Skipping Frames durring encode?

[dr9553]

When I go to encode a VIDEO_TS folder to xvid, the info above the "open" box says that a file is 29.97 but when I go to encode it and look at the info there are a ton of skipped frames and it switches between 29.97 and 23.98 for a few frames at times. anyone know why this could be? should i just try setting it to NTSC FILM for the encode?

[brysongilbert]

i've been having the same problem with a VOB source (which ffmpegx tells me is 23.976 fps) and mencoder Divx and Xvid (both codecs exhibit the same behavior). despite the fact that i've set 23.976 fps in ffmpegx, the encoder will switch back and forth between that and 29.97 fps at random points during the encode. it skips sometimes as many as 25% of frames, more often 10-15%. i have a feeling this may be why i cannot get an encode job to hit the file size target i'd like, despite a two-pass encode.

so, two questions: does the frame rate setting in ffmpegx actually have an effect, if the encoder is just going to switch when it wants to anyway? and what can i do to fix this frame-skipping problem? the behavior is exhibited regardless of what i choose for frame rate in ffmpegx, and i'm not sure but i don't think i have had this issue before 0.0.9r (i've just upgraded to 0.0.9s with the new binaries as well, and i still have the problem).

[rpg]

most likely your content is either is a mixed progressive/interlaced source or a progressive source with faulty 2:3 pulldown flags.

have you tried running this through pulldown to remove the pulldown flags and return the source to its original format?

open up the ffmpeg package and try using the command line app pulldown. demux your VOB and use pulldown to remove all the flags and reset your film source. then it should stay at 23.976

[brysongilbert]

i'll give that a shot and hope for the best... i was pretty lost on this one having had many successful encodes in the past without any such errors. thanks so much for your help.

[brysongilbert]

okay, so i demuxed my VOB and stripped all flags in the .m2v with the pulldown tool; that went fine. a quick test reveals that your solution was spot-on. problem solved, no more skipped frames or dancing back and forth from 23.976 fps to 29.97. thanks again for your help.

however, in going through these steps, i came across an issue that i'm guessing has more to do with the actual application itself, meaning major may have to address it. after demuxing the VOB, i'm (not surprisingly) left with .m2v and .ac3 files. the problem arises later on when i try to add the .ac3 file to my encode using "Add Audio..." in the Audio tab. i get a dialog box saying "AppleScript Error: NSCannotCreateScriptCommandError (10)". this happens whether i've already dragged and dropped my .m2v file into the summary tab or not, and also happens if i add the .m2v first manually with the "Open.." button.

major?

[major]

I will check this, thank you for reporting.

[major]

Fixed. Check https://www.videohelp.com/forum/viewtopic.php?p=1195000#1195000

[brysongilbert]

incredible, as always. keep up the great work.

[dr9553]

will this pulldown meathod not work if you just click the pulldown button in the tools section? and what if your source claims to be 29.97? will this work for that too?

[foopot]

Hi, where is the pulldown command line app located? I've looked for it within the ffmpegx app support, etc. and can't find it to use. Is this something I have to download separately and use, or are you referring to the pulldown tool button within ffmpegx? I've tried doing the above with the pulldown button and it did eliminate the swapping back and forth of frame rates and skipping of frames, but after encoding the Xvid .avi I end up with a file that has a 23.98 fps rate w/3:2 pull and is in sync at the beginning and goes out of sync by almost a second by the 1 1/2 hr mark. I want to try the pulldown app if it's different than the button, cause' the button is adding flags when the above recommends removing them and I'm pretty sure that's the key to my sync prob. Any help is greatly appreciated.

[brysongilbert]

where is the pulldown command line app located?

if you right-click (or control-click) on your ffmpegX application bundle, and choose Show Package Contents, then navigate to Contents>Resources, you should see a bunch of different files, one of which is the 'pulldown' binary. in order to use it, navigate to that Resources folder in Terminal, type ./pulldown and it'll spew out a list of possible arguments.

[foopot]

Thanks so much! I would have never guessed that in a million years.

[dr9553]

would i use the noriff command to remove the flags?