view src/audio/mint/SDL_mintaudio_dma8.c @ 2661:d38309be5178 gsoc2008_audio_resampling

The windowed sinc filter generation code seems to be working fine. The FIR filtering code is also now working reasonably well. Occasionally the FIR filter will pop, but setting the normalization factor lower seems to help this. I suspect the problem is in the fixed point multiply/add. I also have a hunch the zero stuffing/sample discarding code is not correct, and I'll look at that soon to get it sorted out.
author Aaron Wishnick <schnarf@gmail.com>
date Wed, 02 Jul 2008 08:04:50 +0000
parents 29e07f91bc1f
children 99210400e8b9
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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 DMA 8bits (hardware access)

	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_dma8.h"

/*--- Defines ---*/

#define MINT_AUDIO_DRIVER_NAME "mint_dma8"

/* Debug print info */
#define DEBUG_NAME "audio:dma8: "
#if 0
#define DEBUG_PRINT(what) \
	{ \
		printf what; \
	}
#else
#define DEBUG_PRINT(what)
#endif

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

static unsigned long cookie_snd, cookie_mch;

static void
MINTDMA8_LockDevice(_THIS)
{
    void *oldpile;

    /* Stop replay */
    oldpile = (void *) Super(0);
    DMAAUDIO_IO.control = 0;
    Super(oldpile);
}

static void
MINTDMA8_UnlockDevice(_THIS)
{
    void *oldpile;

    /* Restart replay */
    oldpile = (void *) Super(0);
    DMAAUDIO_IO.control = 3;
    Super(oldpile);
}

static void
MINTDMA8_CloseDevice(_THIS)
{
    if (this->hidden != NULL) {
        /* Stop replay */
        void *oldpile = (void *) Super(0);

        DMAAUDIO_IO.control = 0;
        Super(oldpile);

        DEBUG_PRINT((DEBUG_NAME "closeaudio: replay stopped\n"));

        /* Disable interrupt */
        Jdisint(MFP_DMASOUND);

        DEBUG_PRINT((DEBUG_NAME "closeaudio: interrupt disabled\n"));

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

        DEBUG_PRINT((DEBUG_NAME "closeaudio: no more interrupt running\n"));

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

        DEBUG_PRINT((DEBUG_NAME "closeaudio: buffers freed\n"));
        SDL_free(this->hidden);
        this->hidden = NULL;
    }
}

static int
MINTDMA8_CheckAudio(_THIS)
{
    int i, masterprediv, sfreq;
    unsigned long masterclock;

    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 */
    this->spec.format = AUDIO_S8;

    /* Calculate and select the closest frequency */
    sfreq = 0;
    masterclock = MASTERCLOCK_STE;
    masterprediv = MASTERPREDIV_STE;
    switch (cookie_mch >> 16) {
/*
		case MCH_STE:
			masterclock=MASTERCLOCK_STE;
			masterprediv=MASTERPREDIV_STE;
			break;
*/
    case MCH_TT:
        masterclock = MASTERCLOCK_TT;
        masterprediv = MASTERPREDIV_TT;
        break;
    case MCH_F30:
    case MCH_ARANYM:
        masterclock = MASTERCLOCK_FALCON1;
        masterprediv = MASTERPREDIV_FALCON;
        sfreq = 1;
        break;
    }

    MINTAUDIO_freqcount = 0;
    for (i = sfreq; i < 4; i++) {
        SDL_MintAudio_AddFrequency(this,
                                   masterclock / (masterprediv * (1 << i)),
                                   masterclock, i - sfreq, -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
MINTDMA8_InitAudio(_THIS)
{
    void *oldpile;
    unsigned long buffer;
    unsigned char mode;

    /* Set replay tracks */
    if (cookie_snd & SND_16BIT) {
        Settracks(0, 0);
        Setmontracks(0);
    }

    oldpile = (void *) Super(0);

    /* Stop currently playing sound */
    DMAAUDIO_IO.control = 0;

    /* Set buffer */
    buffer = (unsigned long) SDL_MintAudio_audiobuf[SDL_MintAudio_numbuf];
    DMAAUDIO_IO.start_high = (buffer >> 16) & 255;
    DMAAUDIO_IO.start_mid = (buffer >> 8) & 255;
    DMAAUDIO_IO.start_low = buffer & 255;

    buffer += SDL_MintAudio_audiosize;
    DMAAUDIO_IO.end_high = (buffer >> 16) & 255;
    DMAAUDIO_IO.end_mid = (buffer >> 8) & 255;
    DMAAUDIO_IO.end_low = buffer & 255;

    mode = 3 - MINTAUDIO_frequencies[MINTAUDIO_numfreq].predivisor;
    if (this->spec.channels == 1) {
        mode |= 1 << 7;
    }
    DMAAUDIO_IO.sound_ctrl = mode;

    /* Set interrupt */
    Jdisint(MFP_DMASOUND);
    Xbtimer(XB_TIMERA, 8, 1, SDL_MintAudio_Dma8Interrupt);
    Jenabint(MFP_DMASOUND);

    if (cookie_snd & SND_16BIT) {
        if (Setinterrupt(SI_TIMERA, SI_PLAY) < 0) {
            DEBUG_PRINT((DEBUG_NAME "Setinterrupt() failed\n"));
        }
    }

    /* Go */
    DMAAUDIO_IO.control = 3;    /* playback + repeat */

    Super(oldpile);
}

static int
MINTDMA8_OpenDevice(_THIS, const char *devname, int iscapture)
{
    SDL_MintAudio_device = this;

    /* Check audio capabilities */
    if (MINTDMA8_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 */
    MINTDMA8_InitAudio(this);

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

static int
MINTDMA8_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;
    }

    /* Check if we have 8 bits audio */
    if ((cookie_snd & SND_8BIT) == 0) {
        SDL_SetError(DEBUG_NAME "no 8 bits sound");
        return 0;
    }

    /* Check if audio is lockable */
    if (cookie_snd & SND_16BIT) {
        if (Locksnd() != 1) {
            SDL_SetError(DEBUG_NAME "audio locked by other application");
            return 0;
        }

        Unlocksnd();
    }

    DEBUG_PRINT((DEBUG_NAME "8 bits audio available!\n"));

    /* Set the function pointers */
    impl->OpenDevice = MINTDMA8_OpenDevice;
    impl->CloseDevice = MINTDMA8_CloseDevice;
    impl->LockDevice = MINTDMA8_LockDevice;
    impl->UnlockDevice = MINTDMA8_UnlockDevice;
    impl->OnlyHasDefaultOutputDevice = 1;
    impl->ProvidesOwnCallbackThread = 1;
    impl->SkipMixerLock = 1;

    return 1;
}

AudioBootStrap MINTAUDIO_DMA8_bootstrap = {
    MINT_AUDIO_DRIVER_NAME, "MiNT DMA 8 bits audio driver", MINTDMA8_Init, 0
};

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