libavfilter/vaf_spectrumsynth.c - manifest_repos/ffmpeg - Git at Google

 /*
  * Copyright (c) 2016 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
  */

 /**
  * @file
  * SpectrumSynth filter
  * @todo support float pixel format
  */

 #include "libavcodec/avfft.h"
 #include "libavutil/avassert.h"
 #include "libavutil/channel_layout.h"
 #include "libavutil/ffmath.h"
 #include "libavutil/opt.h"
 #include "libavutil/parseutils.h"
 #include "avfilter.h"
 #include "formats.h"
 #include "audio.h"
 #include "video.h"
 #include "filters.h"
 #include "internal.h"
 #include "window_func.h"

 enum MagnitudeScale { LINEAR, LOG, NB_SCALES };
 enum SlideMode      { REPLACE, SCROLL, FULLFRAME, RSCROLL, NB_SLIDES };
 enum Orientation    { VERTICAL, HORIZONTAL, NB_ORIENTATIONS };

 typedef struct SpectrumSynthContext {
     const AVClass *class;
     int sample_rate;
     int channels;
     int scale;
     int sliding;
     int win_func;
     float overlap;
     int orientation;

     AVFrame *magnitude, *phase;
     FFTContext *fft;            ///< Fast Fourier Transform context
     int fft_bits;               ///< number of bits (FFT window size = 1<<fft_bits)
     FFTComplex **fft_data;      ///< bins holder for each (displayed) channels
     int win_size;
     int size;
     int nb_freq;
     int hop_size;
     int start, end;
     int xpos;
     int xend;
     int64_t pts;
     float factor;
     AVFrame *buffer;
     float *window_func_lut;     ///< Window function LUT
 } SpectrumSynthContext;

 #define OFFSET(x) offsetof(SpectrumSynthContext, x)
 #define A AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_AUDIO_PARAM
 #define V AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM

 static const AVOption spectrumsynth_options[] = {
     { "sample_rate", "set sample rate",  OFFSET(sample_rate), AV_OPT_TYPE_INT, {.i64 = 44100}, 15,  INT_MAX, A },
     { "channels",    "set channels",     OFFSET(channels), AV_OPT_TYPE_INT, {.i64 = 1}, 1, 8, A },
     { "scale",       "set input amplitude scale", OFFSET(scale), AV_OPT_TYPE_INT, {.i64 = LOG}, 0, NB_SCALES-1, V, "scale" },
         { "lin",  "linear",      0, AV_OPT_TYPE_CONST, {.i64=LINEAR}, 0, 0, V, "scale" },
         { "log",  "logarithmic", 0, AV_OPT_TYPE_CONST, {.i64=LOG},    0, 0, V, "scale" },
     { "slide", "set input sliding mode", OFFSET(sliding), AV_OPT_TYPE_INT, {.i64 = FULLFRAME}, 0, NB_SLIDES-1, V, "slide" },
         { "replace",   "consume old columns with new",   0, AV_OPT_TYPE_CONST, {.i64=REPLACE},   0, 0, V, "slide" },
         { "scroll",    "consume only most right column", 0, AV_OPT_TYPE_CONST, {.i64=SCROLL},    0, 0, V, "slide" },
         { "fullframe", "consume full frames",            0, AV_OPT_TYPE_CONST, {.i64=FULLFRAME}, 0, 0, V, "slide" },
         { "rscroll",   "consume only most left column",  0, AV_OPT_TYPE_CONST, {.i64=RSCROLL},   0, 0, V, "slide" },
     { "win_func", "set window function", OFFSET(win_func), AV_OPT_TYPE_INT, {.i64 = 0}, 0, NB_WFUNC-1, A, "win_func" },
         { "rect",     "Rectangular",      0, AV_OPT_TYPE_CONST, {.i64=WFUNC_RECT},     0, 0, A, "win_func" },
         { "bartlett", "Bartlett",         0, AV_OPT_TYPE_CONST, {.i64=WFUNC_BARTLETT}, 0, 0, A, "win_func" },
         { "hann",     "Hann",             0, AV_OPT_TYPE_CONST, {.i64=WFUNC_HANNING},  0, 0, A, "win_func" },
         { "hanning",  "Hanning",          0, AV_OPT_TYPE_CONST, {.i64=WFUNC_HANNING},  0, 0, A, "win_func" },
         { "hamming",  "Hamming",          0, AV_OPT_TYPE_CONST, {.i64=WFUNC_HAMMING},  0, 0, A, "win_func" },
         { "sine",     "Sine",             0, AV_OPT_TYPE_CONST, {.i64=WFUNC_SINE},     0, 0, A, "win_func" },
     { "overlap", "set window overlap",  OFFSET(overlap), AV_OPT_TYPE_FLOAT, {.dbl=1}, 0,  1, A },
     { "orientation", "set orientation", OFFSET(orientation), AV_OPT_TYPE_INT, {.i64=VERTICAL}, 0, NB_ORIENTATIONS-1, V, "orientation" },
         { "vertical",   NULL, 0, AV_OPT_TYPE_CONST, {.i64=VERTICAL},   0, 0, V, "orientation" },
         { "horizontal", NULL, 0, AV_OPT_TYPE_CONST, {.i64=HORIZONTAL}, 0, 0, V, "orientation" },
     { NULL }
 };

