[FFmpeg-user] The newest ffmpeg split video very slowly with async 2 or 1

[Tony Song]

Hi,All.
 I have some mkv files splited by the newest ffmpeg with async.
 ffmpeg works well with somes mkv files,but others very slowly either
-sync 2 or 1
 Below is the abnormal  info.

# ffmpeg -y -ss 00:01:00.00 -t 00:01:00.00 -i /data/test.mkv -vcodec
libx264 -async 2 -f mpegts /data/test.ts

ffmpeg version N-45839-g2d11ee4 Copyright (c) 2000-2012 the FFmpeg
developers
  built on Oct 22 2012 11:33:19 with gcc 4.4.4 (GCC) 20100726 (Red Hat
4.4.4-13)
  configuration: --disable-yasm --enable-libx264 --enable-libass
--enable-gpl --enable-zlib
  libavutil      51. 76.101 / 51. 76.101
  libavcodec     54. 68.100 / 54. 68.100
  libavformat    54. 33.100 / 54. 33.100
  libavdevice    54.  3.100 / 54.  3.100
  libavfilter     3. 20.102 /  3. 20.102
  libswscale      2.  1.101 /  2.  1.101
  libswresample   0. 16.100 /  0. 16.100
  libpostproc    52.  1.100 / 52.  1.100
Input #0, matroska,webm, from '/data/test.mkv':
  Metadata:
    creation_time   : 2012-05-11 12:32:45
  Duration: 00:10:01.08, start: 0.000000, bitrate: 9958 kb/s
    Stream #0:0(eng): Video: h264 (High), yuv420p, 1920x800, SAR 1:1 DAR
12:5, 23.98 fps, 23.98 tbr, 1k tbn, 47.95 tbc (default)
    Stream #0:1(eng): Audio: ac3, 48000 Hz, 5.1(side), s16, 640 kb/s
(default)
    Metadata:
      title           : English
    Stream #0:2(eng): Subtitle: subrip (default) (forced)
    Metadata:
      title           : English
-t is not an input option, keeping it for the next output; consider fixing
your command line.
-async is forwarded to lavfi similarly to -af
aresample=min_comp=0.001:min_hard_comp=0.100000:max_soft_comp=0.000042.
Output #0, mpegts, to '/data/test.ts':
  Metadata:
    encoder         : Lavf54.33.100
    Stream #0:0(eng): Video: h264, yuv420p, 1920x800 [SAR 1:1 DAR 12:5],
q=-1--1, 90k tbn, 23.98 tbc (default)
    Stream #0:1(eng): Audio: mp2, 48000 Hz, stereo, s16, 128 kb/s (default)
    Metadata:
      title           : English
Stream mapping:
  Stream #0:0 -> #0:0 (h264 -> libx264)
  Stream #0:1 -> #0:1 (ac3 -> mp2)
Press [q] to stop, [?] for help
frame=    0 fps=0.0 q=0.0 Lsize=       0kB time=00:00:00.00 bitrate=
0.0kbits/s dup=0 drop=86

Any suggestions are appreciated.

-- 
laugh out loud.