SOUNDWAVE.C

The soundwave program is a command line tool for basic editing of PCM WAV files.

Supports displaying metadata, changing sample rate, and extracting channels

•info Shows the info of the WAV header

•rate Multiplies the sample rate by a real factor

•channel <left|right> ‎ Extracts the left or right channel from a stereo file and produces a mono file

                                                          COMPILE WITH

gcc -Ofast -Wall -Wextra -Werror -pedantic -o soundwave soundwave.c -lm

                                                          COMMAND GUIDE

Show info

./soundwave info < input.wav

Change sample rate

./soundwave rate 0.5 < input.wav > out.wav

./soundwave rate 2.0 < input.wav > out.wav

Extract channel

./soundwave channel left < stereo.wav > left.wav

./soundwave channel right < stereo.wav > right.wav

                                                        WAV Validity Checks

The program checks:

_{RIFF and WAVE tags}

_{fmt chunk (μέγεθος 16)}

_{audio_format == 1}

_{mono or stereo}

_{bits per sample (8 or 16)}

_{block alignment & bytes/sec}

_{existence "data" chunk}

In case of an error, it displays a message on stderr.

                                                             TEST FILE

PATH -----> soundwave/test/

                                                              SOURCES

1. Wikipedia – WAVE PCM Format https://en.wikipedia.org/wiki/WAV#RIFF_WAVE_chunks

Block_Align = channels × BitsPerSample / 8

Byte_Rate = sample_rate × block_align

Subchunk1Size = 16 (PCM)

AudioFormat = 1

---

2. RIFF Specification (Microsoft) https://learn.microsoft.com/en-us/windows/win32/xaudio2/resource-interchange-file-format--riff-

RIFF Header order

file_size = 36 + data_size

---

3. Microsoft – WAVEFORMATEX structure https://learn.microsoft.com/en-us/windows/win32/api/mmreg/ns-mmreg-waveformatex

FormatTag = 1 , PCM

channels → mono/stereo = 1/2

nSamplesPerSec → sample_rate

BitsPerSample = 8, 16, …