pi@raspberrypi:~/ffmpeg $ raspivid -o - -t 0 -vf -hf -fps 5 -b 6000000 | ./ffmpeg -f lavfi -i nullsrc -f h264 -i - -vcodec copy -acodec aac -f flv rtmp://209.85.230.23/live2/xbjs-a3gp-0yvk-ftdg
ffmpeg version 3.1.4-static http://johnvansickle.com/ffmpeg/  Copyright (c) 2000-2016 the FFmpeg developers
  built with gcc 5.4.1 (Debian 5.4.1-2) 20160904
  configuration: --enable-gpl --enable-version3 --enable-static --disable-debug --enable-libmp3lame --enable-libx264 --enable-libwebp --enable-libspeex --enable-libvorbis --enable-libvpx --enable-libfreetype --enable-fontconfig --enable-libxvid --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libtheora --enable-libvo-amrwbenc --enable-gray --enable-libopus --enable-libass --enable-gnutls --enable-libvidstab --enable-libsoxr --enable-frei0r --enable-libfribidi --disable-indev=sndio --disable-outdev=sndio --enable-librtmp --cc=gcc-5 --disable-ffplay
  libavutil      55. 28.100 / 55. 28.100
  libavcodec     57. 48.101 / 57. 48.101
  libavformat    57. 41.100 / 57. 41.100
  libavdevice    57.  0.101 / 57.  0.101
  libavfilter     6. 47.100 /  6. 47.100
  libswscale      4.  1.100 /  4.  1.100
  libswresample   2.  1.100 /  2.  1.100
  libpostproc    54.  0.100 / 54.  0.100
Input #0, lavfi, from 'nullsrc':
  Duration: N/A, start: 0.000000, bitrate: N/A
    Stream #0:0: Video: rawvideo (I420 / 0x30323449), yuv420p, 320x240 [SAR 1:1 DAR 4:3], 25 tbr, 25 tbn, 25 tbc
[h264 @ 0x32f2e70] Stream #0: not enough frames to estimate rate; consider increasing probesize
Input #1, h264, from 'pipe:':
  Duration: N/A, bitrate: N/A
    Stream #1:0: Video: h264 (High), yuv420p, 1920x1080, 25 fps, 25 tbr, 1200k tbn, 50 tbc
[flv @ 0x3316610] Using AVStream.codec to pass codec parameters to muxers is deprecated, use AVStream.codecpar instead.
Output #0, flv, to 'rtmp://209.85.230.23/live2/xbjs-a3gp-0yvk-ftdg':
  Metadata:
    encoder         : Lavf57.41.100
    Stream #0:0: Video: h264 ([7][0][0][0] / 0x0007), yuv420p, 1920x1080, q=2-31, 25 fps, 25 tbr, 1k tbn, 1200k tbc
Stream mapping:
  Stream #1:0 -> #0:0 (copy)
[flv @ 0x3316610] Timestamps are unset in a packet for stream 0. This is deprecated and will stop working in the future. Fix your code to set the timestamps properly
[h264 @ 0x32f2e70] Thread message queue blocking; consider raising the thread_queue_size option (current value: 8)
frame=  215 fps=4.7 q=-1.0 size=   31140kB time=00:00:08.56 bitrate=29797.4kbits/s speed=0.185x