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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/***************************************************************************
* audiooutputenginealsa.cc
*
* Thu Sep 16 11:22:52 CEST 2010
* Copyright 2010 Bent Bisballe Nyeng
* deva@aasimon.org
****************************************************************************/
/*
* This file is part of DrumGizmo.
*
* DrumGizmo is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* DrumGizmo 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with DrumGizmo; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
*/
#include "audiooutputenginealsa.h"
#include "drumgizmo.h"
#include <string>
#include <math.h>
#include <sys/time.h>
#define T(x, msg) if(x < 0) { printf("%s failed: %s\n", msg, snd_strerror(x)); fflush(stdout); return false; }
#define T_(x, msg) if(x < 0) { printf("%s failed: %s\n", msg, snd_strerror(x)); fflush(stdout); return; }
AudioOutputEngineAlsa::AudioOutputEngineAlsa()
{
printf("AudioOutputEngineAlsa\n");
int rc;
std::string pcmname = "default";
rc = snd_pcm_open(&handle, pcmname.c_str(),
SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK);
T_(rc, "snd_pcm_open");
}
AudioOutputEngineAlsa::~AudioOutputEngineAlsa()
{
printf("~AudioOutputEngineAlsa\n");
if(handle) snd_pcm_close(handle);
}
bool AudioOutputEngineAlsa::init(Channels *channels)
{
this->channels = channels;
if(!handle) {
printf("No handle!\n");
return false;
}
int rc;
unsigned int srate = 44100;
snd_pcm_uframes_t frames = 32;
// Allocate a hardware parameters object.
snd_pcm_hw_params_alloca(¶ms);
// if(rc < 0) return false;
// Fill it in with default values.
rc = snd_pcm_hw_params_any(handle, params);
T(rc, "snd_pcm_hw_params_any");
rc = snd_pcm_hw_params_set_access(handle, params,
SND_PCM_ACCESS_MMAP_NONINTERLEAVED);
T(rc, "snd_pcm_hw_params_set_access");
rc = snd_pcm_hw_params_set_format(handle, params, SND_PCM_FORMAT_FLOAT);
T(rc, "snd_pcm_hw_params_set_format");
rc = snd_pcm_hw_params_set_channels(handle, params, channels->size());
T(rc, "snd_pcm_hw_params_set_channels");
rc = snd_pcm_hw_params_set_rate_near(handle, params, &srate, 0);
T(rc, "snd_pcm_hw_params_set_rate_near");
rc = snd_pcm_hw_params_set_period_size_near(handle, params, &frames, 0);
T(rc, "snd_pcm_hw_params_set_period_size_near");
rc = snd_pcm_hw_params(handle, params);
T(rc, "snd_pcm_hw_params");
// SW Params:
/*
rc = snd_pcm_sw_params_current(pcm, sw);
rc = snd_pcm_sw_params_set_start_threshold(pcm, sw, ~0U);
rc = snd_pcm_sw_params_set_stop_threshold(pcm, sw, ~0U);
rc = snd_pcm_sw_params(pcm, sw);
rc = snd_pcm_hw_params_get_buffer_size(hw, &buffer_size);
*/
channels_t nchannels;
rc = snd_pcm_hw_params_get_channels(params, &nchannels);
printf("channels: %d rc: %d\n", nchannels, rc);
T(rc, "snd_pcm_hw_params_get_channels");
if(nchannels != channels->size()) return false;
channel_t c = 0;
Channels::iterator i = channels->begin();
while(i != channels->end()) {
i->num = c;
i++;
c++;
}
return true;
}
#define MICRO 1000000
void AudioOutputEngineAlsa::run(DrumGizmo *drumgizmo)
{
int rc;
snd_pcm_uframes_t nframes;
while(drumgizmo->isRunning()) {
timeval tim;
gettimeofday(&tim, NULL);
useconds_t t1 = tim.tv_sec * MICRO + tim.tv_usec;
snd_pcm_uframes_t offset = 0;
// unsigned int nchannels = 2;
// rc = snd_pcm_hw_params_get_channels(params, &nchannels);
// printf("channels: %d rc: %d\n", nchannels, rc);
// T_(rc, "snd_pcm_hw_params_get_channels");
nframes = snd_pcm_avail_update(handle);
// printf("%d\n", rc);
// T_(rc, "snd_pcm_avail_update");
// rc = snd_pcm_hw_params_get_buffer_size(params, &nframes);
// T_(rc, "nd_pcm_hw_params_get_buffer_size");
// nframes = 960;
const snd_pcm_channel_area_t *areas;
rc = snd_pcm_mmap_begin(handle, &areas, &offset, &nframes);
T_(rc, "snd_pcm_mmap_begin");
drumgizmo->pre((size_t)nframes);
Channels::iterator i = channels->begin();
while(i != channels->end()) {
const snd_pcm_channel_area_t *a = &areas[i->num];
sample_t *p = (sample_t*)a->addr + offset;
memset(p, 0, nframes * sizeof(sample_t));
drumgizmo->getSamples(&(*i), p, (size_t)nframes);
i++;
}
drumgizmo->post((size_t)nframes);
switch(snd_pcm_state(handle)) {
case SND_PCM_STATE_PREPARED:
rc = snd_pcm_mmap_commit(handle, offset, nframes);
T_(rc, "snd_pcm_mmap_commit");
rc = snd_pcm_start(handle);
T_(rc, "snd_pcm_start");
break;
case SND_PCM_STATE_RUNNING:
rc = snd_pcm_mmap_commit(handle, offset, nframes);
T_(rc, "snd_pcm_mmap_commit");
break;
default:
break;
}
useconds_t msec = ((useconds_t)nframes * MICRO)/44100;
gettimeofday(&tim, NULL);
useconds_t t2 = tim.tv_sec * MICRO + tim.tv_usec;
struct timespec slp;
slp.tv_sec = 0;
slp.tv_nsec = (msec - (t2 - t1)) * 1000;
nanosleep(&slp, NULL);
}
}
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