[MEncoder-users] Convert to 3gp failed

[Vincent Chavelle]

Hi, I want to encode a movie to 3gp but I have the following errors...

# mencoder movie.flv -oac lavc -ovc lavc -lavcopts
vcodec=h263p:vbitrate=10:acodec=amr_nb -of lavf -o movie.3gp -vf
scale=160:120 -lavfopts i_certify_that_my_video_stream_does_not_use_b_frames

CPUflags: Type: 6 MMX: 1 MMX2: 1 3DNow: 0 3DNow2: 0 SSE: 1 SSE2: 1
Compiled for x86 CPU with extensions: MMX MMX2 SSE SSE2

success: format: 0  data: 0x0 - 0x1680ef
libavformat file format detected.
VIDEO:  [FLV1]  320x240  0bpp  20.000 fps    0.0 kbps ( 0.0 kbyte/s)
[V] filefmt:35  fourcc:0x31564C46  size:320x240  fps:20.00  ftime:=0.0500
==========================================================================
Opening audio decoder: [mp3lib] MPEG layer-2, layer-3
AUDIO: 22050 Hz, 2 ch, s16le, 64.0 kbit/9.07% (ratio: 8000->88200)
Selected audio codec: [mp3] afm: mp3lib (mp3lib MPEG layer-2, layer-3)
==========================================================================
** MUXER_LAVF
*****************************************************************
You have certified that your video stream does not contain B frames.
REMEMBER: MEncoder's libavformat muxing is presently broken and will
generate
INCORRECT files in the presence of B frames. Moreover, due to bugs MPlayer
will play these INCORRECT files as if nothing were wrong!
*******************************************************************************
OK, exit
Opening video filter: [expand osd=1]
Expand: -1 x -1, -1 ; -1, osd: 1, aspect: 0.000000, round: 1
Opening video filter: [scale w=160 h=120]
==========================================================================
Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
Selected video codec: [ffflv] vfm: ffmpeg (FFmpeg Flash video)
==========================================================================
[amr_nb @ 0x87b9060]Only 8000Hz sample rate supported
Couldn't open codec amr_nb, br=224.

Exiting...



I don't understand... amr_nb is present and the result of configure is :

Checking for AMR narrowband ... yes
Checking for AMR narrowband, fixed point ... no
Checking for AMR wideband ... yes
I need help for encoding !

Thanks in advance,
Vincent