Refactor WAV support

Only tested stereo WAV.

Signed-off-by: Mahyar Koshkouei <deltabeard@users.noreply.github.com>

source/wav.h

@@ -1 +1,41 @@
-int playWav(const char *wav);
+/**
+ * Set decoder parameters for WAV.
+ *
+ * \param	decoder Structure to store parameters.
+ */
+void setWav(struct decoder_fn* decoder);
+
+/**
+ * Initialise WAV playback.
+ *
+ * \param	file	Location of WAV file to play.
+ * \return			0 on success, else failure.
+ */
+int initWav(const char* file);
+
+/**
+ * Get sampling rate of Wav file.
+ *
+ * \return	Sampling rate.
+ */
+uint32_t rateWav(void);
+
+/**
+ * Get number of channels of Wav file.
+ *
+ * \return	Number of channels for opened file.
+ */
+uint8_t channelWav(void);
+
+/**
+ * Read part of open Wav file.
+ *
+ * \param buffer	Output.
+ * \return			Samples read for each channel.
+ */
+uint64_t readWav(void* buffer);
+
+/**
+ * Free Wav file.
+ */
+void exitWav(void);