openmv/src/omv/py/py_micro_speech.c
2020-11-10 23:28:23 +02:00

131 lines
4.9 KiB
C

/*
* This file is part of the OpenMV project.
*
* Copyright (c) 2013-2019 Ibrahim Abdelkader <iabdalkader@openmv.io>
* Copyright (c) 2013-2019 Kwabena W. Agyeman <kwagyeman@openmv.io>
*
* This work is licensed under the MIT license, see the file LICENSE for details.
*
* Micro Speech Python module.
*/
#include <mp.h>
#include "systick.h"
#include "py_assert.h"
#include "py_helper.h"
#include "py/binary.h"
#include "fb_alloc.h"
#include "omv_boardconfig.h"
#include "py/obj.h"
#include "py/objarray.h"
#include "libtf.h"
#if MICROPY_PY_MICRO_SPEECH
#define kMaxAudioSampleSize (512)
#define kAudioSampleFrequency (16000)
// The following values are derived from values used during model training.
// If you change the way you preprocess the input, update all these constants.
#define kFeatureSliceSize (40)
#define kFeatureSliceCount (49)
#define kFeatureElementCount (kFeatureSliceSize * kFeatureSliceCount)
#define kFeatureSliceStrideMs (20)
#define kFeatureSliceDurationMs (30)
#define RAISE_OS_EXCEPTION(msg) nlr_raise(mp_obj_new_exception_msg(&mp_type_OSError, msg))
typedef struct _py_micro_speech_obj {
mp_obj_base_t base;
uint32_t n_slices;
int8_t spectrogram[kFeatureElementCount];
} py_micro_speech_obj_t;
static const mp_obj_type_t py_micro_speech_type;
static void py_micro_speech_print(const mp_print_t *print, mp_obj_t self_in, mp_print_kind_t kind)
{
//py_micro_speech_obj_t *microspeech = MP_OBJ_TO_PTR(self_in);
printf("micro speech object\n");
}
mp_obj_t py_micro_speech_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *args)
{
// check arguments
//mp_arg_check_num(n_args, n_kw, 1, MP_OBJ_FUN_ARGS_MAX, true);
py_micro_speech_obj_t *o = m_new_obj(py_micro_speech_obj_t);
o->base.type = &py_micro_speech_type;
o->n_slices = 0;
memset(o->spectrogram, 0, kFeatureElementCount);
if (libtf_initialize_micro_features() != 0) {
RAISE_OS_EXCEPTION("Failed to initialize micro features!");
}
return MP_OBJ_FROM_PTR(o);
}
mp_obj_t py_micro_speech_audio_callback(mp_obj_t self_in, mp_obj_t buf_in)
{
py_micro_speech_obj_t *microspeech = MP_OBJ_TO_PTR(self_in);
mp_buffer_info_t pcmbuf;
mp_get_buffer_raise(buf_in, &pcmbuf, MP_BUFFER_READ);
//size_t typesize = mp_binary_get_size('@', pcmbuf.typecode, NULL);
if ((pcmbuf.len / 2) != kMaxAudioSampleSize) {
RAISE_OS_EXCEPTION("Audio data size too small!");
}
uint32_t slice_index = 0;
if (microspeech->n_slices < kFeatureSliceCount) {
slice_index = microspeech->n_slices++;
} else {
// Spectrogram is full, move old data up in the spectrogram
// and put the new slice at the end of the spectrogram.
// +-----------+ +-----------+
// | data@20ms | --> | data@40ms |
// +-----------+ -- +-----------+
// | data@40ms | -- --> | data@60ms |
// +-----------+ -- -- +-----------+
// | data@60ms | -- -- | data@80ms |
// +-----------+ -- +-----------+
// | data@80ms | -- |<new slice>|
// +-----------+ +-----------+
slice_index = (kFeatureSliceCount - 1);
memmove(microspeech->spectrogram,
microspeech->spectrogram + kFeatureSliceSize,
kFeatureElementCount - kFeatureSliceSize);
}
printf("slice index %ld\n", slice_index);
size_t num_samples_read;
int8_t *new_slice = microspeech->spectrogram + (slice_index * kFeatureSliceSize);
if (libtf_generate_micro_features((int16_t*) pcmbuf.buf,
kMaxAudioSampleSize, kFeatureSliceSize, new_slice, &num_samples_read)) {
RAISE_OS_EXCEPTION("Feature generation failed!");
}
return mp_const_none;
}
STATIC MP_DEFINE_CONST_FUN_OBJ_2(py_micro_speech_audio_callback_obj, py_micro_speech_audio_callback);
STATIC const mp_rom_map_elem_t py_micro_speech_locals_dict_table[] = {
// instance methods
{ MP_ROM_QSTR(MP_QSTR_audio_callback), MP_ROM_PTR(&py_micro_speech_audio_callback_obj) },
// class constants
};
STATIC MP_DEFINE_CONST_DICT(py_micro_speech_locals_dict, py_micro_speech_locals_dict_table);
static const mp_obj_type_t py_micro_speech_type = {
{ &mp_type_type },
.name = MP_QSTR_MicroSpeech,
.print = py_micro_speech_print,
.make_new = py_micro_speech_make_new,
.locals_dict = (mp_obj_dict_t*)&py_micro_speech_locals_dict,
};
STATIC const mp_rom_map_elem_t module_globals_table[] = {
{ MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_micro_speech) },
{ MP_ROM_QSTR(MP_QSTR_MicroSpeech), MP_ROM_PTR(&py_micro_speech_type) },
};
STATIC MP_DEFINE_CONST_DICT(module_globals, module_globals_table);
const mp_obj_module_t micro_speech_module = {
.base = { &mp_type_module },
.globals = (mp_obj_dict_t*)&module_globals,
};
#endif //MICROPY_PY_MICRO_SPEECH