| 21,11 → 21,12 |
|---|
| static unsigned int channels = 1; /* count of channels */ |
| static unsigned int buffer_time = 500000; /* ring buffer length in us */ |
| static unsigned int period_time = 100000; /* period time in us */ |
| static double freq = 440; /* sinusoidal wave frequency in Hz */ |
| static int verbose = 0; /* verbose flag */ |
| static int resample = 1; /* enable alsa-lib resampling */ |
| static int period_event = 0; /* produce poll event after each period */ |
| |
| #define SOUND_SPEED 340 |
| |
| unsigned int chirp_size; |
| |
| int period=0; |
| 388,24 → 389,24 |
|---|
| fclose(out); |
| |
| #define SIGNAL_SAMPLES 100000 |
| #define SAMPLES 1000 |
| |
| for(n=0; n < (SIGNAL_SAMPLES - SAMPLES);n++){ //spocita korelaci pro mozna spozdeni |
| r=0; |
| for(m=0;m < SAMPLES;m++) r += chirp[m]*signal[m+n]; |
| correlation[n]=r; |
| } |
| for(n=0; n < (SIGNAL_SAMPLES - chirp_size);n++){ //spocita korelaci pro mozna spozdeni |
| r=0; |
| for(m=0;m < 1000;m++) r += chirp[m]*signal[m+n]; |
| correlation[n]=r; |
| } |
| |
| r=0; |
| for(n=0; n < (SIGNAL_SAMPLES - SAMPLES);n++){ //najde nejvetsi shodu (pro nazornost v samostatnem cyklu) |
| if (r < correlation[n]){ |
| delay = n; |
| r = correlation[n]; |
| } |
| } |
| r=0; |
| for(n=0; n < (SIGNAL_SAMPLES - chirp_size);n++){ //najde nejvetsi shodu (pro nazornost v samostatnem cyklu) |
| if (r < correlation[n]){ |
| delay = n; |
| r = correlation[n]; |
| } |
| } |
| |
| printf("\nEcho zacina na: %d vzorku.\n", delay); |
| printf("\nCasove na: %ds", delay); |
| printf("Casove na: %f s\n", ((float)delay/rate)); |
| printf("vzdalenost: %f m\n", (SOUND_SPEED*(float)delay/rate)); |
| |
| snd_pcm_close(playback_handle); |
| snd_pcm_close(capture_handle); |