Initial import

1 files changed, 828 insertions, 0 deletions

diff --git a/Alc/alsa.c b/Alc/alsa.c
new file mode 100644
index 00000000..df866a66
--- /dev/null
+++ b/Alc/alsa.c
@@ -0,0 +1,828 @@
+/**
+ * OpenAL cross platform audio library
+ * Copyright (C) 1999-2007 by authors.
+ * 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 Software Foundation, Inc., 59 Temple Place - Suite 330,
+ *  Boston, MA  02111-1307, USA.
+ * Or go to http://www.gnu.org/copyleft/lgpl.html
+ */
+
+#include "config.h"
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <memory.h>
+#ifdef HAVE_DLFCN_H
+#include <dlfcn.h>
+#endif
+#include "alMain.h"
+#include "AL/al.h"
+#include "AL/alc.h"
+
+#include <alsa/asoundlib.h>
+
+
+typedef struct {
+    snd_pcm_t *pcmHandle;
+    snd_pcm_format_t format;
+    int killNow;
+    ALvoid *thread;
+} alsa_data;
+
+typedef struct {
+    ALCchar *name;
+    int card, dev;
+} DevMap;
+
+static void *alsa_handle;
+#define MAKE_FUNC(f) static typeof(f) * p##f
+MAKE_FUNC(snd_strerror);
+MAKE_FUNC(snd_pcm_open);
+MAKE_FUNC(snd_pcm_close);
+MAKE_FUNC(snd_pcm_nonblock);
+MAKE_FUNC(snd_pcm_frames_to_bytes);
+MAKE_FUNC(snd_pcm_hw_params_malloc);
+MAKE_FUNC(snd_pcm_hw_params_free);
+MAKE_FUNC(snd_pcm_hw_params_any);
+MAKE_FUNC(snd_pcm_hw_params_set_access);
+MAKE_FUNC(snd_pcm_hw_params_set_format);
+MAKE_FUNC(snd_pcm_hw_params_set_channels);
+MAKE_FUNC(snd_pcm_hw_params_set_periods_near);
+MAKE_FUNC(snd_pcm_hw_params_set_rate_near);
+MAKE_FUNC(snd_pcm_hw_params_set_rate);
+MAKE_FUNC(snd_pcm_hw_params_set_buffer_size_near);
+MAKE_FUNC(snd_pcm_hw_params_set_buffer_size_min);
+MAKE_FUNC(snd_pcm_hw_params);
+MAKE_FUNC(snd_pcm_prepare);
+MAKE_FUNC(snd_pcm_start);
+MAKE_FUNC(snd_pcm_resume);
+MAKE_FUNC(snd_pcm_state);
+MAKE_FUNC(snd_pcm_avail_update);
+MAKE_FUNC(snd_pcm_areas_silence);
+MAKE_FUNC(snd_pcm_mmap_begin);
+MAKE_FUNC(snd_pcm_mmap_commit);
+MAKE_FUNC(snd_pcm_drain);
+MAKE_FUNC(snd_pcm_info_malloc);
+MAKE_FUNC(snd_pcm_info_free);
+MAKE_FUNC(snd_pcm_info_set_device);
+MAKE_FUNC(snd_pcm_info_set_subdevice);
+MAKE_FUNC(snd_pcm_info_set_stream);
+MAKE_FUNC(snd_pcm_info_get_name);
+MAKE_FUNC(snd_ctl_pcm_next_device);
+MAKE_FUNC(snd_ctl_pcm_info);
+MAKE_FUNC(snd_ctl_open);
+MAKE_FUNC(snd_ctl_close);
+MAKE_FUNC(snd_ctl_card_info_malloc);
+MAKE_FUNC(snd_ctl_card_info_free);
+MAKE_FUNC(snd_ctl_card_info);
+MAKE_FUNC(snd_ctl_card_info_get_name);
+MAKE_FUNC(snd_card_next);
+#undef MAKE_FUNC
+
+#define MAX_DEVICES 16
+#define MAX_ALL_DEVICES 32
+
+static DevMap allDevNameMap[MAX_ALL_DEVICES];
+static ALCchar *alsaDeviceList[MAX_DEVICES];
+static ALCchar *alsaCaptureDeviceList[MAX_DEVICES];
+
+static int xrun_recovery(snd_pcm_t *handle, int err)
+{
+    if (err == -EPIPE)
+    {    /* under-run */
+        err = psnd_pcm_prepare(handle);
+        if(err >= 0)
+            err = psnd_pcm_start(handle);
+        if (err < 0)
+            printf("Can't recover from underrun, prepare failed: %s\n", psnd_strerror(err));
+    }
+    else if (err == -ESTRPIPE)
+    {
+        while ((err = psnd_pcm_resume(handle)) == -EAGAIN)
+            usleep(1);       /* wait until the suspend flag is released */
+        if (err < 0)
+        {
+            err = psnd_pcm_prepare(handle);
+            if(err >= 0)
