view src/audio/baudio/SDL_beaudio.cc @ 1199:2d6dc7de1145

From: Mike Frysinger <vapier@gentoo.org> To: sdl@libsdl.org Date: Sun, 11 Dec 2005 22:57:37 -0500 Subject: [SDL] exec stack in libsdl update i posted back in September a patch to remove executable stacks: http://www.devolution.com/pipermail/sdl/2005-September/070626.html later in November, a similar patch was merged it seems: http://www.libsdl.org/cgi/cvsweb.cgi/SDL12/src/hermes/mmx_main.asm however, this lacks the additional output format checks that i posted in my patch ... this isnt a problem if the hermes asm code is only ever used to produce ELF objects, but if this is not true, then the additional checks in my original patch will need to be merged -mike
author Ryan C. Gordon <icculus@icculus.org>
date Mon, 12 Dec 2005 09:13:12 +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 */