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stdin
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stdin.txt
From 671953c992bd8a86f70034dee78e1d577329b1d5 Mon Sep 17 00:00:00 2001
From: Rudolf Polzer <divverent@xonotic.org>
Date: Thu, 31 Jan 2013 17:43:14 +0100
Subject: [PATCH 1/5] lavfi/showspectrum: display multiple channels in separate
row
A behaviour similar to the old one can be selected by specifying
"combined=0" as options to the filter. However, multichannel support is
provided in both views.
Signed-off-by: Rudolf Polzer <divverent@xonotic.org>
---
doc/filters.texi | 4 ++
libavfilter/avf_showspectrum.c | 135 +++++++++++++++++++++++++++++++----------
2 files changed, 106 insertions(+), 33 deletions(-)
diff --git a/doc/filters.texi b/doc/filters.texi
index 21e2cff..73674cb 100644
--- a/doc/filters.texi
+++ b/doc/filters.texi
@@ -5709,6 +5709,10 @@ Specify the video size for the output. Default value is @code{640x480}.
@item slide
Specify if the spectrum should slide along the window. Default value is
@code{0}.
+ at item compat
+Specify if the old mode, where up to 2 channels are displayed in same row,
+should be used. Default value is
+ at code{0}.
@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 977fca9..4355b3b 100644
--- a/libavfilter/avf_showspectrum.c
+++ b/libavfilter/avf_showspectrum.c
@@ -37,14 +37,17 @@ typedef struct {
int w, h;
AVFilterBufferRef *outpicref;
int req_fullfilled;
+ int nb_display_channels;
int sliding; ///< 1 if sliding mode, 0 otherwise
+ int combined; ///< use old-style combined channel display mode
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
+ 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)
@@ -54,6 +57,7 @@ static const AVOption showspectrum_options[] = {
{ "size", "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str = "640x480"}, 0, 0, FLAGS },
{ "s", "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str = "640x480"}, 0, 0, FLAGS },
{ "slide", "set sliding mode", OFFSET(sliding), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, FLAGS },
+ { "combined", "set combined mode", OFFSET(combined), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, FLAGS },
{ NULL },
};
@@ -76,8 +80,12 @@ static av_cold int init(AVFilterContext *ctx, const char *args)
static av_cold void uninit(AVFilterContext *ctx)
{
ShowSpectrumContext *showspectrum = ctx->priv;
+ int i;
+ av_freep(&showspectrum->combine_buffer);
av_rdft_end(showspectrum->rdft);
+ for (i = 0; i < showspectrum->nb_display_channels; i++)
+ av_freep(&showspectrum->rdft_data[i]);
av_freep(&showspectrum->rdft_data);
av_freep(&showspectrum->window_func_lut);
avfilter_unref_bufferp(&showspectrum->outpicref);
@@ -90,7 +98,7 @@ static int query_formats(AVFilterContext *ctx)
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_RGB24, AV_PIX_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);
@@ -120,14 +128,17 @@ static int query_formats(AVFilterContext *ctx)
static int config_output(AVFilterLink *outlink)
{
AVFilterContext *ctx = outlink->src;
+ AVFilterLink *inlink = ctx->inputs[0];
ShowSpectrumContext *showspectrum = ctx->priv;
- int i, rdft_bits, win_size;
+ int i, rdft_bits, win_size, h;
outlink->w = showspectrum->w;