+                err = psnd_pcm_start(handle);
+            if (err < 0)
+                printf("Can't recover from suspend, prepare failed: %s\n", psnd_strerror(err));
+        }
+    }
+    return err;
+}
+
+
+static ALuint ALSAProc(ALvoid *ptr)
+{
+    ALCdevice *pDevice = (ALCdevice*)ptr;
+    alsa_data *data = (alsa_data*)pDevice->ExtraData;
+    const snd_pcm_channel_area_t *areas = NULL;
+    snd_pcm_sframes_t avail, commitres;
+    snd_pcm_uframes_t offset, frames;
+    char *WritePtr;
+    int WriteCnt;
+    int err;
+
+    while(!data->killNow)
+    {
+        snd_pcm_state_t state = psnd_pcm_state(data->pcmHandle);
+        if(state == SND_PCM_STATE_XRUN)
+        {
+            err = xrun_recovery(data->pcmHandle, -EPIPE);
+            if (err < 0)
+            {
+                fprintf(stderr, "XRUN recovery failed: %s\n", psnd_strerror(err));
+                break;
+            }
+        }
+        else if (state == SND_PCM_STATE_SUSPENDED)
+        {
+            err = xrun_recovery(data->pcmHandle, -ESTRPIPE);
+            if (err < 0)
+            {
+                fprintf(stderr, "SUSPEND recovery failed: %s\n", psnd_strerror(err));
+                break;
+            }
+        }
+
+        avail = psnd_pcm_avail_update(data->pcmHandle);
+        if(avail < 0)
+        {
+            err = xrun_recovery(data->pcmHandle, avail);
+            if (err < 0)
+            {
+                fprintf(stderr, "available update failed: %s\n", psnd_strerror(err));
+                break;
+            }
+        }
+
+        // make sure there's frames to process
+        if(avail == 0)
+        {
+            usleep(1000);
+            continue;
+        }
+
+        // it is possible that contiguous areas are smaller, thus we use a loop
+        while (avail > 0)
+        {
+            frames = avail;
+
+            err = psnd_pcm_mmap_begin(data->pcmHandle, &areas, &offset, &frames);
+            if (err < 0)
+            {
+                err = xrun_recovery(data->pcmHandle, err);
+                if (err < 0)
+                    fprintf(stderr, "mmap begin error: %s\n", psnd_strerror(err));
+                break;
+            }
+
+            SuspendContext(NULL);
+            if(pDevice->Context)
+            {
+                // If we have an active context, mix data directly into output
+                // buffer
+                WritePtr = (char*)areas->addr + (offset * areas->step / 8);
+                WriteCnt = psnd_pcm_frames_to_bytes(data->pcmHandle, frames);
+
+                aluMixData(pDevice->Context, WritePtr, WriteCnt, pDevice->Format);
+            }
+            else
+                psnd_pcm_areas_silence(areas, offset, pDevice->Channels, frames, data->format);
+            ProcessContext(NULL);
+
+            commitres = psnd_pcm_mmap_commit(data->pcmHandle, offset, frames);
+            if (commitres < 0 || (commitres-frames) != 0)
+            {
+                fprintf(stderr, "mmap commit error: %s\n",
+                        psnd_strerror(commitres >= 0 ? -EPIPE : commitres));
+                break;
+            }
+
+            avail -= frames;
+        }
+    }
+
+    return 0;
+}
+
+static void fill_silence(snd_pcm_t *pcmHandle, snd_pcm_format_t alsaFormat, int channels)
