alsa: Revert 596d1d97f90854bd941db02f1353df8e1196ccc0
[paraslash.git] / alsa_write.c
1 /*
2 * Copyright (C) 2005-2008 Andre Noll <maan@systemlinux.org>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6
7 /** \file alsa_write.c paraslash's alsa output plugin */
8
9 /*
10 * Based in parts on aplay.c from the alsa-utils-1.0.8 package,
11 * Copyright (c) by Jaroslav Kysela <perex@suse.cz>, which is
12 * based on the vplay program by Michael Beck.
13 */
14
15 #include <sys/types.h>
16 #include <dirent.h>
17 #include <alsa/asoundlib.h>
18
19 #include "para.h"
20 #include "fd.h"
21 #include "string.h"
22 #include "list.h"
23 #include "sched.h"
24 #include "ggo.h"
25 #include "write.h"
26 #include "alsa_write.cmdline.h"
27 #include "error.h"
28
29 /** always use 16 bit little endian */
30 #define FORMAT SND_PCM_FORMAT_S16_LE
31
32 /** data specific to the alsa writer */
33 struct private_alsa_write_data {
34 /** the alsa handle */
35 snd_pcm_t *handle;
36 /** determined and set by alsa_open() */
37 size_t bytes_per_frame;
38 /** don't write anything until this time */
39 struct timeval next_chunk;
40 /** the return value of snd_pcm_hw_params_get_buffer_time_max() */
41 unsigned buffer_time;
42 /**
43 * the samplerate given by command line option or the decoder
44 * of the writer node group
45 */
46 unsigned samplerate;
47 /**
48 * the number of channels, also given by command line option or the
49 * decoder of the writer node group
50 */
51 unsigned channels;
52 };
53
54 /*
55 * open and prepare the PCM handle for writing
56 *
57 * Install PCM software and hardware configuration. Exit on errors.
58 */
59 static int alsa_open(struct writer_node *w)
60 {
61 snd_pcm_hw_params_t *hwparams;
62 snd_pcm_sw_params_t *swparams;
63 snd_pcm_uframes_t buffer_size, start_threshold, stop_threshold;
64 int err;
65 snd_pcm_info_t *info;
66 snd_pcm_uframes_t period_size;
67 struct private_alsa_write_data *pad = para_calloc(sizeof(struct
68 private_alsa_write_data));
69 struct alsa_write_args_info *conf = w->conf;
70 struct writer_node_group *wng = w->wng;
71
72 if (!conf->samplerate_given && wng->samplerate)
73 pad->samplerate = *wng->samplerate;
74 else
75 pad->samplerate = conf->samplerate_arg;
76 if (!conf->channels_given && wng->channels)
77 pad->channels = *wng->channels;
78 else
79 pad->channels = conf->channels_arg;
80 PARA_INFO_LOG("%d channel(s), %dHz\n", pad->channels, pad->samplerate);
81 w->private_data = pad;
82 snd_pcm_info_alloca(&info);
83 err = snd_pcm_open(&pad->handle, conf->device_arg,
84 SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK);
85 if (err < 0)
86 return -E_PCM_OPEN;
87 if ((err = snd_pcm_info(pad->handle, info)) < 0)
88 return -E_SND_PCM_INFO;
89
90 snd_pcm_hw_params_alloca(&hwparams);
91 snd_pcm_sw_params_alloca(&swparams);
92 if (snd_pcm_hw_params_any(pad->handle, hwparams) < 0)
93 return -E_BROKEN_CONF;
94 if (snd_pcm_hw_params_set_access(pad->handle, hwparams,
95 SND_PCM_ACCESS_RW_INTERLEAVED) < 0)
96 return -E_ACCESS_TYPE;
97 if (snd_pcm_hw_params_set_format(pad->handle, hwparams, FORMAT) < 0)
98 return -E_SAMPLE_FORMAT;
99 if (snd_pcm_hw_params_set_channels(pad->handle, hwparams,
100 pad->channels) < 0)
101 return -E_CHANNEL_COUNT;
102 if (snd_pcm_hw_params_set_rate_near(pad->handle, hwparams,
103 &pad->samplerate, 0) < 0)
104 return -E_SET_RATE;
105 err = snd_pcm_hw_params_get_buffer_time_max(hwparams, &pad->buffer_time, 0);
106 if (err < 0 || !pad->buffer_time)
107 return -E_GET_BUFFER_TIME;
108 PARA_INFO_LOG("buffer time: %d\n", pad->buffer_time);
109 if (snd_pcm_hw_params_set_buffer_time_near(pad->handle, hwparams,
110 &pad->buffer_time, 0) < 0)
111 return -E_SET_BUFFER_TIME;
112 if (snd_pcm_hw_params(pad->handle, hwparams) < 0)
113 return -E_HW_PARAMS;
114 snd_pcm_hw_params_get_period_size(hwparams, &period_size, 0);
115 snd_pcm_hw_params_get_buffer_size(hwparams, &buffer_size);
116 PARA_INFO_LOG("buffer size: %lu, period_size: %lu\n", buffer_size,
117 period_size);
