---
Is this correct?
---
libavfilter/Makefile | 1 +
libavfilter/allfilters.c | 1 +
libavfilter/avf_showfreqs.c | 333 ++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 335 insertions(+)
create mode 100644 libavfilter/avf_showfreqs.c
diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 1865e49..049bbe8 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -256,6 +256,7 @@ OBJS-$(CONFIG_ADRAWGRAPH_FILTER) +=
f_drawgraph.o
OBJS-$(CONFIG_AVECTORSCOPE_FILTER) += avf_avectorscope.o
OBJS-$(CONFIG_CONCAT_FILTER) += avf_concat.o
OBJS-$(CONFIG_SHOWCQT_FILTER) += avf_showcqt.o
+OBJS-$(CONFIG_SHOWFREQS_FILTER) += avf_showfreqs.o
OBJS-$(CONFIG_SHOWSPECTRUM_FILTER) += avf_showspectrum.o
OBJS-$(CONFIG_SHOWVOLUME_FILTER) += avf_showvolume.o
OBJS-$(CONFIG_SHOWWAVES_FILTER) += avf_showwaves.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index f8e97bc..63a274a 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -271,6 +271,7 @@ void avfilter_register_all(void)
REGISTER_FILTER(AVECTORSCOPE, avectorscope, avf);
REGISTER_FILTER(CONCAT, concat, avf);
REGISTER_FILTER(SHOWCQT, showcqt, avf);
+ REGISTER_FILTER(SHOWFREQS, showfreqs, avf);
REGISTER_FILTER(SHOWSPECTRUM, showspectrum, avf);
REGISTER_FILTER(SHOWVOLUME, showvolume, avf);
REGISTER_FILTER(SHOWWAVES, showwaves, avf);
diff --git a/libavfilter/avf_showfreqs.c b/libavfilter/avf_showfreqs.c
new file mode 100644
index 0000000..54902b9
--- /dev/null
+++ b/libavfilter/avf_showfreqs.c
@@ -0,0 +1,333 @@
+/*
+ * 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 <math.h>
+
+#include "libavcodec/avfft.h"
+#include "libavutil/avassert.h"
+#include "libavutil/channel_layout.h"
+#include "libavutil/intreadwrite.h"
+#include "libavutil/opt.h"
+#include "avfilter.h"
+#include "internal.h"
+
+enum DisplayMode { LINE, BAR, DOT, NB_MODES };
+enum DisplayScale { LINEAR, SQRT, CBRT, LOG, NB_SCALES };
+enum WindowFunc { WFUNC_NONE, WFUNC_HANN, WFUNC_HAMMING, WFUNC_BLACKMAN,
NB_WFUNC };
+
+typedef struct ShowFreqsContext {
+ const AVClass *class;
+ int w, h;
+ RDFTContext *rdft; ///< Real Discrete Fourier Transform context
+ int rdft_bits; ///< number of bits (RDFT window size =
1<<rdft_bits)
+ FFTSample **rdft_data; ///< bins holder for each (displayed) channels
+ float *window_func_lut; ///< Window function LUT
+ int win_func;
+ int nb_channels;
+ int mode;
+ int scale;
+} ShowFreqsContext;
+
+#define OFFSET(x) offsetof(ShowFreqsContext, x)
+#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
+
+static const AVOption showfreqs_options[] = {
+ { "size", "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str =
"1024x512"}, 0, 0, FLAGS },
+ { "s", "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str =
"1024x512"}, 0, 0, FLAGS },
+ { "mode", "set display mode", OFFSET(mode), AV_OPT_TYPE_INT, {.i64=LINE},
LINEAR, NB_MODES-1, FLAGS, "mode" },
+ { "line", "show lines", 0, AV_OPT_TYPE_CONST, {.i64=LINE}, 0, 0,
FLAGS, "mode" },
+ { "bar", "show bars", 0, AV_OPT_TYPE_CONST, {.i64=BAR}, 0, 0,
FLAGS, "mode" },
+ { "dot", "show dots", 0, AV_OPT_TYPE_CONST, {.i64=DOT}, 0, 0,
FLAGS, "mode" },
+ { "scale", "set display scale", OFFSET(scale), AV_OPT_TYPE_INT,
{.i64=SQRT}, LINEAR, NB_SCALES-1, FLAGS, "scale" },
+ { "sqrt", "square root", 0, AV_OPT_TYPE_CONST, {.i64=SQRT}, 0, 0,
FLAGS, "scale" },
+ { "cbrt", "cubic root", 0, AV_OPT_TYPE_CONST, {.i64=CBRT}, 0, 0,
FLAGS, "scale" },
+ { "log", "logarithmic", 0, AV_OPT_TYPE_CONST, {.i64=LOG}, 0, 0,
FLAGS, "scale" },
+ { "lin", "linear", 0, AV_OPT_TYPE_CONST, {.i64=LINEAR}, 0, 0,
FLAGS, "scale" },
