view src/audio/mint/SDL_mintaudio_mcsn.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 (MacSound compatible driver)

	Patrice Mandin
*/

#include <support.h>

/* 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_mcsn.h"

/*--- Defines ---*/

#define MINT_AUDIO_DRIVER_NAME "mint_mcsn"

/* Debug print info */
#define DEBUG_NAME "audio:mcsn: "
#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_mcsn_t *cookie_mcsn = NULL;

static void
MINTMCSN_LockDevice(_THIS)
{
    /* Stop replay */
    Buffoper(0);
}

static void
MINTMCSN_UnlockDevice(_THIS)
{
    /* Restart replay */
    Buffoper(SB_PLA_ENA | SB_PLA_RPT);
}

static void
MINTMCSN_CloseDevice(_THIS)
{
    if (this->hidden != NULL) {
        /* Stop replay */
        SDL_MintAudio_WaitThread();
        Buffoper(0);

        if (!SDL_MintAudio_mint_present) {
            /* Uninstall interrupt */
            Jdisint(MFP_DMASOUND);
        }

        /* 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;
        }

        /* Unlock sound system */
        Unlocksnd();

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

static int
MINTMCSN_CheckAudio(_THIS)
{
    int i;
    unsigned long masterclock, masterprediv;

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

    /* Check formats available */
    MINTAUDIO_freqcount = 0;
    switch (cookie_mcsn->play) {
    case MCSN_ST:
        this->spec.channels = 1;
        this->spec.format = AUDIO_S8;   /* FIXME: is it signed or unsigned ? */
        SDL_MintAudio_AddFrequency(this, 12500, 0, 0, -1);
        break;
    case MCSN_TT:              /* Also STE, Mega STE */
        this->spec.format = AUDIO_S8;
        masterclock = MASTERCLOCK_STE;
        masterprediv = MASTERPREDIV_STE;
        if ((cookie_mch >> 16) == MCH_TT) {
            masterclock = MASTERCLOCK_TT;
            masterprediv = MASTERPREDIV_TT;
        }
        for (i = 0; i < 4; i++) {
            SDL_MintAudio_AddFrequency(this,
                                       masterclock / (masterprediv *
                                                      (1 << i)),
                                       masterclock, 3 - i, -1);
        }
        break;
    case MCSN_FALCON:          /* Also Mac */
        for (i = 1; i < 12; i++) {
            /* Remove unusable Falcon codec predivisors */
            if ((i == 6) || (i == 8) || (i == 10)) {
                continue;
            }
            SDL_MintAudio_AddFrequency(this,
                                       MASTERCLOCK_FALCON1 /
                                       (MASTERPREDIV_FALCON * (i + 1)),
                                       CLK25M, i + 1, -1);
        }
        if (cookie_mcsn->res1 != 0) {
            for (i = 1; i < 4; i++) {
                SDL_MintAudio_AddFrequency(this,
                                           (cookie_mcsn->res1) /
                                           (MASTERPREDIV_FALCON *
                                            (1 << i)), CLKEXT,
                                           (1 << i) - 1, -1);
            }
        }
        this->spec.format |= SDL_AUDIO_MASK_SIGNED;     /* Audio is always signed */
        if ((SDL_AUDIO_BITSIZE(this->spec.format)) == 16) {
            this->spec.format |= SDL_AUDIO_MASK_ENDIAN; /* Audio is always big endian */
            this->spec.channels = 2;    /* 16 bits always stereo */
        }
        break;
    }

#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
MINTMCSN_InitAudio(_THIS)
{
    int channels_mode, prediv, dmaclock;
    void *buffer;

    /* Stop currently playing sound */
    SDL_MintAudio_quit_thread = SDL_FALSE;
    SDL_MintAudio_thread_finished = SDL_TRUE;
    SDL_MintAudio_WaitThread();
    Buffoper(0);

    /* Set replay tracks */
    Settracks(0, 0);
    Setmontracks(0);

