view src/audio/baudio/SDL_beaudio.cc @ 956:4263beff9e38

Date: Mon, 30 Aug 2004 18:20:25 +0200 From: Joost Baas Subject: why call arts artsc? I, and a few other people at the mplayer-docs-mailinglist were wondering why you decided to call arts artsc. I understand usually users have nothing to do with libsdl, just developers, but because you can choose the audio-driver being used by mplayer, one of which is sdl, and you can also choose the sdl subdriver, it is necessary to have a well-known or logical name. artsc is not the logical choice, and it's very hard to look up the right name if you don't know what you're looking for.
author Sam Lantinga <slouken@libsdl.org>
date Fri, 17 Sep 2004 13:25:06 +0000
parents e8157fcb3114
children c9b51268668f
line wrap: on
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/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997  Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
    License as published by the Free Software Foundation; either
    version 2 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public
    License along with this library; if not, write to the Free
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

    Sam Lantinga
    slouken@libsdl.org
*/

#ifdef SAVE_RCSID
static char rcsid =
 "@(#) $Id$";
#endif

/* Allow access to the audio stream on BeOS */

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <SoundPlayer.h>

#include "SDL_BeApp.h"

extern "C" {

#include "SDL_audio.h"
#include "SDL_audio_c.h"
#include "SDL_sysaudio.h"
#include "SDL_systhread_c.h"
#include "SDL_beaudio.h"


/* Audio driver functions */
static int BE_OpenAudio(_THIS, SDL_AudioSpec *spec);
static void BE_WaitAudio(_THIS);
static void BE_PlayAudio(_THIS);
static Uint8 *BE_GetAudioBuf(_THIS);
static void BE_CloseAudio(_THIS);

/* Audio driver bootstrap functions */

static int Audio_Available(void)
{
	return(1);
}

static void Audio_DeleteDevice(SDL_AudioDevice *device)
{
	free(device->hidden);
	free(device);
}

static SDL_AudioDevice *Audio_CreateDevice(int devindex)
{
	SDL_AudioDevice *device;

	/* Initialize all variables that we clean on shutdown */
	device = (SDL_AudioDevice *)malloc(sizeof(SDL_AudioDevice));
	if ( device ) {
		memset(device, 0, (sizeof *device));
		device->hidden = (struct SDL_PrivateAudioData *)
				malloc((sizeof *device->hidden));
	}
	if ( (device == NULL) || (device->hidden == NULL) ) {
		SDL_OutOfMemory();
		if ( device ) {
			free(device);
		}
		return(0);
	}
	memset(device->hidden, 0, (sizeof *device->hidden));

	/* Set the function pointers */
	device->OpenAudio = BE_OpenAudio;
	device->WaitAudio = BE_WaitAudio;
	device->PlayAudio = BE_PlayAudio;
	device->GetAudioBuf = BE_GetAudioBuf;
	device->CloseAudio = BE_CloseAudio;

	device->free = Audio_DeleteDevice;

	return device;
}

AudioBootStrap BAUDIO_bootstrap = {
	"baudio", "BeOS BSoundPlayer",
	Audio_Available, Audio_CreateDevice
};

/* The BeOS callback for handling the audio buffer */
static void FillSound(void *device, void *stream, size_t len, 
					const media_raw_audio_format &format)
{
	SDL_AudioDevice *audio = (SDL_AudioDevice *)device;

	/* Silence the buffer, since it's ours */
	memset(stream, audio->spec.silence, len);

	/* Only do soemthing if audio is enabled */
	if ( ! audio->enabled )
		return;

	if ( ! audio->paused ) {
		if ( audio->convert.needed ) {
			SDL_mutexP(audio->mixer_lock);
			(*audio->spec.callback)(audio->spec.userdata,
				(Uint8 *)audio->convert.buf,audio->convert.len);
			SDL_mutexV(audio->mixer_lock);
			SDL_ConvertAudio(&audio->convert);
			memcpy(stream,audio->convert.buf,audio->convert.len_cvt);
		} else {
			SDL_mutexP(audio->mixer_lock);
			(*audio->spec.callback)(audio->spec.userdata,
						(Uint8 *)stream, len);
			SDL_mutexV(audio->mixer_lock);
		}
	}
	return;
}

/* Dummy functions -- we don't use thread-based audio */
void BE_WaitAudio(_THIS)
{
	return;
}
void BE_PlayAudio(_THIS)
{
	return;
}
Uint8 *BE_GetAudioBuf(_THIS)
{
	return(NULL);
}

void BE_CloseAudio(_THIS)
{
	if ( audio_obj ) {
		audio_obj->Stop();
		delete audio_obj;
		audio_obj = NULL;
	}

	/* Quit the Be Application, if there's nothing left to do */
	SDL_QuitBeApp();
}

int BE_OpenAudio(_THIS, SDL_AudioSpec *spec)
{
	media_raw_audio_format format;

	/* Initialize the Be Application, if it's not already started */
	if ( SDL_InitBeApp() < 0 ) {
		return(-1);
	}

	/* Parse the audio format and fill the Be raw audio format */
	format.frame_rate = (float)spec->freq;
	format.channel_count = spec->channels;
	switch (spec->format&~0x1000) {
		case AUDIO_S8:
			/* Signed 8-bit audio unsupported, convert to U8 */
			spec->format = AUDIO_U8;
		case AUDIO_U8:
			format.format = media_raw_audio_format::B_AUDIO_UCHAR;
			format.byte_order = 0;
			break;
		case AUDIO_U16:
			/* Unsigned 16-bit audio unsupported, convert to S16 */
			spec->format ^= 0x8000;
		case AUDIO_S16:
			format.format = media_raw_audio_format::B_AUDIO_SHORT;
			if ( spec->format & 0x1000 ) {
				format.byte_order = 1; /* Big endian */
			} else {
				format.byte_order = 2; /* Little endian */
			}
			break;
	}
	format.buffer_size = spec->samples;
	
	/* Calculate the final parameters for this audio specification */
	SDL_CalculateAudioSpec(spec);

	/* Subscribe to the audio stream (creates a new thread) */
	{ sigset_t omask;
		SDL_MaskSignals(&omask);
		audio_obj = new BSoundPlayer(&format, "SDL Audio", FillSound,
		                                                 NULL, _this);
		SDL_UnmaskSignals(&omask);
	}
	if ( audio_obj->Start() == B_NO_ERROR ) {
		audio_obj->SetHasData(true);
	} else {
		SDL_SetError("Unable to start Be audio");
		return(-1);
	}

	/* We're running! */
	return(1);
}

};	/* Extern C */