view src/audio/mint/SDL_mintaudio_stfa.c @ 2659:8da698bc1205 gsoc2008_audio_resampling

Fixed lots of bugs in FIR filtering. Fixed point code is closer to working, but there seems to be overflow in the FIR filter resulting in distortion.
author Aaron Wishnick <schnarf@gmail.com>
date Sun, 22 Jun 2008 00:36:35 +0000
parents 29e07f91bc1f
children 99210400e8b9
line wrap: on
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/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2004 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
*/
#include "SDL_config.h"

/*
	MiNT audio driver
	using XBIOS functions (STFA driver)

	Patrice Mandin
*/

/* Mint includes */
#include <mint/osbind.h>
#include <mint/falcon.h>
#include <mint/cookie.h>

#include "SDL_audio.h"
#include "../SDL_audio_c.h"
#include "../SDL_sysaudio.h"

#include "../../video/ataricommon/SDL_atarimxalloc_c.h"

#include "SDL_mintaudio.h"
#include "SDL_mintaudio_stfa.h"

/*--- Defines ---*/

#define MINT_AUDIO_DRIVER_NAME "mint_stfa"

/* Debug print info */
#define DEBUG_NAME "audio:stfa: "
#if 0
#define DEBUG_PRINT(what) \
	{ \
		printf what; \
	}
#else
#define DEBUG_PRINT(what)
#endif

/*--- Static variables ---*/

static unsigned long cookie_snd = 0;
static unsigned long cookie_mch = 0;
static cookie_stfa_t *cookie_stfa = NULL;

static const int freqs[16] = {
    4995, 6269, 7493, 8192,
    9830, 10971, 12538, 14985,
    16384, 19819, 21943, 24576,
    30720, 32336, 43885, 49152
};

static void
MINTSTFA_LockDevice(_THIS)
{
    /* Stop replay */
    void *oldpile = (void *) Super(0);
    cookie_stfa->sound_enable = STFA_PLAY_DISABLE;
    Super(oldpile);
}

static void
MINTSTFA_UnlockDevice(_THIS)
{
    /* Restart replay */
    void *oldpile = (void *) Super(0);
    cookie_stfa->sound_enable = STFA_PLAY_ENABLE | STFA_PLAY_REPEAT;
    Super(oldpile);
}

static void
MINTSTFA_CloseDevice(_THIS)
{
    if (this->hidden != NULL) {
        /* Stop replay */
        void *oldpile = (void *) Super(0);
        cookie_stfa->sound_enable = STFA_PLAY_DISABLE;
        Super(oldpile);

        /* Wait if currently playing sound */
        while (SDL_MintAudio_mutex != 0) {
        }

        /* Clear buffers */
        if (SDL_MintAudio_audiobuf[0]) {
            Mfree(SDL_MintAudio_audiobuf[0]);
            SDL_MintAudio_audiobuf[0] = SDL_MintAudio_audiobuf[1] = NULL;
        }

        SDL_free(this->hidden);
        this->hidden = NULL;
    }
}

static int
MINTSTFA_CheckAudio(_THIS)
{
    int i;

    DEBUG_PRINT((DEBUG_NAME "asked: %d bits, ",
                 SDL_AUDIO_BITSIZE(this->spec.format)));
    DEBUG_PRINT(("float=%d, ", SDL_AUDIO_ISFLOAT(this->spec.format)));
    DEBUG_PRINT(("signed=%d, ", SDL_AUDIO_ISSIGNED(this->spec.format)));
    DEBUG_PRINT(("big endian=%d, ",
                 SDL_AUDIO_ISBIGENDIAN(this->spec.format)));
    DEBUG_PRINT(("channels=%d, ", this->spec.channels));
    DEBUG_PRINT(("freq=%d\n", this->spec.freq));

    if (SDL_AUDIO_BITSIZE(this->spec.format) > 16) {
        this->spec.format = AUDIO_S16SYS;       /* clamp out int32/float32 ... */
    }

    if (this->spec.channels > 2) {
        this->spec.channels = 2;        /* no more than stereo! */
    }

    /* Check formats available */
    MINTAUDIO_freqcount = 0;
    for (i = 0; i < 16; i++) {
        SDL_MintAudio_AddFrequency(this, freqs[i], 0, i, -1);
    }

#if 1
    for (i = 0; i < MINTAUDIO_freqcount; i++) {
        DEBUG_PRINT((DEBUG_NAME "freq %d: %lu Hz, clock %lu, prediv %d\n",
                     i, MINTAUDIO_frequencies[i].frequency,
                     MINTAUDIO_frequencies[i].masterclock,
                     MINTAUDIO_frequencies[i].predivisor));
    }
#endif

    MINTAUDIO_numfreq = SDL_MintAudio_SearchFrequency(this, this->spec.freq);
    this->spec.freq = MINTAUDIO_frequencies[MINTAUDIO_numfreq].frequency;

    DEBUG_PRINT((DEBUG_NAME "obtained: %d bits, ",
                 SDL_AUDIO_BITSIZE(this->spec.format)));
    DEBUG_PRINT(("float=%d, ", SDL_AUDIO_ISFLOAT(this->spec.format)));
    DEBUG_PRINT(("signed=%d, ", SDL_AUDIO_ISSIGNED(this->spec.format)));
    DEBUG_PRINT(("big endian=%d, ",
                 SDL_AUDIO_ISBIGENDIAN(this->spec.format)));
    DEBUG_PRINT(("channels=%d, ", this->spec.channels));
    DEBUG_PRINT(("freq=%d\n", this->spec.freq));

    return 0;
}

static void
MINTSTFA_InitAudio(_THIS)
{
    void *buffer = SDL_MintAudio_audiobuf[SDL_MintAudio_numbuf];
    void *oldpile = (void *) Super(0);