 AVFILTER_DEFINE_CLASS(spectrumsynth);

 static int query_formats(AVFilterContext *ctx)
 {
     SpectrumSynthContext *s = ctx->priv;
     AVFilterFormats *formats = NULL;
     AVFilterChannelLayouts *layout = NULL;
     AVFilterLink *magnitude = ctx->inputs[0];
     AVFilterLink *phase = ctx->inputs[1];
     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_GRAY8, AV_PIX_FMT_GRAY16,
                                                    AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUVJ444P,
                                                    AV_PIX_FMT_YUV444P16, AV_PIX_FMT_NONE };
     int ret, sample_rates[] = { 48000, -1 };

     formats = ff_make_format_list(sample_fmts);
     if ((ret = ff_formats_ref         (formats, &outlink->incfg.formats        )) < 0 ||
         (ret = ff_add_channel_layout  (&layout, FF_COUNT2LAYOUT(s->channels))) < 0 ||
         (ret = ff_channel_layouts_ref (layout , &outlink->incfg.channel_layouts)) < 0)
         return ret;

     sample_rates[0] = s->sample_rate;
     formats = ff_make_format_list(sample_rates);
     if (!formats)
         return AVERROR(ENOMEM);
     if ((ret = ff_formats_ref(formats, &outlink->incfg.samplerates)) < 0)
         return ret;

     formats = ff_make_format_list(pix_fmts);
     if (!formats)
         return AVERROR(ENOMEM);
     if ((ret = ff_formats_ref(formats, &magnitude->outcfg.formats)) < 0)
         return ret;

     formats = ff_make_format_list(pix_fmts);
     if (!formats)
         return AVERROR(ENOMEM);
     if ((ret = ff_formats_ref(formats, &phase->outcfg.formats)) < 0)
         return ret;

     return 0;
 }

 static int config_output(AVFilterLink *outlink)
 {
     AVFilterContext *ctx = outlink->src;
     SpectrumSynthContext *s = ctx->priv;
     int width = ctx->inputs[0]->w;
     int height = ctx->inputs[0]->h;
     AVRational time_base  = ctx->inputs[0]->time_base;
     AVRational frame_rate = ctx->inputs[0]->frame_rate;
     int i, ch, fft_bits;
     float factor, overlap;

     outlink->sample_rate = s->sample_rate;
     outlink->time_base = (AVRational){1, s->sample_rate};

     if (width  != ctx->inputs[1]->w ||
         height != ctx->inputs[1]->h) {
         av_log(ctx, AV_LOG_ERROR,
                "Magnitude and Phase sizes differ (%dx%d vs %dx%d).\n",
                width, height,
                ctx->inputs[1]->w, ctx->inputs[1]->h);
         return AVERROR_INVALIDDATA;
     } else if (av_cmp_q(time_base, ctx->inputs[1]->time_base) != 0) {
         av_log(ctx, AV_LOG_ERROR,
                "Magnitude and Phase time bases differ (%d/%d vs %d/%d).\n",
                time_base.num, time_base.den,
                ctx->inputs[1]->time_base.num,
                ctx->inputs[1]->time_base.den);
         return AVERROR_INVALIDDATA;
     } else if (av_cmp_q(frame_rate, ctx->inputs[1]->frame_rate) != 0) {
         av_log(ctx, AV_LOG_ERROR,
                "Magnitude and Phase framerates differ (%d/%d vs %d/%d).\n",
                frame_rate.num, frame_rate.den,
                ctx->inputs[1]->frame_rate.num,
                ctx->inputs[1]->frame_rate.den);
         return AVERROR_INVALIDDATA;
     }

     s->size = s->orientation == VERTICAL ? height / s->channels : width / s->channels;
     s->xend = s->orientation == VERTICAL ? width : height;

     for (fft_bits = 1; 1 << fft_bits < 2 * s->size; fft_bits++);

     s->win_size = 1 << fft_bits;
     s->nb_freq = 1 << (fft_bits - 1);

     s->fft = av_fft_init(fft_bits, 1);
     if (!s->fft) {
         av_log(ctx, AV_LOG_ERROR, "Unable to create FFT context. "
                "The window size might be too high.\n");
         return AVERROR(EINVAL);
     }
     s->fft_data = av_calloc(s->channels, sizeof(*s->fft_data));
     if (!s->fft_data)
         return AVERROR(ENOMEM);
     for (ch = 0; ch < s->channels; ch++) {
         s->fft_data[ch] = av_calloc(s->win_size, sizeof(**s->fft_data));
         if (!s->fft_data[ch])
             return AVERROR(ENOMEM);
     }

     s->buffer = ff_get_audio_buffer(outlink, s->win_size * 2);
     if (!s->buffer)
         return AVERROR(ENOMEM);

