[FFmpeg-cvslog] avfilter/avf_showspectrum: add unwrapped phase data mode
Paul B Mahol
git at videolan.org
Sun Aug 15 18:01:40 EEST 2021
ffmpeg | branch: master | Paul B Mahol <onemda at gmail.com> | Sun Aug 15 16:37:05 2021 +0200| [83860a3d8c45ee2575eb2b8343c0f27f74b61d5d] | committer: Paul B Mahol
avfilter/avf_showspectrum: add unwrapped phase data mode
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=83860a3d8c45ee2575eb2b8343c0f27f74b61d5d
---
doc/filters.texi | 3 ++-
libavfilter/avf_showspectrum.c | 48 +++++++++++++++++++++++++++++++++++++++++-
2 files changed, 49 insertions(+), 2 deletions(-)
diff --git a/doc/filters.texi b/doc/filters.texi
index bdeb3fedfd..138cc85f8f 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -26897,7 +26897,8 @@ Set scale gain for calculating intensity color values.
Default value is @code{1}.
@item data
-Set which data to display. Can be @code{magnitude}, default or @code{phase}.
+Set which data to display. Can be @code{magnitude}, default or @code{phase},
+or unwrapped phase: @code{uphase}.
@item rotation
Set color rotation, must be in [-1.0, 1.0] range.
diff --git a/libavfilter/avf_showspectrum.c b/libavfilter/avf_showspectrum.c
index 1c94a06e3f..26d8c79a72 100644
--- a/libavfilter/avf_showspectrum.c
+++ b/libavfilter/avf_showspectrum.c
@@ -26,6 +26,7 @@
* (by Michael Niedermayer) and lavfi/avf_showwaves (by Stefano Sabatini).
*/
+#include <float.h>
#include <math.h>
#include "libavutil/tx.h"
@@ -45,7 +46,7 @@
#include "window_func.h"
enum DisplayMode { COMBINED, SEPARATE, NB_MODES };
-enum DataMode { D_MAGNITUDE, D_PHASE, NB_DMODES };
+enum DataMode { D_MAGNITUDE, D_PHASE, D_UPHASE, NB_DMODES };
enum FrequencyScale { F_LINEAR, F_LOG, NB_FSCALES };
enum DisplayScale { LINEAR, SQRT, CBRT, LOG, FOURTHRT, FIFTHRT, NB_SCALES };
enum ColorMode { CHANNEL, INTENSITY, RAINBOW, MORELAND, NEBULAE, FIRE, FIERY, FRUIT, COOL, MAGMA, GREEN, VIRIDIS, PLASMA, CIVIDIS, TERRAIN, NB_CLMODES };
@@ -178,6 +179,7 @@ static const AVOption showspectrum_options[] = {
{ "data", "set data mode", OFFSET(data), AV_OPT_TYPE_INT, {.i64 = 0}, 0, NB_DMODES-1, FLAGS, "data" },
{ "magnitude", NULL, 0, AV_OPT_TYPE_CONST, {.i64=D_MAGNITUDE}, 0, 0, FLAGS, "data" },
{ "phase", NULL, 0, AV_OPT_TYPE_CONST, {.i64=D_PHASE}, 0, 0, FLAGS, "data" },
+ { "uphase", NULL, 0, AV_OPT_TYPE_CONST, {.i64=D_UPHASE}, 0, 0, FLAGS, "data" },
{ "rotation", "color rotation", OFFSET(rotation), AV_OPT_TYPE_FLOAT, {.dbl = 0}, -1, 1, FLAGS },
{ "start", "start frequency", OFFSET(start), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT32_MAX, FLAGS },
{ "stop", "stop frequency", OFFSET(stop), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT32_MAX, FLAGS },
@@ -976,6 +978,7 @@ static float get_value(AVFilterContext *ctx, int ch, int y)
/* get magnitude */
a = magnitudes[y];
break;
+ case D_UPHASE:
case D_PHASE:
/* get phase */
a = phases[y];
@@ -1320,6 +1323,46 @@ static int calc_channel_phases(AVFilterContext *ctx, void *arg, int jobnr, int n
return 0;
}
+static void unwrap(float *x, int N, float tol, float *mi, float *ma)
+{
+ const float rng = 2.f * M_PI;
+ float prev_p = 0.f;
+ float max = -FLT_MAX;
+ float min = FLT_MAX;
+
+ for (int i = 0; i < N; i++) {
+ const float d = x[FFMIN(i + 1, N)] - x[i];
+ const float p = ceilf(fabsf(d) / rng) * rng * (((d < tol) > 0.f) - ((d > -tol) > 0.f));
+
+ x[i] += p + prev_p;
+ prev_p += p;
+ max = fmaxf(x[i], max);
+ min = fminf(x[i], min);
+ }
+
+ *mi = min;
+ *ma = max;
+}
+
+static int calc_channel_uphases(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs)
+{
+ ShowSpectrumContext *s = ctx->priv;
+ const int h = s->orientation == VERTICAL ? s->h : s->w;
+ const int ch = jobnr;
+ float *phases = s->phases[ch];
+ float min, max, scale;
+ int y;
+
+ for (y = 0; y < h; y++)
+ phases[y] = PHASE(y, ch);
+ unwrap(phases, h, M_PI, &min, &max);
+ scale = 1.f / (max - min + FLT_MIN);
+ for (y = 0; y < h; y++)
+ phases[y] = fabsf((phases[y] - min) * scale);
+
+ return 0;
+}
+
static void acalc_magnitudes(ShowSpectrumContext *s)
{
const double w = s->win_scale * (s->scale == LOG ? s->win_scale : 1);
@@ -1551,6 +1594,9 @@ static int activate(AVFilterContext *ctx)
if (s->data == D_PHASE)
ctx->internal->execute(ctx, calc_channel_phases, NULL, NULL, s->nb_display_channels);
+ if (s->data == D_UPHASE)
+ ctx->internal->execute(ctx, calc_channel_uphases, NULL, NULL, s->nb_display_channels);
+
ret = plot_spectrum_column(inlink, fin);
av_frame_free(&fin);
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