force_key_frames does not work for more than one key frame

[shgzs]

hi
I'm new to ffmpeg
I want to convert user-uploaded videos to mp4, to be played later via a online flash-based media player. so to add some seek-point, I use force_key_frames in this way:
(I use 32bit windows static builds)
ffmpeg -i input.mp4 -force_key_frames 1,2,3,4,5 output.mp4

it was ok until build "FFmpeg git-9849515 32-bit Static" dated 2012-04-21 , but next two builds (i.e. git-3bbf3f7 on 2012-04-24 and git-a4b58fd on 2012-04-26) produce this error:

"Invalid duration specification for force_key_frames: 1,2,3,4,5"

there is no error when I use just one point (e.g. -force_key_frames 00:00:01 ), also I tried 64bit build and same error in last two builds was encountered.

• is this a bug or something has changed about parameter entry format?
• is there a better way to make video "scroll-able"?

and this is full output with error in last line:

---

ffmpeg version N-40092-g3bbf3f7 Copyright (c) 2000-2012 the FFmpeg developers

built on Apr 24 2012 00:55:38 with gcc 4.6.3
configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-ru

ntime-cpudetect --enable-avisynth --enable-bzlib --enable-frei0r --enable-libass

--enable-libcelt --enable-libopencore-amrnb --enable-libopencore-amrwb --enable

-libfreetype --enable-libgsm --enable-libmp3lame --enable-libnut --enable-libope
njpeg --enable-librtmp --enable-libschroedinger --enable-libspeex --enable-libth
eora --enable-libutvideo --enable-libvo-aacenc --enable-libvo-amrwbenc --enable-
libvorbis --enable-libvpx --enable-libx264 --enable-libxavs --enable-libxvid --e
nable-zlib

libavutil 51. 47.100 / 51. 47.100
libavcodec 54. 15.100 / 54. 15.100
libavformat 54. 3.100 / 54. 3.100
libavdevice 53. 4.100 / 53. 4.100
libavfilter 2. 72.100 / 2. 72.100
libswscale 2. 1.100 / 2. 1.100
libswresample 0. 11.100 / 0. 11.100
libpostproc 52. 0.100 / 52. 0.100

Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'input.mp4':

Metadata:

major_brand : FACE
minor_version : 1337
compatible_brands: isomavc1FACE
creation_time : 2011-07-26 19:43:30

Duration: 00:01:36.26, start: 0.000000, bitrate: 260 kb/s

Stream #0:0(und): Video: h264 (Constrained Baseline) (avc1 / 0x31637661), yu

v420p, 400x300 [SAR 1:1 DAR 4:3], 182 kb/s, 17.33 fps, 17.33 tbr, 17330 tbn, 34.
66 tbc

Metadata:

creation_time : 2011-07-26 19:43:30
handler_name : GPAC ISO Video Handler

Stream #0:1(und): Audio: aac (mp4a / 0x6134706D), 44100 Hz, stereo, s16, 77

kb/s

Metadata:

creation_time : 2011-07-26 19:43:30
handler_name : GPAC ISO Audio Handler

Invalid duration specification for force_key_frames: 1,2,3,4,5