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         /** the return value of snd_pcm_hw_params_get_buffer_time_max() */
  51         unsigned buffer_time;
  52         unsigned samplerate;
  53         unsigned channels;
  54 };
  55
  56 /*
  57  * open and prepare the PCM handle for writing
  58  *
  59  * Install PCM software and hardware configuration. Exit on errors.
  60  */
  61 static int alsa_open(struct writer_node *w)
  62 {
  63         snd_pcm_hw_params_t *hwparams;
  64         snd_pcm_sw_params_t *swparams;
  65         snd_pcm_uframes_t buffer_size, xfer_align, start_threshold,
  66                 stop_threshold;
  67         int err;
  68         snd_pcm_info_t *info;
  69         snd_pcm_uframes_t period_size;
  70         struct private_alsa_data *pad = para_calloc(sizeof(struct private_alsa_data));
  71         struct alsa_write_args_info *conf = w->conf;
  72         struct writer_node_group *wng = w->wng;
  73
  74         if (!conf->samplerate_given && wng->samplerate)
  75                 pad->samplerate = *wng->samplerate;
  76         else
  77                 pad->samplerate = conf->samplerate_arg;
  78         if (!conf->channels_given && wng->channels)
  79                 pad->channels = *wng->channels;
  80         else
  81                 pad->channels = conf->channels_arg;
  82         PARA_INFO_LOG("%d channel(s), %dHz\n", pad->channels, pad->samplerate);
  83         w->private_data = pad;
  84         snd_pcm_info_alloca(&info);
  85         err = snd_pcm_open(&pad->handle, conf->device_arg,
  86                 SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK);
  87         if (err < 0)
  88                 return -E_PCM_OPEN;
  89         if ((err = snd_pcm_info(pad->handle, info)) < 0)
  90                 return -E_SND_PCM_INFO;
  91
  92         snd_pcm_hw_params_alloca(&hwparams);
  93         snd_pcm_sw_params_alloca(&swparams);
  94         if (snd_pcm_hw_params_any(pad->handle, hwparams) < 0)
  95                 return -E_BROKEN_CONF;
  96         if (snd_pcm_hw_params_set_access(pad->handle, hwparams,
  97                         SND_PCM_ACCESS_RW_INTERLEAVED) < 0)
  98                 return -E_ACCESS_TYPE;
  99         if (snd_pcm_hw_params_set_format(pad->handle, hwparams, FORMAT) < 0)
 100                 return -E_SAMPLE_FORMAT;
 101         if (snd_pcm_hw_params_set_channels(pad->handle, hwparams,
 102                         pad->channels) < 0)
 103                 return -E_CHANNEL_COUNT;
 104         if (snd_pcm_hw_params_set_rate_near(pad->handle, hwparams,
 105                         &pad->samplerate, 0) < 0)
 106                 return -E_SET_RATE;
 107         err = snd_pcm_hw_params_get_buffer_time_max(hwparams, &pad->buffer_time, 0);
 108         if (err < 0 || !pad->buffer_time)
 109                 return -E_GET_BUFFER_TIME;
 110         PARA_INFO_LOG("buffer time: %d\n", pad->buffer_time);
 111         if (snd_pcm_hw_params_set_buffer_time_near(pad->handle, hwparams,
 112                         &pad->buffer_time, 0) < 0)
 113                 return -E_SET_BUFFER_TIME;
 114         if (snd_pcm_hw_params(pad->handle, hwparams) < 0)
 115                 return -E_HW_PARAMS;
 116         snd_pcm_hw_params_get_period_size(hwparams, &period_size, 0);
 117         snd_pcm_hw_params_get_buffer_size(hwparams, &buffer_size);
 118         PARA_INFO_LOG("buffer size: %lu, period_size: %lu\n", buffer_size,
 119                 period_size);
 120         if (period_size == buffer_size)
 121                 return -E_BAD_PERIOD;
 122         snd_pcm_sw_params_current(pad->handle, swparams);
 123         err = snd_pcm_sw_params_get_xfer_align(swparams, &xfer_align);
 124         if (err < 0 || !xfer_align)
 125                 return -E_GET_XFER;
 126         snd_pcm_sw_params_set_avail_min(pad->handle, swparams, period_size);
 127         /* round to closest transfer boundary */
 128         start_threshold = (buffer_size / xfer_align) * xfer_align;
 129         if (start_threshold < 1)
 130                 start_threshold = 1;
 131         if (snd_pcm_sw_params_set_start_threshold(pad->handle, swparams,
 132                         start_threshold) < 0)
