dccp sender: Keep polling until an entry becomes free (Gerrit Renker).
[paraslash.git] / alsa_write.c
1 /*
2 * Copyright (C) 2005-2007 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 "para.h"
16 #include "fd.h"
17 #include "string.h"
18 #include "list.h"
19 #include "sched.h"
20 #include "write.h"
21
22 #include <alsa/asoundlib.h>
23
24 #include "alsa_write.cmdline.h"
25 #include "error.h"
26
27 /** always use 16 bit little endian */
28 #define FORMAT SND_PCM_FORMAT_S16_LE
29
30 /** data specific to the alsa writer */
31 struct private_alsa_write_data {
32 /** the alsa handle */
33 snd_pcm_t *handle;
34 /** determined and set by alsa_open() */
35 size_t bytes_per_frame;
36 /** don't write anything until this time */
37 struct timeval next_chunk;
38 /** the return value of snd_pcm_hw_params_get_buffer_time_max() */
39 unsigned buffer_time;
40 /**
41 * the samplerate given by command line option or the decoder
42 * of the writer node group
43 */
44 unsigned samplerate;
45 /**
46 * the number of channels, also given by command line option or the
47 * decoder of the writer node group
48 */
49 unsigned channels;
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 int err;
64 snd_pcm_info_t *info;
65 snd_pcm_uframes_t period_size;
66 struct private_alsa_write_data *pad = para_calloc(sizeof(struct
67 private_alsa_write_data));
68 struct alsa_write_args_info *conf = w->conf;
69 struct writer_node_group *wng = w->wng;
70
71 if (!conf->samplerate_given && wng->samplerate)
72 pad->samplerate = *wng->samplerate;
73 else
74 pad->samplerate = conf->samplerate_arg;
75 if (!conf->channels_given && wng->channels)
76 pad->channels = *wng->channels;
77 else
78 pad->channels = conf->channels_arg;
79 PARA_INFO_LOG("%d channel(s), %dHz\n", pad->channels, pad->samplerate);
80 w->private_data = pad;
81 snd_pcm_info_alloca(&info);
82 err = snd_pcm_open(&pad->handle, conf->device_arg,
83 SND_PCM_STREAM_PLAYBACK, SND_PCM_NONBLOCK);
84 if (err < 0)
85 return -E_PCM_OPEN;
86 if ((err = snd_pcm_info(pad->handle, info)) < 0)
87 return -E_SND_PCM_INFO;
88
89 snd_pcm_hw_params_alloca(&hwparams);
90 snd_pcm_sw_params_alloca(&swparams);
91 if (snd_pcm_hw_params_any(pad->handle, hwparams) < 0)
92 return -E_BROKEN_CONF;
93 if (snd_pcm_hw_params_set_access(pad->handle, hwparams,
94 SND_PCM_ACCESS_RW_INTERLEAVED) < 0)
95 return -E_ACCESS_TYPE;
96 if (snd_pcm_hw_params_set_format(pad->handle, hwparams, FORMAT) < 0)
97 return -E_SAMPLE_FORMAT;
98 if (snd_pcm_hw_params_set_channels(pad->handle, hwparams,
99 pad->channels) < 0)
100 return -E_CHANNEL_COUNT;
101 if (snd_pcm_hw_params_set_rate_near(pad->handle, hwparams,
102 &pad->samplerate, 0) < 0)
103 return -E_SET_RATE;
104 err = snd_pcm_hw_params_get_buffer_time_max(hwparams, &pad->buffer_time, 0);
105 if (err < 0 || !pad->buffer_time)
106 return -E_GET_BUFFER_TIME;
107 PARA_INFO_LOG("buffer time: %d\n", pad->buffer_time);
108 if (snd_pcm_hw_params_set_buffer_time_near(pad->handle, hwparams,
109 &pad->buffer_time, 0) < 0)
110 return -E_SET_BUFFER_TIME;
111 if (snd_pcm_hw_params(pad->handle, hwparams) < 0)
112 return -E_HW_PARAMS;
113 snd_pcm_hw_params_get_period_size(hwparams, &period_size, 0);
114 snd_pcm_hw_params_get_buffer_size(hwparams, &buffer_size);
115 PARA_INFO_LOG("buffer size: %lu, period_size: %lu\n", buffer_size,
116 period_size);
117 if (period_size == buffer_size)
118 return -E_BAD_PERIOD;
119 snd_pcm_sw_params_current(pad->handle, swparams);
120 err = snd_pcm_sw_params_get_xfer_align(swparams, &xfer_align);
121 if (err < 0 || !xfer_align)
122 return -E_GET_XFER;
123 snd_pcm_sw_params_set_avail_min(pad->handle, swparams, period_size);