outlink->h = showspectrum->h;
+ h = showspectrum->combined ? outlink->h : outlink->h / inlink->channels;
+
/* RDFT window size (precision) according to the requested output frame height */
- for (rdft_bits = 1; 1<<rdft_bits < 2*outlink->h; rdft_bits++);
+ 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) */
@@ -142,12 +153,23 @@ static int config_output(AVFilterLink *outlink)
/* 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 < showspectrum->nb_display_channels; i++)
+ av_freep(&showspectrum->rdft_data[i]);
av_freep(&showspectrum->rdft_data);
- if (av_size_mult(sizeof(*showspectrum->rdft_data), 2 * win_size, &rdft_size) < 0)
+ showspectrum->nb_display_channels = inlink->channels;
+
+ if (av_size_mult(sizeof(*showspectrum->rdft_data),
+ showspectrum->nb_display_channels * win_size, &rdft_size) < 0)
return AVERROR(EINVAL);
- showspectrum->rdft_data = av_malloc(rdft_size);
+ showspectrum->rdft_data = av_malloc(showspectrum->nb_display_channels *
+ sizeof(*showspectrum->rdft_data));
if (!showspectrum->rdft_data)
return AVERROR(ENOMEM);
+ for (i = 0; i < showspectrum->nb_display_channels; i++) {
+ showspectrum->rdft_data[i] = av_malloc(rdft_size);
+ if (!showspectrum->rdft_data[i])
+ return AVERROR(ENOMEM);
+ }
showspectrum->filled = 0;
/* pre-calc windowing function (hann here) */
@@ -173,6 +195,10 @@ static int config_output(AVFilterLink *outlink)
if (showspectrum->xpos >= outlink->w)
showspectrum->xpos = 0;
+ showspectrum->combine_buffer = av_realloc(showspectrum->combine_buffer,
+ outlink->h * 3 *
+ sizeof(*showspectrum->combine_buffer));
+
av_log(ctx, AV_LOG_VERBOSE, "s:%dx%d RDFT window size:%d\n",
showspectrum->w, showspectrum->h, win_size);
return 0;
@@ -213,62 +239,105 @@ static int plot_spectrum_column(AVFilterLink *inlink, AVFilterBufferRef *insampl
AVFilterLink *outlink = ctx->outputs[0];
ShowSpectrumContext *showspectrum = ctx->priv;
AVFilterBufferRef *outpicref = showspectrum->outpicref;
- const int nb_channels = av_get_channel_layout_nb_channels(insamples->audio->channel_layout);
/* 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 << (showspectrum->rdft_bits - 1);
const int win_size = nb_freq << 1;
+ const double w = 1. / sqrt(nb_freq);
- int ch, n, y;
- FFTSample *data[2];
- const int nb_display_channels = FFMIN(nb_channels, 2);
+ int ch, plane, n, y;
const int start = showspectrum->filled;
const int add_samples = FFMIN(win_size - start, nb_samples);
/* fill RDFT input with the number of samples available */
- for (ch = 0; ch < nb_display_channels; ch++) {
+ for (ch = 0; ch < showspectrum->nb_display_channels; ch++) {
const int16_t *p = (int16_t *)insamples->extended_data[ch];
p += showspectrum->consumed;
- data[ch] = showspectrum->rdft_data + win_size * ch; // select channel buffer
for (n = 0; n < add_samples; n++)
- data[ch][start + n] = p[n] * showspectrum->window_func_lut[start + n];
+ showspectrum->rdft_data[ch][start + n] = p[n] * showspectrum->window_func_lut[start + n];
}
showspectrum->filled += add_samples;
/* complete RDFT window size? */
if (showspectrum->filled == win_size) {
+ /* channel height */
+ int h = showspectrum->combined ? outlink->h : outlink->h / showspectrum->nb_display_channels;
+
