/*
* Copyright (c) 2012 Clément Bœsch
* Copyright (c) 2013 Rudolf Polzer <divverent@xonotic.org>
*
* 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 to spectrum (video) transmedia filter, based on ffplay rdft showmode
* (by Michael Niedermayer) and lavfi/avf_showwaves (by Stefano Sabatini).
*/
#include <math.h>
#include "libavcodec/avfft.h"
#include "libavutil/avassert.h"
#include "libavutil/channel_layout.h"
#include "libavutil/opt.h"
#include "avfilter.h"
#include "internal.h"
enum DisplayMode { COMBINED, SEPARATE, NB_MODES };
enum DisplayScale { LINEAR, SQRT, CBRT, LOG, NB_SCALES };
enum ColorMode { CHANNEL, INTENSITY, NB_CLMODES };
typedef struct {
const AVClass *class;
int w, h;
AVFrame *outpicref;
int req_fullfilled;
int nb_display_channels;
int channel_height;
int sliding; ///< 1 if sliding mode, 0 otherwise
enum DisplayMode mode; ///< channel display mode
enum ColorMode color_mode; ///< display color scheme
enum DisplayScale scale;
float saturation; ///< color saturation multiplier
int xpos; ///< x position (current column)
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
int filled; ///< number of samples (per channel) filled in current rdft_buffer
int consumed; ///< number of samples (per channel) consumed from the input frame
float *window_func_lut; ///< Window function LUT
float *combine_buffer; ///< color combining buffer (3 * h items)
} ShowSpectrumContext;
#define OFFSET(x) offsetof(ShowSpectrumContext, x)
#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
static const AVOption showspectrum_options[] = {
{ "size", "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str = "640x512"}, 0, 0, FLAGS },
{ "s", "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str = "640x512"}, 0, 0, FLAGS },
{ "slide", "set sliding mode", OFFSET(sliding), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, FLAGS },
{ "mode", "set channel display mode", OFFSET(mode), AV_OPT_TYPE_INT, {.i64=COMBINED}, COMBINED, NB_MODES-1, FLAGS, "mode" },
{ "combined", "combined mode", 0, AV_OPT_TYPE_CONST, {.i64=COMBINED}, 0, 0, FLAGS, "mode" },
{ "separate", "separate mode", 0, AV_OPT_TYPE_CONST, {.i64=SEPARATE}, 0, 0, FLAGS, "mode" },
{ "color", "set channel coloring", OFFSET(color_mode), AV_OPT_TYPE_INT, {.i64=CHANNEL}, CHANNEL, NB_CLMODES-1, FLAGS, "color" },
{ "channel", "separate color for each channel", 0, AV_OPT_TYPE_CONST, {.i64=CHANNEL}, 0, 0, FLAGS, "color" },
{ "intensity", "intensity based coloring", 0, AV_OPT_TYPE_CONST, {.i64=INTENSITY}, 0, 0, FLAGS, "color" },
{ "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" },
{ "saturation", "color saturation multiplier", OFFSET(saturation), AV_OPT_TYPE_FLOAT, {.dbl = 1}, -10, 10, FLAGS },
{ NULL }
};
AVFILTER_DEFINE_CLASS(showspectrum);
static const struct {
float a, y, u, v;
} intensity_color_table[] = {
{ 0, 0, 0, 0 },
{ 0.13, .03587126228984074, .1573300977624594, -.02548747583751842 },
{ 0.30, .18572281794568020, .1772436246393981, .17475554840414750 },
{ 0.60, .28184980583656130, -.1593064119945782, .47132074554608920 },
{ 0.73, .65830621175547810, -.3716070802232764, .24352759331252930 },
{ 0.78, .76318535758242900, -.4307467689263783, .16866496622310430 },
{ 0.91, .95336363636363640, -.2045454545454546, .03313636363636363 },
{ 1, 1, 0, 0 }
};
static av_cold void uninit(AVFilterContext *ctx)
{
ShowSpectrumContext *s = ctx->priv;
int i;
av_freep(&s->combine_buffer);
av_rdft_end(s->rdft);
for (i = 0; i < s->nb_display_channels; i++)
av_freep(&s->rdft_data[i]);
av_freep(&s->rdft_data);
av_freep(&s->window_func_lut);
av_frame_free(&s->outpicref);
}
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_YUVJ444P, 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];
ShowSpectrumContext *s = ctx->priv;
int i, rdft_bits, win_size, h;
outlink->w = s->w;
outlink->h = s->h;
h = (s->mode == COMBINED) ? outlink->h : outlink->h / inlink->channels;