124 /* round to closest transfer boundary */
125 start_threshold = (buffer_size / xfer_align) * xfer_align;
126 if (start_threshold < 1)
127 start_threshold = 1;
128 if (snd_pcm_sw_params_set_start_threshold(pad->handle, swparams,
129 start_threshold) < 0)
130 return -E_START_THRESHOLD;
131 stop_threshold = buffer_size;
132 if (snd_pcm_sw_params_set_stop_threshold(pad->handle, swparams,
133 stop_threshold) < 0)
134 return -E_STOP_THRESHOLD;
135 if (snd_pcm_sw_params_set_xfer_align(pad->handle, swparams,
136 xfer_align) < 0)
137 return -E_SET_XFER;
138 if (snd_pcm_sw_params(pad->handle, swparams) < 0)
139 return -E_SW_PARAMS;
140 pad->bytes_per_frame = snd_pcm_format_physical_width(FORMAT)
141 * pad->channels / 8;
142 if (snd_pcm_nonblock(pad->handle, 1))
143 PARA_ERROR_LOG("%s\n", "failed to set nonblock mode");
144 return period_size * pad->bytes_per_frame;
145 }
146
147 static int alsa_write_pre_select(struct sched *s, struct writer_node *wn)
148 {
149 struct private_alsa_write_data *pad = wn->private_data;
150 struct writer_node_group *wng = wn->wng;
151 struct timeval diff;
152
153 if (*wng->loaded < pad->bytes_per_frame)
154 return 1;
155 if (tv_diff(now, &pad->next_chunk, &diff) < 0) {
156 if (tv_diff(&s->timeout, &diff, NULL) > 0)
157 s->timeout = diff;
158 } else {
159 s->timeout.tv_sec = 0;
160 s->timeout.tv_usec = 1;
161 }
162 return 1;
163 // PARA_INFO_LOG("timeout: %lu\n", tv2ms(&s->timeout));
164 }
165
166 static int alsa_write_post_select(__a_unused struct sched *s,
167 struct writer_node *wn)
168 {
169 struct private_alsa_write_data *pad = wn->private_data;
170 struct writer_node_group *wng = wn->wng;
171 size_t frames = (*wng->loaded - wn->written) / pad->bytes_per_frame;
172 snd_pcm_sframes_t ret;
173 unsigned char *data = (unsigned char*)wng->buf + wn->written;
174 struct timeval tv;
175
176 // PARA_INFO_LOG("%zd frames\n", frames);
177 if (!frames) {
178 if (*wng->input_eof)
179 wn->written = *wng->loaded;
180 return 1;
181 }
182 if (tv_diff(now, &pad->next_chunk, NULL) < 0)
183 return 1;
184 ret = snd_pcm_writei(pad->handle, data, frames);
185 if (ret == -EPIPE) {
186 PARA_WARNING_LOG("%s", "EPIPE\n");
187 snd_pcm_prepare(pad->handle);
188 return 1;
189 }
190 if (ret < 0) {
191 PARA_WARNING_LOG("%s", "ALSA ERROR\n");
192 return -E_ALSA_WRITE;
193 }
194 ms2tv(pad->buffer_time / 4000, &tv);
195 // ms2tv(1, &tv);
196 tv_add(now, &tv, &pad->next_chunk);
197 wn->written += ret * pad->bytes_per_frame;
198 return 1;
199 }
200
201 static void alsa_close(struct writer_node *wn)
202 {
203 struct private_alsa_write_data *pad = wn->private_data;
204 PARA_INFO_LOG("closing writer node %p\n", wn);
205 snd_pcm_drain(pad->handle);
206 snd_pcm_close(pad->handle);
207 snd_config_update_free_global();
208 free(pad);
209 }
210
211 __malloc static void *alsa_parse_config(const char *options)
212 {
213 struct alsa_write_args_info *conf
214 = para_calloc(sizeof(struct alsa_write_args_info));
215 PARA_INFO_LOG("options: %s, %zd\n", options, strcspn(options, " \t"));
216 int ret = alsa_cmdline_parser_string(options, conf, "alsa_write");
217 if (ret)
218 goto err_out;
219 PARA_INFO_LOG("help given: %d\n", conf->help_given);
220 return conf;
221 err_out:
222 free(conf);
223 return NULL;
224 }
225
226 /**
227 * the init function of the alsa writer
228 *
229 * \param w pointer to the writer to initialize
230 *
231 * \sa struct writer
232 */
233 void alsa_write_init(struct writer *w)
234 {
235 w->open = alsa_open;
236 w->close = alsa_close;
237 w->pre_select = alsa_write_pre_select;
238 w->post_select = alsa_write_post_select;
239 w->parse_config = alsa_parse_config;
240 w->shutdown = NULL; /* nothing to do */
241 }