/* run RDFT on each samples set */
- for (ch = 0; ch < nb_display_channels; ch++)
- av_rdft_calc(showspectrum->rdft, data[ch]);
+ for (ch = 0; ch < showspectrum->nb_display_channels; ch++)
+ av_rdft_calc(showspectrum->rdft, showspectrum->rdft_data[ch]);
/* fill a new spectrum column */
-#define RE(ch) data[ch][2*y + 0]
-#define IM(ch) data[ch][2*y + 1]
-#define MAGNITUDE(re, im) sqrt((re)*(re) + (im)*(im))
+#define RE(y,ch) showspectrum->rdft_data[ch][2*y + 0]
+#define IM(y,ch) showspectrum->rdft_data[ch][2*y + 1]
+#define CPLX_MAGNITUDE(re, im) sqrt((re)*(re) + (im)*(im)) /* is actually hypot(re, im) */
+#define MAGNITUDE(y,ch) CPLX_MAGNITUDE(RE(y,ch), IM(y,ch))
+ /* initialize buffer for combining to black */
for (y = 0; y < outlink->h; y++) {
- // FIXME: bin[0] contains first and last bins
- uint8_t *p = outpicref->data[0] + (outlink->h - y - 1) * outpicref->linesize[0];
- const double w = 1. / sqrt(nb_freq);
- int a = sqrt(w * MAGNITUDE(RE(0), IM(0)));
- int b = nb_display_channels > 1 ? sqrt(w * MAGNITUDE(RE(1), IM(1))) : a;
-
- if (showspectrum->sliding) {
- memmove(p, p + 3, (outlink->w - 1) * 3);
- p += (outlink->w - 1) * 3;
+ showspectrum->combine_buffer[3*y] = 0;
+ showspectrum->combine_buffer[3*y+1] = 127.5;
+ showspectrum->combine_buffer[3*y+2] = 127.5;
+ }
+
+ for (ch = 0; ch < showspectrum->nb_display_channels; ch++) {
+ float yf, uf, vf;
+
+ /* decide channel colors */
+ if (showspectrum->combined) {
+ // reduce range by channel count
+ yf = 1.0f / showspectrum->nb_display_channels;
+ uf = yf;
+ vf = yf;
} else {
- p += showspectrum->xpos * 3;
+ // full range
+ yf = 1.0f;
+ uf = 0.5f;
+ vf = 0.5f;
+ }
+ if (showspectrum->nb_display_channels >= 2) {
+ uf *= cos((2 * M_PI * ch) / showspectrum->nb_display_channels);
+ vf *= sin((2 * M_PI * ch) / showspectrum->nb_display_channels);
+ } else {
+ uf = 0.0f;
+ vf = 0.0f;
}
- a = FFMIN(a, 255);
- b = FFMIN(b, 255);
- p[0] = a;
- p[1] = b;
- p[2] = (a + b) / 2;
+ /* draw the channel */
+ for (y = 0; y < h; y++) {
+ int row = showspectrum->combined ? y : ch * h + y;
+ float a = sqrt(w * MAGNITUDE(y, ch));
+ float *out = &showspectrum->combine_buffer[3 * row];
+ out[0] += a * yf;
+ out[1] += a * vf;
+ out[2] += a * uf;
+ }
}
+
+ /* copy to output */
+ if (showspectrum->sliding) {
+ for (plane = 0; plane < 3; plane++) {
+ for (y = 0; y < outlink->h; y++) {
+ uint8_t *p = outpicref->data[plane] +
+ y * outpicref->linesize[plane];
+ memmove(p, p + 1, outlink->w - 1);
+ }
+ }
+ showspectrum->xpos = outlink->w - 1;
+ }
+ for (plane = 0; plane < 3; plane++) {
+ uint8_t *p = outpicref->data[plane] +
+ (outlink->h - 1) * outpicref->linesize[plane] +
+ showspectrum->xpos;
+ for (y = 0; y < outlink->h; y++) {
+ *p = rint(FFMAX(0, FFMIN(showspectrum->combine_buffer[3*y + plane], 255)));
+ p -= outpicref->linesize[plane];
+ }
+ }
+
outpicref->pts = insamples->pts +
av_rescale_q(showspectrum->consumed,
(AVRational){ 1, inlink->sample_rate },
--
1.8.1.1
From 0b6e1930e7cc0087d1439044fc94ce5a73ad8ae1 Mon Sep 17 00:00:00 2001
From: Rudolf Polzer <divverent@xonotic.org>
Date: Thu, 31 Jan 2013 14:11:24 +0100
Subject: [PATCH 2/5] lavfi/showspectrum: add a "saturation" option to tune
coloring
Signed-off-by: Rudolf Polzer <divverent@xonotic.org>
---
libavfilter/avf_showspectrum.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/libavfilter/avf_showspectrum.c b/libavfilter/avf_showspectrum.c
index 4355b3b..59f9891 100644
--- a/libavfilter/avf_showspectrum.c
+++ b/libavfilter/avf_showspectrum.c
@@ -40,6 +40,7 @@ typedef struct {
int nb_display_channels;
int sliding; ///< 1 if sliding mode, 0 otherwise
int combined; ///< use old-style combined channel display mode
+ 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)
@@ -58,6 +59,7 @@ static const AVOption showspectrum_options[] = {
{ "s", "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str = "640x480"}, 0, 0, FLAGS },
{ "slide", "set sliding mode", OFFSET(sliding), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, FLAGS },
{ "combined", "set combined mode", OFFSET(combined), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, FLAGS },
+ { "saturation", "color saturation multiplier", OFFSET(saturation), AV_OPT_TYPE_FLOAT, {.dbl = 1}, -10, 10, FLAGS },
{ NULL },
};
@@ -305,6 +307,8 @@ static int plot_spectrum_column(AVFilterLink *inlink, AVFilterBufferRef *insampl
uf = 0.0f;
vf = 0.0f;
}
+ uf *= showspectrum->saturation;
+ vf *= showspectrum->saturation;
/* draw the channel */
for (y = 0; y < h; y++) {
--
1.8.1.1
From b753ebde75f0ccfb69a9795ca372c2b1a144b42e Mon Sep 17 00:00:00 2001
From: Rudolf Polzer <divverent@xonotic.org>
Date: Thu, 31 Jan 2013 14:03:39 +0100
Subject: [PATCH 3/5] lavfi/showspectrum: replace sqrt() using macro by a call
to hypot()
hypot() exists on most libcs even before C99, and thus shouldn't be a
problem to use. This avoids a bad case of multiple argument evaluation.
Signed-off-by: Rudolf Polzer <divverent@xonotic.org>
---
libavfilter/avf_showspectrum.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/libavfilter/avf_showspectrum.c b/libavfilter/avf_showspectrum.c
index 59f9891..c15a158 100644
--- a/libavfilter/avf_showspectrum.c
+++ b/libavfilter/avf_showspectrum.c
@@ -275,8 +275,7 @@ static int plot_spectrum_column(AVFilterLink *inlink, AVFilterBufferRef *insampl
/* fill a new spectrum column */
#define RE(y,ch) showspectrum->rdft_data[ch][2*y + 0]
#define IM(y,ch) showspectrum->rdft_data[ch][2*y + 1]
-#define CPLX_MAGNITUDE(re, im) sqrt((re)*(re) + (im)*(im)) /* is actually hypot(re, im) */
-#define MAGNITUDE(y,ch) CPLX_MAGNITUDE(RE(y,ch), IM(y,ch))
+#define MAGNITUDE(y,ch) hypot(RE(y,ch), IM(y,ch))
/* initialize buffer for combining to black */
for (y = 0; y < outlink->h; y++) {
--
1.8.1.1
From 0e7c76b2720a9b46510796c347b774d3f3b809ad Mon Sep 17 00:00:00 2001
From: Rudolf Polzer <divverent@xonotic.org>
Date: Thu, 31 Jan 2013 17:22:50 +0100
Subject: [PATCH 4/5] lavfi/showspectrum: logarithmic scale, intensity based
coloring
Signed-off-by: Rudolf Polzer <divverent@xonotic.org>
---
libavfilter/avf_showspectrum.c | 106 ++++++++++++++++++++++++++++++++++-------
1 file changed, 88 insertions(+), 18 deletions(-)
diff --git a/libavfilter/avf_showspectrum.c b/libavfilter/avf_showspectrum.c
index c15a158..80ec6e6 100644
--- a/libavfilter/avf_showspectrum.c
+++ b/libavfilter/avf_showspectrum.c
@@ -39,7 +39,9 @@ typedef struct {
int req_fullfilled;
int nb_display_channels;
int sliding; ///< 1 if sliding mode, 0 otherwise
- int combined; ///< use old-style combined channel display mode
+ int combined; ///< use combined channel display mode
+ int intensity_colors; ///< use intensity-based coloring
+ int logscale; ///< use logarithmic scale
float saturation; ///< color saturation multiplier
int xpos; ///< x position (current column)
RDFTContext *rdft; ///< Real Discrete Fourier Transform context
@@ -59,12 +61,30 @@ static const AVOption showspectrum_options[] = {
{ "s", "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str = "640x480"}, 0, 0, FLAGS },
{ "slide", "set sliding mode", OFFSET(sliding), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, FLAGS },
{ "combined", "set combined mode", OFFSET(combined), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, FLAGS },
+ { "intensity", "set intensity based coloring", OFFSET(intensity_colors), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, FLAGS },
+ { "logscale", "set logarithmic scale", OFFSET(logscale), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, FLAGS },
{ "saturation", "color saturation multiplier", OFFSET(saturation), AV_OPT_TYPE_FLOAT, {.dbl = 1}, -10, 10, FLAGS },
{ NULL },
};
AVFILTER_DEFINE_CLASS(showspectrum);
+struct intensity_color_table_item
+{
+ float a, y, u, v;
+};
+static const struct intensity_color_table_item intensity_color_table[] =
+{
+ { 0, 0, 0, 0 },
+ { 0.13, .03587126228984074, .1573300977624594, -.02548747583751842 },
+ { 0.3, .1857228179456802, .1772436246393981, .1747555484041475 },
+ { 0.6, .2818498058365613, -.1593064119945782, .4713207455460892 },
+ { 0.73, .6583062117554781, -.3716070802232764, .2435275933125293 },
+ { 0.78, 0.763185357582429, -.4307467689263783, .1686649662231043 },
+ { 0.91, .9533636363636364, -.2045454545454546, .03313636363636363 },
+ { 1, 1, 0, 0 }
+};
+
static av_cold int init(AVFilterContext *ctx, const char *args)
{
ShowSpectrumContext *showspectrum = ctx->priv;
@@ -246,7 +266,7 @@ static int plot_spectrum_column(AVFilterLink *inlink, AVFilterBufferRef *insampl
* height (or half the RDFT window size) */
const int nb_freq = 1 << (showspectrum->rdft_bits - 1);
const int win_size = nb_freq << 1;
- const double w = 1. / sqrt(nb_freq);
+ const double w = 1. / sqrt(nb_freq) / 32768.;
int ch, plane, n, y;
const int start = showspectrum->filled;
@@ -287,36 +307,86 @@ static int plot_spectrum_column(AVFilterLink *inlink, AVFilterBufferRef *insampl
for (ch = 0; ch < showspectrum->nb_display_channels; ch++) {
float yf, uf, vf;
- /* decide channel colors */
+ /* decide color range */
if (showspectrum->combined) {
// reduce range by channel count
- yf = 1.0f / showspectrum->nb_display_channels;
+ yf = 256.0f / showspectrum->nb_display_channels;
uf = yf;
vf = yf;
- } else {
+ } else if (showspectrum->intensity_colors) {
// full range
- yf = 1.0f;
- uf = 0.5f;
- vf = 0.5f;
- }
- if (showspectrum->nb_display_channels >= 2) {
- uf *= cos((2 * M_PI * ch) / showspectrum->nb_display_channels);
- vf *= sin((2 * M_PI * ch) / showspectrum->nb_display_channels);
+ yf = 256.0f;
+ uf = 256.0f;
+ vf = 256.0f;
} else {
- uf = 0.0f;
- vf = 0.0f;
+ // full range
+ yf = 256.0f;
+ uf = 128.0f;
+ vf = 128.0f;
}
+
uf *= showspectrum->saturation;
vf *= showspectrum->saturation;
+ /* decide channel colors */
+ if (!showspectrum->intensity_colors) {
+ if (showspectrum->nb_display_channels >= 2) {
+ uf *= sin((2 * M_PI * ch) / showspectrum->nb_display_channels);
+ vf *= cos((2 * M_PI * ch) / showspectrum->nb_display_channels);
+ } else {
+ uf = 0.0f;
+ vf = 0.0f;
+ }
+ }
+
/* draw the channel */
for (y = 0; y < h; y++) {
int row = showspectrum->combined ? y : ch * h + y;
- float a = sqrt(w * MAGNITUDE(y, ch));
float *out = &showspectrum->combine_buffer[3 * row];
- out[0] += a * yf;
- out[1] += a * vf;
- out[2] += a * uf;
+
+ /* get magnitude */
+ float a = w * MAGNITUDE(y, ch);
+
+ /* apply scale */
+ if (showspectrum->logscale)
+ a = 1 - log(FFMAX(FFMIN(1, a), 1e-6)) / log(1e-6); // zero = -120dBFS
+ else
+ a = sqrt(a);
+
+ if (showspectrum->intensity_colors) {
+ 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;
+ }
}
}
--
1.8.1.1
From 0f55c57379d4a037f32ef4575210d06d117b9897 Mon Sep 17 00:00:00 2001
From: Rudolf Polzer <divverent@xonotic.org>
Date: Thu, 31 Jan 2013 17:35:26 +0100
Subject: [PATCH 5/5] lavfi/showspectrum: simplify saturation logic
Signed-off-by: Rudolf Polzer <divverent@xonotic.org>
---
libavfilter/avf_showspectrum.c | 32 +++++++++++++++++---------------
1 file changed, 17 insertions(+), 15 deletions(-)
diff --git a/libavfilter/avf_showspectrum.c b/libavfilter/avf_showspectrum.c
index 80ec6e6..4798173 100644
--- a/libavfilter/avf_showspectrum.c
+++ b/libavfilter/avf_showspectrum.c
@@ -309,36 +309,38 @@ static int plot_spectrum_column(AVFilterLink *inlink, AVFilterBufferRef *insampl
/* decide color range */
if (showspectrum->combined) {
- // reduce range by channel count
+ /* reduce range by channel count */
yf = 256.0f / showspectrum->nb_display_channels;
uf = yf;
vf = yf;
- } else if (showspectrum->intensity_colors) {
- // full range
+ if (!showspectrum->intensity_colors) {
+ /* adjust saturation for mixed UV coloring */
+ /* this factor is correct for infinite channels, an approximation otherwise */
+ uf *= M_PI;
+ vf *= M_PI;
+ }
+ } else {
+ /* full range */
yf = 256.0f;
uf = 256.0f;
vf = 256.0f;
- } else {
- // full range
- yf = 256.0f;
- uf = 128.0f;
- vf = 128.0f;
}
- uf *= showspectrum->saturation;
- vf *= showspectrum->saturation;
-
/* decide channel colors */
if (!showspectrum->intensity_colors) {
if (showspectrum->nb_display_channels >= 2) {
- uf *= sin((2 * M_PI * ch) / showspectrum->nb_display_channels);
- vf *= cos((2 * M_PI * ch) / showspectrum->nb_display_channels);
+ uf *= 0.5 * sin((2 * M_PI * ch) / showspectrum->nb_display_channels);
+ vf *= 0.5 * cos((2 * M_PI * ch) / showspectrum->nb_display_channels);
} else {
uf = 0.0f;
vf = 0.0f;
}
}
+ /* apply saturation */
+ uf *= showspectrum->saturation;
+ vf *= showspectrum->saturation;
+
/* draw the channel */
for (y = 0; y < h; y++) {
int row = showspectrum->combined ? y : ch * h + y;
@@ -360,8 +362,8 @@ static int plot_spectrum_column(AVFilterLink *inlink, AVFilterBufferRef *insampl
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
+ /* 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;
--
1.8.1.1
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