src/audio/nto/SDL_nto_audio.c
author Ryan C. Gordon <icculus@icculus.org>
Thu, 24 Aug 2006 12:10:46 +0000
changeset 1982 3b4ce57c6215
parent 1895 c121d94672cb
child 2007 cff63f857ff3
permissions -rw-r--r--
First shot at new audio data types (int32 and float32). Notable changes: - Converters between types are autogenerated. Instead of making multiple passes over the data with seperate filters for endianess, size, signedness, etc, converting between data types is always one specialized filter. This simplifies SDL_BuildAudioCVT(), which otherwise had a million edge cases with the new types, and makes the actually conversions more CPU cache friendly. Left a stub for adding specific optimized versions of these routines (SSE/MMX/Altivec, assembler, etc) - Autogenerated converters are built by SDL/src/audio/sdlgenaudiocvt.pl. This does not need to be run unless tweaking the code, and thus doesn't need integration into the build system. - Went through all the drivers and tried to weed out all the "Uint16" references that are better specified with the new SDL_AudioFormat typedef. - Cleaned out a bunch of hardcoded bitwise magic numbers and replaced them with new SDL_AUDIO_* macros. - Added initial float32 and int32 support code. Theoretically, existing drivers will push these through converters to get the data they want to feed to the hardware. Still TODO: - Optimize and debug new converters. - Update the CoreAudio backend to accept float32 data directly. - Other backends, too? - SDL_LoadWAV() needs to be updated to support int32 and float32 .wav files (both of which exist and can be generated by 'sox' for testing purposes). - Update the mixer to handle new datatypes. - Optionally update SDL_sound and SDL_mixer, etc.

/*
    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"

#include <errno.h>
#include <unistd.h>
#include <fcntl.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sched.h>
#include <sys/select.h>
#include <sys/neutrino.h>
#include <sys/asoundlib.h>

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

/* The tag name used by NTO audio */
#define DRIVER_NAME "qsa-nto"

/* default channel communication parameters */
#define DEFAULT_CPARAMS_RATE 22050
#define DEFAULT_CPARAMS_VOICES 1
/* FIXME: need to add in the near future flexible logic with frag_size and frags count */
#define DEFAULT_CPARAMS_FRAG_SIZE 4096
#define DEFAULT_CPARAMS_FRAGS_MIN 1
#define DEFAULT_CPARAMS_FRAGS_MAX 1

/* Open the audio device for playback, and don't block if busy */
#define OPEN_FLAGS SND_PCM_OPEN_PLAYBACK

#define QSA_NO_WORKAROUNDS  0x00000000
#define QSA_MMAP_WORKAROUND 0x00000001

struct BuggyCards
{
    char *cardname;
    unsigned long bugtype;
};

#define QSA_WA_CARDS 3

struct BuggyCards buggycards[QSA_WA_CARDS] = {
    {"Sound Blaster Live!", QSA_MMAP_WORKAROUND},
    {"Vortex 8820", QSA_MMAP_WORKAROUND},
    {"Vortex 8830", QSA_MMAP_WORKAROUND},
};

/* Audio driver functions */
static void NTO_ThreadInit(_THIS);
static int NTO_OpenAudio(_THIS, SDL_AudioSpec * spec);
static void NTO_WaitAudio(_THIS);
static void NTO_PlayAudio(_THIS);
static Uint8 *NTO_GetAudioBuf(_THIS);
static void NTO_CloseAudio(_THIS);

/* card names check to apply the workarounds */
static int
NTO_CheckBuggyCards(_THIS, unsigned long checkfor)
{
    char scardname[33];
    int it;

    if (snd_card_get_name(cardno, scardname, 32) < 0) {
        return 0;
    }

    for (it = 0; it < QSA_WA_CARDS; it++) {
        if (SDL_strcmp(buggycards[it].cardname, scardname) == 0) {
            if (buggycards[it].bugtype == checkfor) {
                return 1;
            }
        }
    }

    return 0;
}

static void
NTO_ThreadInit(_THIS)
{
    int status;
    struct sched_param param;