+ { "win_func", "set window function", OFFSET(win_func), AV_OPT_TYPE_INT,
{.i64 = WFUNC_HANN}, 0, NB_WFUNC-1, FLAGS, "win_func" },
+ { "hann", "Hann window", 0, AV_OPT_TYPE_CONST, {.i64 =
WFUNC_HANN}, 0, 0, FLAGS, "win_func" },
+ { "hamming", "Hamming window", 0, AV_OPT_TYPE_CONST, {.i64 =
WFUNC_HAMMING}, 0, 0, FLAGS, "win_func" },
+ { "blackman", "Blackman window", 0, AV_OPT_TYPE_CONST, {.i64 =
WFUNC_BLACKMAN}, 0, 0, FLAGS, "win_func" },
+ { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(showfreqs);
+
+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_S16P,
AV_SAMPLE_FMT_NONE };
+ static const enum AVPixelFormat pix_fmts[] = { AV_PIX_FMT_RGBA,
AV_PIX_FMT_NONE };
+
+ /* set input audio formats */
+ 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);
+
+ /* set output video format */
+ formats = ff_make_format_list(pix_fmts);
+ if (!formats)
+ return AVERROR(ENOMEM);
+ ff_formats_ref(formats, &outlink->in_formats);
+
+ return 0;
+}
+
+static int config_output(AVFilterLink *outlink)
+{
+ AVFilterContext *ctx = outlink->src;
+ AVFilterLink *inlink = ctx->inputs[0];
+ ShowFreqsContext *s = ctx->priv;
+ unsigned win_size;
+ int i, rdft_bits;
+
+ outlink->w = s->w;
+ outlink->h = s->h;
+
+ /* RDFT window size (precision) according to the requested output frame
height */
+ for (rdft_bits = 1; 1 << rdft_bits < 2 * outlink->w; rdft_bits++);
+ win_size = 1 << rdft_bits;
+
+ /* (re-)configuration if the video output changed (or first init) */
+ if (rdft_bits != s->rdft_bits) {
+ size_t rdft_size, rdft_listsize;
+
+ av_rdft_end(s->rdft);
+ s->rdft = av_rdft_init(rdft_bits, DFT_R2C);
+ if (!s->rdft) {
+ av_log(ctx, AV_LOG_ERROR, "Unable to create RDFT context. "
+ "The window size might be too high.\n");
+ return AVERROR(EINVAL);
+ }
+ s->rdft_bits = rdft_bits;
+
+ /* RDFT buffers: x2 for each (display) channel buffer.
+ * Note: we use free and malloc instead of a realloc-like function to
+ * make sure the buffer is aligned in memory for the FFT functions. */
+ for (i = 0; i < s->nb_channels; i++)
+ av_freep(&s->rdft_data[i]);
+ av_freep(&s->rdft_data);
+ s->nb_channels = inlink->channels;
+
+ if (av_size_mult(sizeof(*s->rdft_data),
+ s->nb_channels, &rdft_listsize) < 0)
+ return AVERROR(EINVAL);
+ if (av_size_mult(sizeof(**s->rdft_data),
+ win_size, &rdft_size) < 0)
+ return AVERROR(EINVAL);
+ s->rdft_data = av_malloc(rdft_listsize);
+ if (!s->rdft_data)
+ return AVERROR(ENOMEM);
+ for (i = 0; i < s->nb_channels; i++) {
+ s->rdft_data[i] = av_malloc(rdft_size);
+ if (!s->rdft_data[i])
+ return AVERROR(ENOMEM);
+ }
+
+ /* pre-calc windowing function */
+ s->window_func_lut =
+ av_realloc_f(s->window_func_lut, win_size,
+ sizeof(*s->window_func_lut));
+ if (!s->window_func_lut)
+ return AVERROR(ENOMEM);
+ switch (s->win_func) {
+ case WFUNC_NONE:
+ for (i = 0; i < win_size; i++)
+ s->window_func_lut[i] = 1.;
+ break;
+ case WFUNC_HANN:
+ for (i = 0; i < win_size; i++)
+ s->window_func_lut[i] = .5f * (1 - cos(2*M_PI*i /
(win_size-1)));
+ break;
+ case WFUNC_HAMMING:
+ for (i = 0; i < win_size; i++)
+ s->window_func_lut[i] = .54f - .46f * cos(2*M_PI*i /
(win_size-1));
+ break;
+ case WFUNC_BLACKMAN: {
+ for (i = 0; i < win_size; i++)
+ s->window_func_lut[i] = .42f - .5f*cos(2*M_PI*i /
(win_size-1)) + .08f*cos(4*M_PI*i / (win_size-1));
+ break;
+ }
+ default:
+ av_assert0(0);
+ }
+
+ outlink->sample_aspect_ratio = (AVRational){1,1};
+ }
+
+ outlink->frame_rate = av_make_q(inlink->sample_rate, win_size);
+
+ inlink->min_samples = inlink->max_samples = inlink->partial_buf_size =
+ win_size;
+
