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Diffstat (limited to 'src/audiooutputenginealsa.cc')
| -rw-r--r-- | src/audiooutputenginealsa.cc | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/src/audiooutputenginealsa.cc b/src/audiooutputenginealsa.cc new file mode 100644 index 0000000..635cf70 --- /dev/null +++ b/src/audiooutputenginealsa.cc @@ -0,0 +1,194 @@ +/* -*- 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); + + } +} |