FFmpeg - custom filter addition

stepbystep.txt

// 
// ffmpeg_customfilter
//	- base name - ainfoda (audio filter)
//	- base name - vinfoda (video filter)
//


// 1. create new filein libavfilter/infoda_af.c
// 	use any filters as template, simplest is af_afnull.c
//	filename is arbitrary (all recent named as af_name), but for me all my stuff called with 
//	unified start as better

/*  
  ---------------------------------------------------------
  NAME:         avfilter_af_ainfoda
  PARAMS: 
  DESCRIPTION:
  ---------------------------------------------------------
*/
AVFilter ff_af_ainfoda = {
    .name      = "ainfoda",
    .description = NULL_IF_CONFIG_SMALL("infoda: audio filter"),

    .priv_size      = sizeof(InfodaContext),
    .priv_class     = &ainfoda_class,
    .init           = init,
    .uninit         = uninit,

    .inputs    = NULL,
    .outputs   = NULL,
};


// 2. add to libavfilter/allfilters.c - to the end of similar records

/* infoda filters */
REGISTER_FILTER(AINFODA,       ainfoda,       af);
REGISTER_FILTER(VINFODA,       vinfoda,       vf);

// 3. add to libavfilter/Makefile - to the end of similar records
OBJS-$(CONFIG_AINFODA_FILTER)                += infoda_af.o
OBJS-$(CONFIG_VINFODA_FILTER)                += infoda_vf.o


// after this, if everything ok run
./configure --list-filters |grep infoda
// it should be there

// 3a. if need some dependencies then add to ./configure
ainfoda_filter_deps="libnanomsg"
vinfoda_filter_deps="libnanomsg"
enable libnanomsg

EXTERNAL_LIBRARY_LIST="
...
    libnanomsg

// 4. so we can start to compile
./configure --enable-libx264 --enable-openssl --enable-nonfree --enable-gpl
// not required to enable it manually