view src/audio/baudio/SDL_beaudio.cc @ 1895:c121d94672cb

SDL 1.2 is moving to a branch, and SDL 1.3 is becoming the head.
author Sam Lantinga <slouken@libsdl.org>
date Mon, 10 Jul 2006 21:04:37 +0000
parents 376665398b25
children 46319c67b3d7
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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 the audio stream on BeOS */

#include <SoundPlayer.h>

#include "../../main/beos/SDL_BeApp.h"

extern "C"
{

#include "SDL_audio.h"
#include "../SDL_audio_c.h"
#include "../SDL_sysaudio.h"
#include "../../thread/beos/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)
    {
        SDL_free(device->hidden);
        SDL_free(device);
    }

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

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

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