LDADD = $(LIBINTL) -lm
bin_PROGRAMS = speaker-test
-speaker_test_SOURCES = speaker-test.c pink.c
+speaker_test_SOURCES = speaker-test.c pink.c st2095.c
man_MANS = speaker-test.1
-EXTRA_DIST = readme.txt speaker-test.1 pink.h
+EXTRA_DIST = readme.txt speaker-test.1 pink.h st2095.h
stream of \fIRATE\fP Hz
.TP
-\fB\-t\fP | \fB\-\-test\fP \fBpink\fP|\fBsine\fP|\fBwav\fP
+\fB\-t\fP | \fB\-\-test\fP \fBpink\fP|\fBst2095\fP|\fBsine\fP|\fBwav\fP
\fB\-t pink\fP means use pink noise (default).
Pink noise is perceptually uniform noise -- that is, it sounds like every frequency at once. If you can hear any tone it may indicate resonances in your speaker system or room.
+\fB\-t st2095\fP means use bandlimited pink noise at -18.5dB AES FS, generated according to SMPTE ST-2095:1-2015.
+In addition to speaker localization it may be used for system calibration, for example 85dB for thater drivers, with an extra +10dB for subwoofers.
+Per the spec, it is intended "to be used in calibrating the sound pressure level and
+electroacoustic response of a cinema B-chain system."
+Note that sampling rates less than 48KHz are outside the scope of the spec, and an attempt will be made to construct a reduced rate filter.
+
\fB\-t sine\fP means to use sine wave.
\fB\-t wav\fP means to play WAV files, either pre-defined files or given via \fB\-w\fP option.
The speaker\-test program was written by James Courtier-Dutton.
Pink noise support was added by Nathan Hurst.
Further extensions by Takashi Iwai.
+SMPTE ST-2095:1 band-limited pink noise added by Rick Sayre.
* Some cleanup from Daniel Caujolle-Bert <segfault@club-internet.fr>
* Pink noise option added Nathan Hurst,
* based on generator by Phil Burk (pink.c)
+ * ST-2095 noise option added Rick Sayre,
+ * based on generator specified by SMPTE ST-2095:1-2015
+ * Also switched to stable harmonic oscillator for sine
*
* Changelog:
+ * 0.0.9 Added support for ST-2095 band-limited pink noise output, switched to harmonic oscillator for sine
+ * Changelog:
* 0.0.8 Added support for pink noise output.
* Changelog:
* 0.0.7 Added support for more than 6 channels.
#include <sys/time.h>
#include <math.h>
#include "pink.h"
+#include "st2095.h"
#include "gettext.h"
#include "version.h"
#include "os_compat.h"
TEST_PINK_NOISE = 1,
TEST_SINE,
TEST_WAV,
+ TEST_ST2095_NOISE,
TEST_PATTERN,
};
* Sine generator
*/
typedef struct {
- double phase;
- double max_phase;
- double step;
+ double a;
+ double s;
+ double c;
} sine_t;
static void init_sine(sine_t *sine)
{
- sine->phase = 0;
- sine->max_phase = 1.0 / freq;
- sine->step = 1.0 / (double)rate;
+ // symplectic integration for fast, stable harmonic oscillator
+ sine->a = 2.0*M_PI * freq / rate;
+ sine->c = 1.0;
+ sine->s = 0.0;
}
static value_t generate_sine(void *arg)
sine_t *sine = arg;
value_t res;
- res.f = sin((sine->phase * 2 * M_PI) / sine->max_phase - M_PI);
- res.f *= generator_scale;
+ res.f = sine->s * generator_scale;
if (format != SND_PCM_FORMAT_FLOAT_LE)
res.i = res.f * INT32_MAX;
- sine->phase += sine->step;
- if (sine->phase >= sine->max_phase)
- sine->phase -= sine->max_phase;
+
+ // update the oscillator
+ sine->c -= sine->a * sine->s;
+ sine->s += sine->a * sine->c;
return res;
}
return res;
}
+/* Band-Limited Pink Noise, per SMPTE ST 2095-1
+ * beyond speaker localization, this can be used for setting loudness to standard
+ */
+static value_t generate_st2095_noise(void *arg)
+{
+ st2095_noise_t *st2095 = arg;
+ value_t res;
+
+ res.f = generate_st2095_noise_sample(st2095);
+ if (format != SND_PCM_FORMAT_FLOAT_LE)
+ res.i = res.f * INT32_MAX;
+ return res;
+}
+
/*
* useful for tests
*/
static int pattern;
static sine_t sine;
static pink_noise_t pink;
+static st2095_noise_t st2095;
static void init_loop(void)
{
switch (test_type) {
+ case TEST_ST2095_NOISE:
+ initialize_st2095_noise(&st2095, rate);
+ break;
case TEST_PINK_NOISE:
initialize_pink_noise(&pink, 16);
break;
do_generate(frames, channel, period_size, generate_pink_noise, &pink);
else if (test_type == TEST_PATTERN)
do_generate(frames, channel, period_size, generate_pattern, &pattern);
- else
+ else if (test_type == TEST_ST2095_NOISE) {
+ reset_st2095_noise_measurement(&st2095);
+ do_generate(frames, channel, period_size, generate_st2095_noise, &st2095);
+ printf(_("\tSMPTE ST-2095 noise batch was %2.2fdB RMS\n"),
+ compute_st2095_noise_measurement(&st2095, period_size));
+ } else
do_generate(frames, channel, period_size, generate_sine, &sine);
if ((err = write_buffer(handle, frames, period_size)) < 0)
"-b,--buffer ring buffer size in us\n"
"-p,--period period size in us\n"
"-P,--nperiods number of periods\n"
- "-t,--test pink=use pink noise, sine=use sine wave, wav=WAV file\n"
+ "-t,--test pink=use pink noise, sine=use sine wave, st2095=use SMPTE ST-2095 noise, wav=WAV file\n"
"-l,--nloops specify number of loops to test, 0 = infinite\n"
"-s,--speaker single speaker test. Values 1=Left, 2=right, etc\n"
"-w,--wavfile Use the given WAV file as a test sound\n"
case 't':
if (*optarg == 'p')
test_type = TEST_PINK_NOISE;
- else if (*optarg == 's')
- test_type = TEST_SINE;
- else if (*optarg == 'w')
+ else if (*optarg == 's') {
+ if (optarg[1] == 'i')
+ test_type = TEST_SINE;
+ else if (optarg[1] == 't')
+ test_type = TEST_ST2095_NOISE;
+ else {
+ fprintf(stderr, _("Invalid test type %s\n"), optarg);
+ exit(1);
+ }
+ } else if (*optarg == 'w')
test_type = TEST_WAV;
else if (*optarg == 't')
test_type = TEST_PATTERN;
printf(_("Playback device is %s\n"), device);
printf(_("Stream parameters are %iHz, %s, %i channels\n"), rate, snd_pcm_format_name(format), channels);
switch (test_type) {
+ case TEST_ST2095_NOISE:
+ printf(_("Using SMPTE ST-2095 -18.5dB AES FS band-limited pink noise\n"));
+ break;
case TEST_PINK_NOISE:
printf(_("Using 16 octaves of pink noise\n"));
break;
--- /dev/null
+/*
+ st2095.c
+
+ Generate Bandlimited Pink Noise (-18.5dB AES FS)
+ Using the SMPTE ST 2095:1-2015 standard
+
+ Based on pseudo-code from the above SMPTE standard, which bore the credit
+ "Revised 2015-01-04 by Calvert Dayton"
+
+ Copyleft 2023 Rick Sayre - No rights reserved.
+*/
+
+#include "aconfig.h"
+#include <stdio.h>
+#include <math.h>
+#include "st2095.h"
+
+/************************************************************/
+
+
+void reset_st2095_noise_measurement( st2095_noise_t *st2095 ) {
+ st2095->accum = 0.;
+}
+
+float compute_st2095_noise_measurement( st2095_noise_t *st2095, int period ) {
+ return(10. * log10f(st2095->accum / (float)period) + 3.01);
+}
+
+void initialize_st2095_noise( st2095_noise_t *st2095, int sample_rate) {
+ // Periodicity in samples must be a power of two, <= 2^31
+ // Typical values are 524288, 1048576, 2097152 or 4194304
+ if (sample_rate > 48000) {
+ // Special case LCG step for 1024K samples @ 88.2K or 96k
+ st2095->samplesPerPeriod = 1048576;
+ st2095->randStep = 163841;
+ } else {
+ st2095->samplesPerPeriod = 524288;
+ st2095->randStep = 52737;
+ }
+
+ // set up LCG PRNG
+ st2095->randMax = st2095->samplesPerPeriod - 1;
+ st2095->seed = 0;
+ st2095->scaleFactor = 2.0 / (float)st2095->randMax;
+
+ st2095->maxAmp = powf(10.0, ST2095_MAX_PEAK / 20.0);
+
+ // Calculate omegaT for matched Z transform highpass filters
+ st2095->w0t = 2.0 * M_PI * ST2095_HPFC / (float)sample_rate;
+
+ // Limit LpFc <= Nyquist (actually lower, based on 48 vs 22.4 KHz spec cutoff)
+ // The spec says the filter begins at 22.4KHz, if we ask for a Nyquist-impossible
+ // sampling rate, compute something with the same relationship
+ st2095->LpFc = ST2095_LPFC;
+ float rateratio = 48000. / ST2095_LPFC;
+ if (st2095->LpFc > sample_rate/rateratio)
+ st2095->LpFc = sample_rate/rateratio;
+
+ // Calculate k and k^2 for bilinear transform lowpass filters
+ st2095->k = tanf(( 2.0 * M_PI * st2095->LpFc / (float)sample_rate ) / 2.0);
+ st2095->k2 = st2095->k * st2095->k;
+
+ // Calculate biquad coefficients for bandpass filter components
+ st2095->hp1_a1 = -2.0 * expf(-0.3826835 * st2095->w0t) * cosf(0.9238795 * st2095->w0t);
+ st2095->hp1_a2 = expf(2.0 * -0.3826835 * st2095->w0t);
+ st2095->hp1_b0 = (1.0 - st2095->hp1_a1 + st2095->hp1_a2) / 4.0;
+ st2095->hp1_b1 = -2.0 * st2095->hp1_b0;
+ st2095->hp1_b2 = st2095->hp1_b0;
+
+ st2095->hp2_a1 = -2.0 * expf(-0.9238795 * st2095->w0t) * cosf(0.3826835 * st2095->w0t);
+ st2095->hp2_a2 = expf(2.0 * -0.9238795 * st2095->w0t);
+ st2095->hp2_b0 = (1.0 - st2095->hp2_a1 + st2095->hp2_a2) / 4.0;
+ st2095->hp2_b1 = -2.0 * st2095->hp2_b0;
+ st2095->hp2_b2 = st2095->hp2_b0;
+
+ st2095->lp1_a1 = (2.0 * (st2095->k2 - 1.0)) / (st2095->k2 + (st2095->k / 1.306563) + 1.0);
+ st2095->lp1_a2 = (st2095->k2 - (st2095->k / 1.306563) + 1.0) / (st2095->k2 + (st2095->k / 1.306563) + 1.0);
+ st2095->lp1_b0 = st2095->k2 / (st2095->k2 + (st2095->k / 1.306563) + 1.0);
+ st2095->lp1_b1 = 2.0 * st2095->lp1_b0;
+ st2095->lp1_b2 = st2095->lp1_b0;
+
+ st2095->lp2_a1 = (2.0 * (st2095->k2 - 1.0)) / (st2095->k2 + (st2095->k / 0.541196) + 1.0);
+ st2095->lp2_a2 = (st2095->k2 - (st2095->k / 0.541196) + 1.0) / (st2095->k2 + (st2095->k / 0.541196) + 1.0);
+ st2095->lp2_b0 = st2095->k2 / (st2095->k2 + (st2095->k / 0.541196) + 1.0);
+ st2095->lp2_b1 = 2.0 * st2095->lp2_b0;
+ st2095->lp2_b2 = st2095->lp2_b0;
+
+ // initialize delay lines for bandpass filter
+ st2095->hp1w1 = 0.0;
+ st2095->hp1w2 = 0.0;
+ st2095->hp2w1 = 0.0;
+ st2095->hp2w2 = 0.0;
+ st2095->lp1w1 = 0.0;
+ st2095->lp1w2 = 0.0;
+ st2095->lp2w1 = 0.0;
+ st2095->lp2w2 = 0.0;
+
+ // initialize delay lines for pink filter network
+ st2095->lp1 = 0.0;
+ st2095->lp2 = 0.0;
+ st2095->lp3 = 0.0;
+ st2095->lp4 = 0.0;
+ st2095->lp5 = 0.0;
+ st2095->lp6 = 0.0;
+
+ // cycle the generator for one complete time series to populate filter-bank delay lines
+ for (int i=0; i<st2095->samplesPerPeriod; i++)
+ generate_st2095_noise_sample(st2095);
+ st2095->accum = 0.0;
+}
+
+float generate_st2095_noise_sample( st2095_noise_t *st2095 ) {
+ float white, w, pink;
+
+ // Generate a pseudorandom integer in the range 0 <= seed <= randMax.
+ //# Bitwise AND with randMax zeroes out any unwanted high order bits.
+ st2095->seed = (1664525 * st2095->seed + st2095->randStep) & st2095->randMax;
+ // Scale to a real number in the range -1.0 <= white <= 1.0
+ white = (float)st2095->seed * st2095->scaleFactor - 1.0;
+
+ // Run pink filter; a parallel network of first-order LP filters, scaled to
+ // produce an output signal with target RMS = -21.5 dB FS (-18.5 dB AES FS)
+ // when bandpass filter cutoff frequencies are 10 Hz and 22.4 kHz.
+ st2095->lp1 = 0.9994551 * st2095->lp1 + 0.00198166688621989 * white;
+ st2095->lp2 = 0.9969859 * st2095->lp2 + 0.00263702334184061 * white;
+ st2095->lp3 = 0.9844470 * st2095->lp3 + 0.00643213710202331 * white;
+ st2095->lp4 = 0.9161757 * st2095->lp4 + 0.01438952538362820 * white;
+ st2095->lp5 = 0.6563399 * st2095->lp5 + 0.02698408541064610 * white;
+ pink = st2095->lp1 + st2095->lp2 + st2095->lp3 +
+ st2095->lp4 + st2095->lp5 + st2095->lp6 + white * 0.0342675832159306;
+ st2095->lp6 = white * 0.0088766118009356;
+
+ // Run bandpass filter; a series network of 4 biquad filters
+ // Biquad filters implemented in Direct Form II
+ w = pink - st2095->hp1_a1 * st2095->hp1w1 - st2095->hp1_a2 * st2095->hp1w2;
+ pink = st2095->hp1_b0 * w + st2095->hp1_b1 * st2095->hp1w1 + st2095->hp1_b2 * st2095->hp1w2;
+ st2095->hp1w2 = st2095->hp1w1;
+ st2095->hp1w1 = w;
+
+ w = pink - st2095->hp2_a1 * st2095->hp2w1 - st2095->hp2_a2 * st2095->hp2w2;
+ pink = st2095->hp2_b0 * w + st2095->hp2_b1 * st2095->hp2w1 + st2095->hp2_b2 * st2095->hp2w2;
+ st2095->hp2w2 = st2095->hp2w1;
+ st2095->hp2w1 = w;
+
+ w = pink - st2095->lp1_a1 * st2095->lp1w1 - st2095->lp1_a2 * st2095->lp1w2;
+ pink = st2095->lp1_b0 * w + st2095->lp1_b1 * st2095->lp1w1 + st2095->lp1_b2 * st2095->lp1w2;
+ st2095->lp1w2 = st2095->lp1w1;
+ st2095->lp1w1 = w;
+
+ w = pink - st2095->lp2_a1 * st2095->lp2w1 - st2095->lp2_a2 * st2095->lp2w2;
+ pink = st2095->lp2_b0 * w + st2095->lp2_b1 * st2095->lp2w1 + st2095->lp2_b2 * st2095->lp2w2;
+ st2095->lp2w2 = st2095->lp2w1;
+ st2095->lp2w1 = w;
+
+ // Limit peaks to +/-MaxAmp
+ if (pink > st2095->maxAmp)
+ pink = st2095->maxAmp;
+ else if (pink < -st2095->maxAmp)
+ pink = -st2095->maxAmp;
+
+ // accumulate squared amplitude for RMS computation
+ st2095->accum += (pink * pink);
+ return(pink);
+}
--- /dev/null
+#define ST2095_MAX_PEAK -9.5 // dB
+#define ST2095_HPFC 10.0 // Highpass filter cutoff in Hz
+#define ST2095_LPFC 22400.0 // Lowpass filter cutoff in Hz
+
+typedef struct
+{
+ float maxAmp;
+ int samplesPerPeriod;
+ int randStep;
+ int randMax;
+ int seed;
+ float scaleFactor;
+ float w0t;
+ float k;
+ float k2;
+ float LpFc;
+ // biquad coefficients
+ float hp1_a1, hp1_a2;
+ float hp1_b0, hp1_b1, hp1_b2;
+ float hp2_a1, hp2_a2;
+ float hp2_b0, hp2_b1, hp2_b2;
+ float lp1_a1, lp1_a2;
+ float lp1_b0, lp1_b1, lp1_b2;
+ float lp2_a1, lp2_a2;
+ float lp2_b0, lp2_b1, lp2_b2;
+ // delay-line variables for bandpass filter
+ float hp1w1, hp1w2;
+ float hp2w1, hp2w2;
+ float lp1w1, lp1w2;
+ float lp2w1, lp2w2;
+ // delay-line variables for pink filter network
+ float lp1, lp2, lp3, lp4, lp5, lp6;
+ // statistics accumulator
+ float accum;
+} st2095_noise_t;
+
+void initialize_st2095_noise( st2095_noise_t *st2095, int sample_rate );
+float generate_st2095_noise_sample( st2095_noise_t *st2095 );
+
+void reset_st2095_noise_measurement( st2095_noise_t *st2095 );
+float compute_st2095_noise_measurement( st2095_noise_t *st2095, int period );
git://git.alsa-project.org / alsa-utils.git / commitdiff