[Kdenlive-devel] Advise on using NTSC 4/3 material in PAL 16/9 project

[Dan Dennedy]

I already replied previously to the other interested party or the list
here about the slowmotion producer. I tried it, and I can not get it
to work good. It ends up distorting the image very badly.

On Sat, Apr 5, 2008 at 2:10 PM, Mads Bondo Dydensborg
<mads at dydensborg.dk> wrote:
> mandag 24 Marts 2008 skrev Dan Dennedy:
>
> > On Sun, Mar 23, 2008 at 3:26 PM, Mads Bondo Dydensborg
>
> > >  I have some footage taken with a helmet cam in 640x480 @30 fps (4/3),
>  that I
>  > >  would like to use in a PAL DV 16/9 project.
>  > >
>  > >  What is the best way to get the highest quality of the headcam footage in
>  > >  kdenlive? Should I transcode it using some external program, or just add
>  it
>  > >  as a clip to kdenlive?
>  >
>  > The simplest is to just add it as a clip. MLT does framerate
>  > decimation and image resampling automatically. However, to get more
>  > quality, you need high quality temporal interpolation. Zachard Drew
>  > wrote the motion estimation module[1] in MLT that can use in an inigo
>  > job to transcode it prior to use in kdenlive. However, I do not have
>  > any experience using motion estimation for this. After making sure to
>  > build the module (it is opt-in), try this as a hint to get started:
>  >
>  > $ inigo -profile dv_pal_wide slowmotion:some-ntsc.avi speed=0.8342
>  > -consumer avformat:my.dv ...
>
>  Hi Dan
>
>  I had quite some trouble getting this to work:
>
>  $ /opt/bin/inigo -profile dv_pal_wide -producer slowmotion:avi_0019.avi
>  speed=0.8342 -consumer avformat:0019.dv progress=1
>
>  Turns out, the command line parsing in inigo can be tricked to loop (some more
>  info below).
>
>  This command works (I have still to experiment further):
>
>  $ /opt/bin/inigo -profile dv_pal_wide -consumer avformat:0019.dv progress=1
>  slowmotion:avi_0019.avi speed=0.8342
>
>  The "-producer" is from me misreading the cli syntax of inigo. My bad. But
>  still, I suspect there is a loop in inigo command line parsing. A quick look
>  with gdb seems to indicate a never ending loop in scanning the command line
>  arguments of the first try:
>
>  Program received signal SIGINT, Interrupt.
>  [Switching to Thread -1210513216 (LWP 31948)]
>  0xb6d02b13 in producer_inigo_init (profile=0x8091608, type=producer_type,
>  id=0x804b8c7 "inigo", argv=0xbf9ffef8)
>     at producer_inigo.c:157
>  157                     else if ( !strcmp( argv[ i ], "-attach" ) ||
>  (gdb) bt
>  #0  0xb6d02b13 in producer_inigo_init (profile=0x8091608, type=producer_type,
>  id=0x804b8c7 "inigo",
>     argv=0xbf9ffef8) at producer_inigo.c:157
>  #1  0xb7f591c2 in mlt_repository_create (this=0x8050e28, profile=0x8091608,
>  type=producer_type,
>     service=0x804b8c7 "inigo", input=0xbf9ffef8) at mlt_repository.c:171
>  #2  0xb7f5884c in mlt_factory_producer (profile=0x8091608,
>  service=0x804b8c7 "inigo", input=0xbf9ffef8)
>     at mlt_factory.c:179
>
>  (gdb)
>  145             for ( i = 0; argv[ i ] != NULL; i ++ )
>  (gdb) p i
>  $6 = 1
>  (gdb) p argv[i]
>  $7 = 0xbfa006a5 "dv_pal_wide"
>  (gdb) n
>  147                     if ( !strcmp( argv[ i ], "-group" ) )
>  (gdb) p i
>  $8 = 2
>  (gdb) p argv[i]
>  $9 = 0xbfa006b1 "-producer"
>  (gdb) n
>  157                     else if ( !strcmp( argv[ i ], "-attach" ) ||
>  (gdb) n
>  202                     else if ( !strcmp( argv[ i ], "-repeat" ) )
>
>  This continues, and never matches anything. At some point it hits a i--; - and
>  loops. For ever AFAICT :-/
>
>
>  > It's just that 0.8342 is an approximation, and I do not know how good
>  > the results will be.
>
>  How did you get the 0.8342?
>
>  25/30
>  .83333333333333333333
>  25000/29999
>  .83336111203706790226
>
>
>
>  > Sharing your experience would be valuable.
>
>  My first experience is this: I loose the sound, right?
>
>
>  > There
>  > is a trick to get kdenlive to do this for you without transcoding. You
>  > can convert the above into a westley-based "virtual" clip and load the
>  > .westley into kdenlive:
>  >
>  > $ inigo -profile dv_pal_wide slowmotion:some-ntsc.avi speed=0.8342
>  > -consumer westley:some-ntsc.westley
>
>  Thanks - I have yet to test it out.
>
>  Now, that it actually works for me, I will test with some more clips, and see
>  if I can figure out anything about the quality of the result, and so on.
>
>  Regards
>
>  Mads
>
>  --
>  Mads Bondo Dydensborg   mads at dydensborg.dk   http://www.madsdydensborg.dk/
>
>  Today, the record companies are saying MP3s are the biggest evil. Tomorrow
>  they're going to say they're the greatest thing when they figure
>  them out.
>                                - Gene Kan, Gnutella developer
>