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example/sco_demo_util: send cvsd sine via audio ringbuffer

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This commit is contained in:
Matthias Ringwald 2023-02-27 14:37:57 +01:00
parent 94381a6978
commit 6fb1424bd8
1 changed files with 50 additions and 53 deletions
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103
example/sco_demo_util.c
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@ -101,10 +101,10 @@ static btstack_ring_buffer_t audio_output_ring_buffer;
// input
#if SCO_DEMO_MODE == SCO_DEMO_MODE_MICROPHONE
#define USE_AUDIO_INPUT
#endif
static int audio_input_paused = 0;
static uint8_t audio_input_ring_buffer_storage[2*8000]; // full second input buffer
static btstack_ring_buffer_t audio_input_ring_buffer;
#endif
static int count_sent = 0;
static int count_received = 0;
@ -136,11 +136,10 @@ static const int16_t sine_int16_at_16000hz[] = {
};
// 8 kHz samples for CVSD/SCO packets in little endian
static void sco_demo_sine_wave_int16_at_8000_hz_little_endian(unsigned int num_samples, uint8_t * data){
static void sco_demo_sine_wave_int16_at_8000_hz_host_endian(unsigned int num_samples, int16_t * data){
unsigned int i;
for (i=0; i < num_samples; i++){
int16_t sample = sine_int16_at_16000hz[phase];
little_endian_store_16(data, i * 2, sample);
data[i] = sine_int16_at_16000hz[phase];
// ony use every second sample from 16khz table to get 8khz
phase += 2;
if (phase >= (sizeof(sine_int16_at_16000hz) / sizeof(int16_t))){
@ -228,19 +227,18 @@ static int audio_initialize(int sample_rate){
// -- input -- //
#ifdef USE_AUDIO_INPUT
// init buffers
memset(audio_input_ring_buffer_storage, 0, sizeof(audio_input_ring_buffer_storage));
btstack_ring_buffer_init(&audio_input_ring_buffer, audio_input_ring_buffer_storage, sizeof(audio_input_ring_buffer_storage));
audio_input_paused = 1;
#ifdef USE_AUDIO_INPUT
// config and setup audio recording
const btstack_audio_source_t * audio_source = btstack_audio_source_get_instance();
if (!audio_source) return 0;
audio_source->init(1, sample_rate, &audio_recording_callback);
audio_source->start_stream();
audio_input_paused = 1;
#endif
return 1;
@ -314,54 +312,53 @@ static void sco_demo_receive_CVSD(uint8_t * packet, uint16_t size){
void sco_demo_fill_payload_CVSD(uint8_t * payload_buffer, uint16_t sco_payload_length){
#if SCO_DEMO_MODE == SCO_DEMO_MODE_SINE
const int audio_samples_per_packet = sco_payload_length / BYTES_PER_FRAME;
sco_demo_sine_wave_int16_at_8000_hz_little_endian(audio_samples_per_packet, payload_buffer);
#endif
#if SCO_DEMO_MODE == SCO_DEMO_MODE_MICROPHONE
if (btstack_audio_source_get_instance()){
// CVSD
log_debug("send: bytes avail %u, free %u", btstack_ring_buffer_bytes_available(&audio_input_ring_buffer), btstack_ring_buffer_bytes_free(&audio_input_ring_buffer));
// fill with silence while paused
int bytes_to_copy = sco_payload_length;
if (audio_input_paused){
if (btstack_ring_buffer_bytes_available(&audio_input_ring_buffer) >= CVSD_PA_PREBUFFER_BYTES){
// resume sending
audio_input_paused = 0;
}
}
// get data from ringbuffer
uint16_t pos = 0;
uint8_t * sample_data = payload_buffer;
if (!audio_input_paused){
uint32_t bytes_read = 0;
btstack_ring_buffer_read(&audio_input_ring_buffer, sample_data, bytes_to_copy, &bytes_read);
// flip 16 on big endian systems
// @note We don't use (uint16_t *) casts since all sample addresses are odd which causes crahses on some systems
if (btstack_is_big_endian()){
unsigned int i;
for (i=0;i<bytes_read;i+=2){
uint8_t tmp = sample_data[i*2];
sample_data[i*2] = sample_data[i*2+1];
sample_data[i*2+1] = tmp;
}
}
bytes_to_copy -= bytes_read;
pos += bytes_read;
}
// fill with 0 if not enough
if (bytes_to_copy){
memset(sample_data + pos, 0, bytes_to_copy);
audio_input_paused = 1;
}
}
else {
// just send '0's
memset(payload_buffer, 0, sco_payload_length);
#define REFILL_SAMPLES 16
// re-fill with sine
uint16_t samples_free = btstack_ring_buffer_bytes_free(&audio_input_ring_buffer) / 2;
while (samples_free > 0){
int16_t samples_buffer[REFILL_SAMPLES];
uint16_t samples_to_add = btstack_min(samples_free, REFILL_SAMPLES);
sco_demo_sine_wave_int16_at_8000_hz_host_endian(samples_to_add, samples_buffer);
btstack_ring_buffer_write(&audio_input_ring_buffer, (uint8_t *)samples_buffer, samples_to_add * 2);
samples_free -= samples_to_add;
}
#endif
// resume if pre-buffer is filled
if (audio_input_paused){
if (btstack_ring_buffer_bytes_available(&audio_input_ring_buffer) >= CVSD_PA_PREBUFFER_BYTES){
// resume sending
audio_input_paused = 0;
}
}
uint16_t bytes_to_copy = sco_payload_length;
// get data from ringbuffer
uint16_t pos = 0;
if (!audio_input_paused){
uint16_t samples_to_copy = sco_payload_length / 2;
uint32_t bytes_read = 0;
btstack_ring_buffer_read(&audio_input_ring_buffer, payload_buffer, bytes_to_copy, &bytes_read);
// flip 16 on big endian systems
// @note We don't use (uint16_t *) casts since all sample addresses are odd which causes crahses on some systems
if (btstack_is_big_endian()){
uint16_t i;
for (i=0;i<samples_to_copy/2;i+=2){
uint8_t tmp = payload_buffer[i*2];
payload_buffer[i*2] = payload_buffer[i*2+1];
payload_buffer[i*2+1] = tmp;
}
}
bytes_to_copy -= bytes_read;
pos += bytes_read;
}
// fill with 0 if not enough
if (bytes_to_copy){
memset(payload_buffer + pos, 0, bytes_to_copy);
audio_input_paused = 1;
}
}
// mSBC - 16 kHz