Archipelago » qemu

/*

 * QEMU OSS Audio output driver

 * 

 * Copyright (c) 2003 Vassili Karpov (malc)

 * 

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL

 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

 * THE SOFTWARE.

 */

#include <fcntl.h>

#include <errno.h>

#include <stdio.h>

#include <unistd.h>

#include <string.h>

#include <stdlib.h>

#include <limits.h>

#include <inttypes.h>

#include <sys/types.h>

#include <sys/ioctl.h>

#include <sys/soundcard.h>

#include "vl.h"

/* http://www.df.lth.se/~john_e/gems/gem002d.html */

/* http://www.multi-platforms.com/Tips/PopCount.htm */

static inline uint32_t popcount (uint32_t u)

{

  u = ((u&0x55555555) + ((u>>1)&0x55555555));

  u = ((u&0x33333333) + ((u>>2)&0x33333333));

  u = ((u&0x0f0f0f0f) + ((u>>4)&0x0f0f0f0f));

  u = ((u&0x00ff00ff) + ((u>>8)&0x00ff00ff));

  u = ( u&0x0000ffff) + (u>>16);

  return u;

}

static inline uint32_t lsbindex (uint32_t u)

{

  return popcount ((u&-u)-1);

}

#define MIN(a, b) ((a)>(b)?(b):(a))

#define MAX(a, b) ((a)<(b)?(b):(a))

#define DEREF(x) (void)x

#define log(...) fprintf (stderr, "oss: " __VA_ARGS__)

#define ERRFail(...) do {                                       \

    int _errno = errno;                                         \

    fprintf (stderr, "oss: " __VA_ARGS__);                      \

    fprintf (stderr, "system error: %s\n", strerror (_errno));  \

    abort ();                                                   \

} while (0)

#define Fail(...) do {                          \

    fprintf (stderr, "oss: " __VA_ARGS__);      \

    fprintf (stderr, "\n");                     \

    abort ();                                   \

} while (0)

#ifdef DEBUG_OSS

#define lwarn(...) fprintf (stderr, "oss: " __VA_ARGS__)

#define linfo(...) fprintf (stderr, "oss: " __VA_ARGS__)

#define ldebug(...) fprintf (stderr, "oss: " __VA_ARGS__)

#else

#define lwarn(...)

#define linfo(...)

#define ldebug(...)

#endif

#define IOCTL(args) do {                        \

  int ret = ioctl args;                         \

  if (-1 == ret) {                              \

    ERRFail (#args);                            \

  }                                             \

  ldebug ("ioctl " #args " = %d\n", ret);       \

} while (0)

static int audio_fd = -1;

static int freq;

static int conf_nfrags = 4;

static int conf_fragsize;

static int nfrags;

static int fragsize;

static int bufsize;

static int nchannels;

static int fmt;

static int rpos;

static int wpos;

static int atom;

static int live;

static int leftover;

static int bytes_per_second;

static void *buf;

static enum {DONT, DSP, TID} estimate = TID;

static void (*copy_fn)(void *, void *, int);

static void copy_no_conversion (void *dst, void *src, int size)

{

    memcpy (dst, src, size);

}

static void copy_u16_to_s16 (void *dst, void *src, int size)

{

    int i;

    uint16_t *out, *in;

    out = dst;

    in = src;

    for (i = 0; i < size / 2; i++) {

        out[i] = in[i] + 0x8000;

    }

}

static void pab (struct audio_buf_info *abinfo)

{

    DEREF (abinfo);

    ldebug ("fragments %d, fragstotal %d, fragsize %d, bytes %d\n"

            "rpos %d, wpos %d, live %d\n",

            abinfo->fragments,

            abinfo->fragstotal,

            abinfo->fragsize,

            abinfo->bytes,

            rpos, wpos, live);

}

void AUD_reset (int rfreq, int rnchannels, audfmt_e rfmt)

{

    int fmt_;

    int bits16;

    if (-1 == audio_fd) {

        AUD_open (rfreq, rnchannels, rfmt);

        return;

    }

    switch (rfmt) {

    case AUD_FMT_U8:

        bits16 = 0;

        fmt_ = AFMT_U8;

        copy_fn = copy_no_conversion;

        atom = 1;

        break;

    case AUD_FMT_S8:

