[Libav-user] ffmpeg+libx264+broken ffmpeg default settings detected

[jarno ralli]

Dear all,

This is the first time I post here, so please do forgive me if I'm 
posting to wrong place etc. In any case, I have the infamous "broken 
ffmpeg default settings detected" when using OpenCV+ffmpeg+libx264 in 
Kubuntu 12.10. I have the latest git:ted versions of everything (12 Feb 
2013) and I have compiled ffmpeg, x264 etc. as per 
http://ffmpeg.org/trac/ffmpeg/wiki/UbuntuCompilationGuide.

When trying to write video using H.264 in OpenCV it uses ffmpeg library 
for this purpose. However, when opening the stream I get the following:

[libx264 @ 0x20f7d00] broken ffmpeg default settings detected
[libx264 @ 0x20f7d00] use an encoding preset (e.g. -vpre medium)
[libx264 @ 0x20f7d00] preset usage: -vpre <speed> -vpre <profile>
[libx264 @ 0x20f7d00] speed presets are listed in x264 --help
[libx264 @ 0x20f7d00] profile is optional; x264 defaults to high
Could not open codec 'libx264': Unspecified error

Which is caused by (x264/encoder/encoder.c):

/* Detect default ffmpeg settings and terminate with an error. */
     if( b_open )
     {
         int score = 0;
         score += h->param.analyse.i_me_range == 0;
         score += h->param.rc.i_qp_step == 3;
         score += h->param.i_keyint_max == 12;
         score += h->param.rc.i_qp_min == 2;
         score += h->param.rc.i_qp_max == 31;
         score += h->param.rc.f_qcompress == 0.5;
         score += fabs(h->param.rc.f_ip_factor - 1.25) < 0.01;
         score += fabs(h->param.rc.f_pb_factor - 1.25) < 0.01;
         score += h->param.analyse.inter == 0 && 
h->param.analyse.i_subpel_refine == 8;
         if( score >= 5 )
         {
             x264_log( h, X264_LOG_ERROR, "broken ffmpeg default 
settings detected\n" );
             x264_log( h, X264_LOG_ERROR, "use an encoding preset (e.g. 
-vpre medium)\n" );
             x264_log( h, X264_LOG_ERROR, "preset usage: -vpre <speed> 
-vpre <profile>\n" );
             x264_log( h, X264_LOG_ERROR, "speed presets are listed in 
x264 --help\n" );
             x264_log( h, X264_LOG_ERROR, "profile is optional; x264 
defaults to high\n" );
             return -1;
         }
     }

Now, I have a question: where do these defaults came from...are these 
set in ffmpeg/libavcodecs/libx264.c:

static const AVCodecDefault x264_defaults[] = {
     { "b",                "0" },
     { "bf",               "-1" },
     { "flags2",           "0" },
     { "g",                "-1" },
     { "qmin",             "-1" },
     { "qmax",             "-1" },
     { "qdiff",            "-1" },
     { "qblur",            "-1" },
     { "qcomp",            "-1" },
//     { "rc_lookahead",     "-1" },
     { "refs",             "-1" },
     { "sc_threshold",     "-1" },
     { "trellis",          "-1" },
     { "nr",               "-1" },
     { "me_range",         "-1" },
     { "me_method",        "-1" },
     { "subq",             "-1" },
     { "b_strategy",       "-1" },
     { "keyint_min",       "-1" },
     { "coder",            "-1" },
     { "cmp",              "-1" },
     { "threads",          AV_STRINGIFY(X264_THREADS_AUTO) },
     { "thread_type",      "0" },
     { "flags",            "+cgop" },
     { "rc_init_occupancy","-1" },
     { NULL },
};

My ffmpeg gives the following information:

ffmpeg version N-38355-ge2b703f Copyright (c) 2000-2013 the FFmpeg 
developers
   built on Feb 12 2013 14:31:31 with gcc 4.7 (Ubuntu/Linaro 4.7.2-2ubuntu1)
   configuration: --enable-gpl --enable-libass --enable-libfaac 
--enable-libfdk-aac --enable-libmp3lame --enable-libopencore-amrnb 
--enable-libopencore-amrwb --enable-librtmp --enable-libtheora 
--enable-libvorbis --enable-libvpx --enable-x11grab --enable-libx264 
--enable-nonfree --enable-version3 --enable-shared
   libavutil      52. 17.101 / 52. 17.101
   libavcodec     54. 91.102 / 54. 91.102
   libavformat    54. 62.100 / 54. 62.100
   libavdevice    54.  3.103 / 54.  3.103
   libavfilter     3. 37.101 /  3. 37.101
   libswscale      2.  2.100 /  2.  2.100
   libswresample   0. 17.102 /  0. 17.102
   libpostproc    52.  2.100 / 52.  2.100
Hyper fast Audio and Video encoder

I would be really grateful if someone could give me a hand here!!!

All the best,
Jarno