Merge pull request #944 from openmv/audio_streaming

Add audio streaming function with callback.
This commit is contained in:
Ibrahim Abd Elkader 2020-10-30 21:00:41 +02:00 committed by GitHub
commit 360b5e4339
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2 changed files with 93 additions and 6 deletions

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@ -16,6 +16,8 @@
#include "pdm2pcm_glo.h"
#include "fb_alloc.h"
#include "omv_boardconfig.h"
#include "py/obj.h"
#include "py/objarray.h"
#if MICROPY_PY_AUDIO
@ -35,7 +37,7 @@ static PDM_Filter_Config_t PDM_FilterConfig[2];
#define DMA_XFER_FULL (0x04U)
static volatile uint32_t xfer_status = 0;
#define PDM_BUFFER_SIZE (256*2)
#define PDM_BUFFER_SIZE (4096)
// BDMA can only access D3 SRAM4 memory.
uint8_t PDM_BUFFER[PDM_BUFFER_SIZE] __attribute__ ((aligned (32))) __attribute__((section(".d3_sram_buffer")));
@ -215,7 +217,7 @@ static mp_obj_t py_audio_read_pcm(uint n_args, const mp_obj_t *args, mp_map_t *k
{
mp_buffer_info_t pcmbuf;
mp_get_buffer_raise(args[0], &pcmbuf, MP_BUFFER_WRITE);
int frequency = py_helper_keyword_int(n_args, args, 1, kw_args, MP_OBJ_NEW_QSTR(MP_QSTR_frequency), 16);
uint32_t frequency = py_helper_keyword_int(n_args, args, 1, kw_args, MP_OBJ_NEW_QSTR(MP_QSTR_frequency), 16);
int gain_db = py_helper_keyword_int(n_args, args, 2, kw_args, MP_OBJ_NEW_QSTR(MP_QSTR_gain_db), 24);
float highpass = py_helper_keyword_float(n_args, args, 3, kw_args, MP_OBJ_NEW_QSTR(MP_QSTR_highpass), 0.9883f);
@ -299,15 +301,99 @@ static mp_obj_t py_audio_read_pcm(uint n_args, const mp_obj_t *args, mp_map_t *k
return mp_const_none;
}
static mp_obj_t py_audio_start_streaming(uint n_args, const mp_obj_t *args, mp_map_t *kw_args)
{
mp_obj_t callback = args[0];
mp_obj_t arg_obj = args[1];
uint32_t time = (uint32_t) (py_helper_keyword_float(n_args, args, 2, kw_args, MP_OBJ_NEW_QSTR(MP_QSTR_time), 1.0) * 1000);
uint32_t frequency = py_helper_keyword_int(n_args, args, 3, kw_args, MP_OBJ_NEW_QSTR(MP_QSTR_frequency), 16);
int gain_db = py_helper_keyword_int(n_args, args, 4, kw_args, MP_OBJ_NEW_QSTR(MP_QSTR_gain_db), 24);
float highpass = py_helper_keyword_float(n_args, args, 5, kw_args, MP_OBJ_NEW_QSTR(MP_QSTR_highpass), 0.9883f);
uint32_t decimation_factor = AUDIO_SAI_FREQKHZ/frequency;
uint32_t output_samples = ((PDM_BUFFER_SIZE / 2) * 8) / (decimation_factor * n_channels); // Half transfer
mp_obj_array_t *pcmbuf = mp_obj_new_bytearray_by_ref(output_samples * 4, m_new(int16_t, output_samples * 2));
// Configure PDM library
for (int i=0; i<n_channels; i++) {
PDM_FilterHandler[i].bit_order = PDM_FILTER_BIT_ORDER_MSB;
PDM_FilterHandler[i].endianness = PDM_FILTER_ENDIANNESS_LE;
PDM_FilterHandler[i].high_pass_tap = (uint32_t) (highpass * 2147483647U); // coff * (2^31-1)
PDM_FilterHandler[i].out_ptr_channels = n_channels;
PDM_FilterHandler[i].in_ptr_channels = n_channels;
