[MEncoder-users] B-frames and GOP with MPEG-2 for DVD

[Nicolas Hesler]

Nicolas Hesler wrote:
>  The curious thing about the skipping frames is 
> that my input is exactly 24fps (not 23.976) and my output is 23.976.  If 
> you take the difference (0.024 x the seconds where it was skipping 
> frames, you end up with almost exact integers of 2,4,6, etc.) any ideas 
> on that?
>   
I've just completed another test on a longer video to confirm my 
findings.  Ok, So If you take the exact frame location where the frame 
was skipped and divide it by the incoming frame rate (exactly 24fps (not 
23.976...)) and then multiply that by the difference in frame rate 
between the input (24) and the output (24000/1001), you end up with 
exact integers (2,3,4,5,6,7), although sometimes it does not report 
skipping a frame at a given integer (see below...it doesn't report at 6, 
8, 11, 13). Another number that is recurrent is the difference between 
skipped frames which is usually 1001 frames.  This must all somehow make 
sense.  But I don't know how.  Anyone?


ENABLED SOFT TELECINING, FPS=29.97, INITIAL PATTERN IS TFF:0, RFF:1

1 duplicate frame(s)!
Pos:   1.0s     25f ( 0%)  0.00fps Trem:   0min   0mb  A-V:0.085 [859:224]
Skipping frame!
Pos:  83.4s   2002f ( 5%) 20.63fps Trem:  30min 547mb  A-V:0.061 [2499:224]
Skipping frame!
Pos: 125.1s   3003f ( 7%) 20.49fps Trem:  30min 545mb  A-V:0.062 [2474:223]
Skipping frame!
Pos: 166.8s   4004f (10%) 20.59fps Trem:  29min 493mb  A-V:0.061 [2217:224]
Skipping frame!
Pos: 208.5s   5005f (12%) 20.64fps Trem:  28min 467mb  A-V:0.060 [2085:224]
Skipping frame!
Pos: 292.0s   7007f (17%) 20.60fps Trem:  26min 446mb  A-V:0.059 [1977:224]
Skipping frame!
Pos: 375.4s   9009f (22%) 20.48fps Trem:  25min 445mb  A-V:0.057 [1972:223]
Skipping frame!
Pos: 417.1s  10010f (24%) 20.49fps Trem:  24min 445mb  A-V:0.059 [1970:224]
Skipping frame!
Pos: 500.5s  12012f (29%) 20.43fps Trem:  22min 448mb  A-V:0.061 [1984:224]
Skipping frame!
Pos: 583.9s  14014f (34%) 20.47fps Trem:  21min 449mb  A-V:0.061 [1990:224]
Skipping frame!
Pos: 625.6s  15015f (37%) 20.47fps Trem:  20min 451mb  A-V:0.061 [1999:223]
Skipping frame!
Pos: 667.3s  16016f (39%) 20.50fps Trem:  19min 446mb  A-V:0.062 [1974:224]
Skipping frame!