Add research code for ma_data_source.

research/ma_data_source.h

+#ifndef miniaudio_data_source_h
+#define miniaudio_data_source_h
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+The raw data source. This is the dry mix.
+*/
+typedef enum
+{
+    ma_data_source_type_callbacks,
+    ma_data_source_type_decoder,
+    ma_data_source_type_waveform,
+    ma_data_source_type_noise
+} ma_data_source_type;
+
+typedef struct
+{
+    void* pUserData;
+    ma_uint64 (* onRead)(void* pUserData, void* pFramesOut, ma_uint64 frameCount);
+    ma_result (* onSeek)(void* pUserData, ma_uint64 targetFrame);
+} ma_data_source_callbacks;
+
+typedef struct
+{
+    ma_data_source_type type;
+    ma_data_source_callbacks callbacks;
+    ma_decoder_config decoder;
+    ma_waveform_config waveform;
+    ma_noise_config noise;
+    ma_allocation_callbacks allocationCallbacks;
+} ma_data_source_config;
+
+typedef struct
+{
+    ma_data_source_type type;
+    ma_data_source_callbacks callbacks;
+    union
+    {
+        ma_decoder decoder;
+        ma_waveform waveform;
+        ma_noise noise;
+    } source;
+} ma_data_source;
+
+ma_result ma_data_source_init_callbacks(const ma_data_source_config* pConfig);
+ma_result ma_data_source_init_decoder(ma_decoder_read_proc onRead, ma_decoder_seek_proc onSeek, void* pUserData, const ma_data_source_config* pConfig, ma_data_source* pDataSource);
+ma_result ma_data_source_init_decoder_file(const char* pFilePath, const ma_data_source_config* pConfig, ma_data_source* pDataSource);
+ma_result ma_data_source_init_decoder_memory(const void* pData, size_t dataSize, const ma_data_source_config* pConfig, ma_data_source* pDataSource);
+ma_result ma_data_source_init_waveform(const ma_data_source_config* pConfig, ma_data_source* pDataSource);
+ma_result ma_data_source_init_noise(const ma_data_source_config* pConfig, ma_data_source* pDataSource);
+ma_uint64 ma_data_source_read_pcm_frames(ma_data_source* pDataSource, void* pFramesOut, ma_uint64 frameCount);
+ma_result ma_data_source_seek_to_pcm_frame(ma_data_source* pDataSource, ma_uint64 targetPCMFrame);
+
+#ifdef __cplusplus
+}
+#endif
+#endif  /* miniaudio_data_source_h */