avfilter: add showvolume filter

Signed-off-by: Paul B Mahol <onemda@gmail.com>

Changelog

@@ -9,6 +9,7 @@ version <next>:
 - DirectDraw Surface image/texture decoder
 - ssim filter
 - rewritten ASF demuxer
+- showvolume filter
 
 
 version 2.7:

doc/filters.texi

@@ -11992,6 +11992,39 @@ ffplay -f lavfi 'amovie=input.mp3, asplit [a][out1];
 @end example
 @end itemize
 
+@section showvolume
+
+Convert input audio volume to a video output.
+
+The filter accepts the following options:
+
+@table @option
+@item rate, r
+Set video rate.
+
+@item b
+Set border width, allowed range is [0, 5]. Default is 1.
+
+@item w
+Set channel width, allowed range is [40, 1080]. Default is 400.
+
+@item h
+Set channel height, allowed range is [1, 100]. Default is 20.
+
+@item f
+Set fade, allowed range is [1, 255]. Default is 20.
+
+@item c
+Set volume color expression.
+
+The expression can use the following variables:
+
+@table @option
+@item VOLUME
+Current max volume of channel in dB.
+@end table
+@end table
+
 @section showwaves
 
 Convert input audio to a video output, representing the samples waves.

libavfilter/Makefile

@@ -241,6 +241,7 @@ OBJS-$(CONFIG_AVECTORSCOPE_FILTER)           += avf_avectorscope.o
 OBJS-$(CONFIG_CONCAT_FILTER)                 += avf_concat.o
 OBJS-$(CONFIG_SHOWCQT_FILTER)                += avf_showcqt.o
 OBJS-$(CONFIG_SHOWSPECTRUM_FILTER)           += avf_showspectrum.o
+OBJS-$(CONFIG_SHOWVOLUME_FILTER)             += avf_showvolume.o
 OBJS-$(CONFIG_SHOWWAVES_FILTER)              += avf_showwaves.o
 OBJS-$(CONFIG_SHOWWAVESPIC_FILTER)           += avf_showwaves.o
 

libavfilter/allfilters.c

@@ -256,6 +256,7 @@ void avfilter_register_all(void)
     REGISTER_FILTER(CONCAT,         concat,         avf);
     REGISTER_FILTER(SHOWCQT,        showcqt,        avf);
     REGISTER_FILTER(SHOWSPECTRUM,   showspectrum,   avf);
+    REGISTER_FILTER(SHOWVOLUME,     showvolume,     avf);
     REGISTER_FILTER(SHOWWAVES,      showwaves,      avf);
     REGISTER_FILTER(SHOWWAVESPIC,   showwavespic,   avf);
 

