[FFmpeg-cvslog] avfilter/avf_showspectrum: add window overlap support
Paul B Mahol
git at videolan.org
Thu Dec 31 12:37:28 CET 2015
ffmpeg | branch: master | Paul B Mahol <onemda at gmail.com> | Tue Dec 29 16:52:16 2015 +0100| [15e1fd9883b4a2898635212b4e167823755d1653] | committer: Paul B Mahol
avfilter/avf_showspectrum: add window overlap support
Signed-off-by: Paul B Mahol <onemda at gmail.com>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=15e1fd9883b4a2898635212b4e167823755d1653
---
doc/filters.texi | 5 ++++
libavfilter/avf_showspectrum.c | 58 +++++++++++++++++++++++++++++++++-------
2 files changed, 54 insertions(+), 9 deletions(-)
diff --git a/doc/filters.texi b/doc/filters.texi
index 92931aa..8aa3b47 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -14677,6 +14677,11 @@ Default value is @code{hann}.
@item orientation
Set orientation of time vs frequency axis. Can be @code{vertical} or
@code{horizontal}. Default is @code{vertical}.
+
+ at item overlap
+Set ratio of overlap window. Default value is @code{0}.
+When value is @code{1} overlap is set to recommended size for specific
+window function currently used.
@end table
The usage is very similar to the showwaves filter; see the examples in that
diff --git a/libavfilter/avf_showspectrum.c b/libavfilter/avf_showspectrum.c
index d1ac560..5380994 100644
--- a/libavfilter/avf_showspectrum.c
+++ b/libavfilter/avf_showspectrum.c
@@ -1,6 +1,7 @@
/*
* Copyright (c) 2012-2013 Clément Bœsch
* Copyright (c) 2013 Rudolf Polzer <divverent at xonotic.org>
+ * Copyright (c) 2015 Paul B Mahol
*
* This file is part of FFmpeg.
*
@@ -28,9 +29,12 @@
#include <math.h>
#include "libavcodec/avfft.h"
+#include "libavutil/audio_fifo.h"
#include "libavutil/avassert.h"
#include "libavutil/channel_layout.h"
#include "libavutil/opt.h"
+#include "audio.h"
+#include "video.h"
#include "avfilter.h"
#include "internal.h"
#include "window_func.h"
@@ -62,7 +66,10 @@ typedef struct {
int win_func;
double win_scale;
float overlap;
+ int skip_samples;
float *combine_buffer; ///< color combining buffer (3 * h items)
+ AVAudioFifo *fifo;
+ int64_t pts;
} ShowSpectrumContext;
#define OFFSET(x) offsetof(ShowSpectrumContext, x)
@@ -111,6 +118,7 @@ static const AVOption showspectrum_options[] = {
{ "orientation", "set orientation", OFFSET(orientation), AV_OPT_TYPE_INT, {.i64=VERTICAL}, 0, NB_ORIENTATIONS-1, FLAGS, "orientation" },
{ "vertical", NULL, 0, AV_OPT_TYPE_CONST, {.i64=VERTICAL}, 0, 0, FLAGS, "orientation" },
{ "horizontal", NULL, 0, AV_OPT_TYPE_CONST, {.i64=HORIZONTAL}, 0, 0, FLAGS, "orientation" },
+ { "overlap", "set window overlap", OFFSET(overlap), AV_OPT_TYPE_FLOAT, {.dbl = 0}, 0, 1, FLAGS },
{ NULL }
};
@@ -178,6 +186,7 @@ static av_cold void uninit(AVFilterContext *ctx)
av_freep(&s->rdft_data);
av_freep(&s->window_func_lut);
av_frame_free(&s->outpicref);
+ av_audio_fifo_free(s->fifo);
}
static int query_formats(AVFilterContext *ctx)
@@ -217,6 +226,7 @@ static int config_output(AVFilterLink *outlink)
AVFilterLink *inlink = ctx->inputs[0];