     /* pre-calc windowing function */
     s->window_func_lut = av_realloc_f(s->window_func_lut, s->win_size,
                                       sizeof(*s->window_func_lut));
     if (!s->window_func_lut)
         return AVERROR(ENOMEM);
     generate_window_func(s->window_func_lut, s->win_size, s->win_func, &overlap);
     if (s->overlap == 1)
         s->overlap = overlap;
     s->hop_size = (1 - s->overlap) * s->win_size;
     for (factor = 0, i = 0; i < s->win_size; i++) {
         factor += s->window_func_lut[i] * s->window_func_lut[i];
     }
     s->factor = (factor / s->win_size) / FFMAX(1 / (1 - s->overlap) - 1, 1);

     return 0;
 }

 static void read16_fft_bin(SpectrumSynthContext *s,
                            int x, int y, int f, int ch)
 {
     const int m_linesize = s->magnitude->linesize[0];
     const int p_linesize = s->phase->linesize[0];
     const uint16_t *m = (uint16_t *)(s->magnitude->data[0] + y * m_linesize);
     const uint16_t *p = (uint16_t *)(s->phase->data[0] + y * p_linesize);
     float magnitude, phase;

     switch (s->scale) {
     case LINEAR:
         magnitude = m[x] / (double)UINT16_MAX;
         break;
     case LOG:
         magnitude = ff_exp10(((m[x] / (double)UINT16_MAX) - 1.) * 6.);
         break;
     default:
         av_assert0(0);
     }
     phase = ((p[x] / (double)UINT16_MAX) * 2. - 1.) * M_PI;

     s->fft_data[ch][f].re = magnitude * cos(phase);
     s->fft_data[ch][f].im = magnitude * sin(phase);
 }

 static void read8_fft_bin(SpectrumSynthContext *s,
                           int x, int y, int f, int ch)
 {
     const int m_linesize = s->magnitude->linesize[0];
     const int p_linesize = s->phase->linesize[0];
     const uint8_t *m = (uint8_t *)(s->magnitude->data[0] + y * m_linesize);
     const uint8_t *p = (uint8_t *)(s->phase->data[0] + y * p_linesize);
     float magnitude, phase;

     switch (s->scale) {
     case LINEAR:
         magnitude = m[x] / (double)UINT8_MAX;
         break;
     case LOG:
         magnitude = ff_exp10(((m[x] / (double)UINT8_MAX) - 1.) * 6.);
         break;
     default:
         av_assert0(0);
     }
     phase = ((p[x] / (double)UINT8_MAX) * 2. - 1.) * M_PI;

     s->fft_data[ch][f].re = magnitude * cos(phase);
     s->fft_data[ch][f].im = magnitude * sin(phase);
 }

 static void read_fft_data(AVFilterContext *ctx, int x, int h, int ch)
 {
     SpectrumSynthContext *s = ctx->priv;
     AVFilterLink *inlink = ctx->inputs[0];
     int start = h * (s->channels - ch) - 1;
     int end = h * (s->channels - ch - 1);
     int y, f;

     switch (s->orientation) {
     case VERTICAL:
         switch (inlink->format) {
         case AV_PIX_FMT_YUV444P16:
         case AV_PIX_FMT_GRAY16:
             for (y = start, f = 0; y >= end; y--, f++) {
                 read16_fft_bin(s, x, y, f, ch);
             }
             break;
         case AV_PIX_FMT_YUVJ444P:
         case AV_PIX_FMT_YUV444P:
         case AV_PIX_FMT_GRAY8:
             for (y = start, f = 0; y >= end; y--, f++) {
                 read8_fft_bin(s, x, y, f, ch);
             }
             break;
         }
         break;
     case HORIZONTAL:
         switch (inlink->format) {
         case AV_PIX_FMT_YUV444P16:
         case AV_PIX_FMT_GRAY16:
             for (y = end, f = 0; y <= start; y++, f++) {
                 read16_fft_bin(s, y, x, f, ch);
             }
             break;
         case AV_PIX_FMT_YUVJ444P:
         case AV_PIX_FMT_YUV444P:
         case AV_PIX_FMT_GRAY8:
             for (y = end, f = 0; y <= start; y++, f++) {
                 read8_fft_bin(s, y, x, f, ch);
             }
             break;
         }
         break;
     }
 }

 static void synth_window(AVFilterContext *ctx, int x)
 {
     SpectrumSynthContext *s = ctx->priv;
     const int h = s->size;
     int nb = s->win_size;
     int y, f, ch;

     for (ch = 0; ch < s->channels; ch++) {
         read_fft_data(ctx, x, h, ch);

         for (y = h; y <= s->nb_freq; y++) {
             s->fft_data[ch][y].re = 0;
             s->fft_data[ch][y].im = 0;
         }

         for (y = s->nb_freq + 1, f = s->nb_freq - 1; y < nb; y++, f--) {
             s->fft_data[ch][y].re =  s->fft_data[ch][f].re;
             s->fft_data[ch][y].im = -s->fft_data[ch][f].im;
         }

         av_fft_permute(s->fft, s->fft_data[ch]);
         av_fft_calc(s->fft, s->fft_data[ch]);
     }
 }

 static int try_push_frame(AVFilterContext *ctx, int x)
 {
     SpectrumSynthContext *s = ctx->priv;
     AVFilterLink *outlink = ctx->outputs[0];
     const float factor = s->factor;
     int ch, n, i, ret;
     int start, end;
     AVFrame *out;

