430 lines
15 KiB
C
430 lines
15 KiB
C
/*
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Copyright (C) 2004-2006 Jean-Marc Valin
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Copyright (C) 2006 Commonwealth Scientific and Industrial Research
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Organisation (CSIRO) Australia
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions are
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met:
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1. Redistributions of source code must retain the above copyright notice,
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this list of conditions and the following disclaimer.
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2. Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in the
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documentation and/or other materials provided with the distribution.
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THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
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INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
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(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "alsa_device.h"
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#include <stdlib.h>
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#include <alsa/asoundlib.h>
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struct AlsaDevice_ {
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char *device_name;
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int channels;
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int period;
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snd_pcm_t *capture_handle;
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snd_pcm_t *playback_handle;
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int readN, writeN;
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struct pollfd *read_fd, *write_fd;
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};
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#define PERIODS 3
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AlsaDevice *alsa_device_open(char *device_name, unsigned int rate, int channels, int period)
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{
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int dir;
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int err;
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snd_pcm_hw_params_t *hw_params;
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snd_pcm_sw_params_t *sw_params;
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snd_pcm_uframes_t period_size = period;
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snd_pcm_uframes_t buffer_size = PERIODS*period;
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static snd_output_t *jcd_out;
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AlsaDevice *dev = malloc(sizeof(*dev));
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if (!dev)
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return NULL;
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dev->device_name = malloc(1+strlen(device_name));
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if (!dev->device_name)
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{
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free(dev);
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return NULL;
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}
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strcpy(dev->device_name, device_name);
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dev->channels = channels;
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dev->period = period;
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err = snd_output_stdio_attach(&jcd_out, stdout, 0);
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if ((err = snd_pcm_open (&dev->capture_handle, dev->device_name, SND_PCM_STREAM_CAPTURE, 0)) < 0) {
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fprintf (stderr, "cannot open audio device %s (%s)\n",
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dev->device_name,
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snd_strerror (err));
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assert(0);
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}
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if ((err = snd_pcm_hw_params_malloc (&hw_params)) < 0) {
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fprintf (stderr, "cannot allocate hardware parameter structure (%s)\n",
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snd_strerror (err));
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assert(0);
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}
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if ((err = snd_pcm_hw_params_any (dev->capture_handle, hw_params)) < 0) {
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fprintf (stderr, "cannot initialize hardware parameter structure (%s)\n",
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snd_strerror (err));
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assert(0);
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}
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if ((err = snd_pcm_hw_params_set_access (dev->capture_handle, hw_params, SND_PCM_ACCESS_RW_INTERLEAVED)) < 0) {
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fprintf (stderr, "cannot set access type (%s)\n",
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snd_strerror (err));
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assert(0);
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}
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if ((err = snd_pcm_hw_params_set_format (dev->capture_handle, hw_params, SND_PCM_FORMAT_S16_LE)) < 0) {
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fprintf (stderr, "cannot set sample format (%s)\n",
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snd_strerror (err));
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assert(0);
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}
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if ((err = snd_pcm_hw_params_set_rate_near (dev->capture_handle, hw_params, &rate, 0)) < 0) {
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fprintf (stderr, "cannot set sample rate (%s)\n",
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snd_strerror (err));
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assert(0);
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}
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/*fprintf (stderr, "rate = %d\n", rate);*/
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if ((err = snd_pcm_hw_params_set_channels (dev->capture_handle, hw_params, channels)) < 0) {
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fprintf (stderr, "cannot set channel count (%s)\n",
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snd_strerror (err));
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assert(0);
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}
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period_size = period;
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dir = 0;
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if ((err = snd_pcm_hw_params_set_period_size_near (dev->capture_handle, hw_params, &period_size, &dir)) < 0) {
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fprintf (stderr, "cannot set period size (%s)\n",
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snd_strerror (err));
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assert(0);
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}
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if ((err = snd_pcm_hw_params_set_periods (dev->capture_handle, hw_params, PERIODS, 0)) < 0) {
