alsa_writer.c

   1 /*
   2  * Copyright (C) 2005-2006 Andre Noll <maan@systemlinux.org>
   3  *
   4  *     This program is free software; you can redistribute it and/or modify
   5  *     it under the terms of the GNU General Public License as published by
   6  *     the Free Software Foundation; either version 2 of the License, or
   7  *     (at your option) any later version.
   8  *
   9  *     This program is distributed in the hope that it will be useful,
  10  *     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  *     GNU General Public License for more details.
  13  *
  14  *     You should have received a copy of the GNU General Public License
  15  *     along with this program; if not, write to the Free Software
  16  *     Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
  17  */
  18
  19 /** \file alsa_writer.c paraslash's alsa output plugin */
  20
  21 /*
  22  * Based in parts on aplay.c from the alsa-utils-1.0.8 package,
  23  * Copyright (c) by Jaroslav Kysela <perex@suse.cz>, which is
  24  * based on the vplay program by Michael Beck.
  25  */
  26
  27 #include "para.h"
  28 #include "fd.h"
  29 #include "string.h"
  30 #include "list.h"
  31 #include "sched.h"
  32 #include "write.h"
  33
  34 #include <alsa/asoundlib.h>
  35
  36 #include "write.cmdline.h"
  37 #include "error.h"
  38
  39 extern struct gengetopt_args_info conf;
  40
  41 #define FORMAT SND_PCM_FORMAT_S16_LE
  42
  43 /** data specific to the alsa writer */
  44 struct private_alsa_data {
  45 /** the alsa handle */
  46 snd_pcm_t *handle;
  47 /** determined and set by alsa_open() */
  48 size_t bytes_per_frame;
  49 struct timeval next_chunk;
  50 };
  51
  52 /*
  53  * open and prepare the PCM handle for writing
  54  *
  55  * Install PCM software and hardware configuration. Exit on errors.
  56  */
  57 static int alsa_open(struct writer_node *w)
  58 {
  59         snd_pcm_hw_params_t *hwparams;
  60         snd_pcm_sw_params_t *swparams;
  61         snd_pcm_uframes_t buffer_size, xfer_align, start_threshold,
  62                 stop_threshold;
  63         unsigned buffer_time = 0;
  64         int err;
  65         snd_pcm_info_t *info;
  66         snd_pcm_uframes_t period_size;
  67         struct private_alsa_data *pad = para_calloc(sizeof(struct private_alsa_data));
  68         w->private_data = pad;
  69
  70         snd_pcm_info_alloca(&info);
  71         err = snd_pcm_open(&pad->handle, conf.device_arg,
  72                 SND_PCM_STREAM_PLAYBACK, 0);
  73         if (err < 0)
  74                 return -E_PCM_OPEN;
  75         if ((err = snd_pcm_info(pad->handle, info)) < 0)
  76                 return -E_SND_PCM_INFO;
  77
  78         snd_pcm_hw_params_alloca(&hwparams);
  79         snd_pcm_sw_params_alloca(&swparams);
  80         if (snd_pcm_hw_params_any(pad->handle, hwparams) < 0)
  81                 return -E_BROKEN_CONF;
  82         if (snd_pcm_hw_params_set_access(pad->handle, hwparams,
  83                         SND_PCM_ACCESS_RW_INTERLEAVED) < 0)
  84                 return -E_ACCESS_TYPE;
  85         if (snd_pcm_hw_params_set_format(pad->handle, hwparams, FORMAT) < 0)
  86                 return -E_SAMPLE_FORMAT;
  87         if (snd_pcm_hw_params_set_channels(pad->handle, hwparams,
  88                         conf.channels_arg) < 0)
  89                 return -E_CHANNEL_COUNT;
  90         if (snd_pcm_hw_params_set_rate_near(pad->handle, hwparams,
  91                         (unsigned int*) &conf.sample_rate_arg, 0) < 0)
  92                 return -E_SET_RATE;
  93         err = snd_pcm_hw_params_get_buffer_time_max(hwparams, &buffer_time, 0);
  94         if (err < 0 || !buffer_time)
  95                 return -E_GET_BUFFER_TIME;
  96         PARA_DEBUG_LOG("buffer time: %d\n", buffer_time);
  97         if (snd_pcm_hw_params_set_buffer_time_near(pad->handle, hwparams,
  98                         &buffer_time, 0) < 0)
  99                 return -E_SET_BUFFER_TIME;
 100         if (snd_pcm_hw_params(pad->handle, hwparams) < 0)
 101                 return -E_HW_PARAMS;
 102         snd_pcm_hw_params_get_period_size(hwparams, &period_size, 0);
 103         snd_pcm_hw_params_get_buffer_size(hwparams, &buffer_size);
 104         PARA_DEBUG_LOG("buffer size: %lu, period_size: %lu\n", buffer_size,
 105                 period_size);
 106         if (period_size == buffer_size)
 107                 return -E_BAD_PERIOD;
 108         snd_pcm_sw_params_current(pad->handle, swparams);
 109         err = snd_pcm_sw_params_get_xfer_align(swparams, &xfer_align);
 110         if (err < 0 || !xfer_align)
 111                 return -E_GET_XFER;
 112         snd_pcm_sw_params_set_avail_min(pad->handle, swparams, period_size);
