audio merge (malc)

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@1125 c046a42c-6fe2-441c-8c8c-71466251a162

1 files changed, 935 insertions, 0 deletions

diff --git a/audio/audio.c b/audio/audio.c
new file mode 100644
index 0000000000..f55e1a28cc
--- /dev/null
+++ b/audio/audio.c
@@ -0,0 +1,935 @@
+/*
+ * QEMU Audio subsystem
+ * 
+ * Copyright (c) 2003-2004 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 <assert.h>
+#include <limits.h>
+#include "vl.h"
+
+#define AUDIO_CAP "audio"
+#include "audio/audio.h"
+
+#define USE_SDL_AUDIO
+#define USE_WAV_AUDIO
+
+#if defined __linux__ || (defined _BSD && !defined __APPLE__)
+#define USE_OSS_AUDIO
+#endif
+
+#ifdef USE_OSS_AUDIO
+#include "audio/ossaudio.h"
+#endif
+
+#ifdef USE_SDL_AUDIO
+#include "audio/sdlaudio.h"
+#endif
+
+#ifdef USE_WAV_AUDIO
+#include "audio/wavaudio.h"
+#endif
+
+#ifdef USE_FMOD_AUDIO
+#include "audio/fmodaudio.h"
+#endif
+
+#define QC_AUDIO_DRV    "QEMU_AUDIO_DRV"
+#define QC_VOICES    "QEMU_VOICES"
+#define QC_FIXED_FORMAT "QEMU_FIXED_FORMAT"
+#define QC_FIXED_FREQ   "QEMU_FIXED_FREQ"
+
+extern void SB16_init (void);
+
+#ifdef USE_ADLIB
+extern void Adlib_init (void);
+#endif
+
+#ifdef USE_GUS
+extern void GUS_init (void);
+#endif
+
+static void (*hw_ctors[]) (void) = {
+    SB16_init,
+#ifdef USE_ADLIB
+    Adlib_init,
+#endif
+#ifdef USE_GUS
+    GUS_init,
+#endif
+    NULL
+};
+
+static HWVoice *hw_voice;
+
+AudioState audio_state = {
+    1,                          /* use fixed settings */
+    44100,                      /* fixed frequency */
+    2,                          /* fixed channels */
+    AUD_FMT_S16,                /* fixed format */
+    1,                          /* number of hw voices */
+    -1                          /* voice size */
+};
+
+/* http://www.df.lth.se/~john_e/gems/gem002d.html */
+/* http://www.multi-platforms.com/Tips/PopCount.htm */
+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;
+}
+
+inline uint32_t lsbindex (uint32_t u)
+{
+    return popcount ((u&-u)-1);
+}
+
+int audio_get_conf_int (const char *key, int defval)
+{
+    int val = defval;
+    char *strval;
+
+    strval = getenv (key);
+    if (strval) {
+        val = atoi (strval);
+    }
+
+    return val;
+}
+
+const char *audio_get_conf_str (const char *key, const char *defval)
+{
+    const char *val = getenv (key);
+    if (!val)
+        return defval;
+    else
+        return val;
+}
+
+void audio_log (const char *fmt, ...)