+ av_log(ctx, AV_LOG_VERBOSE, "s:%dx%d RDFT window size:%d\n",
+ s->w, s->h, win_size);
+ return 0;
+}
+
+static int plot_freqs(AVFilterLink *inlink, AVFrame *insamples)
+{
+ AVFilterContext *ctx = inlink->dst;
+ AVFilterLink *outlink = ctx->outputs[0];
+ ShowFreqsContext *s = ctx->priv;
+ AVFrame *out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
+
+ /* nb_freq contains the power of two superior or equal to the output image
+ * height (or half the RDFT window size) */
+ const int nb_freq = 1 << (s->rdft_bits - 1);
+ const int win_size = nb_freq << 1;
+ const double w = 1. / (nb_freq * 32768.);
+ int ch, n, x;
+
+ /* fill RDFT input with the number of samples available */
+ for (ch = 0; ch < s->nb_channels; ch++) {
+ const int16_t *p = (int16_t *)insamples->extended_data[ch];
+
+ for (n = 0; n < insamples->nb_samples; n++)
+ s->rdft_data[ch][n] = p[n] * s->window_func_lut[n];
+ for (; n < win_size; n++)
+ s->rdft_data[ch][n] = 0;
+ }
+
+ /* run RDFT on each samples set */
+ for (ch = 0; ch < s->nb_channels; ch++)
+ av_rdft_calc(s->rdft, s->rdft_data[ch]);
+
+#define RE(x, ch) s->rdft_data[ch][2 * (x) + 0]
+#define IM(x, ch) s->rdft_data[ch][2 * (x) + 1]
+#define MAGNITUDE(x, ch) hypot(RE(x, ch), IM(x, ch))
+
+ for (ch = 0; ch < s->nb_channels; ch++) {
+ for (x = 0; x < outlink->w; x++) {
+ double a = w * MAGNITUDE(x, ch);
+ int y, prev_y, i;
+
+ switch(s->scale) {
+ case SQRT:
+ a = 1.0 - sqrt(a);
+ break;
+ case CBRT:
+ a = 1.0 - cbrt(a);
+ break;
+ case LOG:
+ a = log(FFMAX(FFMIN(1, a), 1e-6)) / log(1e-6); // zero =
-120dBFS
+ break;
+ case LINEAR:
+ a = 1.0 - a;
+ break;
+ }
+ y = a * (outlink->h - 1);
+
+ switch(s->mode) {
+ case LINE:
+ if (x == 0) {
+ prev_y = y;
+ }
+ if (y <= prev_y) {
+ for (i = y; i <= prev_y; i++)
+ AV_WL32(out->data[0] + i * out->linesize[0] + x * 4,
0xffffffff);
+ } else {
+ for (i = prev_y; i <= y; i++)
+ AV_WL32(out->data[0] + i * out->linesize[0] + x * 4,
0xffffffff);
+ }
+ prev_y = y;
+ break;
+ case BAR:
+ for (; y < outlink->h; y++)
+ AV_WL32(out->data[0] + y * out->linesize[0] + x * 4,
0xffffffff);
+ break;
+ case DOT:
+ AV_WL32(out->data[0] + y * out->linesize[0] + x * 4,
0xffffffff);
+ break;
+ }
+ }
+ }
+
+ out->pts = insamples->pts;
+ return ff_filter_frame(outlink, out);
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *insamples)
+{
+ AVFilterContext *ctx = inlink->dst;
+ ShowFreqsContext *s = ctx->priv;
+ unsigned win_size = 1 << s->rdft_bits;
+ int ret;
+
+ av_assert0(insamples->nb_samples <= win_size);
+ ret = plot_freqs(inlink, insamples);
+
+ av_frame_free(&insamples);
+ return ret;
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+ ShowFreqsContext *s = ctx->priv;
+ int i;
+
+ av_rdft_end(s->rdft);
+ for (i = 0; i < s->nb_channels; i++)
+ av_freep(&s->rdft_data[i]);
+ av_freep(&s->rdft_data);
+ av_freep(&s->window_func_lut);
+}
+
+static const AVFilterPad showfreqs_inputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_AUDIO,
+ .filter_frame = filter_frame,
+ },
+ { NULL }
+};
+
+static const AVFilterPad showfreqs_outputs[] = {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .config_props = config_output,
+ },
+ { NULL }
+};
+
+AVFilter ff_avf_showfreqs = {
+ .name = "showfreqs",
+ .description = NULL_IF_CONFIG_SMALL("Convert input audio to a
frequencies video output."),
+ .uninit = uninit,
+ .query_formats = query_formats,
+ .priv_size = sizeof(ShowFreqsContext),
+ .inputs = showfreqs_inputs,
+ .outputs = showfreqs_outputs,
+ .priv_class = &showfreqs_class,
+};
--
2.4.5
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