76fps? I did a test run and I don't notice any difference...

[bugster]

Keep it at 23.976fps. By converting it to 29.976 fps you are simply increasing the number of frames, thus spreading the available bitrate accross more frames. If you are converting it to mpeg-2 for SVCD or DVD you will need to apply 3:2 pulldown.

[Sakuya]

So what would happen after I converted it to 29.76? It looks fine...

[adam]

If you simply convert it to 29.97fps then one of two things will happen depending on what encoder and settings you use. 1) it will just speed the movie up by about 20% making it play in super fast motion. 2) random frames will be repeated making it play in super choppy motion.

If you do a proper telecine to 29.97fps then each frame will be split into two fields and the fields will be repeated in a specific pattern so that the fps is increased to 29.97fps, but you don't get any of the side effects mentioned above. The 3:2 pulldown filter in TMPGenc (On the Advanced tab NOT on the video tab!) can do this but there is no need because your dvd player will do it for you if you just encode at 23.976fps. As bugster said, if encoding in mpeg2 you must include the 3:2 pulldown flag, otherwise just encode and author normally.

Encoding in 29.97fps as opposed to 23.976fps is a bad move. You lose about 15% quality because of all the increased frames, and since you have more frames to analyze and encode the encoding takes longer to complete. You lose an additional amount of quality because your video is now interlaced and all software encoders produce worse quality encoding interlaced footage as opposed to progressive footage. Finally, since your footage is interlaced you have additional things to worry about such as field order and interlacing artifacts.

[videocheez]

You may want to downloading this. I use this prog. to run pulldown on my 23.976fps files prior to authoring.