+{
+    va_list ap;
+    va_start (ap, fmt);
+    vfprintf (stderr, fmt, ap);
+    va_end (ap);
+}
+
+/*
+ * Soft Voice
+ */
+void pcm_sw_free_resources (SWVoice *sw)
+{
+    if (sw->buf) qemu_free (sw->buf);
+    if (sw->rate) st_rate_stop (sw->rate);
+    sw->buf = NULL;
+    sw->rate = NULL;
+}
+
+int pcm_sw_alloc_resources (SWVoice *sw)
+{
+    sw->buf = qemu_mallocz (sw->hw->samples * sizeof (st_sample_t));
+    if (!sw->buf)
+        return -1;
+
+    sw->rate = st_rate_start (sw->freq, sw->hw->freq);
+    if (!sw->rate) {
+        qemu_free (sw->buf);
+        sw->buf = NULL;
+        return -1;
+    }
+    return 0;
+}
+
+void pcm_sw_fini (SWVoice *sw)
+{
+    pcm_sw_free_resources (sw);
+}
+
+int pcm_sw_init (SWVoice *sw, HWVoice *hw, int freq,
+                 int nchannels, audfmt_e fmt)
+{
+    int bits = 8, sign = 0;
+
+    switch (fmt) {
+    case AUD_FMT_S8:
+        sign = 1;
+    case AUD_FMT_U8:
+        break;
+
+    case AUD_FMT_S16:
+        sign = 1;
+    case AUD_FMT_U16:
+        bits = 16;
+        break;
+    }
+
+    sw->hw = hw;
+    sw->freq = freq;
+    sw->fmt = fmt;
+    sw->nchannels = nchannels;
+    sw->shift = (nchannels == 2) + (bits == 16);
+    sw->align = (1 << sw->shift) - 1;
+    sw->left = 0;
+    sw->pos = 0;
+    sw->wpos = 0;
+    sw->live = 0;
+    sw->ratio = (sw->hw->freq * ((int64_t) INT_MAX)) / sw->freq;
+    sw->bytes_per_second = sw->freq << sw->shift;
+    sw->conv = mixeng_conv[nchannels == 2][sign][bits == 16];
+
+    pcm_sw_free_resources (sw);
+    return pcm_sw_alloc_resources (sw);
+}
+
+/* Hard voice */
+void pcm_hw_free_resources (HWVoice *hw)
+{
+    if (hw->mix_buf)
+        qemu_free (hw->mix_buf);
+    hw->mix_buf = NULL;
+}
+
+int pcm_hw_alloc_resources (HWVoice *hw)
+{
+    hw->mix_buf = qemu_mallocz (hw->samples * sizeof (st_sample_t));
+    if (!hw->mix_buf)
+        return -1;
+    return 0;
+}
+
+
+void pcm_hw_fini (HWVoice *hw)
+{
+    if (hw->active) {
+        ldebug ("pcm_hw_fini: %d %d %d\n", hw->freq, hw->nchannels, hw->fmt);
+        pcm_hw_free_resources (hw);
+        hw->pcm_ops->fini (hw);
+        memset (hw, 0, audio_state.drv->voice_size);
+    }
+}
+
+void pcm_hw_gc (HWVoice *hw)
+{
+    if (hw->nb_voices)
+        return;
+
+    pcm_hw_fini (hw);
+}
+
+int pcm_hw_get_live (HWVoice *hw)
+{
+    int i, alive = 0, live = hw->samples;
+
+    for (i = 0; i < hw->nb_voices; i++) {
+        if (hw->pvoice[i]->live) {
+            live = audio_MIN (hw->pvoice[i]->live, live);
+            alive += 1;
+        }
+    }
+
+    if (alive)
+        return live;
+    else
+        return -1;
+}
+
+int pcm_hw_get_live2 (HWVoice *hw, int *nb_active)
+{
+    int i, alive = 0, live = hw->samples;
+
+    *nb_active = 0;
+    for (i = 0; i < hw->nb_voices; i++) {
+        if (hw->pvoice[i]->live) {
+            if (hw->pvoice[i]->live < live) {
+                *nb_active = hw->pvoice[i]->active != 0;
+                live = hw->pvoice[i]->live;
+            }
+            alive += 1;
+        }
+    }
+
+    if (alive)
+        return live;
+    else
+        return -1;
+}
+
+void pcm_hw_dec_live (HWVoice *hw, int decr)
+{
+    int i;
+
+    for (i = 0; i < hw->nb_voices; i++) {
