You need to look into command prompt.

Code:
ffmpeg -formats | grep 264
In result, look for some thing like below.

DE h264 raw H.264 video format
E ipod iPod H.264 MP4 format
D V D h264 H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10
EV libx264 libx264 H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10
text2movsub remove_extra noise mov2textsub mp3decomp mp3comp mjpegadump imxdump h264_mp4toannexb dump_extra aac_adtstoasc