118 if (period_size == buffer_size)
119 return -E_BAD_PERIOD;
120 snd_pcm_sw_params_current(pad->handle, swparams);
121 snd_pcm_sw_params_set_avail_min(pad->handle, swparams, period_size);
122 if (buffer_size < 1)
123 start_threshold = 1;
124 else
125 start_threshold = buffer_size;
126 if (snd_pcm_sw_params_set_start_threshold(pad->handle, swparams,
127 start_threshold) < 0)
128 return -E_START_THRESHOLD;
129 stop_threshold = buffer_size;
130 if (snd_pcm_sw_params_set_stop_threshold(pad->handle, swparams,
131 stop_threshold) < 0)
132 return -E_STOP_THRESHOLD;
133 if (snd_pcm_sw_params(pad->handle, swparams) < 0)
134 PARA_WARNING_LOG("unable to install sw params\n");
135 pad->bytes_per_frame = snd_pcm_format_physical_width(FORMAT)
136 * pad->channels / 8;
137 PARA_INFO_LOG("bytes per frame: %zu\n", pad->bytes_per_frame);
138 if (snd_pcm_nonblock(pad->handle, 1))
139 PARA_ERROR_LOG("failed to set nonblock mode\n");
140 tv_add(now, &(struct timeval ){0, 100 * 1000}, &pad->next_chunk);
141 return period_size * pad->bytes_per_frame;
142 }
143
144 static int alsa_write_pre_select(struct sched *s, struct writer_node *wn)
145 {
146 struct private_alsa_write_data *pad = wn->private_data;
147 struct writer_node_group *wng = wn->wng;
148 struct timeval diff;
149
150 if (*wng->loaded < pad->bytes_per_frame)
151 return 1;
152 if (tv_diff(now, &pad->next_chunk, &diff) < 0) {
153 if (tv_diff(&s->timeout, &diff, NULL) > 0)
154 s->timeout = diff;
155 } else {
156 s->timeout.tv_sec = 0;
157 s->timeout.tv_usec = 1;
158 }
159 return 1;
160 // PARA_INFO_LOG("timeout: %lu\n", tv2ms(&s->timeout));
161 }
162
163 static int alsa_write_post_select(__a_unused struct sched *s,
164 struct writer_node *wn)
165 {
166 struct private_alsa_write_data *pad = wn->private_data;
167 struct writer_node_group *wng = wn->wng;
168 size_t frames = (*wng->loaded - wn->written) / pad->bytes_per_frame;
169 snd_pcm_sframes_t ret;
170 unsigned char *data = (unsigned char*)wng->buf + wn->written;
171 struct timeval tv;
172
173 // PARA_INFO_LOG("%zd frames\n", frames);
174 if (!frames) {
175 if (*wng->input_error)
176 wn->written = *wng->loaded;
177 return 1;
178 }
179 if (tv_diff(now, &pad->next_chunk, NULL) < 0)
180 return 1;
181 ret = snd_pcm_writei(pad->handle, data, frames);
182 if (ret == -EPIPE) {
183 PARA_WARNING_LOG("EPIPE\n");
184 snd_pcm_prepare(pad->handle);
185 return 1;
186 }
187 if (ret < 0 && ret != -EAGAIN) {
188 PARA_WARNING_LOG("alsa error (%zu frames, ret = %d\n",
189 frames, (int)ret);
190 return -E_ALSA_WRITE;
191 }
192 if (ret == -EAGAIN)
193 PARA_DEBUG_LOG("EAGAIN\n");
194 else
195 wn->written += ret * pad->bytes_per_frame;
196 if (ret == frames) /* we wrote everything, try again immediately */
197 pad->next_chunk = *now;
198 else {
199 ms2tv(pad->buffer_time / pad->bytes_per_frame / 1000, &tv);
200 tv_add(now, &tv, &pad->next_chunk);
201 }
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 int ret;
218 struct alsa_write_args_info *conf
219 = para_calloc(sizeof(struct alsa_write_args_info));
220
221 PARA_INFO_LOG("options: %s, %zd\n", options, strcspn(options, " \t"));
222 ret = alsa_cmdline_parser_string(options, conf, "alsa_write");
223 if (ret)
224 goto err_out;
225 PARA_INFO_LOG("help given: %d\n", conf->help_given);
226 return conf;
227 err_out:
228 free(conf);
229 return NULL;
230 }
231
232 /**
233 * the init function of the alsa writer
234 *
235 * \param w pointer to the writer to initialize
236 *
237 * \sa struct writer
238 */
239 void alsa_write_init(struct writer *w)
240 {
241 struct alsa_write_args_info dummy;
242
243 alsa_cmdline_parser_init(&dummy);
244 w->open = alsa_open;
245 w->close = alsa_close;
246 w->pre_select = alsa_write_pre_select;
247 w->post_select = alsa_write_post_select;
248 w->parse_config = alsa_parse_config;
249 w->shutdown = NULL; /* nothing to do */
250 w->help = (struct ggo_help) {
251 .short_help = alsa_write_args_info_help,
252 .detailed_help = alsa_write_args_info_detailed_help
253 };
254 }