2 * Copyright (C) 2005-2006 Andre Noll <maan@systemlinux.org>
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.
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.
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.
19 /** \file alsa_writer.c paraslash's alsa output plugin */
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.
34 #include <alsa/asoundlib.h>
36 #include "alsa_write.cmdline.h"
40 #define FORMAT SND_PCM_FORMAT_S16_LE
42 /** data specific to the alsa writer */
43 struct private_alsa_data {
44 /** the alsa 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() */
55 * open and prepare the PCM handle for writing
57 * Install PCM software and hardware configuration. Exit on errors.
59 static int alsa_open(struct writer_node *w)
61 snd_pcm_hw_params_t *hwparams;
62 snd_pcm_sw_params_t *swparams;
63 snd_pcm_uframes_t buffer_size, xfer_align, start_threshold,
67 snd_pcm_uframes_t period_size;
68 struct private_alsa_data *pad = para_calloc(sizeof(struct private_alsa_data));
69 struct alsa_write_args_info *conf = w->conf;
71 w->private_data = pad;
72 snd_pcm_info_alloca(&info);
73 err = snd_pcm_open(&pad->handle, conf->device_arg,
74 SND_PCM_STREAM_PLAYBACK, 0);
77 if ((err = snd_pcm_info(pad->handle, info)) < 0)
78 return -E_SND_PCM_INFO;
80 snd_pcm_hw_params_alloca(&hwparams);
81 snd_pcm_sw_params_alloca(&swparams);
82 if (snd_pcm_hw_params_any(pad->handle, hwparams) < 0)
83 return -E_BROKEN_CONF;
84 if (snd_pcm_hw_params_set_access(pad->handle, hwparams,
85 SND_PCM_ACCESS_RW_INTERLEAVED) < 0)
86 return -E_ACCESS_TYPE;
87 if (snd_pcm_hw_params_set_format(pad->handle, hwparams, FORMAT) < 0)
88 return -E_SAMPLE_FORMAT;
89 if (snd_pcm_hw_params_set_channels(pad->handle, hwparams,
90 conf->channels_arg) < 0)
91 return -E_CHANNEL_COUNT;
92 if (snd_pcm_hw_params_set_rate_near(pad->handle, hwparams,
93 (unsigned int*) &conf->sample_rate_arg, 0) < 0)
95 err = snd_pcm_hw_params_get_buffer_time_max(hwparams, &pad->buffer_time, 0);
96 if (err < 0 || !pad->buffer_time)
97 return -E_GET_BUFFER_TIME;
98 PARA_INFO_LOG("buffer time: %d\n", pad->buffer_time);
99 if (snd_pcm_hw_params_set_buffer_time_near(pad->handle, hwparams,
100 &pad->buffer_time, 0) < 0)
101 return -E_SET_BUFFER_TIME;
102 if (snd_pcm_hw_params(pad->handle, hwparams) < 0)
104 snd_pcm_hw_params_get_period_size(hwparams, &period_size, 0);
105 snd_pcm_hw_params_get_buffer_size(hwparams, &buffer_size);
106 PARA_INFO_LOG("buffer size: %lu, period_size: %lu\n", buffer_size,
108 if (period_size == buffer_size)
109 return -E_BAD_PERIOD;
110 snd_pcm_sw_params_current(pad->handle, swparams);
111 err = snd_pcm_sw_params_get_xfer_align(swparams, &xfer_align);
112 if (err < 0 || !xfer_align)
114 snd_pcm_sw_params_set_avail_min(pad->handle, swparams, period_size);
115 /* round to closest transfer boundary */
116 start_threshold = (buffer_size / xfer_align) * xfer_align;
117 if (start_threshold < 1)
119 if (snd_pcm_sw_params_set_start_threshold(pad->handle, swparams,
120 start_threshold) < 0)
121 return -E_START_THRESHOLD;
122 stop_threshold = buffer_size;
123 if (snd_pcm_sw_params_set_stop_threshold(pad->handle, swparams,
125 return -E_STOP_THRESHOLD;
126 if (snd_pcm_sw_params_set_xfer_align(pad->handle, swparams,
129 if (snd_pcm_sw_params(pad->handle, swparams) < 0)
131 pad->bytes_per_frame = snd_pcm_format_physical_width(FORMAT)
132 * conf->channels_arg / 8;
133 if (snd_pcm_nonblock(pad->handle, 1))
134 PARA_ERROR_LOG("%s\n", "failed to set nonblock mode");
135 return period_size * pad->bytes_per_frame;
137 static void alsa_write_pre_select(struct sched *s, struct task *t)
139 struct writer_node *wn = t->private_data;
140 struct private_alsa_data *pad = wn->private_data;
141 struct writer_node_group *wng = wn->wng;
145 if (*wng->input_eof && *wng->loaded < pad->bytes_per_frame)
148 if (*wng->loaded < pad->bytes_per_frame)
150 if (tv_diff(&s->now, &pad->next_chunk, &diff) < 0) {
151 if (tv_diff(&s->timeout, &diff, NULL) > 0)
154 s->timeout.tv_sec = 0;
155 s->timeout.tv_usec = 0;
159 static void alsa_write_post_select(struct sched *s, struct task *t)
161 struct writer_node *wn = t->private_data;
162 struct private_alsa_data *pad = wn->private_data;
163 struct writer_node_group *wng = wn->wng;
164 size_t frames = *wng->loaded / pad->bytes_per_frame;
165 snd_pcm_sframes_t ret, result = 0;
166 unsigned char *data = (unsigned char*)wng->buf;
171 t->ret = *wng->loaded;
174 if (tv_diff(&s->now, &pad->next_chunk, NULL) < 0)
176 // PARA_INFO_LOG("%zd frames\n", frames);
177 // while (frames > 0) {
178 ret = snd_pcm_writei(pad->handle, data, frames);
179 if (ret == -EAGAIN || (ret >= 0 && ret < frames)) {
181 ms2tv(pad->buffer_time / 2000, &tv);
182 PARA_DEBUG_LOG("EAGAIN. frames: %d, ret: %lu\n", frames, ret);
183 tv_add(&s->now, &tv, &pad->next_chunk);
184 } else if (ret == -EPIPE) {
185 PARA_WARNING_LOG("%s", "EPIPE\n");
186 snd_pcm_prepare(pad->handle);
187 } else if (ret < 0) {
188 t->ret = -E_ALSA_WRITE;
194 data += ret * pad->bytes_per_frame;
196 // if (ret == -EAGAIN)
199 t->ret = result * pad->bytes_per_frame;
200 // PARA_INFO_LOG("ret: %d, frames: %zd\n", t->ret, frames);
203 static void alsa_close(struct writer_node *wn)
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();
212 __malloc void *alsa_parse_config(char *options)
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");
220 PARA_INFO_LOG("help given: %d\n", conf->help_given);
227 /** the init function of the alsa writer */
228 void alsa_writer_init(struct writer *w)
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 */