+{
+    const snd_pcm_channel_area_t *areas = NULL;
+    snd_pcm_sframes_t avail, commitres;
+    snd_pcm_uframes_t offset, frames;
+    int err;
+
+    avail = psnd_pcm_avail_update(pcmHandle);
+    if(avail < 0)
+    {
+        err = xrun_recovery(pcmHandle, avail);
+        if (err < 0)
+        {
+            fprintf(stderr, "available update failed: %s\n", psnd_strerror(err));
+            return;
+        }
+    }
+
+    // it is possible that contiguous areas are smaller, thus we use a loop
+    while (avail > 0)
+    {
+        frames = avail;
+
+        err = psnd_pcm_mmap_begin(pcmHandle, &areas, &offset, &frames);
+        if (err < 0)
+        {
+            err = xrun_recovery(pcmHandle, err);
+            if (err < 0)
+            {
+                fprintf(stderr, "mmap begin error: %s\n", psnd_strerror(err));
+                break;
+            }
+            continue;
+        }
+
+        psnd_pcm_areas_silence(areas, offset, channels, frames, alsaFormat);
+
+        commitres = psnd_pcm_mmap_commit(pcmHandle, offset, frames);
+        if (commitres < 0 || (commitres-frames) != 0)
+        {
+            fprintf(stderr, "mmap commit error: %s\n",
+                    psnd_strerror(commitres >= 0 ? -EPIPE : commitres));
+            break;
+        }
+
+        avail -= frames;
+    }
+}
+
+static ALCboolean alsa_open_playback(ALCdevice *device, const ALCchar *deviceName)
+{
+    snd_pcm_uframes_t bufferSizeInFrames;
+    snd_pcm_hw_params_t *p = NULL;
+    unsigned int periods;
+    alsa_data *data;
+    char driver[64];
+    int i;
+
+    strncpy(driver, GetConfigValue("alsa", "default", "default"), sizeof(driver)-1);
+    driver[sizeof(driver)-1] = 0;
+    if(deviceName)
+    {
+        size_t idx;
+
+        for(idx = 0;idx < MAX_ALL_DEVICES;idx++)
+        {
+            if(allDevNameMap[idx].name &&
+               strcmp(deviceName, allDevNameMap[idx].name) == 0)
+            {
+                if(idx > 0)
+                    sprintf(driver, "hw:%d,%d", allDevNameMap[idx].card, allDevNameMap[idx].dev);
+                goto open_alsa;
+            }
+        }
+        for(idx = 0;idx < MAX_DEVICES;idx++)
+        {
+            if(alsaDeviceList[idx] &&
+               strcmp(deviceName, alsaDeviceList[idx]) == 0)
+            {
+                if(idx > 0)
+                    sprintf(driver, "hw:%d,0", idx-1);
+                goto open_alsa;
+            }
+        }
+        return ALC_FALSE;
+    }
+
+    if(deviceName)
+        strcpy(device->szDeviceName, deviceName);
+    else
+        strcpy(device->szDeviceName, alsaDeviceList[0]);
+
+open_alsa:
+    data = (alsa_data*)calloc(1, sizeof(alsa_data));
+
+    i = psnd_pcm_open(&data->pcmHandle, driver, SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK);
+    if(i < 0)
+    {
+        usleep(200000);
+        i = psnd_pcm_open(&data->pcmHandle, driver, SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK);
+    }
+    if(i >= 0)
+    {
+        i = psnd_pcm_nonblock(data->pcmHandle, 0);
+        if(i < 0)
+            psnd_pcm_close(data->pcmHandle);
+    }
+    if(i < 0)
+    {
+        free(data);
+        return ALC_FALSE;
+    }
+
+    switch(device->Format)
+    {
