Sink: added set_max_write_size() and set_max_write_delay_ms()

Author: pschatzmann

src/BluetoothA2DPSink.cpp

@@ -116,7 +116,7 @@ void BluetoothA2DPSink::start(const char *name) {
   ESP_LOGD(BT_AV_TAG, "%s", __func__);
   log_free_heap();
 
-  is_autoreconnect_allowed = (reconnect_status == AutoReconnect);  
+  is_autoreconnect_allowed = (reconnect_status == AutoReconnect);
 
   if (is_start_disabled) {
     ESP_LOGE(BT_AV_TAG, "re-start not supported after end(true)");
@@ -129,7 +129,6 @@ void BluetoothA2DPSink::start(const char *name) {
   }
   ESP_LOGI(BT_AV_TAG, "Device name will be set to '%s'", this->bt_name);
 
-
   if (is_autoreconnect_allowed) {
     // Initialize NVS
     init_nvs();
@@ -274,7 +273,6 @@ bool BluetoothA2DPSink::app_work_dispatch(app_callback_t p_cback,
   return false;
 }
 
-
 void BluetoothA2DPSink::app_alloc_meta_buffer(esp_avrc_ct_cb_param_t *param) {
   ESP_LOGD(BT_AV_TAG, "%s", __func__);
   esp_avrc_ct_cb_param_t *rc = (esp_avrc_ct_cb_param_t *)(param);
@@ -992,7 +990,6 @@ void BluetoothA2DPSink::audio_data_callback(const uint8_t *data, uint32_t len) {
   }
 }
 
-
 bool BluetoothA2DPSink::is_avrc_connected() { return avrc_connection_state; }
 
 void BluetoothA2DPSink::execute_avrc_command(int cmd) {
@@ -1094,7 +1091,6 @@ void BluetoothA2DPSink::confirm_pin_code(int code) {
   }
 }
 
-
 size_t BluetoothA2DPSink::i2s_write_data(const uint8_t *data,
                                          size_t item_size) {
   if (!is_output) return item_size;
@@ -1109,9 +1105,11 @@ size_t BluetoothA2DPSink::i2s_write_data(const uint8_t *data,
   int processed = 0;
   while (open > 0) {
     int written =
-        out->write(data + processed, std::min(open, A2DP_I2S_MAX_WRITE_SIZE));
+        out->write(data + processed, std::min(open, max_write_size));
     open -= written;
     processed += written;
+    // add some delay between the writes
+    delay_ms(max_write_delay_ms);
   }
   return processed;
 }

src/BluetoothA2DPSink.h

@@ -335,6 +335,12 @@ class BluetoothA2DPSink : public BluetoothA2DPCommon {
   /// Checks if output is active
   bool is_output_active() { return is_i2s_active; }
 
+  /// defines the max write size: default is A2DP_I2S_MAX_WRITE_SIZE
+  void set_max_write_size(int size) { max_write_size = size; }
+
+  /// defines a small delay after each write: default is 0 ms
+  void set_max_write_delay_ms(int delay) { max_write_delay_ms = delay; }
+
 #if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(4, 0, 0)
   /// Provides the result of the last result for the
   /// esp_avrc_tg_get_rn_evt_cap() callback (Available from ESP_IDF_4)
@@ -402,6 +408,8 @@ class BluetoothA2DPSink : public BluetoothA2DPCommon {
   void (*rssi_callbak)(esp_bt_gap_cb_param_t::read_rssi_delta_param &rssi) =
       nullptr;
   int reconnect_delay = 1000;
+  int max_write_size = A2DP_I2S_MAX_WRITE_SIZE;
+  int max_write_delay_ms = A2DP_I2S_MAX_WRITE_DELAY_MS;
 
 #if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(4, 0, 0)
   esp_avrc_rn_evt_cap_mask_t s_avrc_peer_rn_cap = {0};

src/config.h

@@ -25,6 +25,10 @@
 #  define A2DP_I2S_MAX_WRITE_SIZE 1024 * 5
 #endif
 
+#ifndef A2DP_I2S_MAX_WRITE_DELAY_MS 
+#  define A2DP_I2S_MAX_WRITE_DELAY_MS 0
+#endif
+
 // Maximum wait time for status change in 100 ms when calling end()
 #ifndef A2DP_DISCONNECT_LIMIT 
 #  define A2DP_DISCONNECT_LIMIT 20