ossaudio.c

qemu虚拟机代码

/*
 * QEMU OSS audio driver
 *
 * Copyright (c) 2003-2005 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 <sys/mman.h>
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/soundcard.h>
#include "vl.h"

#define AUDIO_CAP "oss"
#include "audio_int.h"

typedef struct OSSVoiceOut {
    HWVoiceOut hw;
    void *pcm_buf;
    int fd;
    int nfrags;
    int fragsize;
    int mmapped;
    int old_optr;
} OSSVoiceOut;

typedef struct OSSVoiceIn {
    HWVoiceIn hw;
    void *pcm_buf;
    int fd;
    int nfrags;
    int fragsize;
    int old_optr;
} OSSVoiceIn;

static struct {
    int try_mmap;
    int nfrags;
    int fragsize;
    const char *devpath_out;
    const char *devpath_in;
} conf = {
    .try_mmap = 0,
    .nfrags = 4,
    .fragsize = 4096,
    .devpath_out = "/dev/dsp",
    .devpath_in = "/dev/dsp"
};

struct oss_params {
    int freq;
    audfmt_e fmt;
    int nchannels;
    int nfrags;
    int fragsize;
};

static void GCC_FMT_ATTR (2, 3) oss_logerr (int err, const char *fmt, ...)
{
    va_list ap;

    va_start (ap, fmt);
    AUD_vlog (AUDIO_CAP, fmt, ap);
    va_end (ap);

    AUD_log (AUDIO_CAP, "Reason: %s\n", strerror (err));
}

static void GCC_FMT_ATTR (3, 4) oss_logerr2 (
    int err,
    const char *typ,
    const char *fmt,
    ...
    )
{
    va_list ap;

    AUD_log (AUDIO_CAP, "Could not initialize %s\n", typ);

    va_start (ap, fmt);
    AUD_vlog (AUDIO_CAP, fmt, ap);
    va_end (ap);

    AUD_log (AUDIO_CAP, "Reason: %s\n", strerror (err));
}

static void oss_anal_close (int *fdp)
{
    int err = close (*fdp);
    if (err) {
        oss_logerr (errno, "Failed to close file(fd=%d)\n", *fdp);
    }
    *fdp = -1;
}

static int oss_write (SWVoiceOut *sw, void *buf, int len)
{
    return audio_pcm_sw_write (sw, buf, len);
}

static int aud_to_ossfmt (audfmt_e fmt)
{
    switch (fmt) {
    case AUD_FMT_S8:
        return AFMT_S8;

    case AUD_FMT_U8:
        return AFMT_U8;

    case AUD_FMT_S16:
        return AFMT_S16_LE;

    case AUD_FMT_U16:
        return AFMT_U16_LE;

    default:
        dolog ("Internal logic error: Bad audio format %d\n", fmt);
#ifdef DEBUG_AUDIO
        abort ();
#endif
        return AFMT_U8;
    }
}

static int oss_to_audfmt (int ossfmt, audfmt_e *fmt, int *endianness)
{
    switch (ossfmt) {
    case AFMT_S8:
        *endianness =0;
        *fmt = AUD_FMT_S8;
        break;

    case AFMT_U8:
        *endianness = 0;
        *fmt = AUD_FMT_U8;
        break;

    case AFMT_S16_LE:
        *endianness = 0;
        *fmt = AUD_FMT_S16;
        break;

    case AFMT_U16_LE:
        *endianness = 0;
        *fmt = AUD_FMT_U16;
        break;

    case AFMT_S16_BE:
        *endianness = 1;
        *fmt = AUD_FMT_S16;
        break;

    case AFMT_U16_BE:
        *endianness = 1;
        *fmt = AUD_FMT_U16;
        break;

    default:
        dolog ("Unrecognized audio format %d\n", ossfmt);
        return -1;
    }

    return 0;
}

#if defined DEBUG_MISMATCHES || defined DEBUG
static void oss_dump_info (struct oss_params *req, struct oss_params *obt)
{
    dolog ("parameter | requested value | obtained value\n");
    dolog ("format    |      %10d |     %10d\n", req->fmt, obt->fmt);
    dolog ("channels  |      %10d |     %10d\n",
           req->nchannels, obt->nchannels);
    dolog ("frequency |      %10d |     %10d\n", req->freq, obt->freq);
    dolog ("nfrags    |      %10d |     %10d\n", req->nfrags, obt->nfrags);
    dolog ("fragsize  |      %10d |     %10d\n",
           req->fragsize, obt->fragsize);
}
#endif

static int oss_open (int in, struct oss_params *req,
                     struct oss_params *obt, int *pfd)
{
    int fd;
    int mmmmssss;
    audio_buf_info abinfo;
    int fmt, freq, nchannels;
    const char *dspname = in ? conf.devpath_in : conf.devpath_out;
    const char *typ = in ? "ADC" : "DAC";

    fd = open (dspname, (in ? O_RDONLY : O_WRONLY) | O_NONBLOCK);
    if (-1 == fd) {
        oss_logerr2 (errno, typ, "Failed to open `%s'\n", dspname);
        return -1;
    }

    freq = req->freq;
    nchannels = req->nchannels;
    fmt = req->fmt;

    if (ioctl (fd, SNDCTL_DSP_SAMPLESIZE, &fmt)) {
        oss_logerr2 (errno, typ, "Failed to set sample size %d\n", req->fmt);
        goto err;
    }

