[FFmpeg-user] ffmpeg read from UDP/Port

[Alex Lin]

Hi all,

I am using Windows 7 64 bit, and I downloaded the 64 bit version of
ffmpeg: ffmpeg-20140916-git-b76d613-win64-static.7z

I have spent the entire day experimenting with ffmpeg today but I haven't
quite figure out if ffmpeg is the right solution to my problem yet, so I
would like to get some opinions.

I am receiving H264 encoded packets through RTP with sample rate of 90,000,
and I need to record these packets. The file format doesn't really matter
at this point.

Currently, I have a server sending the H264 packets to port 50002 of my
machine (192.168.1.200), so I run the following ffmpeg command on my
machine:

ffmpeg -i udp://192.168.1.200:50002 -f mp4 hello.mp4

Then the following shows

ffmpeg version N-66289-gb76d613 Copyright (c) 2000-2014 the FFmpeg
developers
  built on Sep 15 2014 22:11:04 with gcc 4.8.3 (GCC)
  configuration: --enable-gpl --enable-version3 --disable-w32threads
--enable-avisynth --enable-bzlib --enable-fontconfig --enable-frei0r
--enable-gnutls --enable-iconv --enable-libass --enable-libbluray
--enable-libbs2b --enable-libcaca --enable-libfreetype --enable-libgme
--enable-libgsm --enable-
libilbc --enable-libmodplug --enable-libmp3lame --enable-libopencore-amrnb
--enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus
--enable-librtmp --enable-libschroedinger --enable-libsoxr
--enable-libspeex --enable-libtheora --enable-libtwolame
--enable-libvidstab --enable-libvo-aacenc --
enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx
--enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265
--enable-libxavs --enable-libxvid --enable-decklink --enable-zlib
  libavutil      54.  7.100 / 54.  7.100
  libavcodec     56.  1.100 / 56.  1.100
  libavformat    56.  4.101 / 56.  4.101
  libavdevice    56.  0.100 / 56.  0.100
  libavfilter     5.  1.100 /  5.  1.100
  libswscale      3.  0.100 /  3.  0.100
  libswresample   1.  1.100 /  1.  1.100
  libpostproc    53.  0.100 / 53.  0.100

The server starts sending video packets, and nothing happens on the command
prompt with the ffmpeg command.
The server stops sending video packets, and nothing happens still (I waited
for at least 5 minutes), so I pressed Ctrl+C, then I see this

udp://192.168.1.200:50002: Invalid data found when processing input
Received signal 2: terminating.

am I using ffmpeg correctly? and are the H264 packets I am receiving not
supported?
I have looked around and did not see any debug log generated by ffmpeg, so
I don't really know where else to look.
If it is necessary, I can provide a packet capture with the H264 packets.

Thanks in advance.
AL