    /* Select replay format */
    channels_mode = STEREO16;
    switch (SDL_AUDIO_BITSIZE(this->spec.format)) {
    case 8:
        if (this->spec.channels == 2) {
            channels_mode = STEREO8;
        } else {
            channels_mode = MONO8;
        }
        break;
    }
    if (Setmode(channels_mode) < 0) {
        DEBUG_PRINT((DEBUG_NAME "Setmode() failed\n"));
    }

    dmaclock = MINTAUDIO_frequencies[MINTAUDIO_numfreq].masterclock;
    prediv = MINTAUDIO_frequencies[MINTAUDIO_numfreq].predivisor;
    switch (cookie_mcsn->play) {
    case MCSN_TT:
        Devconnect(DMAPLAY, DAC, CLK25M, CLKOLD, 1);
        Soundcmd(SETPRESCALE, prediv);
        DEBUG_PRINT((DEBUG_NAME "STE/TT prescaler selected\n"));
        break;
    case MCSN_FALCON:
        Devconnect(DMAPLAY, DAC, dmaclock, prediv, 1);
        DEBUG_PRINT((DEBUG_NAME "Falcon prescaler selected\n"));
        break;
    }

    /* Set buffer */
    buffer = SDL_MintAudio_audiobuf[SDL_MintAudio_numbuf];
    if (Setbuffer(0, buffer, buffer + this->spec.size) < 0) {
        DEBUG_PRINT((DEBUG_NAME "Setbuffer() failed\n"));
    }

    if (SDL_MintAudio_mint_present) {
        SDL_MintAudio_thread_pid = tfork(SDL_MintAudio_Thread, 0);
    } else {
        /* Install interrupt */
        Jdisint(MFP_DMASOUND);
        Xbtimer(XB_TIMERA, 8, 1, SDL_MintAudio_XbiosInterrupt);
        Jenabint(MFP_DMASOUND);

        if (Setinterrupt(SI_TIMERA, SI_PLAY) < 0) {
            DEBUG_PRINT((DEBUG_NAME "Setinterrupt() failed\n"));
        }
    }

    /* Go */
    Buffoper(SB_PLA_ENA | SB_PLA_RPT);
    DEBUG_PRINT((DEBUG_NAME "hardware initialized\n"));
}

static int
MINTMCSN_OpenDevice(_THIS, const char *devname, int iscapture)
{
    /* Lock sound system */
    if (Locksnd() != 1) {
        SDL_SetError("MINTMCSN_OpenDevice: Audio system already in use");
        return 0;
    }

    SDL_MintAudio_device = this;

    /* Check audio capabilities */
    if (MINTMCSN_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_free(this->hidden);
        this->hidden = NULL;
        SDL_OutOfMemory();
        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 */
    MINTMCSN_InitAudio(this);

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

static int
MINTMCSN_Init(SDL_AudioDriverImpl * impl)
{
    unsigned long dummy = 0;

    SDL_MintAudio_mint_present = (Getcookie(C_MiNT, &dummy) == C_FOUND);

    /* We can't use XBIOS in interrupt with Magic, don't know about thread */
    if (Getcookie(C_MagX, &dummy) == C_FOUND) {
        return 0;
    }

    /* 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;
    }

    /* Check if we have 16 bits audio */
    if ((cookie_snd & SND_16BIT) == 0) {
        SDL_SetError(DEBUG_NAME "no 16-bit sound");
        return 0;
    }

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

    /* Check if interrupt at end of replay */
    if (cookie_mcsn->pint == 0) {
        SDL_SetError(DEBUG_NAME "no interrupt at end of replay");
        return 0;
    }

    /* Check if audio is lockable */
    if (Locksnd() != 1) {
        SDL_SetError(DEBUG_NAME "audio locked by other application");
        return 0;
    }

    Unlocksnd();

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

    /* Set the function pointers */
    impl->OpenDevice = MINTMCSN_OpenDevice;
    impl->CloseDevice = MINTMCSN_CloseDevice;
    impl->LockDevice = MINTMCSN_LockDevice;
    impl->UnlockDevice = MINTMCSN_UnlockDevice;
    impl->OnlyHasDefaultOutputDevice = 1;
    impl->ProvidesOwnCallbackThread = 1;
    impl->SkipMixerLock = 1;

    return 1;
}

AudioBootStrap MINTAUDIO_MCSN_bootstrap = {
    MINT_AUDIO_DRIVER_NAME, "MiNT MCSN audio driver", MINTMCSN_Init, 0
};

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