Stream i2s without hiccups I think

bridadan · Jun 18, 2020 · b37929f · b37929f
1 parent 363784e
commit b37929f
Showing 1 changed file with 68 additions and 40 deletions.
diff --git a/main/main.c b/main/main.c
@@ -6,8 +6,6 @@
 
 #define SAMPLE_RATE     (44100)
 #define I2S_NUM         (0)
-#define WAVE_FREQ_HZ    (100)
-#define PI              (3.14159265)
 #define I2S_BCK_IO      (GPIO_NUM_14)
 #define I2S_WS_IO       (GPIO_NUM_25)
 #define I2S_DO_IO       (GPIO_NUM_26)
@@ -19,6 +17,7 @@
 #define DMA_BUF_SIZE_MS 5
 #define DMA_BUF_SIZE_BYTES (SAMPLE_RATE * SIZE_OF_SAMPLE * NUM_CHANNELS * DMA_BUF_SIZE_MS) / 1000
 #define DMA_BUF_NUMBER 5
+#define MAX_FRAMES_TO_READ ((DMA_BUF_SIZE_BYTES / NUM_CHANNELS) / SIZE_OF_SAMPLE)
 
 #define DR_FLAC_NO_STDIO
 #define DR_FLAC_NO_OGG
@@ -28,7 +27,8 @@
 
 
 
-static xQueueHandle i2s_evt_queue = NULL;
+static xQueueHandle i2s_event_queue = NULL;
+static xQueueHandle control_event_queue = NULL;
 
 extern const uint8_t flac_file_start[] asm("_binary_flac_sample_small_flac_start");
 extern const uint8_t flac_file_end[] asm("_binary_flac_sample_small_flac_end");
@@ -51,14 +51,15 @@ void init_i2s() {
         .data_out_num = I2S_DO_IO,
         .data_in_num = I2S_PIN_NO_CHANGE,
     };
-    i2s_driver_install(I2S_NUM, &i2s_config, 0, NULL);
+    i2s_driver_install(I2S_NUM, &i2s_config, 10, &i2s_event_queue);
     i2s_set_pin(I2S_NUM, &pin_config);
 }
 
 static unsigned int flac_file_index;
 static unsigned int flac_file_size;
 static drflac *pFlac;
 static drflac_int16 i2s_buf[DMA_BUF_SIZE_BYTES];
+static uint32_t i2s_buf_start, i2s_buf_end;
 
 size_t onRead(void *pUserData, void *pBufferOut, size_t bytesToRead) {
     size_t bytes_written = 0;
@@ -104,43 +105,44 @@ uint32_t min(uint32_t a, uint32_t b) {
     return a <= b ? a : b;
 }
 
-void write_all_to_i2s(drflac_uint64 frames_read) {
-    uint32_t bytes_read = frames_read * NUM_CHANNELS * SIZE_OF_SAMPLE;
-    //printf("writing %u/%u\n", bytes_read,DMA_BUF_SIZE_BYTES);
-    size_t total_bytes_written = 0;
-    size_t bytes_written = 0;
-    while (total_bytes_written < bytes_read) {
+void fill_i2s_buffer() {
+    drflac_uint64 frames_read;
+    size_t bytes_written = 1;
+
+    if (flac_file_index == flac_file_size) {
+        i2s_stop(I2S_NUM);
+        return;
+    }
+
+    while (flac_file_index != flac_file_size && bytes_written > 0) {
+        if (!(i2s_buf_end - i2s_buf_start)) {
+            i2s_buf_start = 0;
+            frames_read = drflac_read_pcm_frames_s16(pFlac, MAX_FRAMES_TO_READ, i2s_buf);
+            if (frames_read != MAX_FRAMES_TO_READ) {
+                // TODO handle end of stream
+            }
+            i2s_buf_end = frames_read * NUM_CHANNELS;
+        }
+
         esp_err_t result = i2s_write(
             I2S_NUM,
-            &(i2s_buf[total_bytes_written]),
-            bytes_read - total_bytes_written,
+            &(i2s_buf[i2s_buf_start]),
+            (i2s_buf_end - i2s_buf_start) * SIZE_OF_SAMPLE,
             &bytes_written,
-            100
+            0
         );
         assert(result == ESP_OK);
-        total_bytes_written += bytes_written;
-        //printf("total_bytes_written: %u/%u\r\n", total_bytes_written, bytes_read);
-    }
-}
+        i2s_buf_start += bytes_written / SIZE_OF_SAMPLE;
 