    /* Stop replay */
    cookie_stfa->sound_enable = STFA_PLAY_DISABLE;

    /* Select replay format */
    cookie_stfa->sound_control =
        MINTAUDIO_frequencies[MINTAUDIO_numfreq].predivisor;
    if (SDL_AUDIO_BITSIZE(this->spec.format) == 8) {
        cookie_stfa->sound_control |= STFA_FORMAT_8BIT;
    } else {
        cookie_stfa->sound_control |= STFA_FORMAT_16BIT;
    }
    if (this->spec.channels == 2) {
        cookie_stfa->sound_control |= STFA_FORMAT_STEREO;
    } else {
        cookie_stfa->sound_control |= STFA_FORMAT_MONO;
    }
    if (SDL_AUDIO_ISSIGNED(this->spec.format) != 0) {
        cookie_stfa->sound_control |= STFA_FORMAT_SIGNED;
    } else {
        cookie_stfa->sound_control |= STFA_FORMAT_UNSIGNED;
    }
    if (SDL_AUDIO_ISBIGENDIAN(this->spec.format) != 0) {
        cookie_stfa->sound_control |= STFA_FORMAT_BIGENDIAN;
    } else {
        cookie_stfa->sound_control |= STFA_FORMAT_LITENDIAN;
    }

    /* Set buffer */
    cookie_stfa->sound_start = (unsigned long) buffer;
    cookie_stfa->sound_end = (unsigned long) (buffer + this->spec.size);

    /* Set interrupt */
    cookie_stfa->stfa_it = SDL_MintAudio_StfaInterrupt;

    /* Restart replay */
    cookie_stfa->sound_enable = STFA_PLAY_ENABLE | STFA_PLAY_REPEAT;

    Super(oldpile);

    DEBUG_PRINT((DEBUG_NAME "hardware initialized\n"));
}

static int
MINTSTFA_OpenDevice(_THIS, const char *devname, int iscapture)
{
    SDL_MintAudio_device = this;

    /* Check audio capabilities */
    if (MINTSTFA_CheckAudio(this) == -1) {
        return 0;
    }

    /* 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));

    SDL_CalculateAudioSpec(&this->spec);

    /* Allocate memory for audio buffers in DMA-able RAM */
    DEBUG_PRINT((DEBUG_NAME "buffer size=%d\n", this->spec.size));

    SDL_MintAudio_audiobuf[0] =
        Atari_SysMalloc(this->spec.size * 2, MX_STRAM);
    if (SDL_MintAudio_audiobuf[0] == NULL) {
        SDL_OutOfMemory();
        SDL_free(this->hidden);
        this->hidden = NULL;
        return 0;
    }
    SDL_MintAudio_audiobuf[1] = SDL_MintAudio_audiobuf[0] + this->spec.size;
    SDL_MintAudio_numbuf = 0;
    SDL_memset(SDL_MintAudio_audiobuf[0], this->spec.silence,
               this->spec.size * 2);
    SDL_MintAudio_audiosize = this->spec.size;
    SDL_MintAudio_mutex = 0;

    DEBUG_PRINT((DEBUG_NAME "buffer 0 at 0x%08x\n",
                 SDL_MintAudio_audiobuf[0]));
    DEBUG_PRINT((DEBUG_NAME "buffer 1 at 0x%08x\n",
                 SDL_MintAudio_audiobuf[1]));

    SDL_MintAudio_CheckFpu();

    /* Setup audio hardware */
    MINTSTFA_InitAudio(this);

    return 1;                   /* good to go. */
}


static int
MINTSTFA_Init(SDL_AudioDriverImpl * impl)
{
    /* Cookie _MCH present ? if not, assume ST machine */
    if (Getcookie(C__MCH, &cookie_mch) == C_NOTFOUND) {
        cookie_mch = MCH_ST;
    }

    /* Cookie _SND present ? if not, assume ST machine */
    if (Getcookie(C__SND, &cookie_snd) == C_NOTFOUND) {
        cookie_snd = SND_PSG;
    }

    /* Cookie STFA present ? */
    if (Getcookie(C_STFA, (long *) &cookie_stfa) != C_FOUND) {
        SDL_SetError(DEBUG_NAME "no STFA audio");
        return (0);
    }

    SDL_MintAudio_stfa = cookie_stfa;

    DEBUG_PRINT((DEBUG_NAME "STFA audio available!\n"));

    /* Set the function pointers */
    impl->OpenDevice = MINTSTFA_OpenDevice;
    impl->CloseDevice = MINTSTFA_CloseDevice;
    impl->LockDevice = MINTSTFA_LockDevice;
    impl->UnlockDevice = MINTSTFA_UnlockDevice;
    impl->OnlyHasDefaultOutputDevice = 1;
    impl->ProvidesOwnCallbackThread = 1;
    impl->SkipMixerLock = 1;

    return 1;
}

AudioBootStrap MINTAUDIO_STFA_bootstrap = {
    MINT_AUDIO_DRIVER_NAME, "MiNT STFA audio driver", MINTSTFA_Init, 0
};

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