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fprintf (stderr, "cannot set number of periods (%s)\n",
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snd_strerror (err));
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assert(0);
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}
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buffer_size = period_size * PERIODS;
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dir=0;
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if ((err = snd_pcm_hw_params_set_buffer_size_near (dev->capture_handle, hw_params, &buffer_size)) < 0) {
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fprintf (stderr, "cannot set buffer time (%s)\n",
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snd_strerror (err));
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assert(0);
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}
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if ((err = snd_pcm_hw_params (dev->capture_handle, hw_params)) < 0) {
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fprintf (stderr, "cannot set capture parameters (%s)\n",
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snd_strerror (err));
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assert(0);
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}
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/*snd_pcm_dump_setup(dev->capture_handle, jcd_out);*/
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snd_pcm_hw_params_free (hw_params);
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if ((err = snd_pcm_sw_params_malloc (&sw_params)) < 0) {
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fprintf (stderr, "cannot allocate software parameters structure (%s)\n",
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snd_strerror (err));
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assert(0);
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}
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if ((err = snd_pcm_sw_params_current (dev->capture_handle, sw_params)) < 0) {
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fprintf (stderr, "cannot initialize software parameters structure (%s)\n",
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snd_strerror (err));
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assert(0);
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}
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if ((err = snd_pcm_sw_params_set_avail_min (dev->capture_handle, sw_params, period)) < 0) {
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fprintf (stderr, "cannot set minimum available count (%s)\n",
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snd_strerror (err));
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assert(0);
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}
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if ((err = snd_pcm_sw_params (dev->capture_handle, sw_params)) < 0) {
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fprintf (stderr, "cannot set software parameters (%s)\n",
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snd_strerror (err));
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assert(0);
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}
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if ((err = snd_pcm_open (&dev->playback_handle, dev->device_name, SND_PCM_STREAM_PLAYBACK, 0)) < 0) {
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fprintf (stderr, "cannot open audio device %s (%s)\n",
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dev->device_name,
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snd_strerror (err));
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assert(0);
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}
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if ((err = snd_pcm_hw_params_malloc (&hw_params)) < 0) {
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fprintf (stderr, "cannot allocate hardware parameter structure (%s)\n",
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snd_strerror (err));
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assert(0);
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}
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if ((err = snd_pcm_hw_params_any (dev->playback_handle, hw_params)) < 0) {
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fprintf (stderr, "cannot initialize hardware parameter structure (%s)\n",
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snd_strerror (err));
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assert(0);
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}
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if ((err = snd_pcm_hw_params_set_access (dev->playback_handle, hw_params, SND_PCM_ACCESS_RW_INTERLEAVED)) < 0) {
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fprintf (stderr, "cannot set access type (%s)\n",
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snd_strerror (err));
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assert(0);
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}
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if ((err = snd_pcm_hw_params_set_format (dev->playback_handle, hw_params, SND_PCM_FORMAT_S16_LE)) < 0) {
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fprintf (stderr, "cannot set sample format (%s)\n",
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snd_strerror (err));
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assert(0);
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}
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if ((err = snd_pcm_hw_params_set_rate_near (dev->playback_handle, hw_params, &rate, 0)) < 0) {
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fprintf (stderr, "cannot set sample rate (%s)\n",
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snd_strerror (err));
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assert(0);
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}
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/*fprintf (stderr, "rate = %d\n", rate);*/
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if ((err = snd_pcm_hw_params_set_channels (dev->playback_handle, hw_params, channels)) < 0) {
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fprintf (stderr, "cannot set channel count (%s)\n",
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snd_strerror (err));
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assert(0);
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}
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period_size = period;
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dir = 0;
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if ((err = snd_pcm_hw_params_set_period_size_near (dev->playback_handle, hw_params, &period_size, &dir)) < 0) {
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fprintf (stderr, "cannot set period size (%s)\n",
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snd_strerror (err));
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assert(0);
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}
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if ((err = snd_pcm_hw_params_set_periods (dev->playback_handle, hw_params, PERIODS, 0)) < 0) {
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fprintf (stderr, "cannot set number of periods (%s)\n",
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snd_strerror (err));
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assert(0);
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}
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buffer_size = period_size * PERIODS;
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dir=0;
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if ((err = snd_pcm_hw_params_set_buffer_size_near (dev->playback_handle, hw_params, &buffer_size)) < 0) {
