f64603ccc41fef8ac64cafed91ad20bd33742769
[paraslash.git] / oss_write.c
1 /*
2 * Copyright (C) 2009 Andre Noll <maan@systemlinux.org>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6
7 /** \file oss_write.c Paraslash's oss output plugin. */
8
9 #include <regex.h>
10 #include <sys/ioctl.h>
11 #include <fcntl.h>
12 #include <dirent.h>
13 #include <sys/soundcard.h>
14 #include <stdbool.h>
15
16 #include "para.h"
17 #include "fd.h"
18 #include "string.h"
19 #include "list.h"
20 #include "sched.h"
21 #include "ggo.h"
22 #include "buffer_tree.h"
23 #include "write.h"
24 #include "write_common.h"
25 #include "oss_write.cmdline.h"
26 #include "error.h"
27
28 /** Always use 16 bit little endian. */
29 #define FORMAT AFMT_S16_LE
30
31 /** Data specific to the oss writer. */
32 struct private_oss_write_data {
33 /** The file handle of the device. */
34 int fd;
35 /**
36 * The samplerate given by command line option or the decoder
37 * of the writer node group.
38 */
39 int samplerate;
40 /**
41 * The number of channels, given by command line option or the
42 * decoder of the writer node group.
43 */
44 int channels;
45 /** Four bytes for stereo streams, two bytes for mono streams. */
46 int bytes_per_frame;
47 };
48
49 static void oss_pre_select_btr(struct sched *s, struct task *t)
50 {
51 struct writer_node *wn = container_of(t, struct writer_node, task);
52 struct private_oss_write_data *powd = wn->private_data;
53 int ret = btr_node_status(wn->btrn, wn->min_iqs, BTR_NT_LEAF);
54
55 t->error = 0;
56 if (ret < 0)
57 goto min_delay;
58 if (ret == 0)
59 return;
60 if (!powd)
61 goto min_delay;
62 para_fd_set(powd->fd, &s->wfds, &s->max_fileno);
63 return;
64 min_delay:
65 s->timeout.tv_sec = 0;
66 s->timeout.tv_usec = 1;
67 }
68
69 static void oss_close(struct writer_node *wn)
70 {
71 struct private_oss_write_data *powd = wn->private_data;
72
73 close(powd->fd);
74 oss_cmdline_parser_free(wn->conf);
75 free(powd);
76 }
77
78 /*
79 * The Open Sound System Programmer's Guide sayeth:
80 *
81 * Set sampling parameters always so that number of channels (mono/stereo) is
82 * set before selecting sampling rate (speed). Failing to do this will make
83 * your program incompatible with cards such as the SoundBlaster Pro which
84 * supports 44.1 kHz in mono but just 22.05 kHz in stereo. A program which
85 * selects 44.1 kHz speed and then sets the device to stereo mode will
86 * incorrectly believe that the device is still in 44.1 kHz mode when actually
87 * the speed is decreased to 22.05 kHz.
88 */
89 static int oss_init(struct writer_node *wn, unsigned samplerate, unsigned channels)
90 {
91 int ret, format = FORMAT, ch, rate;
92 struct oss_write_args_info *conf = wn->conf;
93 struct private_oss_write_data *powd = wn->private_data;
94
95 PARA_INFO_LOG("opening %s\n", conf->device_arg);
96 ret = para_open(conf->device_arg, O_WRONLY, 0);
97 if (ret < 0)
98 return ret;
99 powd->fd = ret;
100 ret = mark_fd_nonblocking(powd->fd);
101 if (ret < 0)
102 goto err;
103 /* set PCM format */
104 ret = ioctl(powd->fd, SNDCTL_DSP_SETFMT, &format);
105 if (ret < 0) {
106 ret = -ERRNO_TO_PARA_ERROR(errno);
107 goto err;
108 }
109 ret = -E_BAD_SAMPLE_FORMAT;
110 if (format != FORMAT)
111 goto err;
112 /* set number of channels */
113 if (!conf->channels_given && channels != 0)
114 ch = channels;
115 else
116 ch = conf->channels_arg;
117 ret = -E_BAD_CHANNEL_COUNT;
118 if (ch == 0)
119 goto err;
120 powd->channels = ch;
121 ret = ioctl(powd->fd, SNDCTL_DSP_CHANNELS, &ch);
122 if (ret < 0) {
123 ret = -ERRNO_TO_PARA_ERROR(errno);
124 goto err;
125 }
126 if (powd->channels != ch)
127 goto err;
128 powd->bytes_per_frame = ch * 2;
129
130 /*
131 * Set sampling rate
132 *
133 * If we request a higher sampling rate than is supported by the
134 * device, the the highest possible speed is automatically used. The
135 * value actually used is returned as the new value of the argument.