+        if (hw->pvoice[i]->live) {
+            hw->pvoice[i]->live -= decr;
+        }
+    }
+}
+
+void pcm_hw_clear (HWVoice *hw, void *buf, int len)
+{
+    if (!len)
+        return;
+
+    switch (hw->fmt) {
+    case AUD_FMT_S16:
+    case AUD_FMT_S8:
+        memset (buf, len << hw->shift, 0x00);
+        break;
+
+    case AUD_FMT_U8:
+        memset (buf, len << hw->shift, 0x80);
+        break;
+
+    case AUD_FMT_U16:
+        {
+            unsigned int i;
+            uint16_t *p = buf;
+            int shift = hw->nchannels - 1;
+
+            for (i = 0; i < len << shift; i++) {
+                p[i] = INT16_MAX;
+            }
+        }
+        break;
+    }
+}
+
+int pcm_hw_write (SWVoice *sw, void *buf, int size)
+{
+    int hwsamples, samples, isamp, osamp, wpos, live, dead, left, swlim, blck;
+    int ret = 0, pos = 0;
+    if (!sw)
+        return size;
+
+    hwsamples = sw->hw->samples;
+    samples = size >> sw->shift;
+
+    if (!sw->live) {
+        sw->wpos = sw->hw->rpos;
+    }
+    wpos = sw->wpos;
+    live = sw->live;
+    dead = hwsamples - live;
+    swlim = (dead * ((int64_t) INT_MAX)) / sw->ratio;
+    swlim = audio_MIN (swlim, samples);
+
+    ldebug ("size=%d live=%d dead=%d swlim=%d wpos=%d\n",
+           size, live, dead, swlim, wpos);
+    if (swlim)
+        sw->conv (sw->buf, buf, swlim);
+
+    while (swlim) {
+        dead = hwsamples - live;
+        left = hwsamples - wpos;
+        blck = audio_MIN (dead, left);
+        if (!blck) {
+            /* dolog ("swlim=%d\n", swlim); */
+            break;
+        }
+        isamp = swlim;
+        osamp = blck;
+        st_rate_flow (sw->rate, sw->buf + pos, sw->hw->mix_buf + wpos, &isamp, &osamp);
+        ret += isamp;
+        swlim -= isamp;
+        pos += isamp;
+        live += osamp;
+        wpos = (wpos + osamp) % hwsamples;
+    }
+
+    sw->wpos = wpos;
+    sw->live = live;
+    return ret << sw->shift;
+}
+
+int pcm_hw_init (HWVoice *hw, int freq, int nchannels, audfmt_e fmt)
+{
+    int sign = 0, bits = 8;
+
+    pcm_hw_fini (hw);
+    ldebug ("pcm_hw_init: %d %d %d\n", freq, nchannels, fmt);
+    if (hw->pcm_ops->init (hw, freq, nchannels, fmt)) {
+        memset (hw, 0, audio_state.drv->voice_size);
+        return -1;
+    }
+
+    switch (hw->fmt) {
+    case AUD_FMT_S8:
+        sign = 1;
+    case AUD_FMT_U8:
+        break;
+
+    case AUD_FMT_S16:
+        sign = 1;
+    case AUD_FMT_U16:
+        bits = 16;
+        break;
+    }
+
+    hw->nb_voices = 0;
+    hw->active = 1;
+    hw->shift = (hw->nchannels == 2) + (bits == 16);
+    hw->bytes_per_second = hw->freq << hw->shift;
+    hw->align = (1 << hw->shift) - 1;
+    hw->samples = hw->bufsize >> hw->shift;
+    hw->clip = mixeng_clip[hw->nchannels == 2][sign][bits == 16];
+    if (pcm_hw_alloc_resources (hw)) {
+        pcm_hw_fini (hw);
+        return -1;
+    }
+    return 0;
+}
+
+static int dist (void *hw)
+{
+    if (hw) {
+        return (((uint8_t *) hw - (uint8_t *) hw_voice)
+                / audio_state.voice_size) + 1;
+    }
+    else {
+        return 0;
+    }
+}
+
+#define ADVANCE(hw) hw ? advance (hw, audio_state.voice_size) : hw_voice
+
