TheGameCreators - CodeBase - WAV sound loop functions and functions to read a WAV file's channels, sample rate, and length

Category: Sound

Version: 1.0

Information

Uploaded: 30th Jan 2013 01:50

Modified: 31st Jan 2013 23:51

Author: Naphier

Summary

BEWARE! If meta data such as artist's name, track title, etc. is stored in the beginning of the file these functions will not work. LoopWav(filename$,iNum_loops,iOffset,iVolume,iDecay_rate) GetWavChannels(filename$) GetWavSampleRate(filename$) GetWavLength(filename$)

Full Description

// Sound Function Library Test Driver // Last revision: 2013-01-29 // //----------------------------------------------------------------------------- #include "SoundLibrary.agc" // globals require for LoopWav() global LoopsPlayed = 0 global LoopTimer = GetMilliseconds() global sound_ID // parameters iNum_loops = 0 iOffset = -100 iVolume = 100 iDecay_rate = 5 filename$ = "sound3.wav" repeat Print("Channels: " + Str(GetWavChannels(filename$))) Print("Sample Rate: " + Str(GetWavSampleRate(filename$))) Print("Wav length: " + Str(GetWavLength(filename$))) LoopsPlayed = LoopWav(filename$,iNum_loops,iOffset,iVolume,iDecay_rate) Sync() until GetSoundExists(sound_ID) = 0 Escape() END function Escape() // Pauses the termination of the program until ESC is pressed escape_text = CreateText("Press ESC or Back to exit...") SetTextColor(escape_text,255,255,255,255) SetTextDepth(escape_text,10000) SetTextMaxWidth(escape_text,100) SetTextPosition(escape_text,0,(98-GetTextSize(escape_text))) Sync() repeat until GetRawKeyPressed(27) = 1 DeleteText(escape_text) endfunction

AGK Source Code

` This code was downloaded from The Game Creators

` It is reproduced here with full permission

` http://www.thegamecreators.com

//-----------------------------------------------------------------------------

// This file and any accompanying data files are free to use.

// Sound Function Library

//      LoopWav(filename$,iNum_loops,iOffset,iVolume,iDecay_rate)

//          GetWavChannels(filename$)

//          GetWavSampleRate(filename$)

//          GetWavLength(filename$)

// Last revision: 2013-01-29

//-----------------------------------------------------------------------------

// wav file format structure courtesy of http://www.neurotraces.com/scilab/scilab2/node24.html

//  Field	bytes	format	contains

//  1	    0...3	str4	"RIFF" in ASCII

//  2	    4...7	int4	Total bytes minus 8

//  3	    8...15	str4	"WAVEfmt" Eighth character is a space

//  4   	16...19	int4	16 for PCM format

//  5   	20...21	int2	1 for PCM format

//  6   	22...23	int2	channels

//  7	    24...27	int4	sampling frequency

//  8   	28...31	int4	bytes per second

//  9   	32...33	int2	bytes by capture

//  10  	34...35	int2	bits per sample

//  11  	36:39	str4	"data"

//  12  	40:43	int4	bytes in data

//===================================================================================

//global LoopsPlayed = 0

//global LoopTimer = GetMilliseconds()

//global sound_ID

function LoopWav(filename$,iNum_loops,iOffset,iVolume,iDecay_rate)

// LoopWav() returns the number of loops that have been played 'LoopsPlayed'

//      which must be stored in a global variable so that the function

//      can be called inside of the main loop and be updated properly.

// A global variable for the loop timer and sound file ID must also be kept.

// Parameter Options

// use 0 num_loops for infinite looping

// set offset to increase or decrease the time between loops (milliseconds)

// set volume for the initial volume of the sound

// set decay_rate to the amount of volume reduction per loop

//      if you have initial volume of 100 and 50 loops you might

//      set the decay_rate to 2 for a smooth fade out

// parameter error checks

if GetFileExists(filename$) = 0

Message("LoopWav file '" + filename$ + "' does not exist")

end

endif

if iNum_loops < 0 or iVolume < 0 or iDecay_rate < -100 or iDecay_rate > 100

Message("Parameter out of range in LoopWav()")

end

endif

wav_time# = GetWavLength(filename$)

if wav_time# + iOffset <= 0

Message("Length of loop in LoopWav() is 0 or smaller")

end

endif

// if this is the first call of the function then load the sound file

if LoopsPlayed = 0

sound_ID = LoadSound(filename$)

endif

// if the time since the last play of the sound is greater than or equal

//      to the length of the wav file plus offset

//      OR this is the first time the function is called

if ((GetMilliseconds() - LoopTimer) >= (wav_time# + iOffset)) or LoopsPlayed = 0

// set volume depending on loops played and decay rate

iVolume = iVolume - iDecay_rate * LoopsPlayed

// if sound decayed or iNum_loops have been played

//  then quit function and delete sound

if iVolume <= 0 or (LoopsPlayed > 0 and LoopsPlayed = iNum_loops)

DeleteSound(sound_ID)

exitfunction

endif

PlaySound(sound_ID,iVolume)

inc LoopsPlayed

LoopTimer = GetMilliseconds()

endif

endfunction LoopsPlayed

function GetWavChannels(filename$)

// Returns the number of channels in a wav file.

// 1 for mono       2 for stereo

if GetFileExists(filename$) = 0

Message("GetWavChannels file '" + filename$ + "' does not exist")

end

endif

wav_file = OpenToRead(filename$)

for byte = 0 to 21

ReadByte(wav_file)

next byte

channels = ReadByte(wav_file)

channels = channels + ReadByte(wav_file)

CloseFile(wav_file)

endfunction channels

function GetWavSampleRate(filename$)

// Returns the sample rate of the wav file in hertz

if GetFileExists(filename$) = 0

Message("GetWavSampleRate file '" + filename$ + "' does not exist")

end

endif

wav_file = OpenToRead(filename$)

for byte = 0 to 27

ReadByte(wav_file)

next byte

sample_rate = ReadInteger(wav_file)

CloseFile(wav_file)

endfunction sample_rate

function GetWavLength(filename$)

// Returns the length of the wav file in milliseconds

if GetFileExists(filename$) = 0

Message("GetWavSampleRate file '" + filename$ + "' does not exist")

end

endif

channels = GetWavChannels(filename$)

sample_rate = GetWavSampleRate(filename$)

wav_file = OpenToRead(filename$)

for byte = 0 to 39

ReadByte(wav_file)

next byte

bytes_in_data = ReadInteger(wav_file)

CloseFile(wav_file)

wav_time# = bytes_in_data*1000.0 / (channels*sample_rate)

endfunction wav_time#

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Author Name:	Naphier
CodeBase Entries:	8

CodeBase - WAV sound loop functions and functions to read a WAV file's channels, sample rate, and length

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AGK Source Code

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