static void ALSA_MMap_Submit (soundcardinfo_t *sc, int start, int end)
{
int state;
int count = end - start;
const snd_pcm_channel_area_t *areas;
snd_pcm_uframes_t nframes;
snd_pcm_uframes_t offset;
nframes = count / sc->sn.numchannels;
psnd_pcm_avail_update (sc->handle);
psnd_pcm_mmap_begin (sc->handle, &areas, &offset, &nframes);
state = psnd_pcm_state (sc->handle);
switch (state) {
case SND_PCM_STATE_PREPARED:
psnd_pcm_mmap_commit (sc->handle, offset, nframes);
psnd_pcm_start (sc->handle);
break;
case SND_PCM_STATE_RUNNING:
psnd_pcm_mmap_commit (sc->handle, offset, nframes);
break;
default:
break;
}
}
static unsigned int ALSA_MMap_GetDMAPos (soundcardinfo_t *sc)
{
const snd_pcm_channel_area_t *areas;
snd_pcm_uframes_t offset;
snd_pcm_uframes_t nframes = sc->sn.samples / sc->sn.numchannels;
psnd_pcm_avail_update (sc->handle);
psnd_pcm_mmap_begin (sc->handle, &areas, &offset, &nframes);
offset *= sc->sn.numchannels;
nframes *= sc->sn.numchannels;
sc->sn.samplepos = offset;
sc->sn.buffer = areas->addr;
return sc->sn.samplepos;
}
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 err;
while(!data->killNow)
{
int state = verify_state(data->pcmHandle);
if(state < 0)
{
AL_PRINT("Invalid state detected: %s\n", psnd_strerror(state));
aluHandleDisconnect(pDevice);
break;
}
avail = psnd_pcm_avail_update(data->pcmHandle);
if(avail < 0)
{
AL_PRINT("available update failed: %s\n", psnd_strerror(avail));
continue;
}
// make sure there's frames to process
if(avail >= 0 && avail < (snd_pcm_sframes_t)pDevice->UpdateSize)
{
if(state != SND_PCM_STATE_RUNNING)
{
err = psnd_pcm_start(data->pcmHandle);
if(err < 0)
{
AL_PRINT("start failed: %s\n", psnd_strerror(err));
continue;
}
}
if(psnd_pcm_wait(data->pcmHandle, 1000) == 0)
AL_PRINT("Wait timeout... buffer size too low?\n");
continue;
}
avail -= avail%pDevice->UpdateSize;
// 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)
{
AL_PRINT("mmap begin error: %s\n", psnd_strerror(err));
break;
}
WritePtr = (char*)areas->addr + (offset * areas->step / 8);
aluMixData(pDevice, WritePtr, frames);
commitres = psnd_pcm_mmap_commit(data->pcmHandle, offset, frames);
if(commitres < 0 || (commitres-frames) != 0)
{
AL_PRINT("mmap commit error: %s\n",
psnd_strerror(commitres >= 0 ? -EPIPE : commitres));
break;
}
avail -= frames;
}
}
return 0;
}
