CS 3005: Programming in C++

WAV File Output

Introduction

A WAV file is a file format that can be used to store sound data. It is actually a specific use of the RIFF file format. The WAV file consists of single RIFF chuck, that contains the “RIFF” header, a “fmt ” sub-chunk and a “data” sub-chunk. The “RIFF” header describes the file format, and the “fmt ” sub-chunk contains information about the audio format, such as the number of channels, and the “data” sub-chunk contains the actual audio data.

RIFF Header

The “RIFF” header has three pieces of information.

The ID, consisting of the 4 characters “RIFF”
The Size, a 32-bit integer, which is the number of bytes in the file after the size. Or, in other words, the number of bytes in the file minus 8.
The Format, consisting of the 4 characters “WAVE”.

Assignment

In this assignment, you will start to create a class, WAVFile that supports the writing of WAV files.

Programming Requirements

Depends on the AudioTrack class.

Create `library-audiofiles/endian_io.{h,cpp}`

Declare the following functions in the header file, and implement them in the cpp file. Some of the functions belong to the little_endian_io namespace, and others to the big_endian_io namespace. Be sure to declare them correctly.

`little_endian_io` Functions:

std::ostream& write_word(std::ostream& output_stream, int value, unsigned size); Writes size bytes of value to output_stream. Starts with the least significant byte.
std::ostream& write_4_bytes(std::ostream& output_stream, int value); Uses write_word to write 4 bytes.
std::ostream& write_3_bytes(std::ostream& output_stream, int value); Uses write_word to write 3 bytes.
std::ostream& write_2_bytes(std::ostream& output_stream, int value); Uses write_word to write 2 bytes.
std::ostream& write_1_bytes(std::ostream& output_stream, int value); Uses write_word to write 1 bytes.

`big_endian_io` Functions:

std::ostream& write_string(std::ostream& output_stream, const std::string& value); Writes the string value to output_stream in order from first to last byte of the string.

Create `library-audiofiles/WAVFile.{h,cpp}`

`WAVFile` Class

Data Members:

The WAVFile class should contain data members to track the following information. These data members should be protected or private. They are not allowed to be public.

int samples per second; The sampling rate of the data for the wave file.
int bits per sample; The number of bits per sample in the wave file. Constrained to a multiple of 8 (specifically 8, 16, 24, or 32).

`public` Methods:

WAVFile(int samples_per_second, int bits_per_sample); Initializes data members from the parameters to 0 in the initialization part of the constructor. Uses the setter methods to attempt to set the data members from parameters. Note, this means, if samples_per_second is less than 1 then the data member will still be set to 0, or if bits_per_sample is not a multiple of 8, then the data member will be set to 0.
int getSamplesPerSecond() const; Returns the value of the data member.
int getBitsPerSample() const; Returns the value of the data member.
void setSamplesPerSecond(const int samples_per_second); Assigns the value of the data member. If the new value is less than 1, then the method should do nothing.
void setBitsPerSample(const int bits_per_sample); Assigns the value of the data member. If the new value is not a multiple of 8 (8, 16, 24, or 32), then the method should do nothing.

Update `library-audiofiles/Makefile`

Add the WAVFile and endian files to the Makefile so the headers are installed and the .o file are added to the library.

Additional Documentation

Grading Instructions

To receive credit for this assignment:

your code must be pushed to your repository for this class on GitHub
all unit tests must pass
all acceptance tests must pass
all programs must build, run, and execute as described in the assignment descriptions.

Extra Challenges (Not Required)

None at this time

Last Updated 02/04/2025