Jo Engine Function prototypes for audio. More...

Data Structures
struct	jo_sound

Macros
#define	JO_SOUND_MAX_CHANNEL
	Channels of sounds (2 slots of the SCSP each; the slots 16 and 17 take the CD audio).
#define	JO_DEFAULT_AUDIO_VOLUME
	Default audio volume.
#define	JO_MAX_AUDIO_VOLUME
	Max audio volume available for jo_audio_set_volume().
#define	JO_MIN_AUDIO_VOLUME
	Min audio volume available for jo_audio_set_volume().
#define	JO_AUDIO_CD_VOLUME_MAX
	Maximum level of the CD audio (see jo_audio_set_cd_volume()), the default.

Enumerations
enum	jo_sound_mode { JoSoundMono8Bit , JoSoundMono16Bit , JoSoundStereo8Bit , JoSoundStereo16Bit }

Functions
void	jo_audio_play_cd_track (const int from_track, const int to_track, const bool repeat_infinitely)
	Play a track from the CD.
void	jo_audio_stop_cd (void)
	Stop playing audio track.
void	jo_audio_pause_cd (void)
	Pause the audio track played by jo_audio_play_cd_track().
void	jo_audio_resume_cd (void)
	Resume the audio track paused by jo_audio_pause_cd().
bool	jo_audio_is_cd_paused (void)
	Check if the CD audio is paused (see jo_audio_pause_cd()).
bool	jo_audio_is_cd_playing (void)
	Check if the CD drive is playing.
void	jo_audio_set_volume (const unsigned char vol)
	Set the audio volume.
void	jo_audio_set_cd_volume (const unsigned char level)
	Set the level of the CD audio in the mix (the music tracks of the CD, see jo_audio_play_cd_track()).
bool	jo_audio_is_channel_playing (const unsigned char channel)
	Checks whether a given audio channel is currently playing a sound.
void	jo_audio_play_sound_on_channel (jo_sound *const sound, const unsigned char channel)
	Play a sound on a specific channel.
void	jo_audio_play_sound_loop_on_channel (jo_sound *const sound, const unsigned char channel)
	Play a sound again and again on a specific channel, until the channel is stopped (an engine for instance).
void	jo_audio_set_channel_sample_rate (const unsigned char channel, const unsigned short sample_rate)
	Change the sampling rate of the sound played on a channel (its pitch: a faster engine for instance).
void	jo_audio_set_channel_volume (const unsigned char channel, const unsigned char volume)
	Change the volume of the sound played on a channel.
void	jo_audio_set_channel_reverb (const unsigned char channel, const unsigned char level)
	Change the send of the sound played on a channel to the reverberation (JO_COMPILE_WITH_AUDIO_DSP_MODULE).
void	jo_audio_play_sound (jo_sound *const sound)
	Play a sound on first available channel.
void	jo_audio_stop_sound (const jo_sound *const sound)
	Stop a sound.
void	jo_audio_stop_channel (const unsigned char channel)
	Stop the sound played on a channel.
bool	jo_audio_load_pcm (const char const filename, const jo_sound_mode mode, jo_sound sound)
	Load PCM file from CD.
bool	jo_audio_load_pcm_async (const char const filename, const jo_sound_mode mode, jo_sound sound)
	Load PCM file from CD asynchronously.
bool	jo_audio_load_wav (const char const filename, jo_sound sound)
	Load a WAV file from CD (PCM, 8 or 16 bits, mono or stereo, any sample rate: the sound gets its mode and its sample rate from the file).
bool	jo_audio_make_resident (jo_sound *sound)
	Keep a sound in the sound RAM (512 KB) and free its copy in the work RAM (the jo_malloc() memory).
void	jo_audio_free_resident (void)
	Forget all the resident sounds (a new level): their room in the sound RAM is free again.
void	jo_audio_free_pcm (jo_sound *sound)
	Free pcm sound loaded with jo_audio_load_pcm().
int	jo_audio_usage_percent (void)
	Get audio channel usage.

Detailed Description

Jo Engine Function prototypes for audio.

Author: Johannes Fetz

Bug: No known bugs.

Data Structure Documentation

◆ jo_sound

struct jo_sound

Data Fields
unsigned char	current_playing_channel
char *	data
unsigned int	data_length
jo_sound_mode	mode
char	pan
unsigned int	resident
unsigned char	reverb
unsigned short	sample_rate
unsigned char	volume

Macro Definition Documentation

◆ JO_AUDIO_CD_VOLUME_MAX

#define JO_AUDIO_CD_VOLUME_MAX

Maximum level of the CD audio (see jo_audio_set_cd_volume()), the default.

◆ JO_DEFAULT_AUDIO_VOLUME

#define JO_DEFAULT_AUDIO_VOLUME

Default audio volume.

◆ JO_MAX_AUDIO_VOLUME

#define JO_MAX_AUDIO_VOLUME

Max audio volume available for jo_audio_set_volume().

◆ JO_MIN_AUDIO_VOLUME

#define JO_MIN_AUDIO_VOLUME

Min audio volume available for jo_audio_set_volume().

◆ JO_SOUND_MAX_CHANNEL

#define JO_SOUND_MAX_CHANNEL

Channels of sounds (2 slots of the SCSP each; the slots 16 and 17 take the CD audio).

Enumeration Type Documentation

◆ jo_sound_mode

enum jo_sound_mode

Enumerator
JoSoundMono8Bit
JoSoundMono16Bit
JoSoundStereo8Bit
JoSoundStereo16Bit

Function Documentation

◆ jo_audio_free_pcm()

void jo_audio_free_pcm ( jo_sound * sound )

Free pcm sound loaded with jo_audio_load_pcm().

Parameters

sound Sound definition

◆ jo_audio_free_resident()

void jo_audio_free_resident ( void )

Forget all the resident sounds (a new level): their room in the sound RAM is free again.

Remarks: The jo_sound of the resident sounds must not be played any more

◆ jo_audio_is_cd_paused()

bool jo_audio_is_cd_paused ( void )

Check if the CD audio is paused (see jo_audio_pause_cd()).

Returns: true if the CD audio is paused

Warning: Requires JO_COMPILE_WITH_FS_MODULE

◆ jo_audio_is_cd_playing()

bool jo_audio_is_cd_playing ( void )

Check if the CD drive is playing.

Returns: true if the CD audio is playing

Remarks: Useful to know when the last track is finished (without repeat)

Warning: Requires JO_COMPILE_WITH_FS_MODULE; The CD drive is also in "play" status when a file is loading

◆ jo_audio_is_channel_playing()

bool jo_audio_is_channel_playing ( const unsigned char channel )

Checks whether a given audio channel is currently playing a sound.

Parameters

channel Channel to check (0 to JO_SOUND_MAX_CHANNEL - 1)

Returns: true if the channel is playing, false otherwise

◆ jo_audio_load_pcm()

bool jo_audio_load_pcm	(	const char *const	filename,
		const jo_sound_mode	mode,
		jo_sound *	sound )

Load PCM file from CD.

Parameters

filename	Pcm filename (example: A.PCM)
mode	PCM audio mode (JoSoundMono16Bit, etc)
sound	Sound definition (output)

Remarks: To convert any audio file to PCM under Linux or Windows => http://ffmpeg.org; ffmpeg -i A.WAV -f s8 -ar 44100 A.PCM; ffmpeg -i A.MP3 -f s8 -ac 1 -ar 8000 A.PCM

Returns: true if succeed otherwise false

◆ jo_audio_load_pcm_async()

bool jo_audio_load_pcm_async	(	const char *const	filename,
		const jo_sound_mode	mode,
		jo_sound *	sound )

Load PCM file from CD asynchronously.

Parameters

filename	Pcm filename (example: A.PCM)
mode	PCM audio mode (JoSoundMono16Bit, etc)
sound	Sound definition (output)

Remarks: To convert any audio file to PCM under Linux or Windows => http://ffmpeg.org; ffmpeg -i A.WAV -f s8 -ar 44100 A.PCM; ffmpeg -i A.MP3 -f s8 -ac 1 -ar 8000 A.PCM

Returns: true if succeed otherwise false

◆ jo_audio_load_wav()

bool jo_audio_load_wav	(	const char *const	filename,
		jo_sound *	sound )

Load a WAV file from CD (PCM, 8 or 16 bits, mono or stereo, any sample rate: the sound gets its mode and its sample rate from the file).

Parameters

filename	WAV filename (example: SHOT.WAV)
sound	Sound definition (output)

Remarks: The samples are converted for the SCSP (16 bits: big endian; 8 bits: signed; stereo: the left samples then the right ones). A WAV file can be listened to on a computer: export them with any audio tool (16 bits recommended: 8 bits samples hiss in the quiet parts, the end of an echo)

Returns: true if succeed otherwise false

◆ jo_audio_make_resident()

bool jo_audio_make_resident ( jo_sound * sound )

Keep a sound in the sound RAM (512 KB) and free its copy in the work RAM (the jo_malloc() memory).

Parameters

sound Sound loaded (jo_audio_load_pcm(), jo_audio_load_wav())

Remarks: The resident sounds fill the sound RAM from its end; the other sounds are copied before them when they play. Many sounds in 16 bits fit there and not in the work RAM

Returns: true if succeed, false if the sound RAM has no room (the sound stays in the work RAM)

◆ jo_audio_pause_cd()

void jo_audio_pause_cd ( void )

Pause the audio track played by jo_audio_play_cd_track().

Remarks: Nothing happens if the CD is not playing or already paused; You can load files while the CD audio is paused

Warning: Requires JO_COMPILE_WITH_FS_MODULE

◆ jo_audio_play_cd_track()

void jo_audio_play_cd_track	(	const int	from_track,
		const int	to_track,
		const bool	repeat_infinitely )

Play a track from the CD.

Parameters

from_track	First track index to play
to_track	Last track index to play
repeat_infinitely	Play tracks infinitely or not

Warning: Requires JO_COMPILE_WITH_FS_MODULE

◆ jo_audio_play_sound()

void jo_audio_play_sound ( jo_sound *const sound )

Play a sound on first available channel.

Parameters

sound Sound definition

◆ jo_audio_play_sound_loop_on_channel()

void jo_audio_play_sound_loop_on_channel	(	jo_sound *const	sound,
		const unsigned char	channel )

Play a sound again and again on a specific channel, until the channel is stopped (an engine for instance).

Parameters

sound	Sound definition
channel	Channel (0 to JO_SOUND_MAX_CHANNEL - 1)

Remarks: Nothing is played if the channel is still playing a sound (see jo_audio_stop_channel()); See jo_audio_set_channel_sample_rate() and jo_audio_set_channel_volume() to change it while it plays

◆ jo_audio_play_sound_on_channel()

void jo_audio_play_sound_on_channel	(	jo_sound *const	sound,
		const unsigned char	channel )

Play a sound on a specific channel.

Parameters

sound	Sound definition
channel	Channel (0 to JO_SOUND_MAX_CHANNEL - 1)

Remarks: Nothing is played if the channel is still playing a sound (see jo_audio_stop_channel())

◆ jo_audio_resume_cd()

void jo_audio_resume_cd ( void )

Resume the audio track paused by jo_audio_pause_cd().

Remarks: The playback continues from the pause position until the end of the last track given to jo_audio_play_cd_track(); Nothing happens if the CD audio is not paused

Warning: Requires JO_COMPILE_WITH_FS_MODULE

◆ jo_audio_set_cd_volume()

void jo_audio_set_cd_volume ( const unsigned char level )

Set the level of the CD audio in the mix (the music tracks of the CD, see jo_audio_play_cd_track()).

Parameters

level 0 (silent) to JO_AUDIO_CD_VOLUME_MAX (7, the default): each step halves the volume (-6 dB)

Remarks: The sounds are not changed: a music too loud for the sounds of the game is lowered with it

◆ jo_audio_set_channel_reverb()

void jo_audio_set_channel_reverb	(	const unsigned char	channel,
		const unsigned char	level )

Change the send of the sound played on a channel to the reverberation (JO_COMPILE_WITH_AUDIO_DSP_MODULE).

Parameters

channel	Channel (0 to JO_SOUND_MAX_CHANNEL - 1)
level	0 (none), 1 to 7 (-36 to 0 dB, 6 dB steps)

◆ jo_audio_set_channel_sample_rate()

void jo_audio_set_channel_sample_rate	(	const unsigned char	channel,
		const unsigned short	sample_rate )

Change the sampling rate of the sound played on a channel (its pitch: a faster engine for instance).

Parameters

channel	Channel (0 to JO_SOUND_MAX_CHANNEL - 1)
sample_rate	Sampling rate (Hz, 1378 to 88200: 44100 / 32 to 44100 x 2)

◆ jo_audio_set_channel_volume()

void jo_audio_set_channel_volume	(	const unsigned char	channel,
		const unsigned char	volume )

Change the volume of the sound played on a channel.

Parameters

channel	Channel (0 to JO_SOUND_MAX_CHANNEL - 1)
volume	Volume: 0 (JO_MIN_AUDIO_VOLUME) to 127 (JO_MAX_AUDIO_VOLUME)

◆ jo_audio_set_volume()

void jo_audio_set_volume ( const unsigned char vol )

Set the audio volume.

Parameters

vol	Volume level from 0 to 127

◆ jo_audio_stop_cd()

void jo_audio_stop_cd ( void )

Stop playing audio track.

Warning: Requires JO_COMPILE_WITH_FS_MODULE

◆ jo_audio_stop_channel()

void jo_audio_stop_channel ( const unsigned char channel )

Stop the sound played on a channel.

Parameters

channel Channel (0 to JO_SOUND_MAX_CHANNEL - 1)

Remarks: jo_audio_play_sound_on_channel() doesn't play on a busy channel: stop it first to restart a sound (for instance the shots of an automatic weapon, longer than the time between 2 shots)

◆ jo_audio_stop_sound()

void jo_audio_stop_sound ( const jo_sound *const sound )

Stop a sound.

Parameters

sound Sound definition

◆ jo_audio_usage_percent()

int jo_audio_usage_percent ( void )

Get audio channel usage.

Returns: Audio channel usage percent

Remarks: jo_printf(0, 0, "Audio channel usage: %d%% ", jo_audio_usage_percent());

Data Structures

Macros

Enumerations

Functions

Detailed Description

Data Structure Documentation

◆ jo_sound

Macro Definition Documentation

◆ JO_AUDIO_CD_VOLUME_MAX

◆ JO_DEFAULT_AUDIO_VOLUME

◆ JO_MAX_AUDIO_VOLUME

◆ JO_MIN_AUDIO_VOLUME

◆ JO_SOUND_MAX_CHANNEL

Enumeration Type Documentation

◆ jo_sound_mode

Function Documentation

◆ jo_audio_free_pcm()

◆ jo_audio_free_resident()

◆ jo_audio_is_cd_paused()

◆ jo_audio_is_cd_playing()

◆ jo_audio_is_channel_playing()

◆ jo_audio_load_pcm()

◆ jo_audio_load_pcm_async()

◆ jo_audio_load_wav()

◆ jo_audio_make_resident()

◆ jo_audio_pause_cd()

◆ jo_audio_play_cd_track()

◆ jo_audio_play_sound()

◆ jo_audio_play_sound_loop_on_channel()

◆ jo_audio_play_sound_on_channel()

◆ jo_audio_resume_cd()

◆ jo_audio_set_cd_volume()

◆ jo_audio_set_channel_reverb()

◆ jo_audio_set_channel_sample_rate()

◆ jo_audio_set_channel_volume()

◆ jo_audio_set_volume()

◆ jo_audio_stop_cd()

◆ jo_audio_stop_channel()

◆ jo_audio_stop_sound()

◆ jo_audio_usage_percent()