s->channel_height = h;
/* RDFT window size (precision) according to the requested output frame height */
for (rdft_bits = 1; 1 << rdft_bits < 2 * h; 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;
AVFrame *outpicref;
av_rdft_end(s->rdft);
s->rdft = av_rdft_init(rdft_bits, DFT_R2C);
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_display_channels; i++)
av_freep(&s->rdft_data[i]);
av_freep(&s->rdft_data);
s->nb_display_channels = inlink->channels;
if (av_size_mult(sizeof(*s->rdft_data),
s->nb_display_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_display_channels; i++) {
s->rdft_data[i] = av_malloc(rdft_size);
if (!s->rdft_data[i])
return AVERROR(ENOMEM);
}
s->filled = 0;
/* pre-calc windowing function (hann here) */
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);
for (i = 0; i < win_size; i++)
s
->window_func_lut
[i
] = .5f * (1 - cos(2*M_PI
*i
/ (win_size
-1)));
/* prepare the initial picref buffer (black frame) */
av_frame_free(&s->outpicref);
s->outpicref = outpicref =
ff_get_video_buffer(outlink, outlink->w, outlink->h);
if (!outpicref)
return AVERROR(ENOMEM);
outlink->sample_aspect_ratio = (AVRational){1,1};
for (i = 0; i < outlink->h; i++) {
memset(outpicref
->data
[0] + i
* outpicref
->linesize
[0], 0, outlink
->w
); memset(outpicref
->data
[1] + i
* outpicref
->linesize
[1], 128, outlink
->w
); memset(outpicref
->data
[2] + i
* outpicref
->linesize
[2], 128, outlink
->w
); }
}
if (s->xpos >= outlink->w)
s->xpos = 0;
s->combine_buffer =
av_realloc_f(s->combine_buffer, outlink->h * 3,
sizeof(*s->combine_buffer));
av_log(ctx, AV_LOG_VERBOSE, "s:%dx%d RDFT window size:%d\n",
s->w, s->h, win_size);
return 0;
}
inline static int push_frame(AVFilterLink *outlink)
{
ShowSpectrumContext *s = outlink->src->priv;
s->xpos++;
if (s->xpos >= outlink->w)
s->xpos = 0;
s->filled = 0;
s->req_fullfilled = 1;
return ff_filter_frame(outlink, av_frame_clone(s->outpicref));
}
static int request_frame(AVFilterLink *outlink)
{
ShowSpectrumContext *s = outlink->src->priv;
AVFilterLink *inlink = outlink->src->inputs[0];
int ret;
s->req_fullfilled = 0;
do {
ret = ff_request_frame(inlink);
} while (!s->req_fullfilled && ret >= 0);
if (ret == AVERROR_EOF && s->outpicref)
push_frame(outlink);
return ret;
}
static int plot_spectrum_column(AVFilterLink *inlink, AVFrame *insamples, int nb_samples)
{
int ret;
AVFilterContext *ctx = inlink->dst;
AVFilterLink *outlink = ctx->outputs[0];
ShowSpectrumContext *s = ctx->priv;
AVFrame *outpicref = s->outpicref;
/* 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.
/ (sqrt(nb_freq
) * 32768.
);
int ch, plane, n, y;
const int start = s->filled;
const int add_samples = FFMIN(win_size - start, nb_samples);
/* fill RDFT input with the number of samples available */
for (ch = 0; ch < s->nb_display_channels; ch++) {
const int16_t *p = (int16_t *)insamples->extended_data[ch];
p += s->consumed;
for (n = 0; n < add_samples; n++)
s->rdft_data[ch][start + n] = p[n] * s->window_func_lut[start + n];
}
s->filled += add_samples;
/* complete RDFT window size? */
if (s->filled == win_size) {
/* channel height */
int h = s->channel_height;
/* run RDFT on each samples set */
for (ch = 0; ch < s->nb_display_channels; ch++)
av_rdft_calc(s->rdft, s->rdft_data[ch]);
/* fill a new spectrum column */
#define RE(y, ch) s->rdft_data[ch][2 * y + 0]
#define IM(y, ch) s->rdft_data[ch][2 * y + 1]
#define MAGNITUDE(y, ch) hypot(RE(y, ch), IM(y, ch))
/* initialize buffer for combining to black */
for (y = 0; y < outlink->h; y++) {
s->combine_buffer[3 * y ] = 0;
s->combine_buffer[3 * y + 1] = 127.5;
s->combine_buffer[3 * y + 2] = 127.5;
}
for (ch = 0; ch < s->nb_display_channels; ch++) {
float yf, uf, vf;
/* decide color range */
switch (s->mode) {
case COMBINED:
// reduce range by channel count
yf = 256.0f / s->nb_display_channels;
switch (s->color_mode) {
case INTENSITY:
uf = yf;
vf = yf;
break;