    if (ioctl (fd, SNDCTL_DSP_CHANNELS, &nchannels)) {
        oss_logerr2 (errno, typ, "Failed to set number of channels %d\n",
                     req->nchannels);
        goto err;
    }

    if (ioctl (fd, SNDCTL_DSP_SPEED, &freq)) {
        oss_logerr2 (errno, typ, "Failed to set frequency %d\n", req->freq);
        goto err;
    }

    if (ioctl (fd, SNDCTL_DSP_NONBLOCK)) {
        oss_logerr2 (errno, typ, "Failed to set non-blocking mode\n");
        goto err;
    }

    mmmmssss = (req->nfrags << 16) | lsbindex (req->fragsize);
    if (ioctl (fd, SNDCTL_DSP_SETFRAGMENT, &mmmmssss)) {
        oss_logerr2 (errno, typ, "Failed to set buffer length (%d, %d)\n",
                     req->nfrags, req->fragsize);
        goto err;
    }

    if (ioctl (fd, in ? SNDCTL_DSP_GETISPACE : SNDCTL_DSP_GETOSPACE, &abinfo)) {
        oss_logerr2 (errno, typ, "Failed to get buffer length\n");
        goto err;
    }

    obt->fmt = fmt;
    obt->nchannels = nchannels;
    obt->freq = freq;
    obt->nfrags = abinfo.fragstotal;
    obt->fragsize = abinfo.fragsize;
    *pfd = fd;

#ifdef DEBUG_MISMATCHES
    if ((req->fmt != obt->fmt) ||
        (req->nchannels != obt->nchannels) ||
        (req->freq != obt->freq) ||
        (req->fragsize != obt->fragsize) ||
        (req->nfrags != obt->nfrags)) {
        dolog ("Audio parameters mismatch\n");
        oss_dump_info (req, obt);
    }
#endif

#ifdef DEBUG
    oss_dump_info (req, obt);
#endif
    return 0;

 err:
    oss_anal_close (&fd);
    return -1;
}

static int oss_run_out (HWVoiceOut *hw)
{
    OSSVoiceOut *oss = (OSSVoiceOut *) hw;
    int err, rpos, live, decr;
    int samples;
    uint8_t *dst;
    st_sample_t *src;
    struct audio_buf_info abinfo;
    struct count_info cntinfo;
    int bufsize;

    live = audio_pcm_hw_get_live_out (hw);
    if (!live) {
        return 0;
    }

    bufsize = hw->samples << hw->info.shift;

    if (oss->mmapped) {
        int bytes;

        err = ioctl (oss->fd, SNDCTL_DSP_GETOPTR, &cntinfo);
        if (err < 0) {
            oss_logerr (errno, "SNDCTL_DSP_GETOPTR failed\n");
            return 0;
        }

        if (cntinfo.ptr == oss->old_optr) {
            if (abs (hw->samples - live) < 64) {
                dolog ("warning: Overrun\n");
            }
            return 0;
        }

        if (cntinfo.ptr > oss->old_optr) {
            bytes = cntinfo.ptr - oss->old_optr;
        }
        else {
            bytes = bufsize + cntinfo.ptr - oss->old_optr;
        }

        decr = audio_MIN (bytes >> hw->info.shift, live);
    }
    else {
        err = ioctl (oss->fd, SNDCTL_DSP_GETOSPACE, &abinfo);
        if (err < 0) {
            oss_logerr (errno, "SNDCTL_DSP_GETOPTR failed\n");
            return 0;
        }

        if (abinfo.bytes < 0 || abinfo.bytes > bufsize) {
            ldebug ("warning: Invalid available size, size=%d bufsize=%d\n",
                    abinfo.bytes, bufsize);
            return 0;
        }

        decr = audio_MIN (abinfo.bytes >> hw->info.shift, live);
        if (!decr) {
            return 0;
        }
    }

    samples = decr;
    rpos = hw->rpos;
    while (samples) {
        int left_till_end_samples = hw->samples - rpos;
        int convert_samples = audio_MIN (samples, left_till_end_samples);

        src = hw->mix_buf + rpos;
        dst = advance (oss->pcm_buf, rpos << hw->info.shift);

        hw->clip (dst, src, convert_samples);
        if (!oss->mmapped) {
            int written;

            written = write (oss->fd, dst, convert_samples << hw->info.shift);
            /* XXX: follow errno recommendations ? */
            if (written == -1) {
                oss_logerr (
                    errno,
                    "Failed to write %d bytes of audio data from %p\n",
                    convert_samples << hw->info.shift,
                    dst
                    );
                continue;
            }

            if (written != convert_samples << hw->info.shift) {
                int wsamples = written >> hw->info.shift;
                int wbytes = wsamples << hw->info.shift;
                if (wbytes != written) {
                    dolog ("warning: Misaligned write %d (requested %d), "
                           "alignment %d\n",
                           wbytes, written, hw->info.align + 1);
                }
                mixeng_clear (src, wsamples);
                decr -= wsamples;
                rpos = (rpos + wsamples) % hw->samples;
                break;
            }
        }

        mixeng_clear (src, convert_samples);

        rpos = (rpos + convert_samples) % hw->samples;
        samples -= convert_samples;