ffmpeg usage to encode a video to H264 codec format

Question

I have a *.mp4 video file(MPEG4 video codec) and I am trying to convert this to a H264 video codec format(raw h.264 format) using ffmpeg on Linux(Version - FFmpeg version SVN-r0.5.1-4:0.5.1-1ubuntu1, Copyright (c) 2000-2009 Fabrice Bellard,) using command line as shown below,

ffmpeg -i input .mp4 output.h264 

but I get an error saying -

Unsupported codec for output stream #0.0

Then when i try this option:

ffmpeg -i input .mp4 -formats h264 output.h264 

it still does not work, and gives -

Seems stream 0 codec frame rate differs from container frame rate: 59.94 (5994/100) -> 29.97 (30000/1001)
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'Rapture.mp4':
  Duration: 00:02:06.44, start: 0.000000, bitrate: 26574 kb/s
    Stream #0.0(eng): Video: h264, yuv420p, 1920x1080, 29.97 tbr, 29.97 tbn, 59.94 tbc
    Stream #0.1(eng): Audio: aac, 48000 Hz, stereo, s16

And then it prints out help on the formats which we get when we do ffmpeg -formats

When I checked the help, ffmpeg -formats, I see below information related to H264 file format and codec:

File format : 

DE h264            raw H.264 video format

Codecs:

D V D  h264         H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10

My questions :

1. How can I convert the video to a H264 encoded video (raw H264 video format)

2. When I do ffmpeg -formats, I see many acronyms for the codecs supported, I see many acronyms before the codec name/type such as - D V D S E A, what do they stand for?

3. How to use the ffmpeg options -vcodec and -formats?

Answer 1

I used these options to convert to the H.264/AAC .mp4 format for HTML5 playback (I think it may help other guys with this problem in some way):

ffmpeg -i input.flv -vcodec mpeg4 -acodec aac output.mp4