alsa_write.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_write.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_write_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_write_data *pad = para_calloc(sizeof(struct
  71                 private_alsa_write_data));
  72         struct alsa_write_args_info *conf = w->conf;
  73         struct writer_node_group *wng = w->wng;
  74
  75         if (!conf->samplerate_given && wng->samplerate)
  76                 pad->samplerate = *wng->samplerate;
  77         else
  78                 pad->samplerate = conf->samplerate_arg;
  79         if (!conf->channels_given && wng->channels)
  80                 pad->channels = *wng->channels;
  81         else
  82                 pad->channels = conf->channels_arg;
  83         PARA_INFO_LOG("%d channel(s), %dHz\n", pad->channels, pad->samplerate);
  84         w->private_data = pad;
  85         snd_pcm_info_alloca(&info);
  86         err = snd_pcm_open(&pad->handle, conf->device_arg,
  87                 SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK);
  88         if (err < 0)
  89                 return -E_PCM_OPEN;
  90         if ((err = snd_pcm_info(pad->handle, info)) < 0)
  91                 return -E_SND_PCM_INFO;
  92
  93         snd_pcm_hw_params_alloca(&hwparams);
  94         snd_pcm_sw_params_alloca(&swparams);
  95         if (snd_pcm_hw_params_any(pad->handle, hwparams) < 0)
  96                 return -E_BROKEN_CONF;
  97         if (snd_pcm_hw_params_set_access(pad->handle, hwparams,
  98                         SND_PCM_ACCESS_RW_INTERLEAVED) < 0)
  99                 return -E_ACCESS_TYPE;
 100         if (snd_pcm_hw_params_set_format(pad->handle, hwparams, FORMAT) < 0)
 101                 return -E_SAMPLE_FORMAT;
 102         if (snd_pcm_hw_params_set_channels(pad->handle, hwparams,
 103                         pad->channels) < 0)
 104                 return -E_CHANNEL_COUNT;
 105         if (snd_pcm_hw_params_set_rate_near(pad->handle, hwparams,
 106                         &pad->samplerate, 0) < 0)
 107                 return -E_SET_RATE;
 108         err = snd_pcm_hw_params_get_buffer_time_max(hwparams, &pad->buffer_time, 0);
 109         if (err < 0 || !pad->buffer_time)
 110                 return -E_GET_BUFFER_TIME;
 111         PARA_INFO_LOG("buffer time: %d\n", pad->buffer_time);
 112         if (snd_pcm_hw_params_set_buffer_time_near(pad->handle, hwparams,
 113                         &pad->buffer_time, 0) < 0)
 114                 return -E_SET_BUFFER_TIME;
 115         if (snd_pcm_hw_params(pad->handle, hwparams) < 0)
 116                 return -E_HW_PARAMS;
 117         snd_pcm_hw_params_get_period_size(hwparams, &period_size, 0);
 118         snd_pcm_hw_params_get_buffer_size(hwparams, &buffer_size);
 119         PARA_INFO_LOG("buffer size: %lu, period_size: %lu\n", buffer_size,
 120                 period_size);
 121         if (period_size == buffer_size)
 122                 return -E_BAD_PERIOD;
 123         snd_pcm_sw_params_current(pad->handle, swparams);
 124         err = snd_pcm_sw_params_get_xfer_align(swparams, &xfer_align);
 125         if (err < 0 || !xfer_align)
 126                 return -E_GET_XFER;
 127         snd_pcm_sw_params_set_avail_min(pad->handle, swparams, period_size);
 128         /* round to closest transfer boundary */
 129         start_threshold = (buffer_size / xfer_align) * xfer_align;
 130         if (start_threshold < 1)
 131                 start_threshold = 1;
 132         if (snd_pcm_sw_params_set_start_threshold(pad->handle, swparams,
 133                         start_threshold) < 0)
 134                 return -E_START_THRESHOLD;
 135         stop_threshold = buffer_size;
 136         if (snd_pcm_sw_params_set_stop_threshold(pad->handle, swparams,
 137                         stop_threshold) < 0)
 138                 return -E_STOP_THRESHOLD;
 139         if (snd_pcm_sw_params_set_xfer_align(pad->handle, swparams,
