From d294dae6e0ec3188b5a6e64d5a11b34883223c94 Mon Sep 17 00:00:00 2001
From: Drahflow <drahflow@gmx.de>
Date: Tue, 6 May 2014 14:52:05 +0200
Subject: [PATCH] Frequence analysis
---
fastclient/Makefile | 3 +
fastclient/snow.c | 1 +
fastclient/spectrum.c | 211 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 215 insertions(+)
create mode 100644 fastclient/spectrum.c
diff --git a/fastclient/Makefile b/fastclient/Makefile
index 032ab9a..7c4c4bc 100644
--- a/fastclient/Makefile
+++ b/fastclient/Makefile
@@ -7,5 +7,8 @@ snow: snow.o
client: client.o
g++ -lzmq -o $@ $<
+spectrum: spectrum.o
+ g++ -lzmq -lpthread -lasound -lfftw3 -o $@ $<
+
%.o: %.c
g++ -W -Wall -Wextra -pedantic -std=c++11 -c -o $@ $<
diff --git a/fastclient/snow.c b/fastclient/snow.c
index 619bdfd..553ea68 100644
--- a/fastclient/snow.c
+++ b/fastclient/snow.c
@@ -90,5 +90,6 @@ int main (void) {
zmq_close(requester);
zmq_ctx_destroy(context);
+
return 0;
}
diff --git a/fastclient/spectrum.c b/fastclient/spectrum.c
new file mode 100644
index 0000000..6b90577
--- /dev/null
+++ b/fastclient/spectrum.c
@@ -0,0 +1,211 @@
+/* Use the newer ALSA API */
+#define ALSA_PCM_NEW_HW_PARAMS_API
+
+#include <alsa/asoundlib.h>
+#include <fftw3.h>
+#include <zmq.h>
+#include <string.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <pthread.h>
+#include <vector>
+#include <math.h>
+
+#define FFTWSIZE 2048
+#define MINPOS 0
+
+#define WIDTH 480
+#define HEIGHT 70
+
+#define CMD_PIXEL 0
+#define CMD_BLIT 1
+
+#define MAXPOS (FFTWSIZE / 8)
+
+struct msgBlit {
+ uint8_t cmd;
+ uint32_t x;
+ uint32_t y;
+ uint32_t w;
+ uint32_t h;
+ volatile uint8_t data[0];
+} __attribute__ ((packed));
+
+msgBlit *screen;
+
+void *blitScreen(void *) {
+ void *context = zmq_ctx_new ();
+ void *requester;
+
+ requester = zmq_socket (context, ZMQ_REQ);
+ zmq_connect(requester, "tcp://mensadisplay:5556");
+ // zmq_connect(requester, "tcp://192.168.178.147:5570");
+ // zmq_connect(requester, "tcp://localhost:5556");
+
+ while(1) {
+ zmq_msg_t msg;
+ zmq_msg_init_size(&msg, sizeof(msgBlit) + WIDTH * HEIGHT);
+
+ memcpy(zmq_msg_data(&msg), screen, sizeof(msgBlit) + WIDTH * HEIGHT);
+ zmq_msg_send(&msg, requester, ZMQ_SNDMORE);
+
+ zmq_msg_init_size(&msg, 0);
+ zmq_msg_send(&msg, requester, 0);
+ zmq_recv(requester, NULL, 0, 0);
+ }
+
+ zmq_close(requester);
+ zmq_ctx_destroy(context);
+
+ return nullptr;
+}
+
+int main() {
+ int rc;
+ int size;
+ snd_pcm_t *handle;
+ snd_pcm_hw_params_t *params;
+ unsigned int val;
+ int dir;
+ snd_pcm_uframes_t frames;
+ char *buffer;
+
+ screen = reinterpret_cast<msgBlit *>(malloc(sizeof(msgBlit) + WIDTH * HEIGHT));
+ screen->cmd = CMD_BLIT;
+ screen->x = 0;
+ screen->y = 0;
+ screen->w = WIDTH;
+ screen->h = HEIGHT;
+
+ pthread_t blitter;
+ pthread_create(&blitter, nullptr, blitScreen, nullptr);
+
+ fftw_complex *in, *out;
+ fftw_plan plan;
+
+ in = (fftw_complex *)fftw_malloc(sizeof(fftw_complex) * FFTWSIZE);
+ out = (fftw_complex *)fftw_malloc(sizeof(fftw_complex) * FFTWSIZE);
+ plan = fftw_plan_dft_1d(FFTWSIZE, in, out, FFTW_FORWARD, FFTW_ESTIMATE);
+
+ /* Open PCM device for recording (capture). */
+ rc = snd_pcm_open(&handle, "hw:1,0",
+ SND_PCM_STREAM_CAPTURE, 0);
+ if (rc < 0) {
+ fprintf(stderr,
+ "unable to open pcm device: %s\n",
+ snd_strerror(rc));
+ exit(1);
+ }
+
+ /* Allocate a hardware parameters object. */
+ snd_pcm_hw_params_alloca(¶ms);
+
+ /* Fill it in with default values. */
+ snd_pcm_hw_params_any(handle, params);
+
+ /* Set the desired hardware parameters. */
+
+ /* Interleaved mode */
+ snd_pcm_hw_params_set_access(handle, params,
+ SND_PCM_ACCESS_RW_INTERLEAVED);
+
+ /* Signed 16-bit little-endian format */
+ snd_pcm_hw_params_set_format(handle, params,
+ SND_PCM_FORMAT_S16_LE);
+
+ /* Two channels (stereo) */
+ snd_pcm_hw_params_set_channels(handle, params, 2);
+
+ /* 44100 bits/second sampling rate (CD quality) */
+ val = 44100;
+ snd_pcm_hw_params_set_rate_near(handle, params,
+ &val, &dir);
+
+ /* Set period size to FFTWSIZE frames. */
+ frames = FFTWSIZE;
+ snd_pcm_hw_params_set_period_size_near(handle,
+ params, &frames, &dir);
+
+ /* Write the parameters to the driver */
+ rc = snd_pcm_hw_params(handle, params);
+ if (rc < 0) {
+ fprintf(stderr,
+ "unable to set hw parameters: %s\n",
+ snd_strerror(rc));
+ exit(1);
+ }
+
+ /* Use a buffer large enough to hold one period */
+ snd_pcm_hw_params_get_period_size(params,
+ &frames, &dir);
+ size = frames * 4; /* 2 bytes/sample, 2 channels */
+ buffer = (char *) malloc(size);
+
+// /* We want to loop for 5 seconds */
+// snd_pcm_hw_params_get_period_time(params,
+// &val, &dir);
+// const long one_second = 1000000 / val;
+// const long refresh = one_second / 30;
+
+ double minVol[MAXPOS];
+ double maxVol[MAXPOS];
+ for(int i = 0; i < MAXPOS; ++i) {
+ minVol[i] = maxVol[i] = 0;
+ }
+
+ while (1) {
+ rc = snd_pcm_readi(handle, buffer, frames);
+ if (rc == -EPIPE) {
+ /* EPIPE means overrun */
+ fprintf(stderr, "overrun occurred\n");
+ snd_pcm_prepare(handle);
+ continue;
+ } else if (rc < 0) {
+ fprintf(stderr,
+ "error from read: %s\n",
+ snd_strerror(rc));
+ } else if (rc != (int)frames) {
+ fprintf(stderr, "short read, read %d frames\n", rc);
+ } else {
+ for(int pos = 0; pos < FFTWSIZE; ++pos) {
+ // printf("%d, %d, %d, %d\n", buffer[pos * 4], buffer[pos * 4 + 1], buffer[pos * 4 + 2], buffer[pos * 4 + 3]);
+ in[pos][0] = buffer[pos * 4 + 1];
+ in[pos][1] = 0;
+ }
+
+ fftw_execute(plan);
+
+ for(int pos = 0; pos < MAXPOS; ++pos) {
+ double vol = 0;
+ for(int i = 0; i < 1; i++) {
+ vol += fabs(out[pos+i][0]) + fabs(out[pos+i][1]);
+ }
+
+ if(vol < minVol[pos]) minVol[pos] = vol;
+ if(vol > maxVol[pos]) maxVol[pos] = vol;
+
+ int level = log(1000 * (vol - minVol[pos]) / maxVol[pos]) * HEIGHT / 6.9;
+
+ int xStart = pos * WIDTH / MAXPOS;
+ int xEnd = (pos + 1) * WIDTH / MAXPOS;
+ for(int x = xStart; x < xEnd; ++x) {
+ int yCross = std::min(HEIGHT, std::max(0, HEIGHT - level));
+
+ for(int y = 0; y < yCross; ++y) {
+ screen->data[y * WIDTH + x] = 0;
+ }
+ for(int y = yCross; y < HEIGHT; ++y) {
+ screen->data[y * WIDTH + x] = 1;
+ }
+ }
+ }
+ }
+ }
+
+ snd_pcm_drain(handle);
+ snd_pcm_close(handle);
+ free(buffer);
+
+ return 0;
+}
--
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