avfilter: add LIBVMAF filter

This one changes the previous vmaf patch to libvmaf to keep it separate from the
native implementation of vmaf inside ffmpeg later.
Signed-off-by: Ashish Singh <ashk43712@gmail.com>
Signed-off-by: Ronald S. Bultje <rsbultje@gmail.com>

Changelog

@@ -27,6 +27,7 @@ version <next>:
 - additional frame format support for Interplay MVE movies
 - support for decoding through D3D11VA in ffmpeg
 - limiter video filter
+- libvmaf video filter
 
 version 3.3:
 - CrystalHD decoder moved to new decode API

configure

@@ -256,6 +256,7 @@ External library support:
   --enable-libtwolame      enable MP2 encoding via libtwolame [no]
   --enable-libv4l2         enable libv4l2/v4l-utils [no]
   --enable-libvidstab      enable video stabilization using vid.stab [no]
+  --enable-libvmaf         enable vmaf filter via libvmaf [no]
   --enable-libvo-amrwbenc  enable AMR-WB encoding via libvo-amrwbenc [no]
   --enable-libvorbis       enable Vorbis en/decoding via libvorbis,
                            native implementation exists [no]
@@ -1569,6 +1570,7 @@ EXTERNAL_LIBRARY_LIST="
     libtheora
     libtwolame
     libv4l2
+    libvmaf
     libvorbis
     libvpx
     libwavpack
@@ -3186,6 +3188,7 @@ uspp_filter_deps="gpl avcodec"
 vaguedenoiser_filter_deps="gpl"
 vidstabdetect_filter_deps="libvidstab"
 vidstabtransform_filter_deps="libvidstab"
+vmaf_filter_deps="libvmaf"
 zmq_filter_deps="libzmq"
 zoompan_filter_deps="swscale"
 zscale_filter_deps="libzimg"
@@ -5902,6 +5905,8 @@ enabled libtwolame        && require libtwolame twolame.h twolame_init -ltwolame
                                die "ERROR: libtwolame must be installed and version must be >= 0.3.10"; }
 enabled libv4l2           && require_pkg_config libv4l2 libv4l2.h v4l2_ioctl
 enabled libvidstab        && require_pkg_config "vidstab >= 0.98" vid.stab/libvidstab.h vsMotionDetectInit
+enabled libvmaf           && { check_lib libvmaf "libvmaf.h" "compute_vmaf" -lvmaf -lstdc++ -lpthread -lm ||
+                               die "ERROR: libvmaf must be installed"; }
 enabled libvo_amrwbenc    && require libvo_amrwbenc vo-amrwbenc/enc_if.h E_IF_init -lvo-amrwbenc
 enabled libvorbis         && require_pkg_config vorbis vorbis/codec.h vorbis_info_init &&
                              require_pkg_config vorbisenc vorbis/vorbisenc.h vorbis_encode_init

doc/filters.texi

@@ -9639,6 +9639,70 @@ The formula that generates the correction is:
 where @var{r_0} is halve of the image diagonal and @var{r_src} and @var{r_tgt} are the
 distances from the focal point in the source and target images, respectively.
 
+@section libvmaf
+
+Obtain the average VMAF (Video Multi-Method Assessment Fusion)
+score between two input videos.
+
+This filter takes two input videos.
+
+Both video inputs must have the same resolution and pixel format for
+this filter to work correctly. Also it assumes that both inputs
+have the same number of frames, which are compared one by one.
+
+The obtained average VMAF score is printed through the logging system.
+
+It requires Netflix's vmaf library (libvmaf) as a pre-requisite.
+After installing the library it can be enabled using:
+@code{./configure --enable-libvmaf}.
+If no model path is specified it uses the default model: @code{vmaf_v0.6.1.pkl}.
+
+On the below examples the input file @file{main.mpg} being processed is
+compared with the reference file @file{ref.mpg}.
+
+The filter has following options:
+
+@table @option
+@item model_path
+Set the model path which is to be used for SVM.
+Default value: @code{"vmaf_v0.6.1.pkl"}
+
+@item log_path
+Set the file path to be used to store logs.
+
+@item log_fmt
+Set the format of the log file (xml or json).
+
+@item enable_transform
+Enables transform for computing vmaf.
+
+@item phone_model
+Invokes the phone model which will generate VMAF scores higher than in the
+regular model, which is more suitable for laptop, TV, etc. viewing conditions.
+
+@item psnr
+Enables computing psnr along with vmaf.
+
+@item ssim
+Enables computing ssim along with vmaf.
+
+@item ms_ssim
+Enables computing ms_ssim along with vmaf.
+
+@item pool
+Set the pool method to be used for computing vmaf.
+@end table
+
+For example:
+@example
+ffmpeg -i main.mpg -i ref.mpg -lavfi libvmaf -f null -
+@end example
+
+Example with options:
+@example
+ffmpeg -i main.mpg -i ref.mpg -lavfi libvmaf="psnr=1:enable-transform=1" -f null -
+@end example
+
 @section limiter
 
 Limits the pixel components values to the specified range [min, max].

libavfilter/Makefile

@@ -216,6 +216,7 @@ OBJS-$(CONFIG_INTERLACE_FILTER)              += vf_interlace.o
 OBJS-$(CONFIG_INTERLEAVE_FILTER)             += f_interleave.o
 OBJS-$(CONFIG_KERNDEINT_FILTER)              += vf_kerndeint.o
 OBJS-$(CONFIG_LENSCORRECTION_FILTER)         += vf_lenscorrection.o
+OBJS-$(CONFIG_LIBVMAF_FILTER)                += vf_libvmaf.o dualinput.o framesync.o
 OBJS-$(CONFIG_LIMITER_FILTER)                += vf_limiter.o
 OBJS-$(CONFIG_LOOP_FILTER)                   += f_loop.o
 OBJS-$(CONFIG_LUMAKEY_FILTER)                += vf_lumakey.o

libavfilter/allfilters.c

@@ -228,6 +228,7 @@ static void register_all(void)
     REGISTER_FILTER(INTERLEAVE,     interleave,     vf);
     REGISTER_FILTER(KERNDEINT,      kerndeint,      vf);
     REGISTER_FILTER(LENSCORRECTION, lenscorrection, vf);
+    REGISTER_FILTER(LIBVMAF,        libvmaf,        vf);
     REGISTER_FILTER(LIMITER,        limiter,        vf);
     REGISTER_FILTER(LOOP,           loop,           vf);
     REGISTER_FILTER(LUMAKEY,        lumakey,        vf);