[MEncoder-users] How to transcode video clips to nv12(YUV420 semi-plannar) format?

[Tuff Li]

Hi Experts,

I met one problem of mencoder:

Now, I am testing a HW H.264 encoder, this encoder need YUV420
semi-planner(nv12) as the input format, so I tried to convert some video clips
to this format, but it seems mencoder can not do this...

when I tried to run "mencoder -vf format=nv12 -nosound -ovc raw -of rawvideo
-ofps 30 -o vga_nv12_test.yuv ACM_1011_Traffic.avi", I always got below message:

MEncoder SVN-r29463-4.3.3 (C) 2000-2009 MPlayer Team
success: format: 0  data: 0x0 - 0xae6800
AVI file format detected.
[aviheader] Video stream found, -vid 0
[aviheader] Audio stream found, -aid 1
VIDEO:  [DX50]  640x480  24bpp  29.970 fps  3028.4 kbps (369.7 kbyte/s)
[V] filefmt:3  fourcc:0x30355844  size:640x480  fps:29.970  ftime:=0.0334
Opening video filter: [expand osd=1]
Expand: -1 x -1, -1 ; -1, osd: 1, aspect: 0.000000, round: 1
Opening video filter: [format fmt=nv12]
==========================================================================
Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
Selected video codec: [ffodivx] vfm: ffmpeg (FFmpeg MPEG-4)
==========================================================================
VDec: vo config request - 640 x 480 (preferred colorspace: Planar YV12)
Could not find matching colorspace - retrying with -vf scale...
Opening video filter: [scale]
The selected video_out device is incompatible with this codec.
Try appending the scale filter to your filter list,
e.g. -vf spp,scale instead of -vf spp.
VDec: vo config request - 640 x 480 (preferred colorspace: Planar YV12)
Could not find matching colorspace - retrying with -vf scale...
Opening video filter: [scale]
The selected video_out device is incompatible with this codec.
Try appending the scale filter to your filter list,
e.g. -vf spp,scale instead of -vf spp.

But mencoder help told this:
mencoder -vf format=fmt=help
MEncoder SVN-r29463-4.3.3 (C) 2000-2009 MPlayer Team
Available formats: 444p 422p 411p yuy2 uyvy yvu9 if09 yv12 i420 iyuv clpl hm12
y800 y8 nv12 nv21 bgr24 bgr32 bgr16 bgr15 bgr8 bgr4 bg4b bgr1 rgb24 rgb32 rgb16
rgb15 rgb8 rgb4 rg4b rgb1 rgba argb bgra abgr mjpeg mjpg

Something I did was wrong?

Any comments are appreciated...



Best Regards,
Tuff Li