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posix/wav_util: add wav_reader_get_num_channels and wav_reader_get_sampling_rate

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This commit is contained in:
Matthias Ringwald 2022-02-23 11:27:24 +01:00
parent 79b7ea2d2d
commit e2bf7a9a29
2 changed files with 48 additions and 18 deletions
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51
platform/posix/wav_util.c
View File

@ -48,19 +48,22 @@
#include "btstack_util.h" #include "btstack_util.h"
#include "btstack_debug.h" #include "btstack_debug.h"
/* wav reader state */
static int wav_reader_fd; static int wav_reader_fd;
static int bytes_per_sample = 2; static int wav_reader_bytes_per_sample = 2;
static struct {
uint8_t num_channels;
uint32_t sampling_rate;
} wav_reader_state;
/* Write wav file utils */ /* wav writer state */
typedef struct wav_writer_state { static struct {
FILE * wav_file; FILE * wav_file;
int total_num_samples; int total_num_samples;
int num_channels; int num_channels;
int sampling_frequency; int sampling_frequency;
int frame_count; int frame_count;
} wav_writer_state_t; } wav_writer_state;
wav_writer_state_t wav_writer_state;
static void little_endian_fstore_16(FILE *wav_file, uint16_t value){ static void little_endian_fstore_16(FILE *wav_file, uint16_t value){
@ -183,7 +186,11 @@ int wav_writer_write_int16(int num_samples, int16_t * data){
return 0; return 0;
} }
/** WAV Reader Implementation */
int wav_reader_open(const char * filepath){ int wav_reader_open(const char * filepath){
memset (&wav_reader_state, 0, sizeof(wav_reader_state));
wav_reader_fd = open(filepath, O_RDONLY); wav_reader_fd = open(filepath, O_RDONLY);
if (!wav_reader_fd) { if (!wav_reader_fd) {
log_error("Can't open file %s", filepath); log_error("Can't open file %s", filepath);
@ -193,19 +200,31 @@ int wav_reader_open(const char * filepath){
uint8_t buf[40]; uint8_t buf[40];
__read(wav_reader_fd, buf, sizeof(buf)); __read(wav_reader_fd, buf, sizeof(buf));
int num_channels = little_endian_read_16(buf, 22); wav_reader_state.num_channels = little_endian_read_16(buf, 22);
int block_align = little_endian_read_16(buf, 32); if ((wav_reader_state.num_channels < 1) || (wav_reader_state.num_channels > 2)) {
if (num_channels != 1 && num_channels != 2) { log_error("Unexpected num channels %d", wav_reader_state.num_channels);
log_error("Unexpected num channels %d", num_channels);
return 1; return 1;
} }
bytes_per_sample = block_align/num_channels;
if (bytes_per_sample > 2){ wav_reader_state.sampling_rate = little_endian_read_32(buf, 24);
bytes_per_sample = bytes_per_sample/8;
int block_align = little_endian_read_16(buf, 32);
wav_reader_bytes_per_sample = block_align / wav_reader_state.num_channels;
if (wav_reader_bytes_per_sample > 2){
wav_reader_bytes_per_sample = wav_reader_bytes_per_sample / 8;
} }
return 0; return 0;
} }
uint8_t wav_reader_get_num_channels(void){
return wav_reader_state.num_channels;
}
uint32_t wav_reader_get_sampling_rate(void){
return wav_reader_state.sampling_rate;
}
int wav_reader_close(void){ int wav_reader_close(void){
close(wav_reader_fd); close(wav_reader_fd);
return 0; return 0;
@ -218,7 +237,7 @@ int wav_reader_read_int8(int num_samples, int8_t * data){
int bytes_read = 0; int bytes_read = 0;
for (i=0; i<num_samples; i++){ for (i=0; i<num_samples; i++){
if (bytes_per_sample == 2){ if (wav_reader_bytes_per_sample == 2){
uint8_t buf[2]; uint8_t buf[2];
bytes_read +=__read(wav_reader_fd, &buf, 2); bytes_read +=__read(wav_reader_fd, &buf, 2);
data[i] = buf[1]; data[i] = buf[1];
@ -228,7 +247,7 @@ int wav_reader_read_int8(int num_samples, int8_t * data){
data[i] = buf[0] + 128; data[i] = buf[0] + 128;
} }
} }
if (bytes_read == num_samples*bytes_per_sample) { if (bytes_read == num_samples * wav_reader_bytes_per_sample) {
return 0; return 0;
} else { } else {
return 1; return 1;
@ -244,7 +263,7 @@ int wav_reader_read_int16(int num_samples, int16_t * data){
bytes_read +=__read(wav_reader_fd, &buf, 2); bytes_read +=__read(wav_reader_fd, &buf, 2);
data[i] = little_endian_read_16(buf, 0); data[i] = little_endian_read_16(buf, 0);
} }
if (bytes_read == num_samples*bytes_per_sample) { if (bytes_read == num_samples * wav_reader_bytes_per_sample) {
return 0; return 0;
} else { } else {
return 1; return 1;

13
platform/posix/wav_util.h
View File

@ -79,10 +79,21 @@ int wav_writer_close(void);
/** /**
* Open singleton war reader * Open singleton wav reader
* @return 0 if ok * @return 0 if ok
*/ */
int wav_reader_open(const char * filepath); int wav_reader_open(const char * filepath);
/**
* Get number of channels
*/
uint8_t wav_reader_get_num_channels(void);
/**
* Get sampling rate
*/
uint32_t wav_reader_get_sampling_rate(void);
/** /**
* Read Int8 samples * Read Int8 samples
* @return 0 if ok * @return 0 if ok