libavfilter/avf_showvolume.c

@@ -0,0 +1,230 @@
+/*
+ * Copyright (c) 2015 Paul B Mahol
+ *
+ * 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
+ */
+
+#include "libavutil/channel_layout.h"
+#include "libavutil/eval.h"
+#include "libavutil/intreadwrite.h"
+#include "libavutil/opt.h"
+#include "libavutil/parseutils.h"
+#include "avfilter.h"
+#include "formats.h"
+#include "audio.h"
+#include "video.h"
+#include "internal.h"
+
+typedef struct ShowVolumeContext {
+    const AVClass *class;
+    int w, h;
+    int f, b;
+    AVRational frame_rate;
+    char *color;
+
+    AVFrame *out;
+    AVExpr *c_expr;
+} ShowVolumeContext;
+
+#define OFFSET(x) offsetof(ShowVolumeContext, x)
+#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
+
+static const AVOption showvolume_options[] = {
+    { "rate", "set video rate",  OFFSET(frame_rate), AV_OPT_TYPE_VIDEO_RATE, {.str="25"}, 0, 0, FLAGS },
+    { "r",    "set video rate",  OFFSET(frame_rate), AV_OPT_TYPE_VIDEO_RATE, {.str="25"}, 0, 0, FLAGS },
+    { "b", "set border width",   OFFSET(b), AV_OPT_TYPE_INT, {.i64=1}, 0, 5, FLAGS },
+    { "w", "set channel width",  OFFSET(w), AV_OPT_TYPE_INT, {.i64=400}, 40, 1080, FLAGS },
+    { "h", "set channel height", OFFSET(h), AV_OPT_TYPE_INT, {.i64=20}, 1, 100, FLAGS },
+    { "f", "set fade",           OFFSET(f), AV_OPT_TYPE_INT, {.i64=20}, 1, 255, FLAGS },
+    { "c", "set volume color expression", OFFSET(color), AV_OPT_TYPE_STRING, {.str="if(gte(VOLUME,-2), if(gte(VOLUME,-1),0xff, 0xffff),0xff00)"}, 0, 0, FLAGS },
+    { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(showvolume);
+
+static const char *const var_names[] = {   "VOLUME", NULL };
+enum                                   { VAR_VOLUME, VAR_VARS_NB };
+
+static av_cold int init(AVFilterContext *ctx)
+{
+    ShowVolumeContext *s = ctx->priv;
+    int ret;
+
+    if (s->color) {
+        ret = av_expr_parse(&s->c_expr, s->color, var_names,
+                            NULL, NULL, NULL, NULL, 0, ctx);
+        if (ret < 0)
+            return ret;
+    }
+
+    return 0;
+}
+
+static int query_formats(AVFilterContext *ctx)
+{
+    AVFilterFormats *formats = NULL;
+    AVFilterChannelLayouts *layouts = NULL;
+    AVFilterLink *inlink = ctx->inputs[0];
+    AVFilterLink *outlink = ctx->outputs[0];
+    static const enum AVSampleFormat sample_fmts[] = { AV_SAMPLE_FMT_FLTP, AV_SAMPLE_FMT_NONE };
+    static const enum AVPixelFormat pix_fmts[] = { AV_PIX_FMT_RGBA, AV_PIX_FMT_NONE };
+
+    formats = ff_make_format_list(sample_fmts);
+    if (!formats)
+        return AVERROR(ENOMEM);
+    ff_formats_ref(formats, &inlink->out_formats);
+
+    layouts = ff_all_channel_layouts();
+    if (!layouts)
+        return AVERROR(ENOMEM);
+    ff_channel_layouts_ref(layouts, &inlink->out_channel_layouts);
+
+    formats = ff_all_samplerates();
+    if (!formats)
+        return AVERROR(ENOMEM);
+    ff_formats_ref(formats, &inlink->out_samplerates);
+
+    formats = ff_make_format_list(pix_fmts);
+    if (!formats)
+        return AVERROR(ENOMEM);
+    ff_formats_ref(formats, &outlink->in_formats);
+
+    return 0;
+}
+
+static int config_input(AVFilterLink *inlink)
+{
+    AVFilterContext *ctx = inlink->dst;
+    ShowVolumeContext *s = ctx->priv;
+    int nb_samples;
+
+    nb_samples = FFMAX(1024, ((double)inlink->sample_rate / av_q2d(s->frame_rate)) + 0.5);
+    inlink->partial_buf_size =
+    inlink->min_samples =
+    inlink->max_samples = nb_samples;
+
+    return 0;
+}
+
+static int config_output(AVFilterLink *outlink)
+{
+    ShowVolumeContext *s = outlink->src->priv;
+    AVFilterLink *inlink = outlink->src->inputs[0];
+
+    outlink->w = s->w;
+    outlink->h = s->h * inlink->channels + (inlink->channels - 1) * s->b;
+    outlink->sample_aspect_ratio = (AVRational){1,1};
+    outlink->frame_rate = s->frame_rate;
+
+    return 0;
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *insamples)
+{
+    AVFilterContext *ctx = inlink->dst;
+    AVFilterLink *outlink = ctx->outputs[0];
+    ShowVolumeContext *s = ctx->priv;
+    int c, i, j, k;
+    double values[VAR_VARS_NB];
+
+    if (!s->out || s->out->width  != outlink->w ||
+                   s->out->height != outlink->h) {
+        av_frame_free(&s->out);
+        s->out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
+        if (!s->out) {
+            av_frame_free(&insamples);
+            return AVERROR(ENOMEM);
+        }
+
+        for (i = 0; i < outlink->h; i++)
+            memset(s->out->data[0] + i * s->out->linesize[0], 0, outlink->w * 4);
+    }
+    s->out->pts = insamples->pts;
+
+    for (j = 0; j < outlink->h; j++) {
+        uint8_t *dst = s->out->data[0] + j * s->out->linesize[0];
+        for (k = 0; k < s->w; k++) {
+            dst[k * 4 + 0] = FFMAX(dst[k * 4 + 0] - s->f, 0);
+            dst[k * 4 + 1] = FFMAX(dst[k * 4 + 1] - s->f, 0);
+            dst[k * 4 + 2] = FFMAX(dst[k * 4 + 2] - s->f, 0);
+            dst[k * 4 + 3] = FFMAX(dst[k * 4 + 3] - s->f, 0);
+        }
+    }
+
+    for (c = 0; c < inlink->channels; c++) {
+        float *src = (float *)insamples->extended_data[c];
+        float max = 0;
+        int color;
+
+        for (i = 0; i < insamples->nb_samples; i++)
+            max = FFMAX(max, src[i]);
+
+        max = av_clipf(max, 0, 1);
+        values[VAR_VOLUME] = 20.0 * log(max) / M_LN10;
+        color = av_expr_eval(s->c_expr, values, NULL);
+
+        for (j = 0; j < s->h; j++) {
+            uint8_t *dst = s->out->data[0] + (c * s->h + c * s->b + j) * s->out->linesize[0];
+
+            for (k = 0; k < s->w * max; k++)
+                AV_WN32A(dst + k * 4, color);
+        }
+    }
+
+    av_frame_free(&insamples);
+
+    return ff_filter_frame(outlink, av_frame_clone(s->out));
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+    ShowVolumeContext *s = ctx->priv;
+
+    av_frame_free(&s->out);
+    av_expr_free(s->c_expr);
+}
+
+static const AVFilterPad showvolume_inputs[] = {
+    {
+        .name         = "default",
+        .type         = AVMEDIA_TYPE_AUDIO,
+        .config_props = config_input,
+        .filter_frame = filter_frame,
+    },
+    { NULL }
+};
+
+static const AVFilterPad showvolume_outputs[] = {
+    {
+        .name         = "default",
+        .type         = AVMEDIA_TYPE_VIDEO,
+        .config_props = config_output,
+    },
+    { NULL }
+};
+
+AVFilter ff_avf_showvolume = {
+    .name          = "showvolume",
+    .description   = NULL_IF_CONFIG_SMALL("Convert input audio volume to video output."),
+    .init          = init,
+    .uninit        = uninit,
+    .query_formats = query_formats,
+    .priv_size     = sizeof(ShowVolumeContext),
+    .inputs        = showvolume_inputs,
+    .outputs       = showvolume_outputs,
+    .priv_class    = &showvolume_class,
+};

libavfilter/version.h

@@ -30,7 +30,7 @@
 #include "libavutil/version.h"
 
 #define LIBAVFILTER_VERSION_MAJOR  5
-#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, \