     synth_window(ctx, x);

     for (ch = 0; ch < s->channels; ch++) {
         float *buf = (float *)s->buffer->extended_data[ch];
         int j, k;

         start = s->start;
         end = s->end;
         k = end;
         for (i = 0, j = start; j < k && i < s->win_size; i++, j++) {
             buf[j] += s->fft_data[ch][i].re;
         }

         for (; i < s->win_size; i++, j++) {
             buf[j] = s->fft_data[ch][i].re;
         }

         start += s->hop_size;
         end = j;

         if (start >= s->win_size) {
             start -= s->win_size;
             end -= s->win_size;

             if (ch == s->channels - 1) {
                 float *dst;
                 int c;

                 out = ff_get_audio_buffer(outlink, s->win_size);
                 if (!out) {
                     av_frame_free(&s->magnitude);
                     av_frame_free(&s->phase);
                     return AVERROR(ENOMEM);
                 }

                 out->pts = s->pts;
                 s->pts += s->win_size;
                 for (c = 0; c < s->channels; c++) {
                     dst = (float *)out->extended_data[c];
                     buf = (float *)s->buffer->extended_data[c];

                     for (n = 0; n < s->win_size; n++) {
                         dst[n] = buf[n] * factor;
                     }
                     memmove(buf, buf + s->win_size, s->win_size * 4);
                 }

                 ret = ff_filter_frame(outlink, out);
                 if (ret < 0)
                     return ret;
             }
         }
     }

     s->start = start;
     s->end = end;

     return 0;
 }

 static int try_push_frames(AVFilterContext *ctx)
 {
     SpectrumSynthContext *s = ctx->priv;
     int ret, x;

     if (!(s->magnitude && s->phase))
         return 0;

     switch (s->sliding) {
     case REPLACE:
         ret = try_push_frame(ctx, s->xpos);
         s->xpos++;
         if (s->xpos >= s->xend)
             s->xpos = 0;
         break;
     case SCROLL:
         s->xpos = s->xend - 1;
         ret = try_push_frame(ctx, s->xpos);
         break;
     case RSCROLL:
         s->xpos = 0;
         ret = try_push_frame(ctx, s->xpos);
         break;
     case FULLFRAME:
         for (x = 0; x < s->xend; x++) {
             ret = try_push_frame(ctx, x);
             if (ret < 0)
                 break;
         }
         break;
     default:
         av_assert0(0);
     }

     av_frame_free(&s->magnitude);
     av_frame_free(&s->phase);
     return ret;
 }

 static int activate(AVFilterContext *ctx)
 {
     SpectrumSynthContext *s = ctx->priv;
     AVFrame **staging[2] = { &s->magnitude, &s->phase };
     int64_t pts;
     int i, ret;

     FF_FILTER_FORWARD_STATUS_BACK_ALL(ctx->outputs[0], ctx);

     for (i = 0; i < 2; i++) {
         if (*staging[i])
             continue;
         ret = ff_inlink_consume_frame(ctx->inputs[i], staging[i]);
         if (ret < 0)
             return ret;
         if (ret) {
             ff_filter_set_ready(ctx, 10);
             return try_push_frames(ctx);
         }
     }

     for (i = 0; i < 2; i++) {
         if (ff_inlink_acknowledge_status(ctx->inputs[i], &ret, &pts)) {
             ff_outlink_set_status(ctx->outputs[0], ret, pts);
             ff_inlink_set_status(ctx->inputs[1 - i], ret);
             return 0;
         }
     }

     if (ff_outlink_frame_wanted(ctx->outputs[0])) {
         for (i = 0; i < 2; i++) {
             if (!*staging[i])
                 ff_inlink_request_frame(ctx->inputs[i]);
         }
     }

     return FFERROR_NOT_READY;
 }

 static av_cold void uninit(AVFilterContext *ctx)
 {
     SpectrumSynthContext *s = ctx->priv;
     int i;

     av_frame_free(&s->magnitude);
     av_frame_free(&s->phase);
     av_frame_free(&s->buffer);
     av_fft_end(s->fft);
     if (s->fft_data) {
         for (i = 0; i < s->channels; i++)
             av_freep(&s->fft_data[i]);
     }
     av_freep(&s->fft_data);
     av_freep(&s->window_func_lut);
 }

 static const AVFilterPad spectrumsynth_inputs[] = {
     {
         .name         = "magnitude",
         .type         = AVMEDIA_TYPE_VIDEO,
     },
     {
         .name         = "phase",
         .type         = AVMEDIA_TYPE_VIDEO,
     },
     { NULL }
 };

 static const AVFilterPad spectrumsynth_outputs[] = {
     {
         .name          = "default",
         .type          = AVMEDIA_TYPE_AUDIO,
         .config_props  = config_output,
     },
     { NULL }
 };

 AVFilter ff_vaf_spectrumsynth = {
     .name          = "spectrumsynth",
     .description   = NULL_IF_CONFIG_SMALL("Convert input spectrum videos to audio output."),
     .uninit        = uninit,
     .query_formats = query_formats,
     .activate      = activate,
     .priv_size     = sizeof(SpectrumSynthContext),
     .inputs        = spectrumsynth_inputs,
     .outputs       = spectrumsynth_outputs,
     .priv_class    = &spectrumsynth_class,
 };
	/*
	* Copyright (c) 2016 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
	*/

	/**
	* @file
	* SpectrumSynth filter
	* @todo support float pixel format
	*/

	#include "libavcodec/avfft.h"
	#include "libavutil/avassert.h"
	#include "libavutil/channel_layout.h"
	#include "libavutil/ffmath.h"
	#include "libavutil/opt.h"
	#include "libavutil/parseutils.h"
	#include "avfilter.h"
	#include "formats.h"
	#include "audio.h"
	#include "video.h"
	#include "filters.h"
	#include "internal.h"
	#include "window_func.h"

	enum MagnitudeScale { LINEAR, LOG, NB_SCALES };
	enum SlideMode { REPLACE, SCROLL, FULLFRAME, RSCROLL, NB_SLIDES };
	enum Orientation { VERTICAL, HORIZONTAL, NB_ORIENTATIONS };

	typedef struct SpectrumSynthContext {
	const AVClass *class;
	int sample_rate;
	int channels;
	int scale;
	int sliding;
	int win_func;
	float overlap;
	int orientation;

	AVFrame magnitude, phase;
	FFTContext *fft; ///< Fast Fourier Transform context
	int fft_bits; ///< number of bits (FFT window size = 1<<fft_bits)
	FFTComplex **fft_data; ///< bins holder for each (displayed) channels
	int win_size;
	int size;
	int nb_freq;
	int hop_size;
	int start, end;
	int xpos;
	int xend;
	int64_t pts;
	float factor;
	AVFrame *buffer;
	float *window_func_lut; ///< Window function LUT
	} SpectrumSynthContext;

	#define OFFSET(x) offsetof(SpectrumSynthContext, x)
	#define A AV_OPT_FLAG_FILTERING_PARAM\|AV_OPT_FLAG_AUDIO_PARAM
	#define V AV_OPT_FLAG_FILTERING_PARAM\|AV_OPT_FLAG_VIDEO_PARAM

	static const AVOption spectrumsynth_options[] = {
	{ "sample_rate", "set sample rate", OFFSET(sample_rate), AV_OPT_TYPE_INT, {.i64 = 44100}, 15, INT_MAX, A },
	{ "channels", "set channels", OFFSET(channels), AV_OPT_TYPE_INT, {.i64 = 1}, 1, 8, A },
	{ "scale", "set input amplitude scale", OFFSET(scale), AV_OPT_TYPE_INT, {.i64 = LOG}, 0, NB_SCALES-1, V, "scale" },
	{ "lin", "linear", 0, AV_OPT_TYPE_CONST, {.i64=LINEAR}, 0, 0, V, "scale" },
	{ "log", "logarithmic", 0, AV_OPT_TYPE_CONST, {.i64=LOG}, 0, 0, V, "scale" },
	{ "slide", "set input sliding mode", OFFSET(sliding), AV_OPT_TYPE_INT, {.i64 = FULLFRAME}, 0, NB_SLIDES-1, V, "slide" },
	{ "replace", "consume old columns with new", 0, AV_OPT_TYPE_CONST, {.i64=REPLACE}, 0, 0, V, "slide" },
	{ "scroll", "consume only most right column", 0, AV_OPT_TYPE_CONST, {.i64=SCROLL}, 0, 0, V, "slide" },
	{ "fullframe", "consume full frames", 0, AV_OPT_TYPE_CONST, {.i64=FULLFRAME}, 0, 0, V, "slide" },
	{ "rscroll", "consume only most left column", 0, AV_OPT_TYPE_CONST, {.i64=RSCROLL}, 0, 0, V, "slide" },
	{ "win_func", "set window function", OFFSET(win_func), AV_OPT_TYPE_INT, {.i64 = 0}, 0, NB_WFUNC-1, A, "win_func" },
	{ "rect", "Rectangular", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_RECT}, 0, 0, A, "win_func" },
	{ "bartlett", "Bartlett", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_BARTLETT}, 0, 0, A, "win_func" },
	{ "hann", "Hann", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_HANNING}, 0, 0, A, "win_func" },
	{ "hanning", "Hanning", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_HANNING}, 0, 0, A, "win_func" },
	{ "hamming", "Hamming", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_HAMMING}, 0, 0, A, "win_func" },
	{ "sine", "Sine", 0, AV_OPT_TYPE_CONST, {.i64=WFUNC_SINE}, 0, 0, A, "win_func" },
	{ "overlap", "set window overlap", OFFSET(overlap), AV_OPT_TYPE_FLOAT, {.dbl=1}, 0, 1, A },
	{ "orientation", "set orientation", OFFSET(orientation), AV_OPT_TYPE_INT, {.i64=VERTICAL}, 0, NB_ORIENTATIONS-1, V, "orientation" },
	{ "vertical", NULL, 0, AV_OPT_TYPE_CONST, {.i64=VERTICAL}, 0, 0, V, "orientation" },
	{ "horizontal", NULL, 0, AV_OPT_TYPE_CONST, {.i64=HORIZONTAL}, 0, 0, V, "orientation" },
	{ NULL }
	};

	AVFILTER_DEFINE_CLASS(spectrumsynth);

	static int query_formats(AVFilterContext *ctx)
	{
	SpectrumSynthContext *s = ctx->priv;
	AVFilterFormats *formats = NULL;
	AVFilterChannelLayouts *layout = NULL;
	AVFilterLink *magnitude = ctx->inputs[0];
	AVFilterLink *phase = ctx->inputs[1];
	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_GRAY8, AV_PIX_FMT_GRAY16,
	AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUVJ444P,
	AV_PIX_FMT_YUV444P16, AV_PIX_FMT_NONE };
	int ret, sample_rates[] = { 48000, -1 };

	formats = ff_make_format_list(sample_fmts);
	if ((ret = ff_formats_ref (formats, &outlink->incfg.formats )) < 0 \|\|
	(ret = ff_add_channel_layout (&layout, FF_COUNT2LAYOUT(s->channels))) < 0 \|\|
	(ret = ff_channel_layouts_ref (layout , &outlink->incfg.channel_layouts)) < 0)
	return ret;

	sample_rates[0] = s->sample_rate;
	formats = ff_make_format_list(sample_rates);
	if (!formats)
	return AVERROR(ENOMEM);
	if ((ret = ff_formats_ref(formats, &outlink->incfg.samplerates)) < 0)
	return ret;

	formats = ff_make_format_list(pix_fmts);
	if (!formats)
	return AVERROR(ENOMEM);
	if ((ret = ff_formats_ref(formats, &magnitude->outcfg.formats)) < 0)
	return ret;

	formats = ff_make_format_list(pix_fmts);
	if (!formats)
	return AVERROR(ENOMEM);
	if ((ret = ff_formats_ref(formats, &phase->outcfg.formats)) < 0)
	return ret;

	return 0;
	}

	static int config_output(AVFilterLink *outlink)
	{
	AVFilterContext *ctx = outlink->src;
	SpectrumSynthContext *s = ctx->priv;
	int width = ctx->inputs[0]->w;
	int height = ctx->inputs[0]->h;
	AVRational time_base = ctx->inputs[0]->time_base;
	AVRational frame_rate = ctx->inputs[0]->frame_rate;
	int i, ch, fft_bits;
	float factor, overlap;

	outlink->sample_rate = s->sample_rate;
	outlink->time_base = (AVRational){1, s->sample_rate};

	if (width != ctx->inputs[1]->w \|\|
	height != ctx->inputs[1]->h) {
	av_log(ctx, AV_LOG_ERROR,
	"Magnitude and Phase sizes differ (%dx%d vs %dx%d).\n",
	width, height,
	ctx->inputs[1]->w, ctx->inputs[1]->h);
	return AVERROR_INVALIDDATA;
	} else if (av_cmp_q(time_base, ctx->inputs[1]->time_base) != 0) {
	av_log(ctx, AV_LOG_ERROR,
	"Magnitude and Phase time bases differ (%d/%d vs %d/%d).\n",
	time_base.num, time_base.den,
	ctx->inputs[1]->time_base.num,
	ctx->inputs[1]->time_base.den);
	return AVERROR_INVALIDDATA;
	} else if (av_cmp_q(frame_rate, ctx->inputs[1]->frame_rate) != 0) {
	av_log(ctx, AV_LOG_ERROR,
	"Magnitude and Phase framerates differ (%d/%d vs %d/%d).\n",
	frame_rate.num, frame_rate.den,
	ctx->inputs[1]->frame_rate.num,
	ctx->inputs[1]->frame_rate.den);
	return AVERROR_INVALIDDATA;
	}

	s->size = s->orientation == VERTICAL ? height / s->channels : width / s->channels;
	s->xend = s->orientation == VERTICAL ? width : height;

	for (fft_bits = 1; 1 << fft_bits < 2 * s->size; fft_bits++);

	s->win_size = 1 << fft_bits;
	s->nb_freq = 1 << (fft_bits - 1);

	s->fft = av_fft_init(fft_bits, 1);
	if (!s->fft) {
	av_log(ctx, AV_LOG_ERROR, "Unable to create FFT context. "
	"The window size might be too high.\n");
	return AVERROR(EINVAL);
	}
	s->fft_data = av_calloc(s->channels, sizeof(*s->fft_data));
	if (!s->fft_data)
	return AVERROR(ENOMEM);
	for (ch = 0; ch < s->channels; ch++) {
	s->fft_data[ch] = av_calloc(s->win_size, sizeof(**s->fft_data));
	if (!s->fft_data[ch])
	return AVERROR(ENOMEM);
	}

	s->buffer = ff_get_audio_buffer(outlink, s->win_size * 2);
	if (!s->buffer)
	return AVERROR(ENOMEM);

	/* pre-calc windowing function */
	s->window_func_lut = av_realloc_f(s->window_func_lut, s->win_size,
	sizeof(*s->window_func_lut));
	if (!s->window_func_lut)
	return AVERROR(ENOMEM);
	generate_window_func(s->window_func_lut, s->win_size, s->win_func, &overlap);
	if (s->overlap == 1)
	s->overlap = overlap;
	s->hop_size = (1 - s->overlap) * s->win_size;
	for (factor = 0, i = 0; i < s->win_size; i++) {
	factor += s->window_func_lut[i] * s->window_func_lut[i];
	}
	s->factor = (factor / s->win_size) / FFMAX(1 / (1 - s->overlap) - 1, 1);

	return 0;
	}

	static void read16_fft_bin(SpectrumSynthContext *s,
	int x, int y, int f, int ch)
	{
	const int m_linesize = s->magnitude->linesize[0];
	const int p_linesize = s->phase->linesize[0];
	const uint16_t m = (uint16_t )(s->magnitude->data[0] + y * m_linesize);
	const uint16_t p = (uint16_t )(s->phase->data[0] + y * p_linesize);
	float magnitude, phase;

	switch (s->scale) {
	case LINEAR:
	magnitude = m[x] / (double)UINT16_MAX;
	break;
	case LOG:
	magnitude = ff_exp10(((m[x] / (double)UINT16_MAX) - 1.) * 6.);
	break;
	default:
	av_assert0(0);
	}
	phase = ((p[x] / (double)UINT16_MAX) * 2. - 1.) * M_PI;

	s->fft_data[ch][f].re = magnitude * cos(phase);
	s->fft_data[ch][f].im = magnitude * sin(phase);
	}

	static void read8_fft_bin(SpectrumSynthContext *s,
	int x, int y, int f, int ch)
	{
	const int m_linesize = s->magnitude->linesize[0];
	const int p_linesize = s->phase->linesize[0];
	const uint8_t m = (uint8_t )(s->magnitude->data[0] + y * m_linesize);
	const uint8_t p = (uint8_t )(s->phase->data[0] + y * p_linesize);
	float magnitude, phase;

	switch (s->scale) {
	case LINEAR:
	magnitude = m[x] / (double)UINT8_MAX;
	break;
	case LOG:
	magnitude = ff_exp10(((m[x] / (double)UINT8_MAX) - 1.) * 6.);
	break;
	default:
	av_assert0(0);
	}
	phase = ((p[x] / (double)UINT8_MAX) * 2. - 1.) * M_PI;

	s->fft_data[ch][f].re = magnitude * cos(phase);
	s->fft_data[ch][f].im = magnitude * sin(phase);
	}

	static void read_fft_data(AVFilterContext *ctx, int x, int h, int ch)
	{
	SpectrumSynthContext *s = ctx->priv;
	AVFilterLink *inlink = ctx->inputs[0];
	int start = h * (s->channels - ch) - 1;
	int end = h * (s->channels - ch - 1);
	int y, f;

	switch (s->orientation) {
	case VERTICAL:
	switch (inlink->format) {
	case AV_PIX_FMT_YUV444P16:
	case AV_PIX_FMT_GRAY16:
	for (y = start, f = 0; y >= end; y--, f++) {
	read16_fft_bin(s, x, y, f, ch);
	}
	break;
	case AV_PIX_FMT_YUVJ444P:
	case AV_PIX_FMT_YUV444P:
	case AV_PIX_FMT_GRAY8:
	for (y = start, f = 0; y >= end; y--, f++) {
	read8_fft_bin(s, x, y, f, ch);
	}
	break;
	}
	break;
	case HORIZONTAL:
	switch (inlink->format) {
	case AV_PIX_FMT_YUV444P16:
	case AV_PIX_FMT_GRAY16:
	for (y = end, f = 0; y <= start; y++, f++) {
	read16_fft_bin(s, y, x, f, ch);
	}
	break;
	case AV_PIX_FMT_YUVJ444P:
	case AV_PIX_FMT_YUV444P:
	case AV_PIX_FMT_GRAY8:
	for (y = end, f = 0; y <= start; y++, f++) {
	read8_fft_bin(s, y, x, f, ch);
	}
	break;
	}
	break;
	}
	}

	static void synth_window(AVFilterContext *ctx, int x)
	{
	SpectrumSynthContext *s = ctx->priv;
	const int h = s->size;
	int nb = s->win_size;
	int y, f, ch;

	for (ch = 0; ch < s->channels; ch++) {
	read_fft_data(ctx, x, h, ch);

	for (y = h; y <= s->nb_freq; y++) {
	s->fft_data[ch][y].re = 0;
	s->fft_data[ch][y].im = 0;
	}

	for (y = s->nb_freq + 1, f = s->nb_freq - 1; y < nb; y++, f--) {
	s->fft_data[ch][y].re = s->fft_data[ch][f].re;
	s->fft_data[ch][y].im = -s->fft_data[ch][f].im;
	}

	av_fft_permute(s->fft, s->fft_data[ch]);
	av_fft_calc(s->fft, s->fft_data[ch]);
	}
	}

	static int try_push_frame(AVFilterContext *ctx, int x)
	{
	SpectrumSynthContext *s = ctx->priv;
	AVFilterLink *outlink = ctx->outputs[0];
	const float factor = s->factor;
	int ch, n, i, ret;
	int start, end;
	AVFrame *out;

	synth_window(ctx, x);

