+++ /dev/null
-/*
- * This file is part of DisOrder
- * Copyright (C) 2005, 2006, 2007 Richard Kettlewell
- *
- * This program 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 3 of the License, or
- * (at your option) any later version.
- *
- * This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
- */
-/** @file server/speaker-alsa.c
- * @brief Support for @ref BACKEND_ALSA */
-
-#include "common.h"
-
-#if HAVE_ALSA_ASOUNDLIB_H
-
-#include <unistd.h>
-#include <poll.h>
-#include <alsa/asoundlib.h>
-
-#include "configuration.h"
-#include "syscalls.h"
-#include "log.h"
-#include "speaker-protocol.h"
-#include "speaker.h"
-
-/** @brief The current PCM handle */
-static snd_pcm_t *pcm;
-
-/** @brief Last seen buffer size */
-static snd_pcm_uframes_t last_pcm_bufsize;
-
-/** @brief ALSA backend initialization */
-static void alsa_init(void) {
- info("selected ALSA backend");
-}
-
-/** @brief Log ALSA parameters */
-static void log_params(snd_pcm_hw_params_t *hwparams,
- snd_pcm_sw_params_t *swparams) {
- snd_pcm_uframes_t f;
-
- return; /* too verbose */
- if(hwparams) {
- /* TODO */
- }
- if(swparams) {
- snd_pcm_sw_params_get_silence_size(swparams, &f);
- info("sw silence_size=%lu", (unsigned long)f);
- snd_pcm_sw_params_get_silence_threshold(swparams, &f);
- info("sw silence_threshold=%lu", (unsigned long)f);
-#if HAVE_SND_PCM_SW_PARAMS_GET_SLEEP_MIN
- {
- unsigned u;
-
- snd_pcm_sw_params_get_sleep_min(swparams, &u);
- info("sw sleep_min=%lu", (unsigned long)u);
- }
-#endif
- snd_pcm_sw_params_get_start_threshold(swparams, &f);
- info("sw start_threshold=%lu", (unsigned long)f);
- snd_pcm_sw_params_get_stop_threshold(swparams, &f);
- info("sw stop_threshold=%lu", (unsigned long)f);
-#if HAVE_SND_PCM_SW_PARAMS_GET_XFER_ALIGN
- snd_pcm_sw_params_get_xfer_align(swparams, &f);
- info("sw xfer_align=%lu", (unsigned long)f);
-#endif
- }
-}
-
-/** @brief ALSA deactivation */
-static void alsa_deactivate(void) {
- if(pcm) {
- int err;
-
- if((err = snd_pcm_nonblock(pcm, 0)) < 0)
- fatal(0, "error calling snd_pcm_nonblock: %d", err);
- D(("draining pcm"));
- snd_pcm_drain(pcm);
- D(("closing pcm"));
- snd_pcm_close(pcm);
- pcm = 0;
- device_state = device_closed;
- D(("released audio device"));
- }
-}
-
-/** @brief ALSA backend activation */
-static void alsa_activate(void) {
- if(!pcm) {
- snd_pcm_hw_params_t *hwparams;
- snd_pcm_sw_params_t *swparams;
- snd_pcm_uframes_t pcm_bufsize;
- int err;
- int sample_format = 0;
- unsigned rate;
-
- D(("snd_pcm_open"));
- if((err = snd_pcm_open(&pcm,
- config->device,
- SND_PCM_STREAM_PLAYBACK,
- SND_PCM_NONBLOCK))) {
- error(0, "error from snd_pcm_open: %d", err);
- goto error;
- }
- snd_pcm_hw_params_alloca(&hwparams);
- D(("set up hw params"));
- if((err = snd_pcm_hw_params_any(pcm, hwparams)) < 0)
- fatal(0, "error from snd_pcm_hw_params_any: %d", err);
- if((err = snd_pcm_hw_params_set_access(pcm, hwparams,
- SND_PCM_ACCESS_RW_INTERLEAVED)) < 0)
- fatal(0, "error from snd_pcm_hw_params_set_access: %d", err);
- switch(config->sample_format.bits) {
- case 8:
- sample_format = SND_PCM_FORMAT_S8;
- break;
- case 16:
- switch(config->sample_format.endian) {
- case ENDIAN_LITTLE: sample_format = SND_PCM_FORMAT_S16_LE; break;
- case ENDIAN_BIG: sample_format = SND_PCM_FORMAT_S16_BE; break;
- default:
- error(0, "unrecognized byte format %d", config->sample_format.endian);
- goto fatal;
- }
- break;
- default:
- error(0, "unsupported sample size %d", config->sample_format.bits);
- goto fatal;
- }
- if((err = snd_pcm_hw_params_set_format(pcm, hwparams,
- sample_format)) < 0) {
- error(0, "error from snd_pcm_hw_params_set_format (%d): %d",
- sample_format, err);
- goto fatal;
- }
- rate = config->sample_format.rate;
- if((err = snd_pcm_hw_params_set_rate_near(pcm, hwparams, &rate, 0)) < 0) {
- error(0, "error from snd_pcm_hw_params_set_rate (%d): %d",