        Fail ("can not play 8bit signed");

    case AUD_FMT_S16:

        bits16 = 1;

        fmt_ = AFMT_S16_LE;

        copy_fn = copy_no_conversion;

        atom = 2;

        break;

    case AUD_FMT_U16:

        bits16 = 1;

        fmt_ = AFMT_S16_LE;

        copy_fn = copy_u16_to_s16;

        atom = 2;

        break;

    default:

        abort ();

    }

    if ((fmt_ == fmt) && (bits16 + 1 == nchannels) && (rfreq == freq))

        return;

    else {

        AUD_open (rfreq, rnchannels, rfmt);

    }

}

void AUD_open (int rfreq, int rnchannels, audfmt_e rfmt)

{

    int fmt_;

    int mmmmssss;

    struct audio_buf_info abinfo;

    int _fmt;

    int _freq;

    int _nchannels;

    int bits16;

    bits16 = 0;

    switch (rfmt) {

    case AUD_FMT_U8:

        bits16 = 0;

        fmt_ = AFMT_U8;

        copy_fn = copy_no_conversion;

        atom = 1;

        break;

    case AUD_FMT_S8:

        Fail ("can not play 8bit signed");

    case AUD_FMT_S16:

        bits16 = 1;

        fmt_ = AFMT_S16_LE;

        copy_fn = copy_no_conversion;

        atom = 2;

        break;

    case AUD_FMT_U16:

        bits16 = 1;

        fmt_ = AFMT_S16_LE;

        copy_fn = copy_u16_to_s16;

        atom = 2;

        break;

    default:

        abort ();

    }

    if (buf) {

        free (buf);

        buf = 0;

    }

    if (-1 != audio_fd)

        close (audio_fd);

    audio_fd = open ("/dev/dsp", O_WRONLY | O_NONBLOCK);

    if (-1 == audio_fd) {

        ERRFail ("can not open /dev/dsp");

    }

    _fmt = fmt_;

    _freq = rfreq;

    _nchannels = rnchannels;

    IOCTL ((audio_fd, SNDCTL_DSP_RESET, 1));

    IOCTL ((audio_fd, SNDCTL_DSP_SAMPLESIZE, &_fmt));

    IOCTL ((audio_fd, SNDCTL_DSP_CHANNELS, &_nchannels));

    IOCTL ((audio_fd, SNDCTL_DSP_SPEED, &_freq));

    IOCTL ((audio_fd, SNDCTL_DSP_NONBLOCK));

    /* from oss.pdf:

    The argument to this call is an integer encoded as 0xMMMMSSSS (in

    hex). The 16 least significant bits determine the fragment

    size. The size is 2^SSSS. For examp le SSSS=0008 gives fragment

    size of 256 bytes (2^8). The minimum is 16 bytes (SSSS=4) and the

    maximum is total_buffer_size/2. Some devices or processor

    architectures may require larger fragments - in this case the

    requested fragment size is automatically increased.

    So ahem... 4096 = 2^12, and grand total 0x0004000c

    */

    mmmmssss = (conf_nfrags << 16) | conf_fragsize;

    IOCTL ((audio_fd, SNDCTL_DSP_SETFRAGMENT, &mmmmssss));

    linfo ("_fmt = %d, fmt = %d\n"

           "_channels = %d, rnchannels = %d\n"

           "_freq = %d, freq = %d\n",

           _fmt, fmt_,

           _nchannels, rnchannels,

           _freq, rfreq);

    if (_fmt != fmt_) {

        Fail ("format %d != %d", _fmt, fmt_);

    }

    if (_nchannels != rnchannels) {

        Fail ("channels %d != %d", _nchannels, rnchannels);

    }

    if (_freq != rfreq) {

        Fail ("freq %d != %d", _freq, rfreq);

    }

    IOCTL ((audio_fd, SNDCTL_DSP_GETOSPACE, &abinfo));

    nfrags = abinfo.fragstotal;

    fragsize = abinfo.fragsize;

    freq = _freq;

    fmt = _fmt;

    nchannels = rnchannels;

    atom <<= nchannels >>  1;

    bufsize = nfrags * fragsize;

    bytes_per_second = (freq << (nchannels >> 1)) << bits16;

    linfo ("bytes per second %d\n", bytes_per_second);

    linfo ("fragments %d, fragstotal %d, fragsize %d, bytes %d, bufsize %d\n",

           abinfo.fragments,

           abinfo.fragstotal,

           abinfo.fragsize,

           abinfo.bytes,

           bufsize);

    if (NULL == buf) {

        buf = malloc (bufsize);

        if (NULL == buf) {

            abort ();

