@@ -74,6 +74,7 @@ easier to use. The changes are:

 - replacement Indeo 3 decoder

 - new ffmpeg option: -map_channel

 - volume audio filter added

+- earwax audio filter added

 version 0.8:

@@ -224,6 +224,17 @@ expressed in the form "[@var{c0} @var{c1} @var{c2} @var{c3} @var{c4} @var{c5}

 @var{c6} @var{c7}]"

 @end table

+@section earwax

+

+Make audio easier to listen to on headphones.

+

+This filter adds `cues' to 44.1kHz stereo (i.e. audio CD format) audio

+so that when listened to on headphones the stereo image is moved from

+inside your head (standard for headphones) to outside and in front of

+the listener (standard for speakers).

+

+Ported from SoX.

+

 @section volume

 Adjust the input audio volume.

@@ -28,6 +28,7 @@ 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_EARWAX_FILTER)                 += af_earwax.o

 OBJS-$(CONFIG_VOLUME_FILTER)                 += af_volume.o

 OBJS-$(CONFIG_ABUFFER_FILTER)                += asrc_abuffer.o

new file mode 100644

@@ -0,0 +1,161 @@

+/*

+ * Copyright (c) 2011 Mina Nagy Zaki

+ * Copyright (c) 2000 Edward Beingessner And Sundry Contributors.

+ * This source code is freely redistributable and may be used for any purpose.

+ * This copyright notice must be maintained.  Edward Beingessner And Sundry

+ * Contributors are not responsible for the consequences of using this

+ * software.

+ *

+ * 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

+ * Stereo Widening Effect. Adds audio cues to move stereo image in

+ * front of the listener. Adapted from the libsox earwax effect.

+ */

+

+#include "libavutil/audioconvert.h"

+#include "avfilter.h"

+

+#define NUMTAPS 64

+

+static const int8_t filt[NUMTAPS] = {

+/* 30°  330° */

+    4,   -6,     /* 32 tap stereo FIR filter. */

+    4,  -11,     /* One side filters as if the */

+   -1,   -5,     /* signal was from 30 degrees */

+    3,    3,     /* from the ear, the other as */

+   -2,    5,     /* if 330 degrees. */

+   -5,    0,

+    9,    1,

+    6,    3,     /*                         Input                         */

+   -4,   -1,     /*                   Left         Right                  */

+   -5,   -3,     /*                __________   __________                */

+   -2,   -5,     /*               |          | |          |               */

+   -7,    1,     /*           .---|  Hh,0(f) | |  Hh,0(f) |---.           */

+    6,   -7,     /*          /    |__________| |__________|    \          */

+   30,  -29,     /*         /                \ /                \         */

+   12,   -3,     /*        /                  X                  \        */

+  -11,    4,     /*       /                  / \                  \       */

+   -3,    7,     /*  ____V_____   __________V   V__________   _____V____  */

+  -20,   23,     /* |          | |          |   |          | |          | */

+    2,    0,     /* | Hh,30(f) | | Hh,330(f)|   | Hh,330(f)| | Hh,30(f) | */

+    1,   -6,     /* |__________| |__________|   |__________| |__________| */

+  -14,   -5,     /*      \     ___      /           \      ___     /      */

+   15,  -18,     /*       \   /   \    /    _____    \    /   \   /       */

+    6,    7,     /*        `->| + |<--'    /     \    `-->| + |<-'        */

+   15,  -10,     /*           \___/      _/       \_      \___/           */

+  -14,   22,     /*               \     / \       / \     /               */

+   -7,   -2,     /*                `--->| |       | |<---'                */

+   -4,    9,     /*                     \_/       \_/                     */

+    6,  -12,     /*                                                       */

+    6,   -6,     /*                       Headphones                      */

+    0,  -11,

+    0,   -5,

+    4,    0};

+

+typedef struct {

+    int16_t taps[NUMTAPS * 2];

+} EarwaxContext;

+

+static int query_formats(AVFilterContext *ctx)

