para.h: Fix typo in comment.
[paraslash.git] / oss_write.c
1 /*
2 * Copyright (C) 2009-2010 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 /** Data specific to the oss writer. */
29 struct private_oss_write_data {
30 /** The file handle of the device. */
31 int fd;
32 /** Four bytes for stereo streams, two bytes for mono streams. */
33 int bytes_per_frame;
34 };
35
36 static int get_oss_format(enum sample_format sf)
37 {
38 switch (sf) {
39 case SF_S8: return AFMT_S8;
40 case SF_U8: return AFMT_U8;
41 case SF_S16_LE: return AFMT_S16_LE;
42 case SF_S16_BE: return AFMT_S16_BE;
43 case SF_U16_LE: return AFMT_U16_LE;
44 case SF_U16_BE: return AFMT_U16_BE;
45 default: return AFMT_S16_LE;
46 }
47 }
48
49 static void oss_pre_select(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 sched_min_delay(s);
58 else if (ret > 0)
59 para_fd_set(powd->fd, &s->wfds, &s->max_fileno);
60 }
61
62 static void oss_close(struct writer_node *wn)
63 {
64 struct private_oss_write_data *powd = wn->private_data;
65
66 if (powd->fd >= 0)
67 close(powd->fd);
68 free(powd);
69 }
70
71 /*
72 * The Open Sound System Programmer's Guide sayeth:
73 *
74 * Set sampling parameters always so that number of channels (mono/stereo) is
75 * set before selecting sampling rate (speed). Failing to do this will make
76 * your program incompatible with cards such as the SoundBlaster Pro which
77 * supports 44.1 kHz in mono but just 22.05 kHz in stereo. A program which
78 * selects 44.1 kHz speed and then sets the device to stereo mode will
79 * incorrectly believe that the device is still in 44.1 kHz mode when actually
80 * the speed is decreased to 22.05 kHz.
81 */
82 static int oss_init(struct writer_node *wn, unsigned sample_rate,
83 unsigned channels, int sample_format)
84 {
85 int ret, format;
86 unsigned ch, rate;
87 struct oss_write_args_info *conf = wn->conf;
88 struct private_oss_write_data *powd = wn->private_data;
89
90 PARA_INFO_LOG("opening %s\n", conf->device_arg);
91 ret = para_open(conf->device_arg, O_WRONLY, 0);
92 if (ret < 0)
93 return ret;
94 powd->fd = ret;
95 ret = mark_fd_nonblocking(powd->fd);
96 if (ret < 0)
97 goto err;
98 /* set PCM format */
99 sample_format = format = get_oss_format(sample_format);
100 ret = ioctl(powd->fd, SNDCTL_DSP_SETFMT, &format);
101 if (ret < 0) {
102 ret = -ERRNO_TO_PARA_ERROR(errno);
103 goto err;
104 }
105 ret = -E_BAD_SAMPLE_FORMAT;
106 if (format != sample_format)
107 goto err;
108 /* set number of channels */
109 ch = channels;
110 ret = ioctl(powd->fd, SNDCTL_DSP_CHANNELS, &ch);
111 if (ret < 0) {
112 ret = -ERRNO_TO_PARA_ERROR(errno);
113 goto err;
114 }
115 ret = -E_BAD_CHANNEL_COUNT;
116 if (ch != channels)
117 goto err;
118 if (format == SF_U8 || format == SF_S8)
119 powd->bytes_per_frame = ch;
120 else
121 powd->bytes_per_frame = ch * 2;
122
123 /*
124 * Set sampling rate
125 *
126 * If we request a higher sampling rate than is supported by the
127 * device, the the highest possible speed is automatically used. The
128 * value actually used is returned as the new value of the argument.