+        case AL_FORMAT_MONO8:
+        case AL_FORMAT_STEREO8:
+        case AL_FORMAT_QUAD8:
+            data->format = SND_PCM_FORMAT_U8;
+            break;
+        case AL_FORMAT_MONO16:
+        case AL_FORMAT_STEREO16:
+        case AL_FORMAT_QUAD16:
+            data->format = SND_PCM_FORMAT_S16;
+            break;
+        default:
+            data->format = SND_PCM_FORMAT_UNKNOWN;
+            fprintf(stderr, "Unknown format?! %x\n", device->Format);
+    }
+
+    periods = GetConfigValueInt("alsa", "periods", 4);
+    if((int)periods <= 0)
+        periods = 4;
+    bufferSizeInFrames = device->UpdateFreq;
+
+    psnd_pcm_hw_params_malloc(&p);
+#define ok(func, str) (i=(func),((i<0)?fprintf(stderr,"%s failed: %s\n", str, psnd_strerror(i)),0:1))
+    /* start with the largest configuration space possible */
+    if(!(ok(psnd_pcm_hw_params_any(data->pcmHandle, p), "any") &&
+         /* set interleaved access */
+         ok(psnd_pcm_hw_params_set_access(data->pcmHandle, p, SND_PCM_ACCESS_MMAP_INTERLEAVED), "set access") &&
+         /* set format (implicitly sets sample bits) */
+         ok(psnd_pcm_hw_params_set_format(data->pcmHandle, p, data->format), "set format") &&
+         /* set channels (implicitly sets frame bits) */
+         ok(psnd_pcm_hw_params_set_channels(data->pcmHandle, p, device->Channels), "set channels") &&
+         /* set periods (implicitly constrains period/buffer parameters) */
+         ok(psnd_pcm_hw_params_set_periods_near(data->pcmHandle, p, &periods, NULL), "set periods near") &&
+         /* set rate (implicitly constrains period/buffer parameters) */
+         ok(psnd_pcm_hw_params_set_rate_near(data->pcmHandle, p, &device->Frequency, NULL), "set rate near") &&
+         /* set buffer size in frame units (implicitly sets period size/bytes/time and buffer time/bytes) */
+         ok(psnd_pcm_hw_params_set_buffer_size_near(data->pcmHandle, p, &bufferSizeInFrames), "set buffer size near") &&
+         /* install and prepare hardware configuration */
+         ok(psnd_pcm_hw_params(data->pcmHandle, p), "set params")))
+    {
+        psnd_pcm_hw_params_free(p);
+        psnd_pcm_close(data->pcmHandle);
+        free(data);
+        return ALC_FALSE;
+    }
+#undef ok
+    psnd_pcm_hw_params_free(p);
+
+    device->MaxNoOfSources = 256;
+    device->UpdateFreq = bufferSizeInFrames;
+
+    i = psnd_pcm_prepare(data->pcmHandle);
+    if(i < 0)
+    {
+        fprintf(stderr, "prepare error: %s\n", psnd_strerror(i));
+        psnd_pcm_close(data->pcmHandle);
+        free(data);
+        return ALC_FALSE;
+    }
+
+    fill_silence(data->pcmHandle, data->format, device->Channels);
+    i = psnd_pcm_start(data->pcmHandle);
+    if(i < 0)
+    {
+        fprintf(stderr, "start error: %s\n", psnd_strerror(i));
+        psnd_pcm_close(data->pcmHandle);
+        free(data);
+        return ALC_FALSE;
+    }
+
+    device->ExtraData = data;
+    data->thread = StartThread(ALSAProc, device);
+    if(data->thread == NULL)
+    {
+        psnd_pcm_close(data->pcmHandle);
+        device->ExtraData = NULL;
+        free(data);
+        return ALC_FALSE;
+    }
+
+    return ALC_TRUE;
+}
+
+static void alsa_close_playback(ALCdevice *device)
+{
+    alsa_data *data = (alsa_data*)device->ExtraData;
+    data->killNow = 1;
+    StopThread(data->thread);
+    psnd_pcm_close(data->pcmHandle);
+
+    free(data);
+    device->ExtraData = NULL;
+}
+
+
+static ALCboolean alsa_open_capture(ALCdevice *pDevice, const ALCchar *deviceName, ALCuint frequency, ALCenum format, ALCsizei SampleSize)
+{
+    snd_pcm_format_t alsaFormat;
+    snd_pcm_hw_params_t *p;
+    unsigned int periods = 4;
+    snd_pcm_uframes_t bufferSizeInFrames = SampleSize;
+    alsa_data *data;
+    char driver[64];
+    int i;
+
+    strncpy(driver, GetConfigValue("alsa", "capture", "default"), sizeof(driver)-1);
+    driver[sizeof(driver)-1] = 0;
+    if(deviceName)
+    {
+        size_t idx;
+
+        for(idx = 0;idx < MAX_DEVICES;idx++)
+        {
+            if(alsaCaptureDeviceList[idx] &&
+               strcmp(deviceName, alsaCaptureDeviceList[idx]) == 0)
+            {
+                if(idx > 0)
+                    sprintf(driver, "hw:%d,0", idx-1);
+                goto open_alsa;
+            }
+        }
+        return ALC_FALSE;
+    }
+
+    if(deviceName)
+        strcpy(pDevice->szDeviceName, deviceName);
+    else
+        strcpy(pDevice->szDeviceName, alsaCaptureDeviceList[0]);
+
+open_alsa:
+    data = (alsa_data*)calloc(1, sizeof(alsa_data));
+
+    i = psnd_pcm_open(&data->pcmHandle, driver, SND_PCM_STREAM_CAPTURE, SND_PCM_NONBLOCK);
+    if(i < 0)
+    {
+        usleep(200000);
+        i = psnd_pcm_open(&data->pcmHandle, driver, SND_PCM_STREAM_CAPTURE, SND_PCM_NONBLOCK);
+    }
+    if(i >= 0)
+    {
+        i = psnd_pcm_nonblock(data->pcmHandle, 0);
+        if(i < 0)
+            psnd_pcm_close(data->pcmHandle);
+    }
+    if(i < 0)
+    {
+        free(data);
+        return ALC_FALSE;
+    }
+
+    switch(aluBytesFromFormat(format))
+    {
+        case 1:
+            alsaFormat = SND_PCM_FORMAT_U8;
+            break;
+        case 2:
+            alsaFormat = SND_PCM_FORMAT_S16;
+            break;
+        default:
+            alsaFormat = SND_PCM_FORMAT_UNKNOWN;
+            fprintf(stderr, "Unknown format?! %x\n", format);
+    }
+
+    psnd_pcm_hw_params_malloc(&p);
+#define ok(func, str) (i=(func),((i<0)?fprintf(stderr,"%s failed\n", str),0:1))
+    /* start with the largest configuration space possible */
+    if(!(ok(psnd_pcm_hw_params_any(data->pcmHandle, p), "any") &&
+         /* set interleaved access */
+         ok(psnd_pcm_hw_params_set_access(data->pcmHandle, p, SND_PCM_ACCESS_MMAP_INTERLEAVED), "set access") &&
+         /* set format (implicitly sets sample bits) */
+         ok(psnd_pcm_hw_params_set_format(data->pcmHandle, p, alsaFormat), "set format") &&
+         /* set channels (implicitly sets frame bits) */
+         ok(psnd_pcm_hw_params_set_channels(data->pcmHandle, p, pDevice->Channels), "set channels") &&
+         /* set periods (implicitly constrains period/buffer parameters) */
+         ok(psnd_pcm_hw_params_set_periods_near(data->pcmHandle, p, &periods, NULL), "set periods near") &&
+         /* set rate (implicitly constrains period/buffer parameters) */
+         ok(psnd_pcm_hw_params_set_rate(data->pcmHandle, p, frequency, 0), "set rate") &&
+         /* set buffer size in frame units (implicitly sets period size/bytes/time and buffer time/bytes) */
+         ok(psnd_pcm_hw_params_set_buffer_size_min(data->pcmHandle, p, &bufferSizeInFrames), "set buffer size min") &&
+         /* install and prepare hardware configuration */
+         ok(psnd_pcm_hw_params(data->pcmHandle, p), "set params")))
+    {
+        psnd_pcm_hw_params_free(p);
+        psnd_pcm_close(data->pcmHandle);
+        free(data);
+        return ALC_FALSE;
+    }
+#undef ok
+    psnd_pcm_hw_params_free(p);
+
+    i = psnd_pcm_prepare(data->pcmHandle);
+    if(i < 0)
+    {
+        fprintf(stderr, "prepare error: %s\n", psnd_strerror(i));
+        psnd_pcm_close(data->pcmHandle);
+        free(data);
+        return ALC_FALSE;
+    }
+
+    pDevice->ExtraData = data;
+    return ALC_TRUE;
+}
+
+static void alsa_close_capture(ALCdevice *pDevice)
+{
+    alsa_data *data = (alsa_data*)pDevice->ExtraData;
+    psnd_pcm_close(data->pcmHandle);
+
+    free(data);
+    pDevice->ExtraData = NULL;
+}
+
+static void alsa_start_capture(ALCdevice *pDevice)
+{
+    alsa_data *data = (alsa_data*)pDevice->ExtraData;
+    psnd_pcm_start(data->pcmHandle);
+}
+
+static void alsa_stop_capture(ALCdevice *pDevice)
+{
+    alsa_data *data = (alsa_data*)pDevice->ExtraData;
+    psnd_pcm_drain(data->pcmHandle);
+}
+
+static void alsa_capture_samples(ALCdevice *pDevice, ALCvoid *pBuffer, ALCuint lSamples)
+{
+    alsa_data *data = (alsa_data*)pDevice->ExtraData;
+    const snd_pcm_channel_area_t *areas = NULL;
+    snd_pcm_sframes_t frames, commitres;
+    snd_pcm_uframes_t size, offset;
+    int err;
+
+    frames = psnd_pcm_avail_update(data->pcmHandle);
+    if(frames < 0)
+    {
+        err = xrun_recovery(data->pcmHandle, frames);
+        if (err < 0)
+            fprintf(stderr, "available update failed: %s\n", psnd_strerror(err));
+        else
+            frames = psnd_pcm_avail_update(data->pcmHandle);
+    }
+    if (frames < (snd_pcm_sframes_t)lSamples)
+    {
+        SetALCError(ALC_INVALID_VALUE);
+        return;
+    }
+
+    // it is possible that contiguous areas are smaller, thus we use a loop
+    while (lSamples > 0)
+    {
+        char *Pointer;
+        int Count;
+
+        size = lSamples;
+        err = psnd_pcm_mmap_begin(data->pcmHandle, &areas, &offset, &size);
+        if (err < 0)
+        {
+            err = xrun_recovery(data->pcmHandle, err);
+            if (err < 0)
+            {
+                fprintf(stderr, "mmap begin error: %s\n", psnd_strerror(err));
+                break;
+            }
+            continue;
+        }
+
+        Pointer = (char*)areas->addr + (offset * areas->step / 8);
+        Count = size * pDevice->FrameSize;
+
+        memcpy(pBuffer, Pointer, Count);
+        pBuffer = (char*)pBuffer + Count;
+
+        commitres = psnd_pcm_mmap_commit(data->pcmHandle, offset, size);
+        if (commitres < 0 || (commitres-size) != 0)
+        {
+           fprintf(stderr, "mmap commit error: %s\n",
+                   psnd_strerror(commitres >= 0 ? -EPIPE : commitres));
+           break;
+        }
+
+        lSamples -= size;
+    }
+}
+
+static ALCuint alsa_available_samples(ALCdevice *pDevice)
+{
+    alsa_data *data = (alsa_data*)pDevice->ExtraData;
+    snd_pcm_sframes_t frames = psnd_pcm_avail_update(data->pcmHandle);
