diff options
Diffstat (limited to 'src/test/test_filter.c')
| -rw-r--r-- | src/test/test_filter.c | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/src/test/test_filter.c b/src/test/test_filter.c index 7b7b676..3011930 100644 --- a/src/test/test_filter.c +++ b/src/test/test_filter.c @@ -4,6 +4,7 @@ #include <string.h> #include "../libsample/sample.h" #include "../libfilter/iir_filter.h" +#include "../libfilter/fir_filter.h" #include "../libdebug/debug.h" #define level2db(level) (20 * log10(level)) @@ -40,6 +41,7 @@ int main(void) { iir_filter_t filter_low; iir_filter_t filter_high; + fir_filter_t *fir_low/*, *fir_high*/; sample_t samples[SAMPLERATE]; double level; int iter = 2; @@ -102,6 +104,46 @@ int main(void) printf("\n"); } + double freq = 2000.0; + double tb = 400.0; + printf("testing low-pass FIR filter with %.0fHz transition bandwidth\n", tb); + + fir_low = fir_lowpass_init(SAMPLERATE, freq, tb); + printf("Using %d taps\n", fir_low->ntaps); + + for (i = 0; i < 4001; i += 100) { + gen_samples(samples, (double)i); + fir_process(fir_low, samples, SAMPLERATE); + level = get_level(samples); + printf("%s%s%4d Hz: %.1f dB", debug_amplitude(level), debug_db(level), i, level2db(level)); + if (i == freq) + printf(" cutoff\n"); + else + printf("\n"); + } + fir_exit(fir_low); + +#if 0 + double freq1 = 1000.0, freq2 = 2000.0; + tb = 100.0; + printf("testing two-pass FIR filter\n"); + + fir_high = fir_twopass_init(SAMPLERATE, freq1, freq2, tb); + printf("Using %d taps\n", fir_high->ntaps); + + for (i = 0; i < 4001; i += 100) { + gen_samples(samples, (double)i); + fir_process(fir_high, samples, SAMPLERATE); + level = get_level(samples); + printf("%s%s%4d Hz: %.1f dB", debug_amplitude(level), debug_db(level), i, level2db(level)); + if (i == freq1 || i == freq2) + printf(" cutoff\n"); + else + printf("\n"); + } + fir_exit(fir_high); +#endif + return 0; } |