	for (ch = 0; ch < s->channels; ch++) {
	float buf = (float )s->buffer->extended_data[ch];
	int j, k;

	start = s->start;
	end = s->end;
	k = end;
	for (i = 0, j = start; j < k && i < s->win_size; i++, j++) {
	buf[j] += s->fft_data[ch][i].re;
	}

	for (; i < s->win_size; i++, j++) {
	buf[j] = s->fft_data[ch][i].re;
	}

	start += s->hop_size;
	end = j;

	if (start >= s->win_size) {
	start -= s->win_size;
	end -= s->win_size;

	if (ch == s->channels - 1) {
	float *dst;
	int c;

	out = ff_get_audio_buffer(outlink, s->win_size);
	if (!out) {
	av_frame_free(&s->magnitude);
	av_frame_free(&s->phase);
	return AVERROR(ENOMEM);
	}

	out->pts = s->pts;
	s->pts += s->win_size;
	for (c = 0; c < s->channels; c++) {
	dst = (float *)out->extended_data[c];
	buf = (float *)s->buffer->extended_data[c];

	for (n = 0; n < s->win_size; n++) {
	dst[n] = buf[n] * factor;
	}
	memmove(buf, buf + s->win_size, s->win_size * 4);
	}

	ret = ff_filter_frame(outlink, out);
	if (ret < 0)
	return ret;
	}
	}
	}

	s->start = start;
	s->end = end;

	return 0;
	}

	static int try_push_frames(AVFilterContext *ctx)
	{
	SpectrumSynthContext *s = ctx->priv;
	int ret, x;

	if (!(s->magnitude && s->phase))
	return 0;

	switch (s->sliding) {
	case REPLACE:
	ret = try_push_frame(ctx, s->xpos);
	s->xpos++;
	if (s->xpos >= s->xend)
	s->xpos = 0;
	break;
	case SCROLL:
	s->xpos = s->xend - 1;
	ret = try_push_frame(ctx, s->xpos);
	break;
	case RSCROLL:
	s->xpos = 0;
	ret = try_push_frame(ctx, s->xpos);
	break;
	case FULLFRAME:
	for (x = 0; x < s->xend; x++) {
	ret = try_push_frame(ctx, x);
	if (ret < 0)
	break;
	}
	break;
	default:
	av_assert0(0);
	}

	av_frame_free(&s->magnitude);
	av_frame_free(&s->phase);
	return ret;
	}

	static int activate(AVFilterContext *ctx)
	{
	SpectrumSynthContext *s = ctx->priv;
	AVFrame **staging[2] = { &s->magnitude, &s->phase };
	int64_t pts;
	int i, ret;

	FF_FILTER_FORWARD_STATUS_BACK_ALL(ctx->outputs[0], ctx);

	for (i = 0; i < 2; i++) {
	if (*staging[i])
	continue;
	ret = ff_inlink_consume_frame(ctx->inputs[i], staging[i]);
	if (ret < 0)
	return ret;
	if (ret) {
	ff_filter_set_ready(ctx, 10);
	return try_push_frames(ctx);
	}
	}

	for (i = 0; i < 2; i++) {
	if (ff_inlink_acknowledge_status(ctx->inputs[i], &ret, &pts)) {
	ff_outlink_set_status(ctx->outputs[0], ret, pts);
	ff_inlink_set_status(ctx->inputs[1 - i], ret);
	return 0;
	}
	}

	if (ff_outlink_frame_wanted(ctx->outputs[0])) {
	for (i = 0; i < 2; i++) {
	if (!*staging[i])
	ff_inlink_request_frame(ctx->inputs[i]);
	}
	}

	return FFERROR_NOT_READY;
	}

	static av_cold void uninit(AVFilterContext *ctx)
	{
	SpectrumSynthContext *s = ctx->priv;
	int i;

	av_frame_free(&s->magnitude);
	av_frame_free(&s->phase);
	av_frame_free(&s->buffer);
	av_fft_end(s->fft);
	if (s->fft_data) {
	for (i = 0; i < s->channels; i++)
	av_freep(&s->fft_data[i]);
	}
	av_freep(&s->fft_data);
	av_freep(&s->window_func_lut);
	}

	static const AVFilterPad spectrumsynth_inputs[] = {
	{
	.name = "magnitude",
	.type = AVMEDIA_TYPE_VIDEO,
	},
	{
	.name = "phase",
	.type = AVMEDIA_TYPE_VIDEO,
	},
	{ NULL }
	};

	static const AVFilterPad spectrumsynth_outputs[] = {
	{
	.name = "default",
	.type = AVMEDIA_TYPE_AUDIO,
	.config_props = config_output,
	},
	{ NULL }
	};

	AVFilter ff_vaf_spectrumsynth = {
	.name = "spectrumsynth",
	.description = NULL_IF_CONFIG_SMALL("Convert input spectrum videos to audio output."),
	.uninit = uninit,
	.query_formats = query_formats,
	.activate = activate,
	.priv_size = sizeof(SpectrumSynthContext),
	.inputs = spectrumsynth_inputs,
	.outputs = spectrumsynth_outputs,
	.priv_class = &spectrumsynth_class,
	};