+HWVoice *pcm_hw_find_any (HWVoice *hw)
+{
+    int i = dist (hw);
+    for (; i < audio_state.nb_hw_voices; i++) {
+        hw = ADVANCE (hw);
+        return hw;
+    }
+    return NULL;
+}
+
+HWVoice *pcm_hw_find_any_active (HWVoice *hw)
+{
+    int i = dist (hw);
+    for (; i < audio_state.nb_hw_voices; i++) {
+        hw = ADVANCE (hw);
+        if (hw->active)
+            return hw;
+    }
+    return NULL;
+}
+
+HWVoice *pcm_hw_find_any_active_enabled (HWVoice *hw)
+{
+    int i = dist (hw);
+    for (; i < audio_state.nb_hw_voices; i++) {
+        hw = ADVANCE (hw);
+        if (hw->active && hw->enabled)
+            return hw;
+    }
+    return NULL;
+}
+
+HWVoice *pcm_hw_find_any_passive (HWVoice *hw)
+{
+    int i = dist (hw);
+    for (; i < audio_state.nb_hw_voices; i++) {
+        hw = ADVANCE (hw);
+        if (!hw->active)
+            return hw;
+    }
+    return NULL;
+}
+
+HWVoice *pcm_hw_find_specific (HWVoice *hw, int freq,
+                               int nchannels, audfmt_e fmt)
+{
+    while ((hw = pcm_hw_find_any_active (hw))) {
+        if (hw->freq == freq &&
+            hw->nchannels == nchannels &&
+            hw->fmt == fmt)
+            return hw;
+    }
+    return NULL;
+}
+
+HWVoice *pcm_hw_add (int freq, int nchannels, audfmt_e fmt)
+{
+    HWVoice *hw;
+
+    if (audio_state.fixed_format) {
+        freq = audio_state.fixed_freq;
+        nchannels = audio_state.fixed_channels;
+        fmt = audio_state.fixed_fmt;
+    }
+
+    hw = pcm_hw_find_specific (NULL, freq, nchannels, fmt);
+
+    if (hw)
+        return hw;
+
+    hw = pcm_hw_find_any_passive (NULL);
+    if (hw) {
+        hw->pcm_ops = audio_state.drv->pcm_ops;
+        if (!hw->pcm_ops)
+            return NULL;
+
+        if (pcm_hw_init (hw, freq, nchannels, fmt)) {
+            pcm_hw_gc (hw);
+            return NULL;
+        }
+        else
+            return hw;
+    }
+
+    return pcm_hw_find_any (NULL);
+}
+
+int pcm_hw_add_sw (HWVoice *hw, SWVoice *sw)
+{
+    SWVoice **pvoice = qemu_mallocz ((hw->nb_voices + 1) * sizeof (sw));
+    if (!pvoice)
+        return -1;
+
+    memcpy (pvoice, hw->pvoice, hw->nb_voices * sizeof (sw));
+    qemu_free (hw->pvoice);
+    hw->pvoice = pvoice;
+    hw->pvoice[hw->nb_voices++] = sw;
+    return 0;
+}
+
+int pcm_hw_del_sw (HWVoice *hw, SWVoice *sw)
+{
+    int i, j;
+    if (hw->nb_voices > 1) {
+        SWVoice **pvoice = qemu_mallocz ((hw->nb_voices - 1) * sizeof (sw));
+
+        if (!pvoice) {
+            dolog ("Can not maintain consistent state (not enough memory)\n");
+            return -1;
+        }
+
+        for (i = 0, j = 0; i < hw->nb_voices; i++) {
+            if (j >= hw->nb_voices - 1) {
+                dolog ("Can not maintain consistent state "
+                       "(invariant violated)\n");
+                return -1;
+            }
+            if (hw->pvoice[i] != sw)
+                pvoice[j++] = hw->pvoice[i];
+        }
+        qemu_free (hw->pvoice);
+        hw->pvoice = pvoice;
+        hw->nb_voices -= 1;
+    }
+    else {
+        qemu_free (hw->pvoice);
+        hw->pvoice = NULL;
+        hw->nb_voices = 0;
+    }
+    return 0;
+}
+
