car-stereo/software/main/src/wav.cpp

66 lines
1.6 KiB
C++

#include "esp_log.h"
#include "driver/i2s.h"
#include "wav.h"
#include "i2s.h"
#define WAV_TAG "APP_WAV"
#define WAV_HEADER_SIZE 44
#define I2S_BUFFER_SIZE 512
struct PlayWavParam {
const uint8_t* data;
uint32_t len;
};
static void task(void* param) {
ESP_LOGI(WAV_TAG, "Playing sample...");
PlayWavParam* p = (PlayWavParam*)param;
// Switch to mono since the samples are all in mono to save space
i2s_zero_dma_buffer(I2S_PORT);
i2s_set_clk(I2S_PORT, 44100, 16, I2S_CHANNEL_MONO);
for (uint32_t index = 0; index < p->len; index += I2S_BUFFER_SIZE) {
int rest = p->len - index;
size_t byte_size = I2S_BUFFER_SIZE;
if (rest < I2S_BUFFER_SIZE) {
byte_size = rest;
}
const unsigned char* current = p->data + WAV_HEADER_SIZE + index;
size_t bytes_written;
if (i2s_write(I2S_PORT, current, byte_size, &bytes_written, portMAX_DELAY) != ESP_OK) {
ESP_LOGE(WAV_TAG, "i2s_write has failed");
}
if (bytes_written < byte_size) {
ESP_LOGE(WAV_TAG, "Timeout: not all bytes were written to I2S");
}
}
// Switch back to stereo with the correct samplerate
i2s_zero_dma_buffer(I2S_PORT);
i2s_set_clk(I2S_PORT, i2s::get_sample_rate(), 16, I2S_CHANNEL_STEREO);
ESP_LOGI(WAV_TAG, "Done");
free(p);
vTaskDelete(nullptr);
}
void wav::play(const uint8_t* start, const uint8_t* end) {
ESP_LOGI(WAV_TAG, "Creating Play Wav Task");
uint32_t len = (end - start - WAV_HEADER_SIZE);
PlayWavParam* param = new PlayWavParam;
param->data = start;
param->len = len;
if (xTaskCreatePinnedToCore(task, "PlayWav", 2048, param, configMAX_PRIORITIES - 3, nullptr, 0) != pdPASS) {
ESP_LOGE(WAV_TAG, "Failed to create play wav task");
}
}