/*
A simple sound library for CSE 20211 by Douglas Thain
For course assignments, you should not change this file.
For complete documentation, see:
http://www.nd.edu/~dthain/courses/cse20211/fall2013/wavfile
*/

#ifndef _WAVFILE_H_
#define _WAVFILE_H_

#ifdef __cplusplus
extern "C" {
#endif
#include <stdio.h>
	//#include <inttypes.h>

	struct wavfile_header {
		char	riff_tag[4];
		int	riff_length;
		char	wave_tag[4];
		char	fmt_tag[4];
		int	fmt_length;
		short	audio_format;
		short	num_channels;
		int	sample_rate;
		int	byte_rate;
		short	block_align;
		short	bits_per_sample;
		char	data_tag[4];
		int	data_length;
	};

	/*
		open an audio file with write flag
		and write necessary wav header to it;

		input:
			filename: string of the file name
		output:
			the file pointer of the audio file
	*/
	FILE* wavfile_write_open(const char* filename);

	/*
		write data to the audio file
		input:
			file: file pointer of the FILE
			data: the array of data that need to be written to the file
			length: number of short type numbers that need to be written
	*/
	void wavfile_write(FILE* file, short data[], int length);

	/*
		read data from file
		input:
			file:
				file: file pointer of the file
				data: the array to store data.
				length: the number of short type numbers that need to be fetched.
		output
			the number of bytes that the function fetched fromt the file.
	*/
	long wavfile_read(FILE* file, short data[], int length);

	/*
		close the audio file and write the length to the header
	*/
	void wavfile_write_close(FILE* file);

	/*
		open an audio file for reading and get the header from file
	*/
	FILE* wavfile_read_open(const char* filename, struct wavfile_header* header);

	/*
		read the data of an channel with the specified postion and length
	*/
	void wavfile_read_channel(FILE* file, short data[], int channel_num, int channel_index, int start_pos, int length);
#define WAVFILE_SAMPLES_PER_SECOND 16000

#ifdef __cplusplus
}
#endif
#endif