+SWVoice *pcm_create_voice_pair (int freq, int nchannels, audfmt_e fmt)
+{
+    SWVoice *sw;
+    HWVoice *hw;
+
+    sw = qemu_mallocz (sizeof (*sw));
+    if (!sw)
+        goto err1;
+
+    hw = pcm_hw_add (freq, nchannels, fmt);
+    if (!hw)
+        goto err2;
+
+    if (pcm_hw_add_sw (hw, sw))
+        goto err3;
+
+    if (pcm_sw_init (sw, hw, freq, nchannels, fmt))
+        goto err4;
+
+    return sw;
+
+err4:
+    pcm_hw_del_sw (hw, sw);
+err3:
+    pcm_hw_gc (hw);
+err2:
+    qemu_free (sw);
+err1:
+    return NULL;
+}
+
+SWVoice *AUD_open (SWVoice *sw, const char *name,
+                   int freq, int nchannels, audfmt_e fmt)
+{
+    if (!audio_state.drv) {
+        return NULL;
+    }
+
+    if (sw && freq == sw->freq && sw->nchannels == nchannels && sw->fmt == fmt) {
+        return sw;
+    }
+
+    if (sw) {
+        ldebug ("Different format %s %d %d %d\n",
+                name,
+                sw->freq == freq,
+                sw->nchannels == nchannels,
+                sw->fmt == fmt);
+    }
+
+    if (nchannels != 1 && nchannels != 2) {
+        dolog ("Bogus channel count %d for voice %s\n", nchannels, name);
+        return NULL;
+    }
+
+    if (!audio_state.fixed_format && sw) {
+        pcm_sw_fini (sw);
+        pcm_hw_del_sw (sw->hw, sw);
+        pcm_hw_gc (sw->hw);
+        if (sw->name) {
+            qemu_free (sw->name);
+            sw->name = NULL;
+        }
+        qemu_free (sw);
+        sw = NULL;
+    }
+
+    if (sw) {
+        HWVoice *hw = sw->hw;
+        if (!hw) {
+            dolog ("Internal logic error voice %s has no hardware store\n",
+                   name);
+            return sw;
+        }
+
+        if (pcm_sw_init (sw, hw, freq, nchannels, fmt)) {
+            pcm_sw_fini (sw);
+            pcm_hw_del_sw (hw, sw);
+            pcm_hw_gc (hw);
+            if (sw->name) {
+                qemu_free (sw->name);
+                sw->name = NULL;
+            }
+            qemu_free (sw);
+            return NULL;
+        }
+    }
+    else {
+        sw = pcm_create_voice_pair (freq, nchannels, fmt);
+        if (!sw) {
+            dolog ("Failed to create voice %s\n", name);
+            return NULL;
+        }
+    }
+
+    if (sw->name) {
+        qemu_free (sw->name);
+        sw->name = NULL;
+    }
+    sw->name = qemu_strdup (name);
+    return sw;
+}
+
+int AUD_write (SWVoice *sw, void *buf, int size)
+{
+    int bytes;
+
+    if (!sw->hw->enabled)
+        dolog ("Writing to disabled voice %s\n", sw->name);
+    bytes = sw->hw->pcm_ops->write (sw, buf, size);
+    return bytes;
+}
+
+void AUD_run (void)
+{
+    HWVoice *hw = NULL;
+
+    while ((hw = pcm_hw_find_any_active_enabled (hw))) {
+        int i;
+        if (hw->pending_disable && pcm_hw_get_live (hw) <= 0) {
+            hw->enabled = 0;
+            hw->pcm_ops->ctl (hw, VOICE_DISABLE);
+            for (i = 0; i < hw->nb_voices; i++) {
+                hw->pvoice[i]->live = 0;
+                /* hw->pvoice[i]->old_ticks = 0; */
+            }
+            continue;
+        }
+
+        hw->pcm_ops->run (hw);
+        assert (hw->rpos < hw->samples);
+        for (i = 0; i < hw->nb_voices; i++) {