129 */
130 rate = sample_rate;
131 ret = ioctl(powd->fd, SNDCTL_DSP_SPEED, &rate);
132 if (ret < 0) {
133 ret = -ERRNO_TO_PARA_ERROR(errno);
134 goto err;
135 }
136 if (rate != sample_rate) {
137 unsigned min = PARA_MIN(rate, sample_rate),
138 max = PARA_MAX(rate, sample_rate);
139 /*
140 * Check whether the returned sample rate differs significantly
141 * from the requested one.
142 */
143 ret = -E_BAD_SAMPLERATE;
144 if (100 * max > 110 * min) /* more than 10% deviation */
145 goto err;
146 PARA_NOTICE_LOG("using %dHz rather than %dHz\n", rate,
147 sample_rate);
148 }
149 wn->min_iqs = powd->bytes_per_frame;
150 return 1;
151 err:
152 close(powd->fd);
153 powd->fd = -1;
154 return ret;
155 }
156
157 static void oss_post_select(__a_unused struct sched *s,
158 struct task *t)
159 {
160 struct writer_node *wn = container_of(t, struct writer_node, task);
161 struct private_oss_write_data *powd = wn->private_data;
162 struct btr_node *btrn = wn->btrn;
163 size_t frames, bytes;
164 int ret = btr_node_status(btrn, wn->min_iqs, BTR_NT_LEAF);
165 char *data;
166
167 if (ret < 0)
168 goto out;
169 if (ret == 0)
170 return;
171 if (powd->fd < 0) {
172 int32_t rate, ch, format;
173 get_btr_sample_rate(btrn, &rate);
174 get_btr_channels(btrn, &ch);
175 get_btr_sample_format(btrn, &format);
176 ret = oss_init(wn, rate, ch, format);
177 if (ret < 0)
178 goto out;
179 return;
180 }
181 btr_merge(btrn, wn->min_iqs);
182 bytes = btr_next_buffer(btrn, &data);
183 frames = bytes / powd->bytes_per_frame;
184 if (!frames) { /* eof and less than a single frame available */
185 ret = -E_OSS_EOF;
186 goto out;
187 }
188 ret = 0;
189 if (!FD_ISSET(powd->fd, &s->wfds))
190 goto out;
191 ret = write_nonblock(powd->fd, data, frames * powd->bytes_per_frame);
192 if (ret < 0)
193 goto out;
194 btr_consume(btrn, ret);
195 ret = 0;
196 out:
197 t->error = ret;
198 if (ret < 0)
199 btr_remove_node(btrn);
200 }
201
202 static int oss_open(struct writer_node *wn)
203 {
204 struct private_oss_write_data *powd;
205
206 powd = para_calloc(sizeof(*powd));
207 wn->private_data = powd;
208 powd->fd = -1;
209 return 1;
210 }
211
212 __malloc static void *oss_parse_config(const char *options)
213 {
214 int ret;
215 struct oss_write_args_info *conf = para_calloc(sizeof(*conf));
216
217 ret = oss_cmdline_parser_string(options, conf, "oss_write");
218 if (ret)
219 goto err_out;
220 return conf;
221 err_out:
222 free(conf);
223 return NULL;
224 }
225
226 static void oss_free_config(void *conf)
227 {
228 oss_cmdline_parser_free(conf);
229 }
230
231 /**
232 * The init function of the oss writer.
233 *
234 * \param w Pointer to the writer to initialize.
235 *
236 * \sa struct writer.
237 */
238 void oss_write_init(struct writer *w)
239 {
240 struct oss_write_args_info dummy;
241
242 oss_cmdline_parser_init(&dummy);
243 w->open = oss_open;
244 w->close = oss_close;
245 w->pre_select = oss_pre_select;
246 w->post_select = oss_post_select;
247 w->parse_config = oss_parse_config;
248 w->free_config = oss_free_config;
249 w->shutdown = NULL;
250 w->help = (struct ggo_help) {
251 .short_help = oss_write_args_info_help,
252 .detailed_help = oss_write_args_info_detailed_help
253 };
254 oss_cmdline_parser_free(&dummy);
255 }