ffmpeg : error while re encoding video
ffmpeg
Solution
The quick fix is to add the option `-strict -2` just before the last argument (the name of the output).
There are several different AAC encoders that FFmpeg can use. For the best quality, use the `libfdk_aac` encoder. Unfortunately the license of libfdk_aac is incompatible with the GPL, which means that the GPL does not permit distribution of an executable derived from both libx264 (GPL) (used for H.264 video encoding) and libfdk_aac (used for AAC audio encoding). Nevertheless this can be a great choice if you build FFmpeg yourself. If your FFmpeg was built with libfdk_aac then you can use it with the option `-c:a libfdk_aac` before the output file name.
FFmpeg also has an experimental built-in AAC encoder, which has lower quality at a given bitrate but a compatible license. Because it is experimental it is not used by default, but it can be used if you include the option `-strict experimental` or `-strict -2` just before the output file name, to enable experimental codecs.
For further details see the FFmpeg AAC Encoding Guide.
Problem
I am trying to re-encoding video with ffmpeg, and I am getting this error : ``` [aac @ 0x3752e40] The encoder 'aac' is experimental but experimental codecs are not enabled, add '-strict -2' if you want to use it. ``` The command and the full output:: ``` /root$ /usr/bin/ffmpeg -i http://website.com/uploads/usr_videos/MVI_05571.mp4 -b:v 500k -threads 4 -vf scale=-1:144 -b:a 128k http://website.com/uploads/usr_videos/144p_output.mp4 ffmpeg version 2.5.4 Copyright (c) 2000-2015 the FFmpeg developers built on Feb 18 2015 01:39:38 with gcc 4.4.7 (GCC) 20120313 (Red Hat 4.4.7-11) configuration: libavutil 54. 15.100 / 54. 15.100 libavcodec 56. 13.100 / 56. 13.100 libavformat 56. 15.102 / 56. 15.102 libavdevice 56. 3.100 / 56. 3.100 libavfilter 5. 2.103 / 5. 2.103 libswscale 3. 1.101 / 3. 1.101 libswresample 1. 1.100 / 1. 1.100 Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'http://website.com/uploads/usr_videos/MVI_05571.mp4': Metadata: major_brand : isom minor_version : 512 compatible_brands: isomiso2mp41 encoder : Lavf54.63.104 Duration: 00:01:48.26, start: 0.023220, bitrate: 7122 kb/s Stream #0:0(eng): Video: mpeg4 (Simple Profile) (mp4v / 0x7634706D), yuv420p, 640x360 [SAR 1:1 DAR 16:9], 6990 kb/s, 29 fps, 29 tbr, 14848 tbn, 29 tbc (default) Metadata: handler_name : VideoHandler Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 126 kb/s (default) Metadata: handler_name : SoundHandler [aac @ 0x3752e40] The encoder 'aac' is experimental but experimental codecs are not enabled, add '-strict -2' if you want to use it. ``` So Could anyone till me what this error mean and how can I fix it ? I am using ffmpeg version 2.5 on centOS server.