PDM_Filter_Init(&PDM_FilterHandler[i]);
PDM_FilterConfig[i].mic_gain = gain_db;
PDM_FilterConfig[i].output_samples_number = output_samples;
PDM_FilterConfig[i].decimation_factor = get_decimation_factor(decimation_factor);
PDM_Filter_setConfig(&PDM_FilterHandler[i], &PDM_FilterConfig[i]);
}
// Clear DMA buffer status
xfer_status &= DMA_XFER_NONE;
// Start DMA transfer
if (HAL_SAI_Receive_DMA(&hsai, (uint8_t*) PDM_BUFFER, PDM_BUFFER_SIZE / 2) != HAL_OK) {
RAISE_OS_EXCEPTION("SAI DMA transfer failed!");
}
uint32_t record_start = HAL_GetTick();
while ((HAL_GetTick() - record_start) < time) {
uint32_t start = HAL_GetTick();
// Wait for half transfer complete.
while ((xfer_status & DMA_XFER_HALF) == 0) {
if ((HAL_GetTick() - start) >= 1000) {
HAL_SAI_DMAStop(&hsai);
RAISE_OS_EXCEPTION("SAI DMA transfer timeout!");
}
}
// Clear buffer state.
xfer_status &= ~(DMA_XFER_HALF);
// Convert PDM samples to PCM.
for (int i=0; i<n_channels; i++) {
PDM_Filter(&((uint8_t*)PDM_BUFFER)[i], &((int16_t*)pcmbuf->items)[i], &PDM_FilterHandler[i]);
}
mp_call_function_2(callback, MP_OBJ_FROM_PTR(pcmbuf), arg_obj);
// Wait for transfer complete.
while ((xfer_status & DMA_XFER_FULL) == 0) {
if ((HAL_GetTick() - start) >= 1000) {
HAL_SAI_DMAStop(&hsai);
RAISE_OS_EXCEPTION("SAI DMA transfer timeout!");
}
}
// Clear buffer state.
xfer_status &= ~(DMA_XFER_FULL);
// Convert PDM samples to PCM.
for (int i=0; i<n_channels; i++) {
PDM_Filter(&((uint8_t*)PDM_BUFFER)[PDM_BUFFER_SIZE / 2 + i], &((int16_t*)pcmbuf->items)[i], &PDM_FilterHandler[i]);
}
mp_call_function_2(callback, MP_OBJ_FROM_PTR(pcmbuf), arg_obj);
}
// Stop SAI DMA.
HAL_SAI_DMAStop(&hsai);
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_0(py_audio_init_obj, py_audio_init);
STATIC MP_DEFINE_CONST_FUN_OBJ_1(py_audio_read_pdm_obj, py_audio_read_pdm);
STATIC MP_DEFINE_CONST_FUN_OBJ_KW(py_audio_read_pcm_obj, 1, py_audio_read_pcm);
STATIC MP_DEFINE_CONST_FUN_OBJ_KW(py_audio_start_streaming_obj, 2, py_audio_start_streaming);
static const mp_map_elem_t globals_dict_table[] = {
{ MP_OBJ_NEW_QSTR(MP_QSTR___name__), MP_OBJ_NEW_QSTR(MP_QSTR_audio) },
{ MP_OBJ_NEW_QSTR(MP_QSTR_init), (mp_obj_t)&py_audio_init_obj },
{ MP_OBJ_NEW_QSTR(MP_QSTR_read_pcm), (mp_obj_t)&py_audio_read_pcm_obj },
{ MP_OBJ_NEW_QSTR(MP_QSTR_read_pdm), (mp_obj_t)&py_audio_read_pdm_obj },
{ MP_OBJ_NEW_QSTR(MP_QSTR___name__), MP_OBJ_NEW_QSTR(MP_QSTR_audio) },
{ MP_OBJ_NEW_QSTR(MP_QSTR_init), (mp_obj_t)&py_audio_init_obj },
{ MP_OBJ_NEW_QSTR(MP_QSTR_read_pcm), (mp_obj_t)&py_audio_read_pcm_obj },
{ MP_OBJ_NEW_QSTR(MP_QSTR_read_pdm), (mp_obj_t)&py_audio_read_pdm_obj },
{ MP_OBJ_NEW_QSTR(MP_QSTR_start_streaming), (mp_obj_t)&py_audio_start_streaming_obj },
};
STATIC MP_DEFINE_CONST_DICT(globals_dict, globals_dict_table);

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@ -1256,3 +1256,4 @@ Q(highpass)
Q(frequency)
Q(read_pdm)
Q(read_pcm)
Q(start_streaming)