136 */
137 if (!conf->samplerate_given && samplerate != 0)
138 rate = samplerate;
139 else
140 rate = conf->samplerate_arg;
141 powd->samplerate = rate;
142 ret = ioctl(powd->fd, SNDCTL_DSP_SPEED, &rate);
143 if (ret < 0) {
144 ret = -ERRNO_TO_PARA_ERROR(errno);
145 goto err;
146 }
147 if (rate != powd->samplerate) {
148 int min = PARA_MIN(rate, powd->samplerate),
149 max = PARA_MAX(rate, powd->samplerate);
150 /*
151 * Check whether the returned sample rate differs significantly
152 * from the requested one.
153 */
154 ret = -E_BAD_SAMPLERATE;
155 if (100 * max > 110 * min) /* more than 10% deviation */
156 goto err;
157 PARA_NOTICE_LOG("using %dHz rather than %dHz\n", rate,
158 powd->samplerate);
159 }
160 wn->min_iqs = powd->bytes_per_frame;
161 return 1;
162 err:
163 close(powd->fd);
164 free(powd);
165 return ret;
166 }
167
168 static void oss_post_select_btr(__a_unused struct sched *s,
169 struct task *t)
170 {
171 struct writer_node *wn = container_of(t, struct writer_node, task);
172 struct oss_write_args_info *conf = wn->conf;
173 struct private_oss_write_data *powd = wn->private_data;
174 struct btr_node *btrn = wn->btrn;
175 size_t frames, bytes;
176 int ret = btr_node_status(btrn, wn->min_iqs, BTR_NT_LEAF);
177 char *data;
178
179 if (ret < 0)
180 goto out;
181 if (ret == 0)
182 return;
183 if (powd->fd < 0) {
184 int32_t rate, ch;
185 ret = -1;
186 if (!conf->samplerate_given) /* config option trumps btr_exec */
187 ret = get_btr_samplerate(wn->btrn, &rate);
188 if (ret < 0)
189 rate = conf->samplerate_arg;
190 ret = -1;
191 if (!conf->channels_given)
192 ret = get_btr_channels(wn->btrn, &ch);
193 if (ret < 0)
194 ch = conf->channels_arg;
195 ret = oss_init(wn, rate, ch);
196 if (ret < 0)
197 goto out;
198 return;
199 }
200 bytes = btr_next_buffer(btrn, &data);
201 frames = bytes / powd->bytes_per_frame;
202 if (!frames) { /* eof and less than a single frame available */
203 ret = -E_OSS_EOF;
204 goto out;
205 }
206 ret = 0;
207 if (!FD_ISSET(powd->fd, &s->wfds))
208 goto out;
209 ret = write_nonblock(powd->fd, data, frames * powd->bytes_per_frame, 0);
210 if (ret < 0)
211 goto out;
212 btr_consume(btrn, ret);
213 ret = 0;
214 out:
215 t->error = ret;
216 if (ret < 0)
217 btr_remove_node(btrn);
218 }
219
220 static int oss_open(struct writer_node *wn)
221 {
222 struct writer_node_group *wng;
223 struct private_oss_write_data *powd;
224
225 powd = para_calloc(sizeof(*powd));
226 wn->private_data = powd;
227 if (!wn->btrn) {
228 wng = wn->wng;
229 return oss_init(wn, wng->samplerate ? *wng->samplerate : 0,
230 wng->channels? *wng->channels : 0);
231 }
232 powd->fd = -1;
233 return 1;
234 }
235
236 __malloc static void *oss_parse_config(const char *options)
237 {
238 int ret;
239 struct oss_write_args_info *conf = para_calloc(sizeof(*conf));
240
241 PARA_INFO_LOG("options: %s, %zd\n", options, strcspn(options, " \t"));
242 ret = oss_cmdline_parser_string(options, conf, "oss_write");
243 if (ret)
244 goto err_out;
245 return conf;
246 err_out:
247 free(conf);
248 return NULL;
249 }
250
251 static void oss_free_config(void *conf)
252 {
253 oss_cmdline_parser_free(conf);
254 }
255
256 /**
257 * The init function of the oss writer.
258 *
259 * \param w Pointer to the writer to initialize.
260 *
261 * \sa struct writer.
262 */
263 void oss_write_init(struct writer *w)
264 {
265 struct oss_write_args_info dummy;
266
267 oss_cmdline_parser_init(&dummy);
268 w->open = oss_open;
269 w->close = oss_close;
270 w->pre_select_btr = oss_pre_select_btr;
271 w->post_select_btr = oss_post_select_btr;
272 w->parse_config = oss_parse_config;
273 w->free_config = oss_free_config;
274 w->shutdown = NULL;
275 w->help = (struct ggo_help) {
276 .short_help = oss_write_args_info_help,
277 .detailed_help = oss_write_args_info_detailed_help
278 };
279 oss_cmdline_parser_free(&dummy);
280 }