lavfi: EBU R.128 scanner.

Changelog

@@ -3,6 +3,7 @@ releases are sorted from youngest to oldest.
 
 version next:
 - stream disposition information printing in ffprobe
+- filter for loudness analysis following EBU R128
 
 
 version 1.0:

configure

@@ -1901,6 +1901,7 @@ decimate_filter_deps="gpl avcodec"
 delogo_filter_deps="gpl"
 deshake_filter_deps="avcodec"
 drawtext_filter_deps="libfreetype"
+ebur128_filter_deps="gpl"
 flite_filter_deps="libflite"
 frei0r_filter_deps="frei0r dlopen"
 frei0r_filter_extralibs='$ldl'

doc/filters.texi

@@ -4480,6 +4480,53 @@ setpts=PTS+10/TB
 @end example
 @end itemize
 
+@section ebur128
+
+EBU R128 scanner filter. This filter takes an audio stream as input and outputs
+it unchanged. By default, it logs a message at a frequency of 10Hz with the
+Momentary loudness (identified by @code{M}), Short-term loudness (@code{S}),
+Integrated loudness (@code{I}) and Loudness Range (@code{LRA}).
+
+The filter also has a video output (see the @var{video} option) with a real
+time graph to observe the loudness evolution. The graphic contains the logged
+message mentioned above, so it is not printed anymore when this option is set,
+unless the verbose logging is set. The main graphing area contains the
+short-term loudness (3 seconds of analysis), and the gauge on the right is for
+the momentary loudness (400 milliseconds).
+
+More information about the Loudness Recommendation EBU R128 on
+@url{http://tech.ebu.ch/loudness}.
+
+The filter accepts the following named parameters:
+
+@table @option
+
+@item video
+Activate the video output. The audio stream is passed unchanged whether this
+option is set or no. The video stream will be the first output stream if
+activated. Default is @code{0}.
+
+@item size
+Set the video size. This option is for video only. Default and minimum
+resolution is @code{640x480}.
+
+@item meter
+Set the EBU scale meter. Default is @code{9}. Common values are @code{9} and
+@code{18}, respectively for EBU scale meter +9 and EBU scale meter +18. Any
+other integer value between this range is allowed.
+
+@end table
+
+Example of real-time graph using @command{ffplay}, with a EBU scale meter +18:
+@example
+ffplay -f lavfi -i "amovie=input.mp3,ebur128=video=1:meter=18 [out0][out1]"
+@end example
+
+Run an analysis with @command{ffmpeg}:
+@example
+ffmpeg -nostats -i input.mp3 -filter_complex ebur128 -f null -
+@end example
+
 @section settb, asettb
 
 Set the timebase to use for the output frames timestamps.

libavfilter/Makefile

@@ -66,6 +66,7 @@ OBJS-$(CONFIG_ATEMPO_FILTER)                 += af_atempo.o
 OBJS-$(CONFIG_CHANNELMAP_FILTER)             += af_channelmap.o
 OBJS-$(CONFIG_CHANNELSPLIT_FILTER)           += af_channelsplit.o
 OBJS-$(CONFIG_EARWAX_FILTER)                 += af_earwax.o
+OBJS-$(CONFIG_EBUR128_FILTER)                += f_ebur128.o
 OBJS-$(CONFIG_JOIN_FILTER)                   += af_join.o
 OBJS-$(CONFIG_PAN_FILTER)                    += af_pan.o
 OBJS-$(CONFIG_RESAMPLE_FILTER)               += af_resample.o

libavfilter/allfilters.c

@@ -58,6 +58,7 @@ void avfilter_register_all(void)
     REGISTER_FILTER (CHANNELMAP,  channelmap,  af);
     REGISTER_FILTER (CHANNELSPLIT,channelsplit,af);
     REGISTER_FILTER (EARWAX,      earwax,      af);
+    REGISTER_FILTER (EBUR128,     ebur128,     af);
     REGISTER_FILTER (JOIN,        join,        af);
     REGISTER_FILTER (PAN,         pan,         af);
     REGISTER_FILTER (SILENCEDETECT, silencedetect, af);

libavfilter/version.h

@@ -29,7 +29,7 @@
 #include "libavutil/avutil.h"
 
 #define LIBAVFILTER_VERSION_MAJOR  3
-#define LIBAVFILTER_VERSION_MINOR  18
+#define LIBAVFILTER_VERSION_MINOR  19
 #define LIBAVFILTER_VERSION_MICRO 100
 
 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \