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/* tinywavinfo.c
**
** Copyright 2015, The Android Open Source Project
**
** Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions are met:
** * Redistributions of source code must retain the above copyright
** notice, this list of conditions and the following disclaimer.
** * Redistributions in binary form must reproduce the above copyright
** notice, this list of conditions and the following disclaimer in the
** documentation and/or other materials provided with the distribution.
** * Neither the name of The Android Open Source Project nor the names of
** its contributors may be used to endorse or promote products derived
** from this software without specific prior written permission.
**
** THIS SOFTWARE IS PROVIDED BY The Android Open Source Project ``AS IS'' AND
** ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
** IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
** ARE DISCLAIMED. IN NO EVENT SHALL The Android Open Source Project BE LIABLE
** FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
** DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
** SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
** CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
** OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
** DAMAGE.
*/
#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <signal.h>
#include <math.h>
#define ID_RIFF 0x46464952
#define ID_WAVE 0x45564157
#define ID_FMT 0x20746d66
#define ID_DATA 0x61746164
struct riff_wave_header {
uint32_t riff_id;
uint32_t riff_sz;
uint32_t wave_id;
};
struct chunk_header {
uint32_t id;
uint32_t sz;
};
struct chunk_fmt {
uint16_t audio_format;
uint16_t num_channels;
uint32_t sample_rate;
uint32_t byte_rate;
uint16_t block_align;
uint16_t bits_per_sample;
};
static int close = 0;
void analyse_sample(FILE *file, unsigned int channels, unsigned int bits,
unsigned int data_chunk_size);
void stream_close(int sig)
{
/* allow the stream to be closed gracefully */
signal(sig, SIG_IGN);
close = 1;
}
size_t xfread(void *ptr, size_t size, size_t nmemb, FILE *stream)
{
size_t sz = fread(ptr, size, nmemb, stream);
if (sz != nmemb && ferror(stream)) {
fprintf(stderr, "Error: fread failed\n");
exit(1);
}
return sz;
}
int main(int argc, char **argv)
{
FILE *file;
struct riff_wave_header riff_wave_header;
struct chunk_header chunk_header;
struct chunk_fmt chunk_fmt;
char *filename;
int more_chunks = 1;
if (argc < 2) {
fprintf(stderr, "Usage: %s file.wav \n", argv[0]);
return 1;
}
filename = argv[1];
file = fopen(filename, "rb");
if (!file) {
fprintf(stderr, "Unable to open file '%s'\n", filename);
return 1;
}
xfread(&riff_wave_header, sizeof(riff_wave_header), 1, file);
if ((riff_wave_header.riff_id != ID_RIFF) ||
(riff_wave_header.wave_id != ID_WAVE)) {
fprintf(stderr, "Error: '%s' is not a riff/wave file\n", filename);
fclose(file);
return 1;
}
do {
xfread(&chunk_header, sizeof(chunk_header), 1, file);
switch (chunk_header.id) {
case ID_FMT:
xfread(&chunk_fmt, sizeof(chunk_fmt), 1, file);
/* If the format header is larger, skip the rest */
if (chunk_header.sz > sizeof(chunk_fmt))
fseek(file, chunk_header.sz - sizeof(chunk_fmt), SEEK_CUR);
break;
case ID_DATA:
/* Stop looking for chunks */
more_chunks = 0;
break;
default:
/* Unknown chunk, skip bytes */
fseek(file, chunk_header.sz, SEEK_CUR);
}
} while (more_chunks);
printf("Input File : %s \n", filename);
printf("Channels : %u \n", chunk_fmt.num_channels);
printf("Sample Rate : %u \n", chunk_fmt.sample_rate);
printf("Bits per sample : %u \n\n", chunk_fmt.bits_per_sample);
analyse_sample(file, chunk_fmt.num_channels, chunk_fmt.bits_per_sample,
chunk_header.sz);
fclose(file);
return 0;
}
void analyse_sample(FILE *file, unsigned int channels, unsigned int bits,
unsigned int data_chunk_size)
{
void *buffer;
int size;
int num_read;
int i;
unsigned int ch;
int frame_size = 1024;
unsigned int bytes_per_sample = 0;
float *power;
int total_sample_per_channel;
float normalization_factor;
if (bits == 32)
bytes_per_sample = 4;
else if (bits == 16)
bytes_per_sample = 2;
normalization_factor = (float)pow(2.0, (bits-1));
size = channels * bytes_per_sample * frame_size;
buffer = malloc(size);
if (!buffer) {
fprintf(stderr, "Unable to allocate %d bytes\n", size);
free(buffer);
return;
}
power = (float *) calloc(channels, sizeof(float));
total_sample_per_channel = data_chunk_size / (channels * bytes_per_sample);
/* catch ctrl-c to shutdown cleanly */
signal(SIGINT, stream_close);
do {
num_read = xfread(buffer, 1, size, file);
if (num_read > 0) {
if (2 == bytes_per_sample) {
short *buffer_ptr = (short *)buffer;
for (i = 0; i < num_read / bytes_per_sample; i += channels) {
for (ch = 0; ch < channels; ch++) {
int temp = *buffer_ptr++;
/* Signal Normalization */
float f = (float) temp / normalization_factor;
*(power + ch) += (float) (f * f);
}
}
}
if (4 == bytes_per_sample) {
int *buffer_ptr = (int *)buffer;
for (i = 0; i < num_read / bytes_per_sample; i += channels) {
for (ch = 0; ch < channels; ch++) {
int temp = *buffer_ptr++;
/* Signal Normalization */
float f = (float) temp / normalization_factor;
*(power + ch) += (float) (f * f);
}
}
}
}
}while (!close && num_read > 0);
for (ch = 0; ch < channels; ch++) {
float average_power = 10 * log10((*(power + ch)) / total_sample_per_channel);
if(isinf (average_power)) {
printf("Channel [%2u] Average Power : NO signal or ZERO signal\n", ch);
} else {
printf("Channel [%2u] Average Power : %.2f dB\n", ch, average_power);
}
}
free(buffer);
free(power);
}
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