[MPlayer-users] Is this a bug? 15fps MOV to 30fps mpeg1 halves run time

[Philip Walden]

This is related to the thread "Having trouble producing mpeg from mov".

Thanks to several folks, I have stumbled through getting it to work. 
However, I now have a new problem.

The original 28 sec MOV file in question is 15fps. To mencode it with 
the mpeg1video codec, I need to set  -ofps it to 30 (or 24) fps. The 
resulting mpeg file runs 14 seconds at a visible 2x speed.

My understanding is that -ofps is supposed to transform the output frame 
rate without affecting run or speed.

Is this true, or do I not understand the -ofps option? If not, how can I 
produce an mpeg1 file with the correct run rate?

Here is the command line I am using:

===============

$ mencoder -vf harddup -noskip -ofps  30000/1001 -of mpeg -mpegopts 
format=mpeg1 -ovc lavc -lavcopts vcodec=mpeg1video:keyint=25 -o 
PC290052.mpg PC290052.MOV
MEncoder dev-CVS-060106-08:45-3.2.2 (C) 2000-2006 MPlayer Team
CPU: Advanced Micro Devices Athlon K75 Pluto,Orion (Family: 6, Stepping: 1)
CPUflags: Type: 6 MMX: 1 MMX2: 1 3DNow: 1 3DNow2: 1 SSE: 0 SSE2: 0
Compiled for x86 CPU with extensions: MMX MMX2 3DNow 3DNowEx
 
success: format: 0  data: 0x0 - 0x88f7e6
Quicktime/MOV file format detected.
--------------
MOV track #0: 29 chunks, 434 samples
Image size: 320 x 240 (24 bpp)
Display size: 320 x 240
Fourcc: jpeg  Codec: 'Photo - JPEG'
--------------
MOV: longest streams: A: #-1 (0 samples)  V: #0 (434 samples)
VIDEO:  [jpeg]  320x240  24bpp  15.000 fps    0.0 kbps ( 0.0 kbyte/s)
[V] filefmt:7  fourcc:0x6765706A  size:320x240  fps:15.00  ftime:=0.0667
PACKET SIZE: 2048 bytes
Opening video filter: [expand osd=1]
Expand: -1 x -1, -1 ; -1, osd: 1, aspect: 0.000000, round: 1
Opening video filter: [harddup]
==========================================================================
Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
Selected video codec: [ffmjpeg] vfm: ffmpeg (FFmpeg MJPEG decoder)
==========================================================================
Limiting audio preload to 0.4s
Increasing audio density to 4
VDec: vo config request - 320 x 240 (preferred colorspace: Planar 422P)
Could not find matching colorspace - retrying with -vf scale...
Opening video filter: [scale]
VDec: using Planar 422P as output csp (no 1)
Movie-Aspect is undefined - no prescaling applied.
 
SwScaler: BICUBIC scaler, from Planar 422P to Planar YV12 using MMX2
videocodec: libavcodec (320x240 fourcc=3167706d [mpg1])
New_Face failed. Maybe the font path is wrong.
Please supply the text font file (~/.mplayer/subfont.ttf).
subtitle font: load_sub_face failed.
Writing header...
INITIAL DELAY of 0 frames 18.44fps Trem:   0min   0mb  A-V:0.000 [0:0]
Pos:  14.5s    434f ( 0%) 18.77fps Trem:   0min   0mb  A-V:0.000 [885:0]]
Flushing video frames
Writing index...
 
Overhead: 1.173% (18813 / 1603203)
Writing header...
 
Video stream:  885.678 kbit/s  (110709 B/s)  size: 1603203 bytes  14.481 
secs  434 frames