+    if(frames < 0)
+    {
+        int err = xrun_recovery(data->pcmHandle, frames);
+        if (err < 0)
+            fprintf(stderr, "available update failed: %s\n", psnd_strerror(err));
+        else
+            frames = psnd_pcm_avail_update(data->pcmHandle);
+        if(frames < 0) /* ew.. */
+            SetALCError(ALC_INVALID_DEVICE);
+    }
+    return max(frames, 0);
+}
+
+
+BackendFuncs alsa_funcs = {
+    alsa_open_playback,
+    alsa_close_playback,
+    alsa_open_capture,
+    alsa_close_capture,
+    alsa_start_capture,
+    alsa_stop_capture,
+    alsa_capture_samples,
+    alsa_available_samples
+};
+
+void alc_alsa_init(BackendFuncs *func_list)
+{
+#define error(...) do { \
+    fprintf(stderr, __VA_ARGS__); \
+    fprintf(stderr, "\n"); \
+}while(0)
+    snd_ctl_t *handle;
+    int card, err, dev, idx = 1;
+    snd_ctl_card_info_t *info;
+    snd_pcm_info_t *pcminfo;
+    snd_pcm_stream_t stream = SND_PCM_STREAM_PLAYBACK;
+    char name[128];
+    char *str;
+
+    *func_list = alsa_funcs;
+
+#ifdef HAVE_DLFCN_H
+    alsa_handle = dlopen("libasound.so.2", RTLD_NOW);
+    if(!alsa_handle)
+        return;
+    dlerror();
+
+#define LOAD_FUNC(f) do { \
+    p##f = (typeof(f)*)dlsym(alsa_handle, #f); \
+    if((str=dlerror()) != NULL) \
+    { \
+        dlclose(alsa_handle); \
+        alsa_handle = NULL; \
+        error("Could not load %s from libasound.so.2: %s", #f, str); \
+        return; \
+    } \
+} while(0)
+#else
+    str = NULL;
+    alsa_handle = NULL;
+#define LOAD_FUNC(f) p##f = f
+#endif
+
+LOAD_FUNC(snd_strerror);
+LOAD_FUNC(snd_pcm_open);
+LOAD_FUNC(snd_pcm_close);
+LOAD_FUNC(snd_pcm_nonblock);
+LOAD_FUNC(snd_pcm_frames_to_bytes);
+LOAD_FUNC(snd_pcm_hw_params_malloc);
+LOAD_FUNC(snd_pcm_hw_params_free);
+LOAD_FUNC(snd_pcm_hw_params_any);
+LOAD_FUNC(snd_pcm_hw_params_set_access);
+LOAD_FUNC(snd_pcm_hw_params_set_format);
+LOAD_FUNC(snd_pcm_hw_params_set_channels);
+LOAD_FUNC(snd_pcm_hw_params_set_periods_near);
+LOAD_FUNC(snd_pcm_hw_params_set_rate_near);
+LOAD_FUNC(snd_pcm_hw_params_set_rate);
+LOAD_FUNC(snd_pcm_hw_params_set_buffer_size_near);
+LOAD_FUNC(snd_pcm_hw_params_set_buffer_size_min);
+LOAD_FUNC(snd_pcm_hw_params);
+LOAD_FUNC(snd_pcm_prepare);
+LOAD_FUNC(snd_pcm_start);
+LOAD_FUNC(snd_pcm_resume);
+LOAD_FUNC(snd_pcm_state);
+LOAD_FUNC(snd_pcm_avail_update);
+LOAD_FUNC(snd_pcm_areas_silence);
+LOAD_FUNC(snd_pcm_mmap_begin);
+LOAD_FUNC(snd_pcm_mmap_commit);
+LOAD_FUNC(snd_pcm_drain);
+
+LOAD_FUNC(snd_pcm_info_malloc);
+LOAD_FUNC(snd_pcm_info_free);
+LOAD_FUNC(snd_pcm_info_set_device);
+LOAD_FUNC(snd_pcm_info_set_subdevice);
+LOAD_FUNC(snd_pcm_info_set_stream);
+LOAD_FUNC(snd_pcm_info_get_name);
+LOAD_FUNC(snd_ctl_pcm_next_device);
+LOAD_FUNC(snd_ctl_pcm_info);
+LOAD_FUNC(snd_ctl_open);
+LOAD_FUNC(snd_ctl_close);
+LOAD_FUNC(snd_ctl_card_info_malloc);
+LOAD_FUNC(snd_ctl_card_info_free);
+LOAD_FUNC(snd_ctl_card_info);
+LOAD_FUNC(snd_ctl_card_info_get_name);
+LOAD_FUNC(snd_card_next);
+
+#undef LOAD_FUNC
+
+    psnd_ctl_card_info_malloc(&info);
+    psnd_pcm_info_malloc(&pcminfo);
+
+    card = -1;
+    if(psnd_card_next(&card) < 0 || card < 0)
+        error("no playback cards found...");
+    else
+    {
+        alsaDeviceList[0] = AppendDeviceList("ALSA Software on default");
