view src/audio/dmedia/SDL_irixaudio.c @ 2938:2929ed239d2a

Adjusted default choice of audio driver. If a driver can definitely see available devices, it is chosen. Otherwise, we'll take the first driver that initializes but saw no devices...this might be because it can't enumerate them, or there really aren't any available. This prevents the dsp driver from hogging control when there are no /dev/dsp* nodes (for example, on a Linux box with ALSA and no OSS emulation).
author Ryan C. Gordon <icculus@icculus.org>
date Thu, 01 Jan 2009 07:54:58 +0000
parents 99210400e8b9
children f7b03b6838cb
line wrap: on
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/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2009 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 <errno.h>
#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

void static
IRIXAUDIO_WaitDevice(_THIS)
{
    Sint32 timeleft;

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

static void
IRIXAUDIO_PlayDevice(_THIS)
{
    /* Write the audio data out */
    ALport port = this->hidden->audio_port;
    Uint8 *mixbuf = this->hidden->mixbuf;
    if (alWriteFrames(port, mixbuf, this->spec.samples) < 0) {
        /* Assume fatal error, for now */
        this->enabled = 0;
    }
}

static Uint8 *
IRIXAUDIO_GetDeviceBuf(_THIS)
{
    return (this->hidden->mixbuf);
}

static void
IRIXAUDIO_CloseDevice(_THIS)
{
    if (this->hidden != NULL) {
        if (this->hidden->mixbuf != NULL) {
            SDL_FreeAudioMem(this->hidden->mixbuf);
            this->hidden->mixbuf = NULL;
        }
        if (this->hidden->audio_port != NULL) {
            alClosePort(this->hidden->audio_port);
            this->hidden->audio_port = NULL;
        }
        SDL_free(this->hidden);
        this->hidden = NULL;
    }
}

static int
IRIXAUDIO_OpenDevice(_THIS, const char *devname, int iscapture)
{
    SDL_AudioFormat test_format = SDL_FirstAudioFormat(this->spec.format);
    long width = 0;
    long fmt = 0;
    int valid = 0;

    /* !!! FIXME: Handle multiple devices and capture? */

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

#ifdef OLD_IRIX_AUDIO
    {
        long audio_param[2];
        audio_param[0] = AL_OUTPUT_RATE;
        audio_param[1] = this->spec.freq;
        valid = (ALsetparams(AL_DEFAULT_DEVICE, audio_param, 2) < 0);
    }
#else
    {
        ALpv audio_param;
        audio_param.param = AL_RATE;
        audio_param.value.i = this->spec.freq;
        valid = (alSetParams(AL_DEFAULT_OUTPUT, &audio_param, 1) < 0);
    }
#endif

    while ((!valid) && (test_format)) {
        valid = 1;
        this->spec.format = test_format;

        switch (test_format) {
        case AUDIO_S8:
            width = AL_SAMPLE_8;
            fmt = AL_SAMPFMT_TWOSCOMP;
            break;

        case AUDIO_S16SYS:
            width = AL_SAMPLE_16;
            fmt = AL_SAMPFMT_TWOSCOMP;
            break;

        case AUDIO_F32SYS:
            width = 0;          /* not used here... */
            fmt = AL_SAMPFMT_FLOAT;
            break;

            /* Docs say there is int24, but not int32.... */

        default:
            valid = 0;
            test_format = SDL_NextAudioFormat();
            break;
        }

        if (valid) {
            ALconfig audio_config = alNewConfig();
            valid = 0;
            if (audio_config) {
                if (alSetChannels(audio_config, this->spec.channels) < 0) {
                    if (this->spec.channels > 2) {      /* can't handle > stereo? */
                        this->spec.channels = 2;        /* try again below. */
                    }
                }

                if ((alSetSampFmt(audio_config, fmt) >= 0) &&
                    ((!width) || (alSetWidth(audio_config, width) >= 0)) &&
                    (alSetQueueSize(audio_config, this->spec.samples * 2) >=
                     0)
                    && (alSetChannels(audio_config, this->spec.channels) >=
                        0)) {

                    this->hidden->audio_port = alOpenPort("SDL audio", "w",
                                                          audio_config);
                    if (this->hidden->audio_port == NULL) {
                        /* docs say AL_BAD_CHANNELS happens here, too. */
                        int err = oserror();
                        if (err == AL_BAD_CHANNELS) {
                            this->spec.channels = 2;
                            alSetChannels(audio_config, this->spec.channels);
                            this->hidden->audio_port =
                                alOpenPort("SDL audio", "w", audio_config);
                        }
                    }

                    if (this->hidden->audio_port != NULL) {
                        valid = 1;
                    }
                }

                alFreeConfig(audio_config);
            }
        }
    }

    if (!valid) {
        IRIXAUDIO_CloseDevice(this);
        SDL_SetError("Unsupported audio format");
        return 0;
    }

    /* Update the fragment size as size in bytes */
    SDL_CalculateAudioSpec(&this->spec);

    /* Allocate mixing buffer */
    this->hidden->mixbuf = (Uint8 *) SDL_AllocAudioMem(this->spec.size);
    if (this->hidden->mixbuf == NULL) {
        IRIXAUDIO_CloseDevice(this);
        SDL_OutOfMemory();
        return 0;
    }
    SDL_memset(this->hidden->mixbuf, this->spec.silence, this->spec.size);

    /* We're ready to rock and roll. :-) */
    return 1;
}

static int
IRIXAUDIO_Init(SDL_AudioDriverImpl * impl)
{
    /* Set the function pointers */
    impl->OpenDevice = DSP_OpenDevice;
    impl->PlayDevice = DSP_PlayDevice;
    impl->WaitDevice = DSP_WaitDevice;
    impl->GetDeviceBuf = DSP_GetDeviceBuf;
    impl->CloseDevice = DSP_CloseDevice;
    impl->OnlyHasDefaultOutputDevice = 1;       /* !!! FIXME: not true, I think. */

    return 1;
}

AudioBootStrap IRIXAUDIO_bootstrap = {
    "AL", "IRIX DMedia audio", IRIXAUDIO_Init, 0
};

/* vi: set ts=4 sw=4 expandtab: */