    /* increasing default 10 priority to 25 to avoid jerky sound */
    status = SchedGet(0, 0, &param);
    param.sched_priority = param.sched_curpriority + 15;
    status = SchedSet(0, 0, SCHED_NOCHANGE, &param);
}

/* PCM transfer channel parameters initialize function */
static void
NTO_InitAudioParams(snd_pcm_channel_params_t * cpars)
{
    SDL_memset(cpars, 0, sizeof(snd_pcm_channel_params_t));

    cpars->channel = SND_PCM_CHANNEL_PLAYBACK;
    cpars->mode = SND_PCM_MODE_BLOCK;
    cpars->start_mode = SND_PCM_START_DATA;
    cpars->stop_mode = SND_PCM_STOP_STOP;
    cpars->format.format = SND_PCM_SFMT_S16_LE;
    cpars->format.interleave = 1;
    cpars->format.rate = DEFAULT_CPARAMS_RATE;
    cpars->format.voices = DEFAULT_CPARAMS_VOICES;
    cpars->buf.block.frag_size = DEFAULT_CPARAMS_FRAG_SIZE;
    cpars->buf.block.frags_min = DEFAULT_CPARAMS_FRAGS_MIN;
    cpars->buf.block.frags_max = DEFAULT_CPARAMS_FRAGS_MAX;
}

static int
NTO_AudioAvailable(void)
{
    /*  See if we can open a nonblocking channel.
       Return value '1' means we can.
       Return value '0' means we cannot. */

    int available;
    int rval;
    snd_pcm_t *handle;

    available = 0;
    handle = NULL;

    rval = snd_pcm_open_preferred(&handle, NULL, NULL, OPEN_FLAGS);

    if (rval >= 0) {
        available = 1;

        if ((rval = snd_pcm_close(handle)) < 0) {
            SDL_SetError
                ("NTO_AudioAvailable(): snd_pcm_close failed: %s\n",
                 snd_strerror(rval));
            available = 0;
        }
    } else {
        SDL_SetError
            ("NTO_AudioAvailable(): there are no available audio devices.\n");
    }

    return (available);
}

static void
NTO_DeleteAudioDevice(SDL_AudioDevice * device)
{
    if ((device) && (device->hidden)) {
        SDL_free(device->hidden);
    }
    if (device) {
        SDL_free(device);
    }
}

static SDL_AudioDevice *
NTO_CreateAudioDevice(int devindex)
{
    SDL_AudioDevice *this;

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

    /* Set the function pointers */
    this->ThreadInit = NTO_ThreadInit;
    this->OpenAudio = NTO_OpenAudio;
    this->WaitAudio = NTO_WaitAudio;
    this->PlayAudio = NTO_PlayAudio;
    this->GetAudioBuf = NTO_GetAudioBuf;
    this->CloseAudio = NTO_CloseAudio;

    this->free = NTO_DeleteAudioDevice;

    return this;
}

AudioBootStrap QNXNTOAUDIO_bootstrap = {
    DRIVER_NAME, "QNX6 QSA-NTO Audio",
    NTO_AudioAvailable,
    NTO_CreateAudioDevice
};

/* This function waits until it is possible to write a full sound buffer */
static void
NTO_WaitAudio(_THIS)
{
    fd_set wfds;
    int selectret;

    FD_ZERO(&wfds);
    FD_SET(audio_fd, &wfds);

    do {
        selectret = select(audio_fd + 1, NULL, &wfds, NULL, NULL);
        switch (selectret) {
        case -1:
        case 0:
            SDL_SetError("NTO_WaitAudio(): select() failed: %s\n",
                         strerror(errno));
            return;
        default:
            if (FD_ISSET(audio_fd, &wfds)) {
                return;
            }
            break;
        }
    }
    while (1);
}

static void
NTO_PlayAudio(_THIS)
{
    int written, rval;
    int towrite;
    void *pcmbuffer;

    if (!this->enabled) {
        return;
    }

    towrite = this->spec.size;
    pcmbuffer = pcm_buf;