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fprintf (stderr, "cannot set buffer time (%s)\n",
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snd_strerror (err));
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assert(0);
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}
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if ((err = snd_pcm_hw_params (dev->playback_handle, hw_params)) < 0) {
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fprintf (stderr, "cannot set playback parameters (%s)\n",
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snd_strerror (err));
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assert(0);
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}
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/*snd_pcm_dump_setup(dev->playback_handle, jcd_out);*/
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snd_pcm_hw_params_free (hw_params);
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if ((err = snd_pcm_sw_params_malloc (&sw_params)) < 0) {
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fprintf (stderr, "cannot allocate software parameters structure (%s)\n",
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snd_strerror (err));
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assert(0);
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}
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if ((err = snd_pcm_sw_params_current (dev->playback_handle, sw_params)) < 0) {
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fprintf (stderr, "cannot initialize software parameters structure (%s)\n",
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snd_strerror (err));
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assert(0);
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}
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if ((err = snd_pcm_sw_params_set_avail_min (dev->playback_handle, sw_params, period)) < 0) {
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fprintf (stderr, "cannot set minimum available count (%s)\n",
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snd_strerror (err));
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assert(0);
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}
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if ((err = snd_pcm_sw_params_set_start_threshold (dev->playback_handle, sw_params, period)) < 0) {
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fprintf (stderr, "cannot set start mode (%s)\n",
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snd_strerror (err));
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assert(0);
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}
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if ((err = snd_pcm_sw_params (dev->playback_handle, sw_params)) < 0) {
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fprintf (stderr, "cannot set software parameters (%s)\n",
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snd_strerror (err));
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assert(0);
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}
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snd_pcm_link(dev->capture_handle, dev->playback_handle);
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if ((err = snd_pcm_prepare (dev->capture_handle)) < 0) {
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fprintf (stderr, "cannot prepare audio interface for use (%s)\n",
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snd_strerror (err));
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assert(0);
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}
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if ((err = snd_pcm_prepare (dev->playback_handle)) < 0) {
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fprintf (stderr, "cannot prepare audio interface for use (%s)\n",
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snd_strerror (err));
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assert(0);
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}
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dev->readN = snd_pcm_poll_descriptors_count(dev->capture_handle);
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dev->writeN = snd_pcm_poll_descriptors_count(dev->playback_handle);
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dev->read_fd = malloc(dev->readN*sizeof(*dev->read_fd));
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/*printf ("descriptors: %d %d\n", dev->readN, dev->writeN);*/
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if (snd_pcm_poll_descriptors(dev->capture_handle, dev->read_fd, dev->readN) != dev->readN)
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{
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fprintf (stderr, "cannot obtain capture file descriptors (%s)\n",
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snd_strerror (err));
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assert(0);
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}
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dev->write_fd = malloc(dev->writeN*sizeof(*dev->read_fd));
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if (snd_pcm_poll_descriptors(dev->playback_handle, dev->write_fd, dev->writeN) != dev->writeN)
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{
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fprintf (stderr, "cannot obtain playback file descriptors (%s)\n",
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snd_strerror (err));
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assert(0);
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}
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return dev;
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}
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void alsa_device_close(AlsaDevice *dev)
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{
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snd_pcm_close(dev->capture_handle);
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snd_pcm_close(dev->playback_handle);
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free(dev->device_name);
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free(dev);
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}
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int alsa_device_read(AlsaDevice *dev, short *pcm, int len)
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{
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int err;
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/*fprintf (stderr, "-");*/
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if ((err = snd_pcm_readi (dev->capture_handle, pcm, len)) != len)
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{
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if (err<0)
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{
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//fprintf(stderr, "error %d, EPIPE = %d\n", err, EPIPE);
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if (err == -EPIPE)
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{
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fprintf (stderr, "An overrun has occured, reseting capture\n");
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} else
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{
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fprintf (stderr, "read from audio interface failed (%s)\n",
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snd_strerror (err));
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}
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if ((err = snd_pcm_prepare (dev->capture_handle)) < 0)
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{
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fprintf (stderr, "cannot prepare audio interface for use (%s)\n",
