view src/audio/dmedia/SDL_irixaudio.c @ 1662:782fd950bd46 SDL-1.3

Revamp of the video system in progress - adding support for multiple displays, multiple windows, and a full video mode selection API. WARNING: None of the video drivers have been updated for the new API yet! The API is still under design and very fluid. The code is now run through a consistent indent format: indent -i4 -nut -nsc -br -ce The headers are being converted to automatically generate doxygen documentation.
author Sam Lantinga <slouken@libsdl.org>
date Sun, 28 May 2006 13:04:16 +0000
parents d910939febfa
children 4da1ee79c9af
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/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2006 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 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
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga
    slouken@libsdl.org
*/
#include "SDL_config.h"

/* Allow access to a raw mixing buffer (For IRIX 6.5 and higher) */
/* patch for IRIX 5 by Georg Schwarz 18/07/2004 */

#include "SDL_timer.h"
#include "SDL_audio.h"
#include "../SDL_audiomem.h"
#include "../SDL_audio_c.h"
#include "SDL_irixaudio.h"


#ifndef AL_RESOURCE             /* as a test whether we use the old IRIX audio libraries */
#define OLD_IRIX_AUDIO
#define alClosePort(x) ALcloseport(x)
#define alFreeConfig(x) ALfreeconfig(x)
#define alGetFillable(x) ALgetfillable(x)
#define alNewConfig() ALnewconfig()
#define alOpenPort(x,y,z) ALopenport(x,y,z)
#define alSetChannels(x,y) ALsetchannels(x,y)
#define alSetQueueSize(x,y) ALsetqueuesize(x,y)
#define alSetSampFmt(x,y) ALsetsampfmt(x,y)
#define alSetWidth(x,y) ALsetwidth(x,y)
#endif

/* Audio driver functions */
static int AL_OpenAudio (_THIS, SDL_AudioSpec * spec);
static void AL_WaitAudio (_THIS);
static void AL_PlayAudio (_THIS);
static Uint8 *AL_GetAudioBuf (_THIS);
static void AL_CloseAudio (_THIS);

/* Audio driver bootstrap functions */

static int
Audio_Available (void)
{
    return 1;
}

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

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

    /* Initialize all variables that we clean on shutdown */
    this = (SDL_AudioDevice *) SDL_malloc (sizeof (SDL_AudioDevice));
    if (this) {
        SDL_memset (this, 0, (sizeof *this));
        this->hidden = (struct SDL_PrivateAudioData *)
            SDL_malloc ((sizeof *this->hidden));
    }
    if ((this == NULL) || (this->hidden == NULL)) {
        SDL_OutOfMemory ();
        if (this) {
            SDL_free (this);
        }
        return (0);
    }
    SDL_memset (this->hidden, 0, (sizeof *this->hidden));

    /* Set the function pointers */
    this->OpenAudio = AL_OpenAudio;
    this->WaitAudio = AL_WaitAudio;
    this->PlayAudio = AL_PlayAudio;
    this->GetAudioBuf = AL_GetAudioBuf;
    this->CloseAudio = AL_CloseAudio;

    this->free = Audio_DeleteDevice;

    return this;
}

AudioBootStrap DMEDIA_bootstrap = {
    "AL", "IRIX DMedia audio",
    Audio_Available, Audio_CreateDevice
};


void static
AL_WaitAudio (_THIS)
{
    Sint32 timeleft;

    timeleft = this->spec.samples - alGetFillable (audio_port);
    if (timeleft > 0) {
        timeleft /= (this->spec.freq / 1000);
        SDL_Delay ((Uint32) timeleft);
    }
}

static void
AL_PlayAudio (_THIS)
{
    /* Write the audio data out */
    if (alWriteFrames (audio_port, mixbuf, this->spec.samples) < 0) {
        /* Assume fatal error, for now */
        this->enabled = 0;
    }
}

static Uint8 *
AL_GetAudioBuf (_THIS)
{
    return (mixbuf);
}

static void
AL_CloseAudio (_THIS)
{
    if (mixbuf != NULL) {
        SDL_FreeAudioMem (mixbuf);
        mixbuf = NULL;
    }
    if (audio_port != NULL) {
        alClosePort (audio_port);
        audio_port = NULL;
    }
}

static int
AL_OpenAudio (_THIS, SDL_AudioSpec * spec)
{
    ALconfig audio_config;
#ifdef OLD_IRIX_AUDIO
    long audio_param[2];
#else
    ALpv audio_param;
#endif
    int width;

    /* Determine the audio parameters from the AudioSpec */
    switch (spec->format & 0xFF) {

    case 8:
        {                       /* Signed 8 bit audio data */
            spec->format = AUDIO_S8;
            width = AL_SAMPLE_8;
        }
        break;

    case 16:
        {                       /* Signed 16 bit audio data */
            spec->format = AUDIO_S16MSB;
            width = AL_SAMPLE_16;
        }
        break;

    default:
        {
            SDL_SetError ("Unsupported audio format");
            return (-1);
        }
    }

    /* Update the fragment size as size in bytes */
    SDL_CalculateAudioSpec (spec);

    /* Set output frequency */
#ifdef OLD_IRIX_AUDIO
    audio_param[0] = AL_OUTPUT_RATE;
    audio_param[1] = spec->freq;
    if (ALsetparams (AL_DEFAULT_DEVICE, audio_param, 2) < 0) {
#else
    audio_param.param = AL_RATE;
    audio_param.value.i = spec->freq;
    if (alSetParams (AL_DEFAULT_OUTPUT, &audio_param, 1) < 0) {
#endif
        SDL_SetError ("alSetParams failed");
        return (-1);
    }

    /* Open the audio port with the requested frequency */
    audio_port = NULL;
    audio_config = alNewConfig ();
    if (audio_config &&
        (alSetSampFmt (audio_config, AL_SAMPFMT_TWOSCOMP) >= 0) &&
        (alSetWidth (audio_config, width) >= 0) &&
        (alSetQueueSize (audio_config, spec->samples * 2) >= 0) &&
        (alSetChannels (audio_config, spec->channels) >= 0)) {
        audio_port = alOpenPort ("SDL audio", "w", audio_config);
    }
    alFreeConfig (audio_config);
    if (audio_port == NULL) {
        SDL_SetError ("Unable to open audio port");
        return (-1);
    }

    /* Allocate mixing buffer */
    mixbuf = (Uint8 *) SDL_AllocAudioMem (spec->size);
    if (mixbuf == NULL) {
        SDL_OutOfMemory ();
        return (-1);
    }
    SDL_memset (mixbuf, spec->silence, spec->size);

    /* We're ready to rock and roll. :-) */
    return (0);
}

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