    /* Write the audio data, checking for EAGAIN (buffer full) and underrun */
    do {
        written = snd_pcm_plugin_write(audio_handle, pcm_buf, towrite);
        if (written != towrite) {
            if ((errno == EAGAIN) || (errno == EWOULDBLOCK)) {
                /* Let a little CPU time go by and try to write again */
                SDL_Delay(1);
                /* if we wrote some data */
                towrite -= written;
                pcmbuffer += written * this->spec.channels;
                continue;
            } else {
                if ((errno == EINVAL) || (errno == EIO)) {
                    SDL_memset(&cstatus, 0, sizeof(cstatus));
                    cstatus.channel = SND_PCM_CHANNEL_PLAYBACK;
                    if ((rval =
                         snd_pcm_plugin_status(audio_handle, &cstatus)) < 0) {
                        SDL_SetError
                            ("NTO_PlayAudio(): snd_pcm_plugin_status failed: %s\n",
                             snd_strerror(rval));
                        return;
                    }
                    if ((cstatus.status == SND_PCM_STATUS_UNDERRUN)
                        || (cstatus.status == SND_PCM_STATUS_READY)) {
                        if ((rval =
                             snd_pcm_plugin_prepare(audio_handle,
                                                    SND_PCM_CHANNEL_PLAYBACK))
                            < 0) {
                            SDL_SetError
                                ("NTO_PlayAudio(): snd_pcm_plugin_prepare failed: %s\n",
                                 snd_strerror(rval));
                            return;
                        }
                    }
                    continue;
                } else {
                    return;
                }
            }
        } else {
            /* we wrote all remaining data */
            towrite -= written;
            pcmbuffer += written * this->spec.channels;
        }
    }
    while ((towrite > 0) && (this->enabled));

    /* If we couldn't write, assume fatal error for now */
    if (towrite != 0) {
        this->enabled = 0;
    }

    return;
}

static Uint8 *
NTO_GetAudioBuf(_THIS)
{
    return pcm_buf;
}

static void
NTO_CloseAudio(_THIS)
{
    int rval;

    this->enabled = 0;

    if (audio_handle != NULL) {
        if ((rval =
             snd_pcm_plugin_flush(audio_handle,
                                  SND_PCM_CHANNEL_PLAYBACK)) < 0) {
            SDL_SetError
                ("NTO_CloseAudio(): snd_pcm_plugin_flush failed: %s\n",
                 snd_strerror(rval));
            return;
        }
        if ((rval = snd_pcm_close(audio_handle)) < 0) {
            SDL_SetError("NTO_CloseAudio(): snd_pcm_close failed: %s\n",
                         snd_strerror(rval));
            return;
        }
        audio_handle = NULL;
    }
}

static int
NTO_OpenAudio(_THIS, SDL_AudioSpec * spec)
{
    int rval;
    int format;
    SDL_AudioFormat test_format;
    int found;

    audio_handle = NULL;
    this->enabled = 0;

    if (pcm_buf != NULL) {
        SDL_FreeAudioMem(pcm_buf);
        pcm_buf = NULL;
    }

    /* initialize channel transfer parameters to default */
    NTO_InitAudioParams(&cparams);

    /* Open the audio device */
    rval =
        snd_pcm_open_preferred(&audio_handle, &cardno, &deviceno, OPEN_FLAGS);
    if (rval < 0) {
        SDL_SetError("NTO_OpenAudio(): snd_pcm_open failed: %s\n",
                     snd_strerror(rval));
        return (-1);
    }

    if (!NTO_CheckBuggyCards(this, QSA_MMAP_WORKAROUND)) {
        /* enable count status parameter */
        if ((rval =
             snd_pcm_plugin_set_disable(audio_handle,
                                        PLUGIN_DISABLE_MMAP)) < 0) {
            SDL_SetError("snd_pcm_plugin_set_disable failed: %s\n",
                         snd_strerror(rval));
            return (-1);
        }
    }