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snd_strerror (err));
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}
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if ((err = snd_pcm_start (dev->capture_handle)) < 0)
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{
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fprintf (stderr, "cannot prepare audio interface for use (%s)\n",
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snd_strerror (err));
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}
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/*alsa_device_read(dev,pcm,len);*/
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} else {
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fprintf (stderr, "Couldn't read as many samples as I wanted (%d instead of %d)\n", err, len);
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}
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return 1;
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}
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return 0;
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}
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int alsa_device_write(AlsaDevice *dev, const short *pcm, int len)
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{
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int err;
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/*fprintf (stderr, "+");*/
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if ((err = snd_pcm_writei (dev->playback_handle, pcm, len)) != len)
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{
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if (err<0)
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{
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if (err == -EPIPE)
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{
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fprintf (stderr, "An underrun has occured, reseting playback, len=%d\n", len);
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} else
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{
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fprintf (stderr, "write to audio interface failed (%s)\n",
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snd_strerror (err));
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}
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if ((err = snd_pcm_prepare (dev->playback_handle)) < 0)
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{
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fprintf (stderr, "cannot prepare audio interface for use (%s)\n",
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snd_strerror (err));
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}
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} else {
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fprintf (stderr, "Couldn't write as many samples as I wanted (%d instead of %d)\n", err, len);
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}
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/*alsa_device_write(dev,pcm,len);*/
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return 1;
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}
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return 0;
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}
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int alsa_device_capture_ready(AlsaDevice *dev, struct pollfd *pfds, unsigned int nfds)
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{
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unsigned short revents=0;
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int err;
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if ((err = snd_pcm_poll_descriptors_revents(dev->capture_handle, pfds, dev->readN, &revents)) < 0)
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{
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//cerr << "error in snd_pcm_poll_descriptors_revents for capture: " << snd_strerror (err) << endl;
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//FIXME: This is a kludge
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fprintf (stderr, "error in alsa_device_capture_ready: %s\n", snd_strerror (err));
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return pfds[0].revents & POLLIN;
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}
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//cerr << (revents & POLLERR) << endl;
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return revents & POLLIN;
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}
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int alsa_device_playback_ready(AlsaDevice *dev, struct pollfd *pfds, unsigned int nfds)
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{
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unsigned short revents=0;
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int err;
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if ((err = snd_pcm_poll_descriptors_revents(dev->playback_handle, pfds+dev->readN, dev->writeN, &revents)) < 0)
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{
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//cerr << "error in snd_pcm_poll_descriptors_revents for playback: " << snd_strerror (err) << endl;
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//FIXME: This is a kludge
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fprintf (stderr, "error in alsa_device_playback_ready: %s\n", snd_strerror (err));
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return pfds[1].revents & POLLOUT;
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}
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//cerr << (revents & POLLERR) << endl;
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return revents & POLLOUT;
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}
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void alsa_device_start(AlsaDevice *dev)
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{
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int i;
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short pcm[dev->period*dev->channels];
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for (i=0;i<dev->period*dev->channels;i++)
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pcm[i] = 0;
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alsa_device_write(dev, pcm, dev->period);
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alsa_device_write(dev, pcm, dev->period);
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snd_pcm_start(dev->capture_handle);
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snd_pcm_start(dev->playback_handle);
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}
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int alsa_device_nfds(AlsaDevice *dev)
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{
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return dev->writeN+dev->readN;
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}
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void alsa_device_getfds(AlsaDevice *dev, struct pollfd *pfds, unsigned int nfds)
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{
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int i;
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assert (nfds >= dev->writeN+dev->readN);
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for (i=0;i<dev->readN;i++)
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pfds[i] = dev->read_fd[i];
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for (i=0;i<dev->writeN;i++)
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pfds[i+dev->readN] = dev->write_fd[i];
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}
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