ffmpeg  -an -y -vcodec rawvideo -f rawvideo -pix_fmt rgb32 -s 800x1280 -i /sdcard/tempfifo /sdcard/output.avi 2> /sdcard/ffmpeg.log

ffmpeg version 0.11.1 Copyright (c) 2000-2012 the FFmpeg developers
  built on Oct 26 2012 00:38:32 with gcc 4.6.x-google 20120106 (prerelease)
  configuration: --arch=arm --cpu=cortex-a8 --target-os=linux --enable-runtime-cpudetect --prefix=/data/data/org.witness.sscvideoproto --enable-pic --disable-shared --enable-static --cross-prefix=/home/oz/android-ndk-r8b//toolchains/arm-linux-androideabi-4.6/prebuilt/linux-x86/bin/arm-linux-androideabi- --sysroot=/home/oz/android-ndk-r8b//platforms/android-3/arch-arm --extra-cflags='-I../x264 -mfloat-abi=softfp -mfpu=neon' --extra-ldflags=-L../x264 --enable-version3 --enable-gpl --disable-doc --enable-yasm --enable-decoders --enable-encoders --enable-muxers --enable-demuxers --enable-parsers --enable-protocols --enable-filters --enable-avresample --enable-libfreetype --disable-indevs --enable-indev=lavfi --enable-indev=fbdev --disable-outdevs --enable-hwaccels --enable-ffmpeg --disable-ffplay --disable-ffprobe --disable-ffserver --disable-network --enable-libx264 --enable-zlib
  libavutil      51. 54.100 / 51. 54.100
  libavcodec     54. 23.100 / 54. 23.100
  libavformat    54.  6.100 / 54.  6.100
  libavdevice    54.  0.100 / 54.  0.100
  libavfilter     2. 77.100 /  2. 77.100
  libswscale      2.  1.100 /  2.  1.100
  libswresample   0. 15.100 /  0. 15.100
  libpostproc    52.  0.100 / 52.  0.100
[rawvideo @ 0x21b2540] Estimating duration from bitrate, this may be inaccurate
Input #0, rawvideo, from '/sdcard/tempfifo':
  Duration: N/A, start: 0.000000, bitrate: N/A
    Stream #0:0: Video: rawvideo (BGRA / 0x41524742), bgra, 800x1280, 25 tbr, 25 tbn, 25 tbc
[buffer @ 0x21be6e0] w:800 h:1280 pixfmt:bgra tb:1/25 sar:0/1 sws_param:flags=2
[buffersink @ 0x21be950] No opaque field provided
[format @ 0x21bea70] auto-inserting filter 'auto-inserted scaler 0' between the filter 'src' and the filter 'format'
[scale @ 0x21bfc10] w:800 h:1280 fmt:bgra sar:0/1 -> w:800 h:1280 fmt:yuv420p sar:0/1 flags:0x4
Output #0, avi, to '/sdcard/output.avi':
  Metadata:
    ISFT            : Lavf54.6.100
    Stream #0:0: Video: mpeg4 (FMP4 / 0x34504D46), yuv420p, 800x1280, q=2-31, 200 kb/s, 25 tbn, 25 tbc
Stream mapping:
  Stream #0:0 -> #0:0 (rawvideo -> mpeg4)
Press [q] to stop, [?] for help
Error while decoding stream #0:0
frame=    0 fps=0.0 q=0.0 Lsize=       6kB time=00:00:00.00 bitrate=   0.0kbits/s
video:0kB audio:0kB global headers:0kB muxing overhead Inf%
Output file is empty, nothing was encoded (check -ss / -t / -frames parameters if used)