+            SWVoice *sw = hw->pvoice[i];
+            if (!sw->active && !sw->live && sw->old_ticks) {
+                int64_t delta = qemu_get_clock (vm_clock) - sw->old_ticks;
+                if (delta > audio_state.ticks_threshold) {
+                    ldebug ("resetting old_ticks for %s\n", sw->name);
+                    sw->old_ticks = 0;
+                }
+            }
+        }
+    }
+}
+
+int AUD_get_free (SWVoice *sw)
+{
+    int free;
+
+    if (!sw)
+        return 4096;
+
+    free = ((sw->hw->samples - sw->live) << sw->hw->shift) * sw->ratio
+        / INT_MAX;
+
+    free &= ~sw->hw->align;
+    if (!free) return 0;
+
+    return free;
+}
+
+int AUD_get_buffer_size (SWVoice *sw)
+{
+    return sw->hw->bufsize;
+}
+
+void AUD_adjust (SWVoice *sw, int bytes)
+{
+    if (!sw)
+        return;
+    sw->old_ticks += (ticks_per_sec * (int64_t) bytes) / sw->bytes_per_second;
+}
+
+void AUD_reset (SWVoice *sw)
+{
+    sw->active = 0;
+    sw->old_ticks = 0;
+}
+
+int AUD_calc_elapsed (SWVoice *sw)
+{
+    int64_t now, delta, bytes;
+    int dead, swlim;
+
+    if (!sw)
+        return 0;
+
+    now = qemu_get_clock (vm_clock);
+    delta = now - sw->old_ticks;
+    bytes = (delta * sw->bytes_per_second) / ticks_per_sec;
+    if (delta < 0) {
+        dolog ("whoops delta(<0)=%lld\n", delta);
+        return 0;
+    }
+
+    dead = sw->hw->samples - sw->live;
+    swlim = ((dead * (int64_t) INT_MAX) / sw->ratio);
+
+    if (bytes > swlim) {
+        return swlim;
+    }
+    else {
+        return bytes;
+    }
+}
+
+void AUD_enable (SWVoice *sw, int on)
+{
+    int i;
+    HWVoice *hw;
+
+    if (!sw)
+        return;
+
+    hw = sw->hw;
+    if (on) {
+        if (!sw->live)
+            sw->wpos = sw->hw->rpos;
+        if (!sw->old_ticks) {
+            sw->old_ticks = qemu_get_clock (vm_clock);
+        }
+    }
+
+    if (sw->active != on) {
+        if (on) {
+            hw->pending_disable = 0;
+            if (!hw->enabled) {
+                hw->enabled = 1;
+                for (i = 0; i < hw->nb_voices; i++) {
+                    ldebug ("resetting voice\n");
+                    sw = hw->pvoice[i];
+                    sw->old_ticks = qemu_get_clock (vm_clock);
+                }
+                hw->pcm_ops->ctl (hw, VOICE_ENABLE);
+            }
+        }
+        else {
+            if (hw->enabled && !hw->pending_disable) {
+                int nb_active = 0;
+                for (i = 0; i < hw->nb_voices; i++) {
+                    nb_active += hw->pvoice[i]->active != 0;
+                }
+
+                if (nb_active == 1) {
+                    hw->pending_disable = 1;
+                }
+            }
+        }
+        sw->active = on;
+    }
+}
+
+static struct audio_output_driver *drvtab[] = {
+#ifdef USE_OSS_AUDIO
+    &oss_output_driver,
+#endif
+#ifdef USE_FMOD_AUDIO
+    &fmod_output_driver,
+#endif
+#ifdef USE_SDL_AUDIO
+    &sdl_output_driver,
+#endif
+#ifdef USE_WAV_AUDIO
+    &wav_output_driver,
+#endif
+};
+
+static int voice_init (struct audio_output_driver *drv)
+{
+    audio_state.opaque = drv->init ();
+    if (audio_state.opaque) {
+        if (audio_state.nb_hw_voices > drv->max_voices) {