+{

+    AVFilterFormats *formats = NULL;

+    avfilter_add_format(&formats, AV_SAMPLE_FMT_S16);

+    avfilter_set_common_sample_formats(ctx, formats);

+    formats = NULL;

+    avfilter_add_format(&formats, AV_CH_LAYOUT_STEREO);

+    avfilter_set_common_channel_layouts(ctx, formats);

+    formats = NULL;

+    avfilter_add_format(&formats, AVFILTER_PACKED);

+    avfilter_set_common_packing_formats(ctx, formats);

+

+    return 0;

+}

+

+static int config_input(AVFilterLink *inlink)

+{

+    if (inlink->sample_rate != 44100) {

+        av_log(inlink->dst, AV_LOG_ERROR,

+               "The earwax filter only works for 44.1kHz audio. Insert "

+               "a resample filter before this\n");

+        return AVERROR(EINVAL);

+    }

+    return 0;

+}

+

+//FIXME: replace with DSPContext.scalarproduct_int16

+static inline int16_t *scalarproduct(const int16_t *in, const int16_t *endin, int16_t *out)

+{

+    int32_t sample;

+    int16_t j;

+

+    while (in < endin) {

+        sample = 32;

+        for (j = 0; j < NUMTAPS; j++)

+            sample += in[j] * filt[j];

+        *out = sample >> 6;

+        out++;

+        in++;

+    }

+

+    return out;

+}

+

+static void filter_samples(AVFilterLink *inlink, AVFilterBufferRef *insamples)

+{

+    AVFilterLink *outlink = inlink->dst->outputs[0];

+    int16_t *taps, *endin, *in, *out;

+    AVFilterBufferRef *outsamples =

+        avfilter_get_audio_buffer(inlink, AV_PERM_WRITE,

+                                  insamples->audio->nb_samples);

+    taps  = ((EarwaxContext *)inlink->dst->priv)->taps;

+    out   = (int16_t *)outsamples->data[0];

+    in    = (int16_t *)insamples ->data[0];

+

+    // copy part of new input and process with saved input

+    memcpy(taps+NUMTAPS, in, NUMTAPS * sizeof(*taps));

+    out   = scalarproduct(taps, taps + NUMTAPS, out);

+

+    // process current input

+    endin = in + insamples->audio->nb_samples * 2 - NUMTAPS;

+    out   = scalarproduct(in, endin, out);

+

+    // save part of input for next round

+    memcpy(taps, endin, NUMTAPS * sizeof(*taps));

+

+    avfilter_filter_samples(outlink, outsamples);

+    avfilter_unref_buffer(insamples);

+}

+

+AVFilter avfilter_af_earwax = {

+    .name           = "earwax",

+    .description    = NULL_IF_CONFIG_SMALL("Widen the stereo image."),

+    .query_formats  = query_formats,

+    .priv_size      = sizeof(EarwaxContext),

+    .inputs  = (AVFilterPad[])  {{  .name           = "default",

+                                    .type           = AVMEDIA_TYPE_AUDIO,

+                                    .filter_samples = filter_samples,

+                                    .config_props   = config_input,

+                                    .min_perms      = AV_PERM_READ, },

+                                 {  .name = NULL}},

+

+    .outputs = (AVFilterPad[])  {{  .name           = "default",

+                                    .type           = AVMEDIA_TYPE_AUDIO, },

+                                 {  .name = NULL}},

+};

@@ -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 (EARWAX,      earwax,      af);

     REGISTER_FILTER (VOLUME,      volume,      af);

     REGISTER_FILTER (ABUFFER,     abuffer,     asrc);

@@ -29,7 +29,7 @@

 #include "libavutil/rational.h"

 #define LIBAVFILTER_VERSION_MAJOR  2

-#define LIBAVFILTER_VERSION_MINOR 46

+#define LIBAVFILTER_VERSION_MINOR 47

 #define LIBAVFILTER_VERSION_MICRO  0

 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \