Clément Bœsch
13 years ago
parent
786f06e109
commit
ddda29b4a7
7 changed files with 334 additions and 3 deletions
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/*
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* Copyright (c) 2012 Clément Bœsch |
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* |
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* This file is part of FFmpeg. |
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* |
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* FFmpeg is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2.1 of the License, or (at your option) any later version. |
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* |
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* FFmpeg is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with FFmpeg; if not, write to the Free Software |
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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*/ |
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/**
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* @file |
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* audio to spectrum (video) transmedia filter, based on ffplay rdft showmode |
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* (by Michael Niedermayer) and lavfi/avf_showwaves (by Stefano Sabatini). |
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*/ |
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#include <math.h> |
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#include "libavcodec/avfft.h" |
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#include "libavutil/audioconvert.h" |
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#include "libavutil/opt.h" |
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#include "avfilter.h" |
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#include "internal.h" |
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typedef struct { |
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const AVClass *class; |
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int w, h; |
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AVFilterBufferRef *outpicref; |
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int req_fullfilled; |
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int xpos; ///< x position (current column)
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RDFTContext *rdft; ///< Real Discrete Fourier Transform context
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int rdft_bits; ///< number of bits (RDFT window size = 1<<rdft_bits)
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FFTSample *rdft_data; ///< bins holder for each (displayed) channels
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int filled; ///< number of samples (per channel) filled in current rdft_buffer
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int consumed; ///< number of samples (per channel) consumed from the input frame
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float *window_func_lut; ///< Window function LUT
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} ShowSpectrumContext; |
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#define OFFSET(x) offsetof(ShowSpectrumContext, x) |
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static const AVOption showspectrum_options[] = { |
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{ "size", "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str = "640x480"}, 0, 0 }, |
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{ "s", "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str = "640x480"}, 0, 0 }, |
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{ NULL }, |
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}; |
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AVFILTER_DEFINE_CLASS(showspectrum); |
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static av_cold int init(AVFilterContext *ctx, const char *args) |
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{ |
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ShowSpectrumContext *showspectrum = ctx->priv; |
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int err; |
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showspectrum->class = &showspectrum_class; |
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av_opt_set_defaults(showspectrum); |
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if ((err = av_set_options_string(showspectrum, args, "=", ":")) < 0) |
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return err; |
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return 0; |
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} |
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static av_cold void uninit(AVFilterContext *ctx) |
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{ |
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ShowSpectrumContext *showspectrum = ctx->priv; |
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av_rdft_end(showspectrum->rdft); |
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av_freep(&showspectrum->rdft_data); |
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av_freep(&showspectrum->window_func_lut); |
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avfilter_unref_bufferp(&showspectrum->outpicref); |
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} |
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static int query_formats(AVFilterContext *ctx) |
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{ |
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AVFilterFormats *formats = NULL; |
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AVFilterChannelLayouts *layouts = NULL; |
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AVFilterLink *inlink = ctx->inputs[0]; |
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AVFilterLink *outlink = ctx->outputs[0]; |
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static const enum AVSampleFormat sample_fmts[] = { AV_SAMPLE_FMT_S16P, -1 }; |
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static const enum PixelFormat pix_fmts[] = { PIX_FMT_RGB24, -1 }; |
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/* set input audio formats */ |
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formats = ff_make_format_list(sample_fmts); |
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if (!formats) |
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return AVERROR(ENOMEM); |
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ff_formats_ref(formats, &inlink->out_formats); |
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layouts = ff_all_channel_layouts(); |
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if (!layouts) |
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return AVERROR(ENOMEM); |
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ff_channel_layouts_ref(layouts, &inlink->out_channel_layouts); |
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formats = ff_all_samplerates(); |
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if (!formats) |
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return AVERROR(ENOMEM); |
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ff_formats_ref(formats, &inlink->out_samplerates); |
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/* set output video format */ |
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formats = ff_make_format_list(pix_fmts); |
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if (!formats) |
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return AVERROR(ENOMEM); |
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ff_formats_ref(formats, &outlink->in_formats); |
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return 0; |
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} |
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static int config_output(AVFilterLink *outlink) |
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{ |
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AVFilterContext *ctx = outlink->src; |
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ShowSpectrumContext *showspectrum = ctx->priv; |
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int i, rdft_bits, win_size; |
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outlink->w = showspectrum->w; |
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outlink->h = showspectrum->h; |
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/* RDFT window size (precision) according to the requested output frame height */ |
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for (rdft_bits = 1; 1<<rdft_bits < 2*outlink->h; rdft_bits++); |
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win_size = 1 << rdft_bits; |
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/* (re-)configuration if the video output changed (or first init) */ |
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if (rdft_bits != showspectrum->rdft_bits) { |
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AVFilterBufferRef *outpicref; |
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av_rdft_end(showspectrum->rdft); |
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showspectrum->rdft = av_rdft_init(rdft_bits, DFT_R2C); |
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showspectrum->rdft_bits = rdft_bits; |
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/* RDFT buffers: x2 for each (display) channel buffer */ |
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showspectrum->rdft_data = |
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av_realloc_f(showspectrum->rdft_data, 2 * win_size, |
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sizeof(*showspectrum->rdft_data)); |
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if (!showspectrum->rdft_data) |
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return AVERROR(ENOMEM); |
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showspectrum->filled = 0; |
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/* pre-calc windowing function (hann here) */ |
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showspectrum->window_func_lut = |
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av_realloc_f(showspectrum->window_func_lut, win_size, |
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sizeof(*showspectrum->window_func_lut)); |
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if (!showspectrum->window_func_lut) |
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return AVERROR(ENOMEM); |
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for (i = 0; i < win_size; i++) |
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showspectrum->window_func_lut[i] = .5f * (1 - cos(2*M_PI*i / (win_size-1))); |
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/* prepare the initial picref buffer (black frame) */ |
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avfilter_unref_bufferp(&showspectrum->outpicref); |
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showspectrum->outpicref = outpicref = |
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ff_get_video_buffer(outlink, AV_PERM_WRITE|AV_PERM_PRESERVE|AV_PERM_REUSE2, |
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outlink->w, outlink->h); |
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if (!outpicref) |
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return AVERROR(ENOMEM); |
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outlink->sample_aspect_ratio = (AVRational){1,1}; |
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memset(outpicref->data[0], 0, outlink->h * outpicref->linesize[0]); |
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} |
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if (showspectrum->xpos >= outlink->w) |
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showspectrum->xpos = 0; |
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av_log(ctx, AV_LOG_VERBOSE, "s:%dx%d RDFT window size:%d\n", |
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showspectrum->w, showspectrum->h, win_size); |
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return 0; |
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} |
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inline static void push_frame(AVFilterLink *outlink) |
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{ |
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ShowSpectrumContext *showspectrum = outlink->src->priv; |
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showspectrum->xpos++; |
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if (showspectrum->xpos >= outlink->w) |
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showspectrum->xpos = 0; |
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showspectrum->filled = 0; |
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showspectrum->req_fullfilled = 1; |
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ff_start_frame(outlink, avfilter_ref_buffer(showspectrum->outpicref, ~AV_PERM_WRITE)); |
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ff_draw_slice(outlink, 0, outlink->h, 1); |
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ff_end_frame(outlink); |
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} |
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static int request_frame(AVFilterLink *outlink) |
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{ |
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ShowSpectrumContext *showspectrum = outlink->src->priv; |
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AVFilterLink *inlink = outlink->src->inputs[0]; |
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int ret; |
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showspectrum->req_fullfilled = 0; |
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do { |
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ret = ff_request_frame(inlink); |
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} while (!showspectrum->req_fullfilled && ret >= 0); |
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if (ret == AVERROR_EOF && showspectrum->outpicref) |
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push_frame(outlink); |
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return ret; |
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} |
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static int plot_spectrum_column(AVFilterLink *inlink, AVFilterBufferRef *insamples, int nb_samples) |
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{ |
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AVFilterContext *ctx = inlink->dst; |
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AVFilterLink *outlink = ctx->outputs[0]; |
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ShowSpectrumContext *showspectrum = ctx->priv; |
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AVFilterBufferRef *outpicref = showspectrum->outpicref; |
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const int nb_channels = av_get_channel_layout_nb_channels(insamples->audio->channel_layout); |
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/* nb_freq contains the power of two superior or equal to the output image
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* height (or half the RDFT window size) */ |
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const int nb_freq = 1 << (showspectrum->rdft_bits - 1); |
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const int win_size = nb_freq << 1; |
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int ch, n, y; |
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FFTSample *data[2]; |
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const int nb_display_channels = FFMIN(nb_channels, 2); |
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const int start = showspectrum->filled; |
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const int add_samples = FFMIN(win_size - start, nb_samples); |
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/* fill RDFT input with the number of samples available */ |
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for (ch = 0; ch < nb_display_channels; ch++) { |
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const int16_t *p = (int16_t *)insamples->extended_data[ch]; |
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p += showspectrum->consumed; |
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data[ch] = showspectrum->rdft_data + win_size * ch; // select channel buffer
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for (n = 0; n < add_samples; n++) |
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data[ch][start + n] = p[n] * showspectrum->window_func_lut[start + n]; |
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} |
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showspectrum->filled += add_samples; |
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/* complete RDFT window size? */ |
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if (showspectrum->filled == win_size) { |
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/* run RDFT on each samples set */ |
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for (ch = 0; ch < nb_display_channels; ch++) |
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av_rdft_calc(showspectrum->rdft, data[ch]); |
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/* fill a new spectrum column */ |
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#define RE(ch) data[ch][2*y + 0] |
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#define IM(ch) data[ch][2*y + 1] |
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#define MAGNITUDE(re, im) sqrt((re)*(re) + (im)*(im)) |
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for (y = 0; y < outlink->h; y++) { |
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// FIXME: bin[0] contains first and last bins
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const int pos = showspectrum->xpos * 3 + (outlink->h - y - 1) * outpicref->linesize[0]; |
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const double w = 1. / sqrt(nb_freq); |
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int a = sqrt(w * MAGNITUDE(RE(0), IM(0))); |
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int b = nb_display_channels > 1 ? sqrt(w * MAGNITUDE(RE(1), IM(1))) : a; |
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a = FFMIN(a, 255); |
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b = FFMIN(b, 255); |
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outpicref->data[0][pos] = a; |
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outpicref->data[0][pos+1] = b; |
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outpicref->data[0][pos+2] = (a + b) / 2; |
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} |
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outpicref->pts = insamples->pts + |
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av_rescale_q(showspectrum->consumed, |
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(AVRational){ 1, inlink->sample_rate }, |
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outlink->time_base); |
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push_frame(outlink); |
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} |
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return add_samples; |
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} |
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static int filter_samples(AVFilterLink *inlink, AVFilterBufferRef *insamples) |
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{ |
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AVFilterContext *ctx = inlink->dst; |
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ShowSpectrumContext *showspectrum = ctx->priv; |
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int left_samples = insamples->audio->nb_samples; |
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showspectrum->consumed = 0; |
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while (left_samples) { |
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const int added_samples = plot_spectrum_column(inlink, insamples, left_samples); |
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showspectrum->consumed += added_samples; |
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left_samples -= added_samples; |
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} |
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avfilter_unref_buffer(insamples); |
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return 0; |
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} |
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AVFilter avfilter_avf_showspectrum = { |
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.name = "showspectrum", |
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.description = NULL_IF_CONFIG_SMALL("Convert input audio to a spectrum video output."), |
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.init = init, |
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.uninit = uninit, |
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.query_formats = query_formats, |
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.priv_size = sizeof(ShowSpectrumContext), |
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.inputs = (const AVFilterPad[]) { |
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{ |
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.name = "default", |
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.type = AVMEDIA_TYPE_AUDIO, |
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.filter_samples = filter_samples, |
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.min_perms = AV_PERM_READ, |
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}, |
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{ .name = NULL } |
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}, |
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.outputs = (const AVFilterPad[]) { |
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{ |
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.name = "default", |
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.type = AVMEDIA_TYPE_VIDEO, |
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.config_props = config_output, |
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.request_frame = request_frame, |
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}, |
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{ .name = NULL } |
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}, |
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}; |
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