+            dolog ("`%s' does not support %d multiple hardware channels\n"
+                   "Resetting to %d\n",
+                   drv->name, audio_state.nb_hw_voices, drv->max_voices);
+            audio_state.nb_hw_voices = drv->max_voices;
+        }
+        hw_voice = qemu_mallocz (audio_state.nb_hw_voices * drv->voice_size);
+        if (hw_voice) {
+            audio_state.drv = drv;
+            return 1;
+        }
+        else {
+            dolog ("Not enough memory for %d `%s' voices (each %d bytes)\n",
+                   audio_state.nb_hw_voices, drv->name, drv->voice_size);
+            drv->fini (audio_state.opaque);
+            return 0;
+        }
+    }
+    else {
+        dolog ("Could not init `%s' audio\n", drv->name);
+        return 0;
+    }
+}
+
+static void audio_vm_stop_handler (void *opaque, int reason)
+{
+    HWVoice *hw = NULL;
+
+    while ((hw = pcm_hw_find_any (hw))) {
+        if (!hw->pcm_ops)
+            continue;
+
+        hw->pcm_ops->ctl (hw, reason ? VOICE_ENABLE : VOICE_DISABLE);
+    }
+}
+
+static void audio_atexit (void)
+{
+    HWVoice *hw = NULL;
+
+    while ((hw = pcm_hw_find_any (hw))) {
+        if (!hw->pcm_ops)
+            continue;
+
+        hw->pcm_ops->ctl (hw, VOICE_DISABLE);
+        hw->pcm_ops->fini (hw);
+    }
+    audio_state.drv->fini (audio_state.opaque);
+}
+
+static void audio_save (QEMUFile *f, void *opaque)
+{
+}
+
+static int audio_load (QEMUFile *f, void *opaque, int version_id)
+{
+    if (version_id != 1)
+        return -EINVAL;
+
+    return 0;
+}
+
+void AUD_init (void)
+{
+    int i;
+    int done = 0;
+    const char *drvname;
+
+    audio_state.fixed_format =
+        !!audio_get_conf_int (QC_FIXED_FORMAT, audio_state.fixed_format);
+    audio_state.fixed_freq =
+        audio_get_conf_int (QC_FIXED_FREQ, audio_state.fixed_freq);
+    audio_state.nb_hw_voices =
+        audio_get_conf_int (QC_VOICES, audio_state.nb_hw_voices);
+
+    if (audio_state.nb_hw_voices <= 0) {
+        dolog ("Bogus number of voices %d, resetting to 1\n",
+               audio_state.nb_hw_voices);
+    }
+
+    drvname = audio_get_conf_str (QC_AUDIO_DRV, NULL);
+    if (drvname) {
+        int found = 0;
+        for (i = 0; i < sizeof (drvtab) / sizeof (drvtab[0]); i++) {
+            if (!strcmp (drvname, drvtab[i]->name)) {
+                done = voice_init (drvtab[i]);
+                found = 1;
+                break;
+            }
+        }
+        if (!found) {
+            dolog ("Unknown audio driver `%s'\n", drvname);
+        }
+    }
+
+    qemu_add_vm_stop_handler (audio_vm_stop_handler, NULL);
+    atexit (audio_atexit);
+
+    if (!done) {
+        for (i = 0; !done && i < sizeof (drvtab) / sizeof (drvtab[0]); i++) {
+            if (drvtab[i]->can_be_default)
+                done = voice_init (drvtab[i]);
+        }
+    }
+
+    audio_state.ticks_threshold = ticks_per_sec / 50;
+    audio_state.freq_threshold = 100;
+
+    register_savevm ("audio", 0, 1, audio_save, audio_load, NULL);
+    if (!done) {
+        dolog ("Can not initialize audio subsystem\n");
+        return;
+    }
+
+    for (i = 0; hw_ctors[i]; i++) {
+        hw_ctors[i] ();
+    }
+}