nausea

curses audio visualizer
git clone git://git.2f30.org/nausea.git
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commit 1ccf163b904a6a3806d44c40e8b5dda3168aa5e4
parent 9878386865195ea70526e4caf5bb663ec332edcb
Author: sin <sin@2f30.org>
Date:   Mon Nov 18 20:24:37 +0000

Memset buffers and average the two channels

Diffstat:
spectrum.c | 36++++++++++++++++++++++--------------
1 file changed, 22 insertions(+), 14 deletions(-)
diff --git a/spectrum.c b/spectrum.c @@ -25,7 +25,6 @@ struct frame { int fd; size_t width; size_t height; - size_t nresult; int16_t *buf; unsigned *res; double *in; @@ -63,23 +62,29 @@ init(struct frame *fr) if (fr->fd == -1) err(1, "open"); - fr->nresult = nsamples / 2 + 1; fr->buf = malloc(nsamples * sizeof(int16_t)); - fr->res = malloc(fr->nresult * sizeof(unsigned)); + fr->res = malloc(nsamples / 2 * sizeof(unsigned)); fr->in = fftw_malloc(nsamples * sizeof(double)); - fr->out = fftw_malloc(fr->nresult * sizeof(fftw_complex)); - fr->plan = fftw_plan_dft_r2c_1d(nsamples, fr->in, fr->out, FFTW_ESTIMATE); + fr->out = fftw_malloc(nsamples * sizeof(fftw_complex)); + + memset(fr->buf, 0, nsamples * sizeof(int16_t)); + memset(fr->res, 0, nsamples / 2 * sizeof(unsigned)); + memset(fr->in, 0, nsamples * sizeof(double)); + memset(fr->out, 0, nsamples * sizeof(fftw_complex)); + + fr->plan = fftw_plan_dft_r2c_1d(nsamples, fr->in, fr->out, + FFTW_ESTIMATE); } static void done(struct frame *fr) { fftw_destroy_plan(fr->plan); - fftw_free(fr->in); fftw_free(fr->out); + fftw_free(fr->in); - free(fr->buf); free(fr->res); + free(fr->buf); close(fr->fd); } @@ -96,11 +101,14 @@ update(struct frame *fr) gotsamples = n / sizeof(int16_t); - for (i = 0, j = 0; i < nsamples; i++) { - if (j < gotsamples) - fr->in[i] = fr->buf[j++]; - else - fr->in[i] = 0; + for (i = 0, j = 0; i < nsamples; i++, j++) { + fr->in[i] = 0; + if (j < gotsamples) { + /* average the two channels */ + fr->in[i] = fr->buf[i * 2 + 0]; + fr->in[i] += fr->buf[i * 2 + 1]; + fr->in[i] /= 2; + } } fftw_execute(fr->plan); @@ -149,12 +157,12 @@ draw(struct frame *fr) /* take most of the left part of the band */ #define BANDCUT 0.9 - freqs_per_col = fr->nresult / fr->width * BANDCUT; + freqs_per_col = (nsamples / 2) / fr->width * BANDCUT; #undef BANDCUT /* scale each frequency to screen */ #define BARSCALE 0.2 - for (i = 0; i < fr->nresult; i++) + for (i = 0; i < nsamples / 2; i++) fr->res[i] = sqrt(fr->out[i][0] * fr->out[i][0] + fr->out[i][1] * fr->out[i][1]) / 100000 * fr->height * BARSCALE;