        }

    }

    rpos = 0;

    wpos = 0;

    live = 0;

}

int AUD_write (void *in_buf, int size)

{

    int to_copy, temp;

    uint8_t *in, *out;

    to_copy = MIN (bufsize - live, size);

    temp = to_copy;

    in = in_buf;

    out = buf;

    while (temp) {

        int copy;

        copy = MIN (temp, bufsize - wpos);

        copy_fn (out + wpos, in, copy);

        wpos += copy;

        if (wpos == bufsize) {

            wpos = 0;

        }

        temp -= copy;

        in += copy;

        live += copy;

    }

    return to_copy;

}

void AUD_run (void)

{

    int res;

    int bytes;

    struct audio_buf_info abinfo;

    if (0 == live)

        return;

    res = ioctl (audio_fd, SNDCTL_DSP_GETOSPACE, &abinfo);

    if (-1 == res) {

        int err;

        err = errno;

        lwarn ("SNDCTL_DSP_GETOSPACE failed with %s\n", strerror (err));

    }

    bytes = abinfo.bytes;

    bytes = MIN (live, bytes);

#if 0

    bytes = (bytes / fragsize) * fragsize;

#endif

    while (bytes) {

        int left, play, written;

        left = bufsize - rpos;

        play = MIN (left, bytes);

        written = write (audio_fd, (void *) ((uint32_t) buf + rpos), play);

        if (-1 == written) {

            if (EAGAIN == errno || EINTR == errno) {

                return;

            }

            else {

                ERRFail ("write audio");

            }

        }

        play = written;

        live -= play;

        rpos += play;

        bytes -= play;

        if (rpos == bufsize) {

            rpos = 0;

        }

    }

}

static int get_dsp_bytes (void)

{

    int res;

    struct count_info info;

    res = ioctl (audio_fd, SNDCTL_DSP_GETOPTR, &info);

    if (-1 == res) {

        int err;

        err = errno;

        lwarn ("SNDCTL_DSP_GETOPTR failed with %s\n", strerror (err));

        return -1;

    }

    else {

        ldebug ("bytes %d\n", info.bytes);

        return info.bytes;

    }

}

void AUD_adjust_estimate (int _leftover)

{

    leftover = _leftover;

}

int AUD_get_free (void)

{

    int free, elapsed;

    free = bufsize - live;

    if (0 == free)

        return 0;

    elapsed = free;

    switch (estimate) {

    case DONT:

        break;

    case DSP:

        {

            static int old_bytes;

            int bytes;

            bytes = get_dsp_bytes ();

            if (bytes <= 0)

                return free;

            elapsed = bytes - old_bytes;

            old_bytes = bytes;

            ldebug ("dsp elapsed %d bytes\n", elapsed);

            break;

        }

    case TID:

        {

            static uint64_t old_ticks;

            uint64_t ticks, delta;

            uint64_t ua_elapsed;

            uint64_t al_elapsed;

            ticks = cpu_get_ticks ();

            delta = ticks - old_ticks;

            old_ticks = ticks;

            ua_elapsed = (delta * bytes_per_second) / ticks_per_sec;

            al_elapsed = ua_elapsed & ~3ULL;

            ldebug ("tid elapsed %llu bytes\n", ua_elapsed);

            if (al_elapsed > (uint64_t) INT_MAX)

                elapsed = INT_MAX;

            else

                elapsed = al_elapsed;

            elapsed += leftover;

        }

    }

    if (elapsed > free) {

        lwarn ("audio can not keep up elapsed %d free %d\n", elapsed, free);

        return free;

    }

    else {

        return elapsed;

    }

}

int AUD_get_live (void)

{

    return live;

}

int AUD_get_buffer_size (void)

{

    return bufsize;

}

void AUD_init (void)

{

    int fsp;

    int _fragsize = 4096;

    DEREF (pab);

    fsp = _fragsize;

    if (0 != (fsp & (fsp - 1))) {

        Fail ("fragment size %d is not power of 2", fsp);

    }

    conf_fragsize = lsbindex (fsp);

}