[FFmpeg-user] Pullup old MPEG-2

Rens Dijkshoorn rens at offlinemedia.nl
Thu Dec 24 16:47:19 CET 2015

> Carl Eugen Hoyos wrote
>> llee782
>> <llee040 <at>
>>  sbcglobal.net> writes:
>>> It appears that the simplest way I've found to
>>> adequately handle this conversion then is to use
>>> something like:
>>> ffmpeg -i 2024_telecine_source.mpg -c:v libx264
>>> -c:a copy -r 24000/1001 2024_telecine_source_film.m4v
>> I don't know if reencoding is really necessary.
>> (It may be.)
>>> Does that work mainly because it removes the soft
>>> telecine flag, as Rens suggested?
>> I don't think "removing" is the right word: FFmpeg
>> doesn't know about the soft telecine flag and
>> therefore cannot write it to the output file.
>> (Is it really possible to write a telecine flag to a
>> m4v file? I thought it is a vob-only thing.)
> I'm just that Rens' .mov output didn't play well for me, and this output
> does.
> Carl Eugen Hoyos wrote
>>> I discovered that running it with just one "-r" value
>>> specified (either "-r 24", or "-r 24000/1001")
>>> resulted in many repeated instances of "Past
>>> duration 0.xxxxxx too large" in the shell output.
>> I think what you write here is not correct.
> I thought I tried it enough times to be able to believe it, but there may be
> something else happening that I'm not aware of, I guess. Anyway, thanks.
> Laine


i had another look now on both source files 2023_telecine_source.mpg
and 2024_telecine_source.mpg. The 2023 is interlace and @ NTSC framerate.
show tipical interlace artifacts so pulldown has been applied. 

This can be restored using a reverse telecine to the film frame rate.
Are you sure the orginal framerate is 24fps in older days they
used sometimes 18 fps to preserve on film stock.

Furter more de frame sizes are a bit odd for NTSC i would expect somthing
like 720x480 if scanning has been done on standard telecini in NTSC.
If so then scaling has been applied somewhere this might have side effects
if not scaled interlaced aware.

I have no explanation why the soft telecine file 2024 should be re-encode
just to remove the flag. Maybe its down to the player software reading this
direct from the mpeg stream and ignoring wrapper info as we just copied
the mpg data accros.

Quicktime7 and X on MAC both play @ 24 fps after the suggested cmd.

I don't have any detailed info on how soft telecine is embedded in
the mpeg stream.



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