ffmpeg -f mjpeg -r 8 -i rtp://239.255.12.42:5607 -vcodec x264 -pix_fmt yuvj422p -r 18 -s qvga -minrate 4000k -maxrate 4000k -quality realtime -b:v 64k -bufsize 1835k -vcodec flv -ab 64k -ar 11025 -f flv rtmp://192.168.1.113:1935/live/camera1


And Output

ffmpeg version 1.2.1 Copyright (c) 2000-2013 the FFmpeg developers
  built on Jun 21 2013 04:25:17 with gcc 4.8.1 (GCC) 20130603 (Red Hat 4.8.1-1)
  configuration: --prefix=/usr --bindir=/usr/bin --datadir=/usr/share/ffmpeg --incdir=/usr/include/ffmpeg --libdir=/usr/lib --mandir=/usr/share/man --arch=armv7hl --optflags='-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -grecord-gcc-switches -march=armv7-a -mfpu=vfpv3-d16 -mfloat-abi=hard' --enable-bzlib --disable-crystalhd --enable-frei0r --enable-gnutls --enable-libass --enable-libcelt --enable-libdc1394 --disable-indev=jack --enable-libfreetype --enable-libgsm --enable-libmp3lame --enable-openal --enable-libopencv --enable-libopenjpeg --enable-libopus --enable-libpulse --enable-libschroedinger --enable-libspeex --enable-libtheora --enable-libvorbis --enable-libv4l2 --enable-libvpx --enable-libx264 --enable-libxvid --enable-x11grab --enable-avfilter --enable-postproc --enable-pthreads --disable-static --enable-shared --enable-gpl --disable-debug --disable-stripping --shlibdir=/usr/lib --disable-runtime-cpudetect --arch=arm --enable-thumb --disable-neon  libavutil      52. 18.100 / 52. 18.100
  libavcodec     54. 92.100 / 54. 92.100
  libavformat    54. 63.104 / 54. 63.104
  libavdevice    54.  3.103 / 54.  3.103
  libavfilter     3. 42.103 /  3. 42.103
  libswscale      2.  2.100 /  2.  2.100
  libswresample   0. 17.102 /  0. 17.102
  libpostproc    52.  2.100 / 52.  2.100
^CCould not find codec parameters for stream 0 (Video: mjpeg): unspecified size
Consider increasing the value for the 'analyzeduration' and 'probesize' options
[mjpeg @ 0x50da0] Estimating duration from bitrate, this may be inaccurate
rtp://239.255.12.42:5607: could not find codec parameters
Received signal 2: terminating.