src/audio/fusionsound/SDL_fsaudio.c
author Sam Lantinga <slouken@libsdl.org>
Thu, 01 Jan 2009 21:34:22 +0000
changeset 2947 fec0db6c44b7
child 3230 816a7a65a59a
permissions -rw-r--r--
Date: Thu, 01 Jan 2009 21:32:12 +0100 From: Couriersud Subject: Fusionsound audio driver attached is a diff containing a audio driver for the FusionSound library. This sound library is closely related to DirectFB and uses the same transport (fusion) as DirectFB when running applications "remote", i.e. over the network. As such, it natively redirects sound where DirectFB redirects video. This may be handy for everyone using SDL over DirectFB.

/*
    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 "SDL_config.h"

/* Allow access to a raw mixing buffer */

#ifdef HAVE_SIGNAL_H
#include <signal.h>
#endif
#include <unistd.h>

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

//#define SDL_AUDIO_DRIVER_FUSIONSOUND_DYNAMIC "libfusionsound.so"

#ifdef SDL_AUDIO_DRIVER_FUSIONSOUND_DYNAMIC
#include "SDL_name.h"
#include "SDL_loadso.h"
#else
#define SDL_NAME(X)	X
#endif

/* The tag name used by fusionsoundc audio */
#define SDL_FS_DRIVER_NAME         "fusionsound"
/* Buffers to use - more than 2 gives a lot of latency */
#define FUSION_BUFFERS				(2)

#ifdef SDL_AUDIO_DRIVER_FUSIONSOUND_DYNAMIC

static const char *fs_library = SDL_AUDIO_DRIVER_FUSIONSOUND_DYNAMIC;
static void *fs_handle = NULL;

static DirectResult(*SDL_NAME(FusionSoundInit)) (int *argc, char *(*argv[]));
static DirectResult(*SDL_NAME(FusionSoundCreate)) (IFusionSound **
                                                   ret_interface);

#define SDL_FS_SYM(x) { #x, (void **) (char *) &SDL_NAME(x) }
static struct
{
    const char *name;
    void **func;
} fs_functions[] = {
/* *INDENT-OFF* */
    SDL_FS_SYM(FusionSoundInit),
    SDL_FS_SYM(FusionSoundCreate),
/* *INDENT-ON* */
};

#undef SDL_FS_SYM

static void
UnloadFusionSoundLibrary()
{
    if (fs_handle != NULL) {
        SDL_UnloadObject(fs_handle);
        fs_handle = NULL;
    }
}

static int
LoadFusionSoundLibrary(void)
{
    int i, retval = -1;

    if (fs_handle == NULL) {
        fs_handle = SDL_LoadObject(fs_library);
        if (fs_handle != NULL) {
            retval = 0;
            for (i = 0; i < SDL_arraysize(fs_functions); ++i) {
                *fs_functions[i].func =
                    SDL_LoadFunction(fs_handle, fs_functions[i].name);
                if (!*fs_functions[i].func) {
                    retval = -1;
                    UnloadFusionSoundLibrary();
                    break;
                }
            }
        }
    }

    return retval;
}

#else

static void
UnloadFusionSoundLibrary()
{
    return;
}

static int
LoadFusionSoundLibrary(void)
{
    return 0;
}

#endif /* SDL_AUDIO_DRIVER_FUSIONSOUND_DYNAMIC */

/* This function waits until it is possible to write a full sound buffer */
static void
SDL_FS_WaitDevice(_THIS)
{
    this->hidden->stream->Wait(this->hidden->stream,
                               this->hidden->mixsamples);
}

static void
SDL_FS_PlayDevice(_THIS)
{
    DirectResult ret;

    ret = this->hidden->stream->Write(this->hidden->stream,
                                      this->hidden->mixbuf,
                                      this->hidden->mixsamples);
    /* If we couldn't write, assume fatal error for now */
    if (ret) {
        this->enabled = 0;
    }
#ifdef DEBUG_AUDIO
    fprintf(stderr, "Wrote %d bytes of audio data\n", this->hidden->mixlen);
#endif
}

static void
SDL_FS_WaitDone(_THIS)
{
    this->hidden->stream->Wait(this->hidden->stream,
                               this->hidden->mixsamples * FUSION_BUFFERS);
}


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


static void
SDL_FS_CloseDevice(_THIS)
{
    if (this->hidden != NULL) {
        if (this->hidden->mixbuf != NULL) {
            SDL_FreeAudioMem(this->hidden->mixbuf);
            this->hidden->mixbuf = NULL;
        }
        if (this->hidden->stream) {
            this->hidden->stream->Release(this->hidden->stream);
            this->hidden->stream = NULL;
        }
        if (this->hidden->fs) {
            this->hidden->fs->Release(this->hidden->fs);
            this->hidden->fs = NULL;
        }
        SDL_free(this->hidden);
        this->hidden = NULL;
    }
}


static int
SDL_FS_OpenDevice(_THIS, const char *devname, int iscapture)
{
    int bytes;
    SDL_AudioFormat test_format = 0, format = 0;
    FSSampleFormat fs_format;
    FSStreamDescription desc;
    DirectResult ret;