 113         /* round to closest transfer boundary */
 114         start_threshold = (buffer_size / xfer_align) * xfer_align;
 115         if (start_threshold < 1)
 116                 start_threshold = 1;
 117         if (snd_pcm_sw_params_set_start_threshold(pad->handle, swparams,
 118                         start_threshold) < 0)
 119                 return -E_START_THRESHOLD;
 120         stop_threshold = buffer_size;
 121         if (snd_pcm_sw_params_set_stop_threshold(pad->handle, swparams,
 122                         stop_threshold) < 0)
 123                 return -E_STOP_THRESHOLD;
 124         if (snd_pcm_sw_params_set_xfer_align(pad->handle, swparams,
 125                         xfer_align) < 0)
 126                 return -E_SET_XFER;
 127         if (snd_pcm_sw_params(pad->handle, swparams) < 0)
 128                 return -E_SW_PARAMS;
 129         pad->bytes_per_frame = snd_pcm_format_physical_width(FORMAT)
 130                 * conf.channels_arg / 8;
 131 //      if (snd_pcm_nonblock(pad->handle, 1))
 132 //              PARA_ERROR_LOG("%s\n", "failed to set nonblock mode");
 133         return period_size * pad->bytes_per_frame;
 134 }
 135 static void alsa_write_pre_select(struct sched *s, struct task *t)
 136 {
 137         struct writer_node *wn = t->private_data;
 138         struct private_alsa_data *pad = wn->private_data;
 139         struct writer_node_group *wng = wn->wng;
 140         struct timeval diff;
 141
 142         t->ret = 0;
 143         if (*wng->eof && *wng->loaded < pad->bytes_per_frame)
 144                 return;
 145         t->ret = 1;
 146         if (*wng->loaded < pad->bytes_per_frame)
 147                 return;
 148         if (tv_diff(&s->now, &pad->next_chunk, &diff) < 0) {
 149                 if (tv_diff(&s->timeout, &diff, NULL) > 0)
 150                         s->timeout = diff;
 151         } else {
 152                 s->timeout.tv_sec = 0;
 153                 s->timeout.tv_usec = 0;
 154         }
 155 }
 156
 157 static void alsa_write_post_select(struct sched *s, struct task *t)
 158 {
 159         struct writer_node *wn = t->private_data;
 160         struct private_alsa_data *pad = wn->private_data;
 161         struct writer_node_group *wng = wn->wng;
 162         size_t frames = *wng->loaded / pad->bytes_per_frame;
 163         snd_pcm_sframes_t ret, result = 0;
 164         unsigned char *data = (unsigned char*)wng->buf;
 165
 166         t->ret = 0;
 167         if (!frames) {
 168                 if (*wng->eof)
 169                         t->ret = *wng->loaded;
 170                 return;
 171         }
 172         if (tv_diff(&s->now, &pad->next_chunk, NULL) < 0)
 173                 return;
 174 //      PARA_INFO_LOG("%zd frames\n", frames);
 175 //      while (frames > 0) {
 176                 ret = snd_pcm_writei(pad->handle, data, frames);
 177                 if (ret == -EAGAIN || (ret >= 0 && ret < frames)) {
 178                         struct timeval tv = {0, 1000 * 10};
 179                         PARA_INFO_LOG("EAGAIN. frames: %d, ret: %lu\n", frames, ret);
 180                         tv_add(&s->now, &tv, &pad->next_chunk);
 181 //                      snd_pcm_wait(pad->handle, 1);
 182                 } else if (ret == -EPIPE) {
 183                         PARA_INFO_LOG("%s", "EPIPE\n");
 184                         snd_pcm_prepare(pad->handle);
 185                 } else if (ret < 0) {
 186                         PARA_INFO_LOG("ALSA ERR %d\n", frames);
 187                         t->ret = -E_ALSA_WRITE;
 188                         return;
 189                 }
 190                 if (ret >= 0) {
 191                         result += ret;
 192                         frames -= ret;
 193                         data += ret * pad->bytes_per_frame;
 194                 }
 195 //              if (ret == -EAGAIN)
 196 //                      break;
 197 //      }
 198         t->ret = result * pad->bytes_per_frame;
 199 //      PARA_INFO_LOG("ret: %d, frames: %zd\n", t->ret, frames);
 200 }
 201
 202 static void alsa_close(struct writer_node *wn)
 203 {
 204         struct private_alsa_data *pad = wn->private_data;
 205         snd_pcm_drain(pad->handle);
 206         snd_pcm_close(pad->handle);
 207         snd_config_update_free_global();
 208         free(pad);
 209 }
 210
 211 /** the init function of the alsa writer */
 212 void alsa_writer_init(struct writer *w)
 213 {
 214         w->open = alsa_open;
 215         w->close = alsa_close;
 216         w->pre_select = alsa_write_pre_select;
 217         w->post_select = alsa_write_post_select;
 218         w->shutdown = NULL; /* nothing to do */
 219 }