lavfi: add asplit filter

Changelog

@@ -10,6 +10,7 @@ version next:
 - dv: add timecode to metadata
 - thumbnail video filter
 - XML output in ffprobe
+- asplit audio filter
 
 
 version 0.9:

doc/filters.texi

@@ -224,6 +224,19 @@ expressed in the form "[@var{c0} @var{c1} @var{c2} @var{c3} @var{c4} @var{c5}
 @var{c6} @var{c7}]"
 @end table
 
+@section asplit
+
+Pass on the input audio to two outputs. Both outputs are identical to
+the input audio.
+
+For example:
+@example
+[in] asplit[out0], showaudio[out1]
+@end example
+
+will create two separate outputs from the same input, one cropped and
+one padded.
+
 @section earwax
 
 Make audio easier to listen to on headphones.

libavfilter/Makefile

@@ -29,6 +29,7 @@ OBJS-$(CONFIG_AFORMAT_FILTER)                += af_aformat.o
 OBJS-$(CONFIG_ANULL_FILTER)                  += af_anull.o
 OBJS-$(CONFIG_ARESAMPLE_FILTER)              += af_aresample.o
 OBJS-$(CONFIG_ASHOWINFO_FILTER)              += af_ashowinfo.o
+OBJS-$(CONFIG_ASPLIT_FILTER)                 += af_asplit.o
 OBJS-$(CONFIG_EARWAX_FILTER)                 += af_earwax.o
 OBJS-$(CONFIG_PAN_FILTER)                    += af_pan.o
 OBJS-$(CONFIG_VOLUME_FILTER)                 += af_volume.o

libavfilter/af_asplit.c

+/*
+ * Copyright (c) 2011 Stefano Sabatini
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * audio splitter
+ */
+
+#include "avfilter.h"
+
+static void filter_samples(AVFilterLink *inlink, AVFilterBufferRef *insamples)
+{
+    avfilter_filter_samples(inlink->dst->outputs[0],
+                            avfilter_ref_buffer(insamples, ~AV_PERM_WRITE));
+    avfilter_filter_samples(inlink->dst->outputs[1],
+                            avfilter_ref_buffer(insamples, ~AV_PERM_WRITE));
+    avfilter_unref_buffer(insamples);
+}
+
+AVFilter avfilter_af_asplit = {
+    .name        = "asplit",
+    .description = NULL_IF_CONFIG_SMALL("Pass on the audio input to two outputs."),
+
+    .inputs = (const AVFilterPad[]) {
+        { .name             = "default",
+          .type             = AVMEDIA_TYPE_AUDIO,
+          .get_audio_buffer = avfilter_null_get_audio_buffer,
+          .filter_samples   = filter_samples, },
+        { .name = NULL}
+    },
+    .outputs = (const AVFilterPad[]) {
+        { .name             = "output1",
+          .type             = AVMEDIA_TYPE_AUDIO, },
+        { .name             = "output2",
+          .type             = AVMEDIA_TYPE_AUDIO, },
+        { .name = NULL}
+    },
+};

libavfilter/allfilters.c

@@ -39,6 +39,7 @@ void avfilter_register_all(void)
     REGISTER_FILTER (ANULL,       anull,       af);
     REGISTER_FILTER (ARESAMPLE,   aresample,   af);
     REGISTER_FILTER (ASHOWINFO,   ashowinfo,   af);
+    REGISTER_FILTER (ASPLIT,      asplit,      af);
     REGISTER_FILTER (EARWAX,      earwax,      af);
     REGISTER_FILTER (PAN,         pan,         af);
     REGISTER_FILTER (VOLUME,      volume,      af);

libavfilter/avfilter.h

@@ -30,7 +30,7 @@
 #include "libavcodec/avcodec.h"
 
 #define LIBAVFILTER_VERSION_MAJOR  2
-#define LIBAVFILTER_VERSION_MINOR 54
+#define LIBAVFILTER_VERSION_MINOR 55
 #define LIBAVFILTER_VERSION_MICRO 100
 
 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \