JEDI-SDL Audio

[DarknessX]

Hey, well, I just setup Free Pascal (pure, not lazarus, etc) to work with Jedi-SDL. It's working fine, compiles, can initiate and exit Jedi-SDL's audio using:

Program testsdl;

uses sdl;

begin
sdl_init(SDL_INIT_AUDIO);

sdl_quit;
end.

But I don't know how to load an audio file, then play/pause/stop it. Any help? Some example code, without using graphical windows? I'm going to be doing all my code via text-based, so all the 'forms' and such don't help me

Also, I can't find the demo programs... I'm using the v1 beta, and I've looked (AFAIK) everywhere.

[paul_nicholls]

Go to here http://jedi-sdl.cvs.sourceforge.net/...Demos/WavTest/

and you will find a SDL_Mixer demo...is this what you were looking for?

cheers,
Paul.

[savage]

You may also want to check out this thread

which discusses an sdl_mixer audio manager class I wrote a while a go.

[DarknessX]

I believe thats what I was looking for, paul_nicholls. But I need it to play mp3's too

[jasonf]

SDL Mixer plays MP3 and OGG Vorbis among others, you just need to make sure you have the correct dlls and units referenced. smpeg I think.

The JEDI-SDL examples in the JEDI-SDL folder will help a lot.

I got a lot of info for using SDL from the book Programming Linux Games by NoStarch press..http://www.nostarch.com/frameset.php?startat=plg

But there's nothing in there you can't glean from the SDL documentation on the libSDL site. http://www.libsdl.org/cgi/docwiki.cgi/SDL_5fmixer

OK, so it's all in C but it's easy to read.

[WILL]

[size=9px]Sorry, I know this is only slightly relevant, but because it was brought up. Even the C examples for things like SDL, OpenGL, etc are super useful because the function names are the same and the values that you pump into them are the same.[/size]

The SDL Audio mixer is pretty decent for cross platform. I don't know of any other way to get the same kind of audio on all 3 major OSes, except for OpenAL. [size=9px](which isn't too bad/hard either tbh)[/size]

One thing to note however the SDL_Mixer does not playback at 44100 Hz on Windows very well. For whatever reason. :scratch: On Linux it's perfectly fine, but for Windows it just gives you a really distorted output. You best bet for Win32/64 would be to playback at 22050 Hz instead.

Oh and before I forget, do look for the included documentation with the latest release. It should have full listing of all the functions you'd need.

[DarknessX]

I couldn't find the examples in the Jedi-SDL folder... I looked. Nothing there

I don't know C, and can't understand enough to be able to figure out the values.

[WILL]

I've recently done a major reconstruction of the new JEDI-SDL site. You can find online documentation there.

EDIT: Sorry forgot to post the link in case you don't know it: jedi-sdl.pascalgamedevelopment.com

[DarknessX]

Well, I'm overly confused. I have no clue how to initialize and play audio. I've been going through examples, code, tutorials, everything I can find, and I'm lost

[WILL]

You're looking for a Demo in the JEDI-SDL 1.0 BETA release. it's located under the path JEDI-SDLv1.0\SDL_Mixer\Demos\WavTest There, albeit sort of hidden.

[size=9px]Psst... Dom, you you need someone to make FPC/Lazarus demos for ya? These are kind of useless to a non-Delphi guy. [/size]


--- Please note that this demo is not very straightforward and could probably be vastly improved. ---


Since you are not using Delphi (or Kylix) you will not be able to just run and test it. So open up the Main.pas file and you'll see all the code you'll need.

Considering that this code is pretty poor to make reference to I'll just cut out all the junk and post what you'll need from it. But don't let that stop you from actually going to check out the demo it's self!

Don't forget to add the DLLs to the game folder!

[pascal]uses
sdl,
sdl_mixer;

// initialization
var
audio_rate: integer;
audio_format: Uint16;
audio_channels: integer;
audio_buffers : integer;
loops: integer;

loops := 0;
if ((SDL_Init(SDL_INIT_AUDIO) < 0)) then
begin
// Could not initialize SDL Audio
SDL_Quit;
exit;
end
else
begin
audio_rate := StrToInt(seAudioRate.Text);
audio_format := StrToInt(seAudioFormat.Text);
audio_channels := StrToInt(seAudioChannels.Text);
audio_buffers := StrToInt(seAudioBuffers.Text);
// Open the audio device
if ( Mix_OpenAudio( audio_rate, audio_format, audio_channels, audio_buffers ) <0> 1) then
// Memo.Lines.Add(Format('Opened audio at %d Hz %d bit %s', [audio_rate, (audio_format and $FF), 'stereo']))
else
// Memo.Lines.Add(Format('Opened audio at %d Hz %d bit %s', [audio_rate, (audio_format and $FF), 'mono']));


// Load the requested wave file * /
wave := Mix_LoadWAV(PChar(Edit1.Text)); // Edit1.Text is the WAV file path string
if (wave = nil) then
exit;

// Play and then exit * /
Mix_PlayChannel(0, wave, loops);
while ( Mix_Playing(0) = 0 ) do
SDL_Delay(100);
end;

// now we closing everything

if ( wave <> nil ) then
begin
Mix_FreeChunk(wave);
wave := nil;
end;
if ( bAudioOpen ) then // bAudioOpen is just some flag that was used to keep track if the audio device was opened.
begin
Mix_CloseAudio;
end;
SDL_Quit;

// Done![/pascal]

If you want more in depth information about all the other functions: Read