    /* Try for a closest match on audio format */
    format = 0;
    /* can't use format as SND_PCM_SFMT_U8 = 0 in nto */
    found = 0;

    for (test_format = SDL_FirstAudioFormat(spec->format); !found;) {
        /* if match found set format to equivalent ALSA format */
        switch (test_format) {
        case AUDIO_U8:
            format = SND_PCM_SFMT_U8;
            found = 1;
            break;
        case AUDIO_S8:
            format = SND_PCM_SFMT_S8;
            found = 1;
            break;
        case AUDIO_S16LSB:
            format = SND_PCM_SFMT_S16_LE;
            found = 1;
            break;
        case AUDIO_S16MSB:
            format = SND_PCM_SFMT_S16_BE;
            found = 1;
            break;
        case AUDIO_U16LSB:
            format = SND_PCM_SFMT_U16_LE;
            found = 1;
            break;
        case AUDIO_U16MSB:
            format = SND_PCM_SFMT_U16_BE;
            found = 1;
            break;
        default:
            break;
        }

        if (!found) {
            test_format = SDL_NextAudioFormat();
        }
    }

    /* assumes test_format not 0 on success */
    if (test_format == 0) {
        SDL_SetError
            ("NTO_OpenAudio(): Couldn't find any hardware audio formats");
        return (-1);
    }

    spec->format = test_format;

    /* Set the audio format */
    cparams.format.format = format;

    /* Set mono or stereo audio (currently only two channels supported) */
    cparams.format.voices = spec->channels;

    /* Set rate */
    cparams.format.rate = spec->freq;

    /* Setup the transfer parameters according to cparams */
    rval = snd_pcm_plugin_params(audio_handle, &cparams);
    if (rval < 0) {
        SDL_SetError
            ("NTO_OpenAudio(): snd_pcm_channel_params failed: %s\n",
             snd_strerror(rval));
        return (-1);
    }

    /* Make sure channel is setup right one last time */
    SDL_memset(&csetup, 0x00, sizeof(csetup));
    csetup.channel = SND_PCM_CHANNEL_PLAYBACK;
    if (snd_pcm_plugin_setup(audio_handle, &csetup) < 0) {
        SDL_SetError("NTO_OpenAudio(): Unable to setup playback channel\n");
        return -1;
    }


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

    pcm_len = spec->size;

    if (pcm_len == 0) {
        pcm_len =
            csetup.buf.block.frag_size * spec->channels *
            (snd_pcm_format_width(format) / 8);
    }

    /* Allocate memory to the audio buffer and initialize with silence (Note that
       buffer size must be a multiple of fragment size, so find closest multiple)
     */
    pcm_buf = (Uint8 *) SDL_AllocAudioMem(pcm_len);
    if (pcm_buf == NULL) {
        SDL_SetError("NTO_OpenAudio(): pcm buffer allocation failed\n");
        return (-1);
    }
    SDL_memset(pcm_buf, spec->silence, pcm_len);

    /* get the file descriptor */
    if ((audio_fd =
         snd_pcm_file_descriptor(audio_handle,
                                 SND_PCM_CHANNEL_PLAYBACK)) < 0) {
        SDL_SetError
            ("NTO_OpenAudio(): snd_pcm_file_descriptor failed with error code: %s\n",
             snd_strerror(rval));
        return (-1);
    }

    /* Trigger audio playback */
    rval = snd_pcm_plugin_prepare(audio_handle, SND_PCM_CHANNEL_PLAYBACK);
    if (rval < 0) {
        SDL_SetError("snd_pcm_plugin_prepare failed: %s\n",
                     snd_strerror(rval));
        return (-1);
    }

    this->enabled = 1;

    /* Get the parent process id (we're the parent of the audio thread) */
    parent = getpid();

    /* We're really ready to rock and roll. :-) */
    return (0);
}

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