ffmpeg unkown libfaac ubuntu 14.04

I Have Installed ffmpeg 2.3 in Ubuntu 14.04

ffmpeg -i demo.mpg -acodec libfaac demo.mp4
ffmpeg version 2.3 Copyright (c) 2000-2014 the FFmpeg developers built on Aug 13 2014 22:15:33 with gcc 4.8 (Ubuntu 4.8.2-19ubuntu1) configuration: libavutil 52. 92.100 / 52. 92.100 libavcodec 55. 69.100 / 55. 69.100 libavformat 55. 48.100 / 55. 48.100 libavdevice 55. 13.102 / 55. 13.102 libavfilter 4. 11.100 / 4. 11.100 libswscale 2. 6.100 / 2. 6.100 libswresample 0. 19.100 / 0. 19.100
Input #0, mpeg, from 'demo.mpg': Duration: 00:04:19.96, start: 0.000000, bitrate: 1646 kb/s Stream #0:0[0x1c0]: Audio: mp2, 44100 Hz, stereo, s16p, 128 kb/s Stream #0:1[0x1e0]: Video: mpeg1video, yuv420p(tv), 640x480 [SAR 1:1 DAR 4:3], 104857 kb/s, 29.97 fps, 29.97 tbr, 90k tbn, 29.97 tbc
Unknown encoder 'libfaac'

Also I Have Installed libavcodec-extra-54

linux:~$ apt-cache policy libavcodec-extra-54
libavcodec-extra-54: Installed: 7:1.2.6-1~trusty1 Candidate: 7:1.2.6-1~trusty1 Version table: *** 7:1.2.6-1~trusty1 0

I have No Idea What To Do Now To Convert Videos With acodec libfaac

3 Answers

You need to just use aac instead.

ffmpeg -i demo.mpg -acodec aac -strict experimental demo.mp4

Actually use libfdk_aac instead.

ffmpeg -i demo.mpg -acodec libfdk_aac demo.mp4

As to why? Well ffmpeg suggested it to me when playing around with the codecs and getting a list.

Enable your extra repos in /etc/apt/sources.list and then you can find libfaac-dev

edit: you might need to recompile ffmpeg?