Encoding H.264 from camera with Android MediaCodec
For your fast playback - frame rate issue, there is nothing you have to do here. Since it is a streaming solution the other side has to be told the frame rate in advance or timestamps with each frame. Both of these are not part of elementary stream. Either pre-determined framerate is chosen or you pass on some sdp or something like that or you use existing protocols like rtsp. In the second case the timestamps are part of the stream sent in form of something like rtp. Then the client has to depay the rtp stream and play it bacl. This is how elementary streaming works. [either fix your frame rate if you have a fixed rate encoder or give timestamps]
Local PC playback will be fast because it will not know the fps. By giving the fps parameter before the input e.g
ffplay -fps 30 in.264
you can control the playback on the PC.
As for the file not being playable: Does it have a SPS and PPS. Also you should have NAL headers enabled - annex b format. I don't know much about android, but this is requirement for any h.264 elementary stream to be playable when they are not in any containers and need to be dumped and played later. If android default is mp4, but default annexb headers will be switched off, so perhaps there is a switch to enable it. Or if you are getting data frame by frame, just add it yourself.
As for color format: I would guess the default should work. So try not setting it. If not try 422 Planar or UVYV / VYUY interleaved formats. usually cameras are one of those. (but not necessary, these may be the ones I have encountered more often).
Android 4.3 (API 18) provides an easy solution. The MediaCodec class now accepts input from Surfaces, which means you can connect the camera's Surface preview to the encoder and bypass all the weird YUV format issues.
There is also a new MediaMuxer class that will convert your raw H.264 stream to a .mp4 file (optionally blending in an audio stream).
See the CameraToMpegTest source for an example of doing exactly this. (It also demonstrates the use of an OpenGL ES fragment shader to perform a trivial edit on the video as it's being recorded.)