-void start_flac_stream() {
-    flac_file_index = 0;
-    flac_file_size = flac_file_end - flac_file_start;
-    //printf("flac_file_size %u\r\n", flac_file_size);
-    pFlac = drflac_open(&onRead, &onSeek, NULL, NULL);
-    uint32_t frames_to_read = (DMA_BUF_SIZE_BYTES / NUM_CHANNELS) / SIZE_OF_SAMPLE;
-    drflac_uint64 frames_read = drflac_read_pcm_frames_s16(pFlac, frames_to_read, i2s_buf);
-    printf("frames_to_read: %u, frames_read: %llu\r\n", frames_to_read, frames_read);
-    while (frames_read == frames_to_read) {
-        write_all_to_i2s(frames_read);
-        frames_read = drflac_read_pcm_frames_s16(pFlac, frames_to_read, i2s_buf);
+        if (!bytes_written) {
+            break;
+        }
     }
-    write_all_to_i2s(frames_read);
 }
 
 static void IRAM_ATTR toggle_button(void *args) {
     int32_t num = 1;
-    xQueueSendFromISR(i2s_evt_queue, &num, NULL);
+    xQueueSendFromISR(control_event_queue, &num, NULL);
 }
 
 void init_gpio() {
@@ -154,30 +156,56 @@ void init_gpio() {
     gpio_isr_handler_add(GPIO_NUM_32, toggle_button, NULL);
 }
 
+void stream() {
+    i2s_event_t i2s_event;
+    while (1) {
+        if (xQueueReceive(i2s_event_queue, &i2s_event, portMAX_DELAY)) {
+            switch (i2s_event.type) {
+            case I2S_EVENT_DMA_ERROR:
+                printf("I2S_EVENT_DMA_ERROR\n");
+            break;
+            case I2S_EVENT_TX_DONE:
+                fill_i2s_buffer();
+            break;
+            case I2S_EVENT_RX_DONE:
+                printf("I2S_EVENT_RX_DONE\n");
+            break;
+            case I2S_EVENT_MAX:
+                printf("I2S_EVENT_MAX\n");
+            break;
+            }
+        }
+    }
+}
+
 void app_main(void)
 {
     int32_t num;
     bool play = true;
-    i2s_evt_queue = xQueueCreate(10, sizeof(uint32_t));
+    control_event_queue = xQueueCreate(10, sizeof(uint32_t));
+    flac_file_index = 0;
+    flac_file_size = flac_file_end - flac_file_start;
+
     init_i2s();
-    //init_gpio();
+    init_gpio();
 
-    start_flac_stream();
-    printf("finished\n");
-    while(1) {
-        vTaskDelay(1000);
-    }
+    pFlac = drflac_open(&onRead, &onSeek, NULL, NULL);
+    i2s_stop(I2S_NUM);
+    fill_i2s_buffer();
+    i2s_start(I2S_NUM);
+
+    xTaskCreatePinnedToCore(stream, "stream", 4096, NULL, 3, NULL, tskNO_AFFINITY);
 
-    /*
     while (1) {
-        if (xQueueReceive(i2s_evt_queue, &num, portMAX_DELAY)) {
+        if (xQueueReceive(control_event_queue, &num, portMAX_DELAY)) {
             play = !play;
             if (play) {
+                printf("start\n");
                 i2s_start(I2S_NUM);
             } else {
+                printf("stop\n");
                 i2s_stop(I2S_NUM);
             }
         }
     }
-    */
 }