    /* 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));

    /* Try for a closest match on audio format */
    for (test_format = SDL_FirstAudioFormat(this->spec.format);
         !format && test_format;) {
#ifdef DEBUG_AUDIO
        fprintf(stderr, "Trying format 0x%4.4x\n", test_format);
#endif
        switch (test_format) {
        case AUDIO_U8:
            fs_format = FSSF_U8;
            bytes = 1;
            format = 1;
            break;
        case AUDIO_S16SYS:
            fs_format = FSSF_S16;
            bytes = 2;
            format = 1;
            break;
        case AUDIO_S32SYS:
            fs_format = FSSF_S32;
            bytes = 4;
            format = 1;
            break;
        case AUDIO_F32SYS:
            fs_format = FSSF_FLOAT;
            bytes = 4;
            format = 1;
            break;
        default:
            format = 0;
            break;
        }
        if (!format) {
            test_format = SDL_NextAudioFormat();
        }
    }

    if (format == 0) {
        SDL_FS_CloseDevice(this);
        SDL_SetError("Couldn't find any hardware audio formats");
        return 0;
    }
    this->spec.format = test_format;

    /* Retrieve the main sound interface. */
    ret = SDL_NAME(FusionSoundCreate) (&this->hidden->fs);
    if (ret) {
        SDL_FS_CloseDevice(this);
        SDL_SetError("Unable to initialize FusionSound: %d", ret);
        return 0;
    }

    this->hidden->mixsamples = this->spec.size / bytes / this->spec.channels;

    /* Fill stream description. */
    desc.flags = FSSDF_SAMPLERATE | FSSDF_BUFFERSIZE |
        FSSDF_CHANNELS | FSSDF_SAMPLEFORMAT | FSSDF_PREBUFFER;
    desc.samplerate = this->spec.freq;
    desc.buffersize = this->spec.size * FUSION_BUFFERS;
    desc.channels = this->spec.channels;
    desc.prebuffer = 10;
    desc.sampleformat = fs_format;

    ret =
        this->hidden->fs->CreateStream(this->hidden->fs, &desc,
                                       &this->hidden->stream);
    if (ret) {
        SDL_FS_CloseDevice(this);
        SDL_SetError("Unable to create FusionSoundStream: %d", ret);
        return 0;
    }

    /* See what we got */
    desc.flags = FSSDF_SAMPLERATE | FSSDF_BUFFERSIZE |
        FSSDF_CHANNELS | FSSDF_SAMPLEFORMAT;
    ret = this->hidden->stream->GetDescription(this->hidden->stream, &desc);

    this->spec.freq = desc.samplerate;
    this->spec.size =
        desc.buffersize / FUSION_BUFFERS * bytes * desc.channels;
    this->spec.channels = desc.channels;

    /* Calculate the final parameters for this audio specification */
    SDL_CalculateAudioSpec(&this->spec);

    /* Allocate mixing buffer */
    this->hidden->mixlen = this->spec.size;
    this->hidden->mixbuf = (Uint8 *) SDL_AllocAudioMem(this->hidden->mixlen);
    if (this->hidden->mixbuf == NULL) {
        SDL_FS_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 void
SDL_FS_Deinitialize(void)
{
    UnloadFusionSoundLibrary();
}


static int
SDL_FS_Init(SDL_AudioDriverImpl * impl)
{
    if (LoadFusionSoundLibrary() < 0) {
        return 0;
    } else {
        DirectResult ret;

        ret = SDL_NAME(FusionSoundInit) (NULL, NULL);
        if (ret) {
            UnloadFusionSoundLibrary();
            SDL_SetError
                ("FusionSound: SDL_FS_init failed (FusionSoundInit: %d)",
                 ret);
            return 0;
        }
    }

    /* Set the function pointers */
    impl->OpenDevice = SDL_FS_OpenDevice;
    impl->PlayDevice = SDL_FS_PlayDevice;
    impl->WaitDevice = SDL_FS_WaitDevice;
    impl->GetDeviceBuf = SDL_FS_GetDeviceBuf;
    impl->CloseDevice = SDL_FS_CloseDevice;
    impl->WaitDone = SDL_FS_WaitDone;
    impl->Deinitialize = SDL_FS_Deinitialize;
    impl->OnlyHasDefaultOutputDevice = 1;

    return 1;
}


AudioBootStrap FUSIONSOUND_bootstrap = {
    SDL_FS_DRIVER_NAME, "FusionSound", SDL_FS_Init, 0
};

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