+        allDevNameMap[0].name = AppendAllDeviceList("ALSA Software on default");
+    }
+
+    while (card >= 0) {
+        sprintf(name, "hw:%d", card);
+        if ((err = psnd_ctl_open(&handle, name, 0)) < 0) {
+            error("control open (%i): %s", card, psnd_strerror(err));
+            goto next_card;
+        }
+        if ((err = psnd_ctl_card_info(handle, info)) < 0) {
+            error("control hardware info (%i): %s", card, psnd_strerror(err));
+            psnd_ctl_close(handle);
+            goto next_card;
+        }
+        if(card < MAX_DEVICES-1) {
+            snprintf(name, sizeof(name), "ALSA Software on %s",
+                     psnd_ctl_card_info_get_name(info));
+            alsaDeviceList[card+1] = AppendDeviceList(name);
+        }
+
+        dev = -1;
+        while (idx < MAX_ALL_DEVICES) {
+            if (psnd_ctl_pcm_next_device(handle, &dev)<0)
+                error("snd_ctl_pcm_next_device");
+            if (dev < 0)
+                break;
+            psnd_pcm_info_set_device(pcminfo, dev);
+            psnd_pcm_info_set_subdevice(pcminfo, 0);
+            psnd_pcm_info_set_stream(pcminfo, stream);
+            if ((err = psnd_ctl_pcm_info(handle, pcminfo)) < 0) {
+                if (err != -ENOENT)
+                    error("control digital audio info (%i): %s", card, psnd_strerror(err));
+                continue;
+            }
+            snprintf(name, sizeof(name), "ALSA Software on %s [%s]",
+                     psnd_ctl_card_info_get_name(info),
+                     psnd_pcm_info_get_name(pcminfo));
+            allDevNameMap[idx].name = AppendAllDeviceList(name);
+            allDevNameMap[idx].card = card;
+            allDevNameMap[idx].dev = dev;
+            idx++;
+        }
+        psnd_ctl_close(handle);
+next_card:
+        if(psnd_card_next(&card) < 0) {
+            error("snd_card_next");
+            break;
+        }
+    }
+
+
+    stream = SND_PCM_STREAM_CAPTURE;
+
+    card = -1;
+    if(psnd_card_next(&card) < 0 || card < 0) {
+        error("no capture cards found...");
+        psnd_pcm_info_free(pcminfo);
+        psnd_ctl_card_info_free(info);
+        return;
+    }
+
+    alsaCaptureDeviceList[0] = AppendCaptureDeviceList("ALSA Capture on default");
+
+    while (card >= 0) {
+        sprintf(name, "hw:%d", card);
+        handle = NULL;
+        if ((err = psnd_ctl_open(&handle, name, 0)) < 0) {
+            error("control open (%i): %s", card, psnd_strerror(err));
+        }
+        if (err >= 0 && (err = psnd_ctl_card_info(handle, info)) < 0) {
+            error("control hardware info (%i): %s", card, psnd_strerror(err));
+            psnd_ctl_close(handle);
+        }
+        else if (err >= 0 && card < MAX_DEVICES-1)
+        {
+            snprintf(name, sizeof(name), "ALSA Capture on %s",
+                     psnd_ctl_card_info_get_name(info));
+            alsaCaptureDeviceList[card+1] = AppendCaptureDeviceList(name);
+        }
+        if(handle) psnd_ctl_close(handle);
+        if(psnd_card_next(&card) < 0) {
+            error("snd_card_next");
+            break;
+        }
+    }
+    psnd_pcm_info_free(pcminfo);
+    psnd_ctl_card_info_free(info);
+#undef error
+}