 140                         xfer_align) < 0)
 141                 return -E_SET_XFER;
 142         if (snd_pcm_sw_params(pad->handle, swparams) < 0)
 143                 return -E_SW_PARAMS;
 144         pad->bytes_per_frame = snd_pcm_format_physical_width(FORMAT)
 145                 * pad->channels / 8;
 146         if (snd_pcm_nonblock(pad->handle, 1))
 147                 PARA_ERROR_LOG("%s\n", "failed to set nonblock mode");
 148         return period_size * pad->bytes_per_frame;
 149 }
 150
 151 static int alsa_write_pre_select(struct sched *s, struct writer_node *wn)
 152 {
 153         struct private_alsa_write_data *pad = wn->private_data;
 154         struct writer_node_group *wng = wn->wng;
 155         struct timeval diff;
 156
 157         if (*wng->loaded < pad->bytes_per_frame)
 158                 return 1;
 159         if (tv_diff(now, &pad->next_chunk, &diff) < 0) {
 160                 if (tv_diff(&s->timeout, &diff, NULL) > 0)
 161                         s->timeout = diff;
 162         } else {
 163                 s->timeout.tv_sec = 0;
 164                 s->timeout.tv_usec = 1;
 165         }
 166         return 1;
 167 //      PARA_INFO_LOG("timeout: %lu\n", tv2ms(&s->timeout));
 168 }
 169
 170 static int alsa_write_post_select(__a_unused struct sched *s,
 171                 struct writer_node *wn)
 172 {
 173         struct private_alsa_write_data *pad = wn->private_data;
 174         struct writer_node_group *wng = wn->wng;
 175         size_t frames = (*wng->loaded - wn->written) / pad->bytes_per_frame;
 176         snd_pcm_sframes_t ret;
 177         unsigned char *data = (unsigned char*)wng->buf + wn->written;
 178         struct timeval tv;
 179
 180 //      PARA_INFO_LOG("%zd frames\n", frames);
 181         if (!frames) {
 182                 if (*wng->input_eof)
 183                         wn->written = *wng->loaded;
 184                 return 1;
 185         }
 186         if (tv_diff(now, &pad->next_chunk, NULL) < 0)
 187                 return 1;
 188         ret = snd_pcm_writei(pad->handle, data, frames);
 189         if (ret == -EPIPE) {
 190                 PARA_WARNING_LOG("%s", "EPIPE\n");
 191                 snd_pcm_prepare(pad->handle);
 192                 return 1;
 193         }
 194         if (ret < 0) {
 195                 PARA_WARNING_LOG("%s", "ALSA ERROR\n");
 196                 return -E_ALSA_WRITE;
 197         }
 198         ms2tv(pad->buffer_time / 4000, &tv);
 199 //      ms2tv(1, &tv);
 200         tv_add(now, &tv, &pad->next_chunk);
 201         wn->written += ret * pad->bytes_per_frame;
 202         return 1;
 203 }
 204
 205 static void alsa_close(struct writer_node *wn)
 206 {
 207         struct private_alsa_write_data *pad = wn->private_data;
 208         PARA_INFO_LOG("closing writer node %p\n", wn);
 209         snd_pcm_drain(pad->handle);
 210         snd_pcm_close(pad->handle);
 211         snd_config_update_free_global();
 212         free(pad);
 213 }
 214
 215 __malloc static void *alsa_parse_config(const char *options)
 216 {
 217         struct alsa_write_args_info *conf
 218                 = para_calloc(sizeof(struct alsa_write_args_info));
 219         PARA_INFO_LOG("options: %s, %d\n", options, strcspn(options, " \t"));
 220         int ret = alsa_cmdline_parser_string(options, conf, "alsa_write");
 221         if (ret)
 222                 goto err_out;
 223         PARA_INFO_LOG("help given: %d\n", conf->help_given);
 224         return conf;
 225 err_out:
 226         free(conf);
 227         return NULL;
 228 }
 229
 230 /** the init function of the alsa writer */
 231 void alsa_write_init(struct writer *w)
 232 {
 233         w->open = alsa_open;
 234         w->close = alsa_close;
 235         w->pre_select = alsa_write_pre_select;
 236         w->post_select = alsa_write_post_select;
 237         w->parse_config = alsa_parse_config;
 238         w->shutdown = NULL; /* nothing to do */
 239 }