ShowSpectrumContext *s = ctx->priv;
int i, rdft_bits, win_size, h, w;
+ float overlap;
outlink->w = s->w;
outlink->h = s->h;
@@ -271,7 +281,14 @@ static int config_output(AVFilterLink *outlink)
sizeof(*s->window_func_lut));
if (!s->window_func_lut)
return AVERROR(ENOMEM);
- ff_generate_window_func(s->window_func_lut, win_size, s->win_func, &s->overlap);
+ ff_generate_window_func(s->window_func_lut, win_size, s->win_func, &overlap);
+ if (s->overlap == 1)
+ s->overlap = overlap;
+ s->skip_samples = (1. - s->overlap) * win_size;
+ if (s->skip_samples < 1) {
+ av_log(ctx, AV_LOG_ERROR, "overlap %f too big\n", s->overlap);
+ return AVERROR(EINVAL);
+ }
for (s->win_scale = 0, i = 0; i < win_size; i++) {
s->win_scale += s->window_func_lut[i] * s->window_func_lut[i];
@@ -296,15 +313,12 @@ static int config_output(AVFilterLink *outlink)
(s->orientation == HORIZONTAL && s->xpos >= outlink->h))
s->xpos = 0;
- outlink->frame_rate = av_make_q(inlink->sample_rate, win_size);
+ outlink->frame_rate = av_make_q(inlink->sample_rate, win_size * (1.-s->overlap));
if (s->orientation == VERTICAL && s->sliding == FULLFRAME)
outlink->frame_rate.den *= outlink->w;
if (s->orientation == HORIZONTAL && s->sliding == FULLFRAME)
outlink->frame_rate.den *= outlink->h;
- inlink->min_samples = inlink->max_samples = inlink->partial_buf_size =
- win_size;
-
if (s->orientation == VERTICAL) {
s->combine_buffer =
av_realloc_f(s->combine_buffer, outlink->h * 3,
@@ -317,6 +331,11 @@ static int config_output(AVFilterLink *outlink)
av_log(ctx, AV_LOG_VERBOSE, "s:%dx%d RDFT window size:%d\n",
s->w, s->h, win_size);
+
+ av_audio_fifo_free(s->fifo);
+ s->fifo = av_audio_fifo_alloc(inlink->format, inlink->channels, win_size);
+ if (!s->fifo)
+ return AVERROR(ENOMEM);
return 0;
}
@@ -516,6 +535,7 @@ static int plot_spectrum_column(AVFilterLink *inlink, AVFrame *insamples)
}
}
+ av_frame_make_writable(s->outpicref);
/* copy to output */
if (s->orientation == VERTICAL) {
if (s->sliding == SCROLL) {
@@ -598,13 +618,33 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *insamples)
AVFilterContext *ctx = inlink->dst;
ShowSpectrumContext *s = ctx->priv;
unsigned win_size = 1 << s->rdft_bits;
+ AVFrame *fin = NULL;
int ret = 0;
- av_assert0(insamples->nb_samples <= win_size);
- if (insamples->nb_samples == win_size)
- ret = plot_spectrum_column(inlink, insamples);
-
+ av_audio_fifo_write(s->fifo, (void **)insamples->extended_data, insamples->nb_samples);
av_frame_free(&insamples);
+ while (av_audio_fifo_size(s->fifo) >= win_size) {
+ fin = ff_get_audio_buffer(inlink, win_size);
+ if (!fin) {
+ ret = AVERROR(ENOMEM);
+ goto fail;
+ }
+
+ fin->pts = s->pts;
+ s->pts += s->skip_samples;
+ ret = av_audio_fifo_peek(s->fifo, (void **)fin->extended_data, win_size);
+ if (ret < 0)
+ goto fail;
+
+ ret = plot_spectrum_column(inlink, fin);
+ av_frame_free(&fin);
+ av_audio_fifo_drain(s->fifo, s->skip_samples);
+ if (ret < 0)
+ goto fail;
+ }
+
+fail:
+ av_frame_free(&fin);
return ret;
}
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