feature/audio-mixer

CMakeLists.txt

@@ -1,13 +1,20 @@
 
 set(srcs
     "audio_player.cpp"
+    "audio_mixer.cpp"
 )
 
 set(includes
     "include"
 )
 
-set(requires "")
+set(requires)
+
+if("${IDF_VERSION_MAJOR}.${IDF_VERSION_MINOR}" VERSION_GREATER_EQUAL "5.3")
+    list(APPEND requires esp_driver_i2s esp_ringbuf)
+else()
+    list(APPEND requires driver)
+endif()
 
 if(CONFIG_AUDIO_PLAYER_ENABLE_MP3)
     list(APPEND srcs "audio_mp3.cpp")
@@ -21,7 +28,6 @@ if(CONFIG_AUDIO_PLAYER_ENABLE_WAV)
 endif()
 
 idf_component_register(SRCS "${srcs}"
-                       REQUIRES "${requires}"
                        INCLUDE_DIRS "${includes}"
-                       REQUIRES driver
+                       REQUIRES "${requires}"
 )

README.md

@@ -7,6 +7,7 @@
 
 * MP3 decoding (via libhelix-mp3)
 * Wav/wave file decoding
+* Audio mixing (multiple concurrent streams)
 
 ## Who is this for?
 
@@ -49,6 +50,40 @@ For MP3 support you'll need the [esp-libhelix-mp3](https://github.com/chmorgan/e
 
 Unity tests are implemented in the [test/](../test) folder.
 
+
+## Audio Mixer
+
+The Audio Mixer allows for concurrent playback of multiple audio streams. It supports two types of streams:
+
+* **Decoder Streams**: For playing MP3 or WAV files. Each stream runs its own decoding task.
+* **Raw PCM Streams**: For writing raw PCM data directly to the mixer.
+
+### Basic Mixer Usage
+
+1. Initialize the mixer with output format and I2S write functions.
+2. Create one or more streams using `audio_stream_new()`.
+3. Start playback on the streams.
+
+```c
+audio_mixer_config_t mixer_cfg = {
+    .write_fn = bsp_i2s_write,
+    .clk_set_fn = bsp_i2s_reconfig_clk,
+    .i2s_format = {
+        .sample_rate = 44100,
+        .bits_per_sample = 16,
+        .channels = 2
+    },
+    // ...
+};
+audio_mixer_init(&mixer_cfg);
+
+audio_stream_config_t stream_cfg = DEFAULT_AUDIO_STREAM_CONFIG("bgm");
+audio_stream_handle_t bgm_stream = audio_stream_new(&stream_cfg);
+
+FILE *f = fopen("/sdcard/music.mp3", "rb");
+audio_stream_play(bgm_stream, f);
+```
+
 ## States
 
 ```mermaid

audio_instance.h

@@ -0,0 +1,35 @@
+#pragma once
+
+#include "esp_err.h"
+#include "include/audio_player.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * Opaque handle for a player instance.
+ * Used for multi-instance control in mixer
+ */
+typedef void* audio_instance_handle_t;
+
+#define CHECK_INSTANCE(i) \
+    ESP_RETURN_ON_FALSE(i != NULL, ESP_ERR_INVALID_ARG, "audio_instance", "instance is NULL")
+
+const char* event_to_string(audio_player_callback_event_t event);
+audio_player_callback_event_t state_to_event(audio_player_state_t state);
+
+audio_player_state_t audio_instance_get_state(audio_instance_handle_t h);
+esp_err_t audio_instance_callback_register(audio_instance_handle_t h, audio_player_cb_t call_back, void *user_ctx);
+
+esp_err_t audio_instance_play(audio_instance_handle_t h, FILE *fp);
+esp_err_t audio_instance_pause(audio_instance_handle_t h);
+esp_err_t audio_instance_resume(audio_instance_handle_t h);
+esp_err_t audio_instance_stop(audio_instance_handle_t h);
+
+esp_err_t audio_instance_new(audio_instance_handle_t *h, audio_player_config_t *config);
+esp_err_t audio_instance_delete(audio_instance_handle_t h);
+
+#ifdef __cplusplus
+}
+#endif