- config->sample_format.rate, err);
- goto fatal;
- }
- if(rate != (unsigned)config->sample_format.rate)
- info("want rate %d, got %u", config->sample_format.rate, rate);
- if((err = snd_pcm_hw_params_set_channels
- (pcm, hwparams, config->sample_format.channels)) < 0) {
- error(0, "error from snd_pcm_hw_params_set_channels (%d): %d",
- config->sample_format.channels, err);
- goto fatal;
- }
- pcm_bufsize = 3 * FRAMES;
- if((err = snd_pcm_hw_params_set_buffer_size_near(pcm, hwparams,
- &pcm_bufsize)) < 0)
- fatal(0, "error from snd_pcm_hw_params_set_buffer_size (%d): %d",
- 3 * FRAMES, err);
- if(pcm_bufsize != 3 * FRAMES && pcm_bufsize != last_pcm_bufsize)
- info("asked for PCM buffer of %d frames, got %d",
- 3 * FRAMES, (int)pcm_bufsize);
- last_pcm_bufsize = pcm_bufsize;
- if((err = snd_pcm_hw_params(pcm, hwparams)) < 0)
- fatal(0, "error calling snd_pcm_hw_params: %d", err);
- D(("set up sw params"));
- snd_pcm_sw_params_alloca(&swparams);
- if((err = snd_pcm_sw_params_current(pcm, swparams)) < 0)
- fatal(0, "error calling snd_pcm_sw_params_current: %d", err);
- if((err = snd_pcm_sw_params_set_avail_min(pcm, swparams, FRAMES)) < 0)
- fatal(0, "error calling snd_pcm_sw_params_set_avail_min %d: %d",
- FRAMES, err);
- if((err = snd_pcm_sw_params(pcm, swparams)) < 0)
- fatal(0, "error calling snd_pcm_sw_params: %d", err);
- D(("acquired audio device"));
- log_params(hwparams, swparams);
- device_state = device_open;
- }
- return;
-fatal:
- abandon();
-error:
- /* We assume the error is temporary and that we'll retry in a bit. */
- if(pcm) {
- snd_pcm_close(pcm);
- pcm = 0;
- device_state = device_error;
- }
- return;
-}
-
-/** @brief Play via ALSA */
-static size_t alsa_play(size_t frames) {
- snd_pcm_sframes_t pcm_written_frames;
- int err;
-
- pcm_written_frames = snd_pcm_writei(pcm,
- playing->buffer + playing->start,
- frames);
- D(("actually play %zu frames, wrote %d",
- frames, (int)pcm_written_frames));
- if(pcm_written_frames < 0) {
- switch(pcm_written_frames) {
- case -EPIPE: /* underrun */
- error(0, "snd_pcm_writei reports underrun");
- if((err = snd_pcm_prepare(pcm)) < 0)
- fatal(0, "error calling snd_pcm_prepare: %d", err);
- return 0;
- case -EAGAIN:
- return 0;
- default:
- fatal(0, "error calling snd_pcm_writei: %d",
- (int)pcm_written_frames);
- }
- } else
- return pcm_written_frames;
-}
-
-static int alsa_slots, alsa_nslots = -1;
-
-/** @brief Fill in poll fd array for ALSA */
-static void alsa_beforepoll(int attribute((unused)) *timeoutp) {
- /* We send sample data to ALSA as fast as it can accept it, relying on
- * the fact that it has a relatively small buffer to minimize pause
- * latency. */
- int retry = 3, err;
-
- alsa_slots = fdno;
- do {
- retry = 0;
- alsa_nslots = snd_pcm_poll_descriptors(pcm, &fds[fdno], NFDS - fdno);
- if((alsa_nslots <= 0
- || !(fds[alsa_slots].events & POLLOUT))
- && snd_pcm_state(pcm) == SND_PCM_STATE_XRUN) {
- error(0, "underrun detected after call to snd_pcm_poll_descriptors()");
- if((err = snd_pcm_prepare(pcm)))
- fatal(0, "error calling snd_pcm_prepare: %d", err);
- } else
- break;
- } while(retry-- > 0);
- if(alsa_nslots >= 0)
- fdno += alsa_nslots;
-}
-
-/** @brief Process poll() results for ALSA */
-static int alsa_ready(void) {
- int err;
-
- unsigned short alsa_revents;
-
- if((err = snd_pcm_poll_descriptors_revents(pcm,
- &fds[alsa_slots],
- alsa_nslots,
- &alsa_revents)) < 0)
- fatal(0, "error calling snd_pcm_poll_descriptors_revents: %d", err);
- if(alsa_revents & (POLLOUT | POLLERR))
- return 1;
- else
- return 0;
-}
-
-const struct speaker_backend alsa_backend = {
- BACKEND_ALSA,
- 0,
- alsa_init,
- alsa_activate,
- alsa_play,
- alsa_deactivate,
- alsa_beforepoll,
- alsa_ready
-};
-
-#endif
-
-/*
-Local Variables:
-c-basic-offset:2
-comment-column:40
-fill-column:79
-indent-tabs-mode:nil
-End:
-*/
~mdw / disorder / blobdiff