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 "alsa_write.cmdline.h"
  37 #include "error.h"
  38
  39
  40 #define FORMAT SND_PCM_FORMAT_S16_LE
  41
  42 /** data specific to the alsa writer */
  43 struct private_alsa_data {
  44         /** the alsa handle */
  45         snd_pcm_t *handle;
  46         /** determined and set by alsa_open() */
  47         size_t bytes_per_frame;
  48         /** don't write anything until this time */
  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         struct alsa_write_args_info *conf = w->conf;
  69
  70         w->private_data = pad;
  71         snd_pcm_info_alloca(&info);
  72         err = snd_pcm_open(&pad->handle, conf->device_arg,
  73                 SND_PCM_STREAM_PLAYBACK, 0);
  74         if (err < 0)
  75                 return -E_PCM_OPEN;
  76         if ((err = snd_pcm_info(pad->handle, info)) < 0)
  77                 return -E_SND_PCM_INFO;
  78
  79         snd_pcm_hw_params_alloca(&hwparams);
  80         snd_pcm_sw_params_alloca(&swparams);
  81         if (snd_pcm_hw_params_any(pad->handle, hwparams) < 0)
  82                 return -E_BROKEN_CONF;
  83         if (snd_pcm_hw_params_set_access(pad->handle, hwparams,
  84                         SND_PCM_ACCESS_RW_INTERLEAVED) < 0)
  85                 return -E_ACCESS_TYPE;
  86         if (snd_pcm_hw_params_set_format(pad->handle, hwparams, FORMAT) < 0)
  87                 return -E_SAMPLE_FORMAT;
  88         if (snd_pcm_hw_params_set_channels(pad->handle, hwparams,
  89                         conf->channels_arg) < 0)
  90                 return -E_CHANNEL_COUNT;
  91         if (snd_pcm_hw_params_set_rate_near(pad->handle, hwparams,
  92                         (unsigned int*) &conf->sample_rate_arg, 0) < 0)
  93                 return -E_SET_RATE;
  94         err = snd_pcm_hw_params_get_buffer_time_max(hwparams, &buffer_time, 0);
  95         if (err < 0 || !buffer_time)
  96                 return -E_GET_BUFFER_TIME;
  97         PARA_DEBUG_LOG("buffer time: %d\n", buffer_time);
  98         if (snd_pcm_hw_params_set_buffer_time_near(pad->handle, hwparams,
  99                         &buffer_time, 0) < 0)
 100                 return -E_SET_BUFFER_TIME;
 101         if (snd_pcm_hw_params(pad->handle, hwparams) < 0)
 102                 return -E_HW_PARAMS;
 103         snd_pcm_hw_params_get_period_size(hwparams, &period_size, 0);
 104         snd_pcm_hw_params_get_buffer_size(hwparams, &buffer_size);
 105         PARA_DEBUG_LOG("buffer size: %lu, period_size: %lu\n", buffer_size,
 106                 period_size);
 107         if (period_size == buffer_size)
 108                 return -E_BAD_PERIOD;
 109         snd_pcm_sw_params_current(pad->handle, swparams);
 110         err = snd_pcm_sw_params_get_xfer_align(swparams, &xfer_align);
 111         if (err < 0 || !xfer_align)
 112                 return -E_GET_XFER;
 113         snd_pcm_sw_params_set_avail_min(pad->handle, swparams, period_size);
 114         /* round to closest transfer boundary */
 115         start_threshold = (buffer_size / xfer_align) * xfer_align;
 116         if (start_threshold < 1)
 117                 start_threshold = 1;
 118         if (snd_pcm_sw_params_set_start_threshold(pad->handle, swparams,
 119                         start_threshold) < 0)
 120                 return -E_START_THRESHOLD;
 121         stop_threshold = buffer_size;
 122         if (snd_pcm_sw_params_set_stop_threshold(pad->handle, swparams,
 123                         stop_threshold) < 0)
 124                 return -E_STOP_THRESHOLD;
 125         if (snd_pcm_sw_params_set_xfer_align(pad->handle, swparams,
 126                         xfer_align) < 0)
 127                 return -E_SET_XFER;
 128         if (snd_pcm_sw_params(pad->handle, swparams) < 0)
 129                 return -E_SW_PARAMS;
 130         pad->bytes_per_frame = snd_pcm_format_physical_width(FORMAT)
 131                 * conf->channels_arg / 8;
 132 //      if (snd_pcm_nonblock(pad->handle, 1))
 133 //              PARA_ERROR_LOG("%s\n", "failed to set nonblock mode");
 134         return period_size * pad->bytes_per_frame;
 135 }
 136 static void alsa_write_pre_select(struct sched *s, struct task *t)
 137 {
 138         struct writer_node *wn = t->private_data;
 139         struct private_alsa_data *pad = wn->private_data;
 140         struct writer_node_group *wng = wn->wng;
 141         struct timeval diff;
 142
 143         t->ret = 0;
 144         if (*wng->input_eof && *wng->loaded < pad->bytes_per_frame)
 145                 return;
 146         t->ret = 1;
 147         if (*wng->loaded < pad->bytes_per_frame)
 148                 return;
 149         if (tv_diff(&s->now, &pad->next_chunk, &diff) < 0) {
 150                 if (tv_diff(&s->timeout, &diff, NULL) > 0)
 151                         s->timeout = diff;
 152         } else {
 153                 s->timeout.tv_sec = 0;
 154                 s->timeout.tv_usec = 0;
 155         }
 156 }
 157
 158 static void alsa_write_post_select(struct sched *s, struct task *t)
 159 {
 160         struct writer_node *wn = t->private_data;
 161         struct private_alsa_data *pad = wn->private_data;
 162         struct writer_node_group *wng = wn->wng;
 163         size_t frames = *wng->loaded / pad->bytes_per_frame;
 164         snd_pcm_sframes_t ret, result = 0;
 165         unsigned char *data = (unsigned char*)wng->buf;
 166
 167         t->ret = 0;
 168         if (!frames) {
 169                 if (*wng->input_eof)
 170                         t->ret = *wng->loaded;
 171                 return;
 172         }
 173         if (tv_diff(&s->now, &pad->next_chunk, NULL) < 0)
 174                 return;
 175 //      PARA_INFO_LOG("%zd frames\n", frames);
 176 //      while (frames > 0) {
 177                 ret = snd_pcm_writei(pad->handle, data, frames);
 178                 if (ret == -EAGAIN || (ret >= 0 && ret < frames)) {
 179                         struct timeval tv = {0, 1000 * 10};
 180                         PARA_INFO_LOG("EAGAIN. frames: %d, ret: %lu\n", frames, ret);
 181                         tv_add(&s->now, &tv, &pad->next_chunk);
 182 //                      snd_pcm_wait(pad->handle, 1);
 183                 } else if (ret == -EPIPE) {
 184                         PARA_INFO_LOG("%s", "EPIPE\n");
 185                         snd_pcm_prepare(pad->handle);
 186                 } else if (ret < 0) {
 187                         PARA_INFO_LOG("ALSA ERR %d\n", frames);
 188                         t->ret = -E_ALSA_WRITE;
 189                         return;
 190                 }
 191                 if (ret >= 0) {
 192                         result += ret;
 193                         frames -= ret;
 194                         data += ret * pad->bytes_per_frame;
 195                 }
 196 //              if (ret == -EAGAIN)
 197 //                      break;
 198 //      }
 199         t->ret = result * pad->bytes_per_frame;
 200 //      PARA_INFO_LOG("ret: %d, frames: %zd\n", t->ret, frames);
 201 }
 202
 203 static void alsa_close(struct writer_node *wn)
 204 {
 205         struct private_alsa_data *pad = wn->private_data;
 206         snd_pcm_drain(pad->handle);
 207         snd_pcm_close(pad->handle);
 208         snd_config_update_free_global();
 209         free(pad);
 210 }
 211
 212 __malloc void *alsa_parse_config(char *options)
 213 {
 214         struct alsa_write_args_info *conf
 215                 = para_calloc(sizeof(struct alsa_write_args_info));
 216         PARA_INFO_LOG("options: %s, %d\n", options, strcspn(options, " \t"));
 217         int ret = alsa_cmdline_parser_string(options, conf, "alsa_write");
 218         if (ret)
 219                 goto err_out;
 220         PARA_INFO_LOG("help given: %d\n", conf->help_given);
 221         return conf;
 222 err_out:
 223         free(conf);
 224         return NULL;
 225 }
 226
 227 /** the init function of the alsa writer */
 228 void alsa_writer_init(struct writer *w)
 229 {
 230         w->open = alsa_open;
 231         w->close = alsa_close;
 232         w->pre_select = alsa_write_pre_select;
 233         w->post_select = alsa_write_post_select;
 234         w->parse_config = alsa_parse_config;
 235         w->shutdown = NULL; /* nothing to do */
 236 }