Help me modify my Sound Server

Ok, I have a "sound server" written in SDL, heres its code:

sndserv.h:

Code:

#include <SDL/SDL.h>
#include <stdio.h>
#include <stdlib.h>
#define null NULL

#define MAX_PLAYING_SOUNDS 10
#define VOLUME_PER_SOUND SDL_MIX_MAXVOLUME / 2

//Desired Audio Specs
#define FREQUENCY	44100;
#define FORMAT		AUDIO_S16
#define SAMPLES		4096
#define CHANNELS	2
#define CALLBACK	AudioCallback
#define USERDATA	NULL

static SDL_AudioSpec desired, obtained;

typedef struct Sound_s {
	Uint8 *samples;
	Uint32 length;
} Sound, *Sound_p;

typedef struct playing_s {
	int active;
	Sound_p sound;
	Uint32 position;
} playing_t, *playing_p;

static playing_t playing[MAX_PLAYING_SOUNDS];

void AudioCallback(void *user_data, Uint8 *audio, int length){
	int i;
	
	memset(audio, 0, length);
	
	for (i = 0; i < MAX_PLAYING_SOUNDS; i++){
		if (playing[i].active){
			Uint8 *sound_buf;
			Uint32 sound_len;
			
			sound_buf = playing[i].sound->samples;
			sound_buf += playing[i].position;
			
			if ((playing[i].position + length) > playing[i].sound->length){
				sound_len = playing[i].sound->length - playing[i].position;
			} else {
				sound_len = length;
			}
			
			SDL_MixAudio(audio, sound_buf, sound_len, VOLUME_PER_SOUND);
			
			playing[i].position += length;
			
			if (playing[i].position >= playing[i].sound->length){
				playing[i].active = 0;
			}
		}
	}
}

int LoadSound(char *filename, Sound_p sound){
	SDL_AudioSpec *spec = &obtained;
	SDL_AudioCVT cvt;
	SDL_AudioSpec loaded;
	Uint8 *new_buf;
	
	if (SDL_LoadWAV(filename, &loaded, &sound->samples, &sound->length) == null){
		printf("Unable to load sound: %s\n", SDL_GetError());
		return 1;
	}
	
	if (SDL_BuildAudioCVT(&cvt, loaded.format, loaded.channels, loaded.freq, spec->format, spec->channels, spec->freq) < 0){
		printf("Unable to convert sound: %s\n", SDL_GetError());
		return 1;
	}
	
	cvt.len = sound->length;
	new_buf = (Uint8 *)malloc(cvt.len * cvt.len_mult);
	if (new_buf == null){
		printf("Out of memory!\n");
		SDL_FreeWAV(sound->samples);
		return 1;
	}
	
	memcpy(new_buf, sound->samples, sound->length);
	
	cvt.buf = new_buf;
	if (SDL_ConvertAudio(&cvt) < 0){
		printf("Audio conversion error:%s\n", SDL_GetError());
		free(new_buf);
		SDL_FreeWAV(sound->samples);
		return 1;
	}
	
	SDL_FreeWAV(sound->samples);
	sound->samples = new_buf;
	sound->length = sound->length * cvt.len_mult;
	
	printf("%s was loaded and converted successfully.\n", filename);
	return 0;
}

void ClearPlayingSounds(void){
	int i;
	for (i = 0; i < MAX_PLAYING_SOUNDS; i++){
		playing[i].active = 0;
	}
}

int PlaySound(Sound_p sound){
	int i;
	for (i = 0; i < MAX_PLAYING_SOUNDS; i++){
		if (playing[i].active == 0){
			break;
		}
	}
	
	if (i == MAX_PLAYING_SOUNDS){
		return 1;
	}
	
	SDL_LockAudio();
	playing[i].active = 1;
	playing[i].sound = sound;
	playing[i].position = 0;
	SDL_UnlockAudio();
	
	return 0;
}


int sndserv_init(){
	desired.freq = FREQUENCY;
	desired.format = FORMAT;
	desired.samples = SAMPLES;
	desired.channels = CHANNELS;
	desired.callback = CALLBACK;
	desired.userdata = USERDATA;
	
	if (SDL_OpenAudio(&desired, &obtained) < 0){
		printf("Unable to open Audio Device");
		return 1;
	}
	
	atexit(SDL_CloseAudio);
	
	ClearPlayingSounds();
	
	SDL_PauseAudio(0);
}

int sndserv_end(){
	SDL_PauseAudio(1);
	SDL_LockAudio();
}

int FreeSound(Sound_p snd){
	SDL_LockAudio();
	free(snd->samples);
	SDL_UnlockAudio();
}

ok heres how a simple example works:

sndtest.c:

Code:

#include <SDL/SDL.h>
#include "sndserv.h"

int main(int argc, char *argv[]){
	Sound explosion;
	
	SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO);
	
	atexit(SDL_Quit);
	
	sndserv_init();
	
	LoadSound("sound/explosion.wav", &explosion);
	
	PlaySound(&explosion);
	
	SDL_Delay(5000);
	
	sndserv_end();
	
	FreeSound(&explosion);
	
	return 0;
}

As you can see you load sounds with LoadSound

How could I modify the function so that LoadSound works like this:

explosion = LoadSound("sound/explosion.wav");

Any help would be greatly appreaciated.

> explosion = LoadSound("sound/explosion.wav");
The first question is why are you ignoring the return result at present, and how do you propose to return error values with this new interface.

I was ignoring the result because this was a simple demo of the "server" and because I forgot.

I plan on giving an error by returning a null pointer.

> #define FREQUENCY 44100;
This is very poor - remove the trailing ;

Heh, typo demon. Thanks