case CHANNEL:
/* adjust saturation for mixed UV coloring */
/* this factor is correct for infinite channels, an approximation otherwise */
uf = yf * M_PI;
vf = yf * M_PI;
break;
default:
av_assert0(0);
}
break;
case SEPARATE:
// full range
yf = 256.0f;
uf = 256.0f;
vf = 256.0f;
break;
default:
av_assert0(0);
}
if (s->color_mode == CHANNEL) {
if (s->nb_display_channels > 1) {
uf
*= 0.5 * sin((2 * M_PI
* ch
) / s
->nb_display_channels
); vf
*= 0.5 * cos((2 * M_PI
* ch
) / s
->nb_display_channels
); } else {
uf = 0.0f;
vf = 0.0f;
}
}
uf *= s->saturation;
vf *= s->saturation;
/* draw the channel */
for (y = 0; y < h; y++) {
int row = (s->mode == COMBINED) ? y : ch * h + y;
float *out = &s->combine_buffer[3 * row];
/* get magnitude */
float a = w * MAGNITUDE(y, ch);
/* apply scale */
switch (s->scale) {
case LINEAR:
break;
case SQRT:
break;
case CBRT:
a = cbrt(a);
break;
case LOG:
a
= 1 - log(FFMAX
(FFMIN
(1, a
), 1e-6)) / log(1e-6); // zero = -120dBFS break;
default:
av_assert0(0);
}
if (s->color_mode == INTENSITY) {
float y, u, v;
int i;
for (i = 1; i < sizeof(intensity_color_table) / sizeof(*intensity_color_table) - 1; i++)
if (intensity_color_table[i].a >= a)
break;
// i now is the first item >= the color
// now we know to interpolate between item i - 1 and i
if (a <= intensity_color_table[i - 1].a) {
y = intensity_color_table[i - 1].y;
u = intensity_color_table[i - 1].u;
v = intensity_color_table[i - 1].v;
} else if (a >= intensity_color_table[i].a) {
y = intensity_color_table[i].y;
u = intensity_color_table[i].u;
v = intensity_color_table[i].v;
} else {
float start = intensity_color_table[i - 1].a;
float end = intensity_color_table[i].a;
float lerpfrac = (a - start) / (end - start);
y = intensity_color_table[i - 1].y * (1.0f - lerpfrac)
+ intensity_color_table[i].y * lerpfrac;
u = intensity_color_table[i - 1].u * (1.0f - lerpfrac)
+ intensity_color_table[i].u * lerpfrac;
v = intensity_color_table[i - 1].v * (1.0f - lerpfrac)
+ intensity_color_table[i].v * lerpfrac;
}
out[0] += y * yf;
out[1] += u * uf;
out[2] += v * vf;
} else {
out[0] += a * yf;
out[1] += a * uf;
out[2] += a * vf;
}
}
}
/* copy to output */
if (s->sliding) {
for (plane = 0; plane < 3; plane++) {
for (y = 0; y < outlink->h; y++) {
uint8_t *p = outpicref->data[plane] +
y * outpicref->linesize[plane];
}
}
s->xpos = outlink->w - 1;
}
for (plane = 0; plane < 3; plane++) {
uint8_t *p = outpicref->data[plane] +
(outlink->h - 1) * outpicref->linesize[plane] +
s->xpos;
for (y = 0; y < outlink->h; y++) {
*p = rint(FFMAX(0, FFMIN(s->combine_buffer[3 * y + plane], 255)));
p -= outpicref->linesize[plane];
}
}
outpicref->pts = insamples->pts +
av_rescale_q(s->consumed,
(AVRational){ 1, inlink->sample_rate },
outlink->time_base);
ret = push_frame(outlink);
if (ret < 0)
return ret;
}
return add_samples;
}
static int filter_frame(AVFilterLink *inlink, AVFrame *insamples)
{
AVFilterContext *ctx = inlink->dst;
ShowSpectrumContext *s = ctx->priv;
int ret = 0, left_samples = insamples->nb_samples;
s->consumed = 0;
while (left_samples) {
int ret = plot_spectrum_column(inlink, insamples, left_samples);
if (ret < 0)
break;
s->consumed += ret;
left_samples -= ret;
}
av_frame_free(&insamples);
return ret;
}
static const AVFilterPad showspectrum_inputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_AUDIO,
.filter_frame = filter_frame,
},
{ NULL }
};
static const AVFilterPad showspectrum_outputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.config_props = config_output,
.request_frame = request_frame,
},
{ NULL }
};
AVFilter avfilter_avf_showspectrum = {
.name = "showspectrum",
.description = NULL_IF_CONFIG_SMALL("Convert input audio to a spectrum video output."),
.uninit = uninit,
.query_formats = query_formats,
.priv_size = sizeof(ShowSpectrumContext),
.inputs = showspectrum_inputs,
.outputs = showspectrum_outputs,
.priv_class = &showspectrum_class,
};