 133                 return -E_START_THRESHOLD;
 134         stop_threshold = buffer_size;
 135         if (snd_pcm_sw_params_set_stop_threshold(pad->handle, swparams,
 136                         stop_threshold) < 0)
 137                 return -E_STOP_THRESHOLD;
 138         if (snd_pcm_sw_params_set_xfer_align(pad->handle, swparams,
 139                         xfer_align) < 0)
 140                 return -E_SET_XFER;
 141         if (snd_pcm_sw_params(pad->handle, swparams) < 0)
 142                 return -E_SW_PARAMS;
 143         pad->bytes_per_frame = snd_pcm_format_physical_width(FORMAT)
 144                 * pad->channels / 8;
 145         if (snd_pcm_nonblock(pad->handle, 1))
 146                 PARA_ERROR_LOG("%s\n", "failed to set nonblock mode");
 147         return period_size * pad->bytes_per_frame;
 148 }
 149
 150 static int alsa_write_pre_select(struct sched *s, struct writer_node *wn)
 151 {
 152         struct private_alsa_data *pad = wn->private_data;
 153         struct writer_node_group *wng = wn->wng;
 154         struct timeval diff;
 155
 156         if (*wng->loaded < pad->bytes_per_frame)
 157                 return 1;
 158         if (tv_diff(&s->now, &pad->next_chunk, &diff) < 0) {
 159                 if (tv_diff(&s->timeout, &diff, NULL) > 0)
 160                         s->timeout = diff;
 161         } else {
 162                 s->timeout.tv_sec = 0;
 163                 s->timeout.tv_usec = 1;
 164         }
 165         return 1;
 166 //      PARA_INFO_LOG("timeout: %lu\n", tv2ms(&s->timeout));
 167 }
 168
 169 static int alsa_write_post_select(struct sched *s, struct writer_node *wn)
 170 {
 171         struct private_alsa_data *pad = wn->private_data;
 172         struct writer_node_group *wng = wn->wng;
 173         size_t frames = (*wng->loaded - wn->written) / pad->bytes_per_frame;
 174         snd_pcm_sframes_t ret;
 175         unsigned char *data = (unsigned char*)wng->buf + wn->written;
 176         struct timeval tv;
 177
 178 //      PARA_INFO_LOG("%zd frames\n", frames);
 179         if (!frames) {
 180                 if (*wng->input_eof)
 181                         wn->written = *wng->loaded;
 182                 return 1;
 183         }
 184         if (tv_diff(&s->now, &pad->next_chunk, NULL) < 0)
 185                 return 1;
 186         ret = snd_pcm_writei(pad->handle, data, frames);
 187         if (ret == -EPIPE) {
 188                 PARA_WARNING_LOG("%s", "EPIPE\n");
 189                 snd_pcm_prepare(pad->handle);
 190                 return 1;
 191         }
 192         if (ret < 0) {
 193                 PARA_WARNING_LOG("%s", "ALSA ERROR\n");
 194                 return -E_ALSA_WRITE;
 195         }
 196         ms2tv(pad->buffer_time / 4000, &tv);
 197 //      ms2tv(1, &tv);
 198         tv_add(&s->now, &tv, &pad->next_chunk);
 199         wn->written += ret * pad->bytes_per_frame;
 200         return 1;
 201 }
 202
 203 static void alsa_close(struct writer_node *wn)
 204 {
 205         struct private_alsa_data *pad = wn->private_data;
 206         PARA_INFO_LOG("closing writer node %p\n", wn);
 207         snd_pcm_drain(pad->handle);
 208         snd_pcm_close(pad->handle);
 209         snd_config_update_free_global();
 210         free(pad);
 211 }
 212
 213 __malloc void *alsa_parse_config(char *options)
 214 {
 215         struct alsa_write_args_info *conf
 216                 = para_calloc(sizeof(struct alsa_write_args_info));
 217         PARA_INFO_LOG("options: %s, %d\n", options, strcspn(options, " \t"));
 218         int ret = alsa_cmdline_parser_string(options, conf, "alsa_write");
 219         if (ret)
 220                 goto err_out;
 221         PARA_INFO_LOG("help given: %d\n", conf->help_given);
 222         return conf;
 223 err_out:
 224         free(conf);
 225         return NULL;
 226 }
 227
 228 /** the init function of the alsa writer */
 229 void alsa_writer_init(struct writer *w)
 230 {
 231         w->open = alsa_open;
 232         w->close = alsa_close;
 233         w->pre_select = alsa_write_pre_select;
 234         w->post_select = alsa_write_post_select;
 235         w->parse_config = alsa_parse_config;
 236         w->shutdown = NULL; /* nothing to do */
 237 }