ref: 22d5cf2a8dcf6534ddf146012ffd8bb0f0692a5a
parent: 52f4fa02202cf66929e44e454b548b4532aceea4
author: robs <robs>
date: Fri Jun 20 17:07:16 EDT 2008
a few updates
--- a/soxeffect.7
+++ b/soxeffect.7
@@ -1102,9 +1102,9 @@
.B gain
effect).
.IP \fB-w\ \fIname\fR
-Window: Hann (default), Hamming, Bartlett, Rectangular, Kaiser. The
+Window: Hann (default), Hamming, Bartlett, Rectangular or Kaiser. The
spectrogram is produced using the Discrete Fourier Transform (DFT)
-algorithm. A significant paramater to this algorithm is the choice of
+algorithm. A significant parameter to this algorithm is the choice of
`window function'. By default, SoX uses the Hann window which has good
all-round frequency-resolution and dynamic-range properties. For better
frequency resolution (but lower dynamic-range), select a Hamming window;
@@ -1113,17 +1113,25 @@
a corresponding
.B \-z
setting.
-.IP \fB-s\ \fInum\fR
-Display style (1 - 4), default 1. There are 2 colour and 2 monochrome
-styles; select the style that works best with the given audio signal and
-your display or printer.
+.IP \fB-s\fR
+Allow slack overlapping of DFT windows.
+This can, in some cases, increase image sharpness and give greater adherence
+to the
+.B \-x
+value, but at the expense of a little spectral loss.
+.IP \fB-m\fR
+Creates a monochrome spectrogram (the default is colour).
+.IP \fB-l\fR
+Creates a `printer friendly' spectrogram with a light background (the
+default has a dark background).
.IP \fB-a\fR
-Toggle the presence of the axes lines. This is sometimes useful in
+Suppress the display of the axes lines. This is sometimes useful in
helping to discern artefacts at the spectrogram edges.
.IP \fB-t\ \fItext\fR
-Text to display above the spectrogram.
+Set the image title\*mtext to display above the spectrogram.
.IP \fB-c\ \fItext\fR
-Text to display below and to the left of the spectrogram.
+Set the image comment\*mtext to display below and to the left of the
+spectrogram.
.IP \fB-o\ \fItext\fR
Name of the spectrogram output PNG file, default `spectrogram.png'.
.RE
--- a/src/spectrogram.c
+++ b/src/spectrogram.c
@@ -99,7 +99,7 @@
double pixels_per_sec, block_norm, max;
int dB_range, gain, style, read, end, end_min, last_end;
char const * out_name, * title, * comment;
- sox_bool no_axes;
+ sox_bool slack_overlap, no_axes;
win_type_t win_type;
} priv_t;
@@ -136,6 +136,7 @@
{priv_t * p = (priv_t *)effp->priv;
int c, callers_optind = optind, callers_opterr = opterr;
+ sox_bool monochrome = sox_false, light_background = sox_false;
assert(array_length(p->bit_rev_table) >= (size_t)dft_br_len(MAX_DFT_SIZE));
@@ -143,25 +144,28 @@
p->pixels_per_sec = 100, p->y_size = 2, p->dB_range = 120;/* non-0 defaults */
p->style = 1, p->out_name = "spectrogram.png", p->comment = "Created by SoX";
- while ((c = getopt(argc, argv, "+x:y:z:g:s:w:t:c:o:a")) != -1) switch (c) {+ while ((c = getopt(argc, argv, "+x:y:z:g:w:st:c:amlo:")) != -1) switch (c) { GETOPT_NUMERIC('x', pixels_per_sec, 1 , 5000) GETOPT_NUMERIC('y', y_size , 1 , 1 + MAX_DFT_SIZE_SHIFT) GETOPT_NUMERIC('z', dB_range , 40 , 180) GETOPT_NUMERIC('g', gain ,-100, 100)- GETOPT_NUMERIC('s', style , 1 , 4)case 'w': p->win_type = enum_option(c, window_options); break;
+ case 's': p->slack_overlap = sox_true; break;
case 't': p->title = optarg; break;
case 'c': p->comment = optarg; break;
- case 'o': p->out_name = optarg; break;
case 'a': p->no_axes = sox_true; break;
+ case 'm': monochrome = sox_true; break;
+ case 'l': light_background = sox_true; break;
+ case 'o': p->out_name = optarg; break;
default: sox_fail("unknown option `-%c'", optopt); return lsx_usage(effp);}
- p->y_size -= 1, p->style -= 1;
+ p->y_size -= 1;
+ p->style = 2 * monochrome + light_background;
argc -= optind, optind = callers_optind, opterr = callers_opterr;
return argc || p->win_type == INT_MAX? lsx_usage(effp) : SOX_SUCCESS;
}
-static int make_window(priv_t * p, int end)
+static double make_window(priv_t * p, int end)
{double sum = 0, * w = end < 0? p->window : p->window + end;
int i, n = p->dft_size - abs(end);
@@ -178,7 +182,7 @@
for (i = 0; i < p->dft_size; ++i) sum += p->window[i];
for (i = 0; i < p->dft_size; ++i) p->window[i] *= 2 / sum
* sqr((double)n / p->dft_size); /* empirical small window adjustment */
- return sum + .5;
+ return sum;
}
static int start(sox_effect_t * effp)
@@ -192,7 +196,9 @@
}
p->end = p->dft_size = DFT_BASE_SIZE << p->y_size;
p->rows = (p->dft_size >> 1) + 1;
- p->step_size = make_window(p, p->last_end = 0);
+ actual = make_window(p, p->last_end = 0);
+ sox_debug("window_density=%g", actual / p->dft_size);+ p->step_size = (p->slack_overlap? sqrt(actual * p->dft_size) : actual) + .5;
p->block_steps = effp->in_signal.rate / p->pixels_per_sec;
p->step_size = p->block_steps / ceil((double)p->block_steps / p->step_size) +.5;
p->block_steps = floor((double)p->block_steps / p->step_size +.5);
@@ -370,7 +376,7 @@
static void print_at_(png_byte * pixels, int cols, int x, int y, int c, char const * text, int orientation)
{ for (;*text; ++text) {- int pos = (*text - ' ') * font_y;
+ int pos = ((*text < ' ' || *text > '~'? '~' + 1 : *text) - ' ') * font_y;
int i, j;
for (i = 0; i < font_y; ++i) {unsigned line = font[pos++];
@@ -387,7 +393,7 @@
}
}
-static int axis(double to, int max_steps, int * limit, char * * prefix)
+static int axis(double to, int max_steps, double * limit, char * * prefix)
{double scale = 1, step = 1;
int i, prefix_num = 0;
@@ -422,8 +428,9 @@
png_structp png = png_create_write_struct(PNG_LIBPNG_VER_STRING, 0, 0,0);
png_infop png_info = png_create_info_struct(png);
png_byte palette[palette_size * 3];
- int i, j, step, limit, tick_len = 2 + do_frame;
+ int i, j, step, tick_len = 2 + do_frame;
char text[200], * prefix;
+ double limit;
if (!file) { sox_fail("failed to create `%s' :(", p->out_name);@@ -526,11 +533,13 @@
" -z num Z-axis (colour) range in dB, default 120\n"
" -g num Apply num dB gain; to shift Z-axis\n"
" -w name Window: Hann (default), Hamming, Bartlett, Rectangular, Kaiser\n"
- " -s num Display style (1 - 4), default 1\n"
- " -a Toggle the presence of the axes' lines\n"
+ " -s Slack overlap\n"
+ " -a Suppress axes' lines\n"
" -t text Title text\n"
" -c text Comment text\n"
- " -o text Name of the spectrogram output file, default `spectrogram.png'\n",
+ " -l Light background\n"
+ " -m Monochrome display\n"
+ " -o text output file name, default `spectrogram.png'\n",
0, getopts, start, flow, drain, stop, NULL, sizeof(priv_t)};
return &handler;
}
--- /dev/null
+++ b/src/test-srcs
@@ -1,0 +1,49 @@
+#!/bin/sh
+
+# Sample rate conversion tests. Create a 30s sweep of 0-48kHz @ 96kHz sampling
+# rate, then use each resampler to convert it to 44.1kHz. Display the results
+# in a PNG file for each converter.
+
+# Set up the following two before running the script:
+SOX=./sox # The actual sox executable
+SSRC_PATH=/usr/local/bin # Path to the two ssrc executables
+
+RANGE=180
+if [ "$1" -ne "" ]; then
+ RANGE="$1"
+fi
+
+# Temporary files
+IN=/tmp/$0-in-$$.wav
+OUT=/tmp/$0-out-$$.wav
+TIME=/tmp/$0-time-$$.wav
+
+# Create input file
+$SOX -r96k -n -twavpcm $IN synth 30 sin 0~48k gain -1
+
+# Test each one
+for src in \
+ "polyphase" \
+ "rabbit -c0" \
+ "rabbit -c1" \
+ "rate -h" \
+ "rate -v" \
+ "resample -q" \
+ "resample -ql" \
+ "ssrc" \
+ "ssrc_hp" \
+ ; do
+ echo $src
+ case "$src" in
+ ssrc*) time -f %U -o $TIME $SSRC_PATH/$src --quiet --rate 44100 $IN $OUT;;
+ *) time -f %U -o $TIME $SOX $IN -r 44.1k $OUT $src;;
+ esac
+ t=`cat $TIME`
+ $SOX $OUT -n spectrogram \
+ -x 20 -z $RANGE -w kaiser \
+ -t " $src " -c "${t}s user time" \+ -o "spectrogram-`echo $src | tr ' ' '_'`.png"
+done
+
+# Clean up
+rm -f $IN $OUT $TIME