You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 
FFmpegAndroid/app/src/main/cpp/visualizer/frank_visualizer.cpp

230 lines
6.3 KiB

//
// Created by frank on 2021/8/16.
//
#include "frank_visualizer.h"
#include <android/log.h>
#define LOG_TAG "frank_visualizer"
#define LOGE(...) ((void)__android_log_print(ANDROID_LOG_ERROR, LOG_TAG, \
__VA_ARGS__))
void short_to_float_array (const short *in, float *out, int len) {
for (int i = 0; i < len; ++i) {
out [i] = (float) (in [i] / (1.0 * 0x8000)) ;
}
}
// float FFT algorithm
void fft_float(filter_sys_t *p_sys) {
int nb_samples = p_sys->nb_samples;
int out_samples = p_sys->out_samples;
fft_state *p_state = nullptr; /* internal FFT data */
DEFINE_WIND_CONTEXT(wind_ctx); /* internal window data */
unsigned i;
float p_output[out_samples]; /* Raw FFT Result */
int16_t p_buffer1[out_samples]; /* Buffer on which we perform the FFT*/
float *p_buffl;
if (p_sys->convert_to_float) {
float p_buff[out_samples];
short_to_float_array((const short *) p_sys->data, p_buff, out_samples);
p_buffl = p_buff;
} else {
p_buffl = (float *) (p_sys->data);
}
int16_t *p_buffs; /* int16_t converted buffer */
int16_t *p_s16_buff; /* int16_t converted buffer */
if (!nb_samples) {
LOGE("no samples yet...");
goto release;
}
/* Allocate the buffer only if the number of samples change */
if (nb_samples != p_sys->i_prev_nb_samples) {
if (p_sys->p_prev_s16_buff) delete [] (p_sys->p_prev_s16_buff);
p_sys->p_prev_s16_buff = new int16_t [nb_samples * p_sys->i_channels];
if (!p_sys->p_prev_s16_buff)
goto release;
p_sys->i_prev_nb_samples = nb_samples;
}
p_buffs = p_s16_buff = p_sys->p_prev_s16_buff;
/* Convert the buffer to int16_t */
for (i = nb_samples * p_sys->i_channels; i--;) {
union {float f; int32_t i;} u{};
u.f = *p_buffl + 384.f;
if (u.i > 0x43c07fff)
*p_buffs = 32767;
else if (u.i < 0x43bf8000)
*p_buffs = -32768;
else
*p_buffs = u.i - 0x43c00000;
p_buffl++; p_buffs++;
}
p_state = visual_fft_init();
if (!p_state) {
LOGE("unable to initialize FFT transform...");
goto release;
}
if (!window_init(out_samples, p_sys->wind_param, &wind_ctx)) {
LOGE("unable to initialize FFT window...");
goto release;
}
p_buffs = p_s16_buff;
for (i = 0 ; i < out_samples; i++) {
p_output[i] = 0;
p_buffer1[i] = *p_buffs;
p_buffs += p_sys->i_channels;
if (p_buffs >= &p_s16_buff[nb_samples * p_sys->i_channels])
p_buffs = p_s16_buff;
}
window_scale_in_place (p_buffer1, &wind_ctx);
fft_perform (p_buffer1, p_output, p_state);
for (i = 0; i < out_samples; ++i) {
int16_t temp = p_output[i] * (2 ^ 16)
/ ((out_samples / 2 * 32768) ^ 2);
p_sys->output[i] = temp & 0xFF;
}
release:
window_close(&wind_ctx);
fft_close(p_state);
}
int fft_fixed_internal(uint8_t *fft, const uint8_t *waveform, int mCaptureSize) {
int32_t workspace[mCaptureSize >> 1];
int32_t nonzero = 0;
for (uint32_t i = 0; i < mCaptureSize; i += 2) {
workspace[i >> 1] =
((waveform[i] ^ 0x80) << 24) | ((waveform[i + 1] ^ 0x80) << 8);
nonzero |= workspace[i >> 1];
}
if (nonzero) {
fixed_fft_real(mCaptureSize >> 1, workspace);
}
for (uint32_t i = 0; i < mCaptureSize; i += 2) {
short tmp = workspace[i >> 1] >> 21;
while (tmp > 127 || tmp < -128) tmp >>= 1;
fft[i] = tmp;
tmp = workspace[i >> 1];
tmp >>= 5;
while (tmp > 127 || tmp < -128) tmp >>= 1;
fft[i + 1] = tmp;
}
return 0;
}
// fixed FFT algorithm
void fft_fixed(filter_sys_t *p_sys) {
int nb_samples = p_sys->nb_samples;
int out_samples = p_sys->out_samples;
DEFINE_WIND_CONTEXT(wind_ctx);
if (!nb_samples) {
LOGE("no samples yet...");
goto release;
}
if (!window_init(out_samples, p_sys->wind_param, &wind_ctx)) {
LOGE("unable to initialize FFT window...");
goto release;
}
window_scale_in_place ((int16_t *) p_sys->data, &wind_ctx);
fft_fixed_internal((uint8_t *) p_sys->output, p_sys->data, out_samples);
release:
window_close(&wind_ctx);
}
FrankVisualizer::FrankVisualizer() {
LOGE("FrankVisualizer init...");
}
FrankVisualizer::~FrankVisualizer() {
LOGE("FrankVisualizer release...");
}
int8_t* FrankVisualizer::fft_run(uint8_t *input_buffer, int nb_samples) {
mFftLock.lock();
fft_context->nb_samples = nb_samples;
memcpy(fft_context->data, input_buffer, static_cast<size_t>(nb_samples));
filter_sys_t *p_sys = fft_context;
#ifdef FIXED_FFT
fft_fixed(p_sys);
#else
fft_float(p_sys);
#endif
mFftLock.unlock();
return fft_context->output;
}
int FrankVisualizer::getOutputSample() {
if (fft_context) {
return fft_context->out_samples;
}
return 0;
}
int FrankVisualizer::init_visualizer() {
fft_context = new filter_sys_t();
filter_sys_t *p_filter = fft_context;
if (!p_filter)
return -1;
p_filter->convert_to_float = false;
p_filter->i_channels = 1;
p_filter->i_prev_nb_samples = 0;
p_filter->p_prev_s16_buff = nullptr;
p_filter->data = nullptr;
p_filter->data_size = 0;
p_filter->nb_samples = 0;
#ifdef FIXED_FFT
p_filter->out_samples = 512;
#else
p_filter->out_samples = FFT_BUFFER_SIZE;
#endif
p_filter->wind_param = new window_param();
/* Fetch the FFT window parameters */
window_get_param(p_filter->wind_param);
p_filter->data_size = MAX_FFT_SIZE;
p_filter->data = new uint8_t[MAX_FFT_SIZE];
memset(p_filter->data, 0, MAX_FFT_SIZE);
p_filter->output = new int8_t[p_filter->out_samples];
memset(p_filter->output, 0, p_filter->out_samples);
return 0;
}
void FrankVisualizer::release_visualizer() {
mFftLock.lock();
filter_sys_t *p_filter = fft_context;
if (!p_filter) return;
if (p_filter->p_prev_s16_buff) {
delete [] (p_filter->p_prev_s16_buff);
}
if (p_filter->wind_param) {
delete (p_filter->wind_param);
}
if (p_filter->data) {
delete [] (p_filter->data);
}
if (p_filter->output) {
delete [] (p_filter->output);
}
delete p_filter;
mFftLock.unlock();
}