Variable Frame Rate on H.264 output

i using ae cs6 (cloud version). trying render compositions 1080p mp4.  each time comp appears render fine.  bringing nle crashes nle.  brought media mediainfo (app sourceforge shows media clip).  says frame rate variable  min: 60fps;  max 60.6 fps.  composition 80 fps, , told renderer keep @ 80.  mediainfo said duration on 6 seconds.  composition little on 4 seconds. overall speed of comp incorrect.  i've been in video business 10 years.  understand frame rates, etc.  never heard of variable frame rates until this.

 

i able launder media file through freeware media format converter, , got constant frame rate proceed in nle project.  time still 6 seconds.  had speed clip in nle correct.

 

since moving cs6 cs4, decided start using h.264 output module.  i've started encountering variable frame rate problem.

 

so questions... variable frame rate, how did 'request' it, why variable frame rate no near comp frame rate, , do mp4 80fps want?

 

this reproducible me.  comps either hdtv 1920x1080 or hdv 1440x1080. 

 

add render queue

select dv settings, change field order none

select h.264 output module

render

 

can explain what's going on?

 

thanks.

 

jerry

where did footage , format shot in?  shot in slow motion or did change frame rate in ae?  why need 80fps footage unless you're going slow down normal frame rate?

 

also, h.264 not lossy format, it's bad intermediate format.  if you're planning on editting footage later on in nle, i'd suggest rendering else.  premiere should work fine h.264, not fcp, although think fixed in fcpx, didn't nle you're using.

 

second of all, h.264 encoder better in adobe media encoder.  check post andrew yoole:

 

3.andrew yoole,

 

jun 8, 2012 6:34 pm   in reply pkaracas

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as other guys have said, don't use ae render using temporal codecs.  temporal codecs h264 rely on storing partial frames based on earlier information.  ae renders , encodes 1 frame @ time, of efficiency of codec h264 lost.  result lower overall quality ae h.264 render if encode externally.

 

adobe media encoder or quicktime 7 encode great quality h.264 files.

 

 

was helpful? yes   no

 

as said i'm not sure why need take 80fps piece of footage nle, if you're trying make footage play in slow motion, you're going have re-interpret frame rate of footage in after effects play @ standard rate.  and, if you're going use ae render queue output more editing, suggest using best settings , outputting production codec such prores, animation, uncompressed 10bit, uncompressed 8bit or black magic. 

 

also i've never used media info app before, know when open quicktime , hit command on mac view inspector, playing fps jumps around.  think happens because player doesn't play correct frame rate @ times.

 

this adobe captivate blog talks variable frame rates in f4v files.  maybe might explain things.

 

http://blogs.adobe.com/captivate/2010/11/f4v-or-f4v-fixed-frame-rate-what-should-i-go-with .html

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