8426753e1355dcf7424f140e281683ea580eb693
[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 /** Four bytes for stereo streams, two bytes for mono streams. */
36 int bytes_per_frame;
37 };
38
39 static void oss_pre_select(struct sched *s, struct task *t)
40 {
41 struct writer_node *wn = container_of(t, struct writer_node, task);
42 struct private_oss_write_data *powd = wn->private_data;
43 int ret = btr_node_status(wn->btrn, wn->min_iqs, BTR_NT_LEAF);
44
45 t->error = 0;
46 if (ret < 0)
47 sched_min_delay(s);
48 else if (ret > 0)
49 para_fd_set(powd->fd, &s->wfds, &s->max_fileno);
50 }
51
52 static void oss_close(struct writer_node *wn)
53 {
54 struct private_oss_write_data *powd = wn->private_data;
55
56 close(powd->fd);
57 free(powd);
58 }
59
60 /*
61 * The Open Sound System Programmer's Guide sayeth:
62 *
63 * Set sampling parameters always so that number of channels (mono/stereo) is
64 * set before selecting sampling rate (speed). Failing to do this will make
65 * your program incompatible with cards such as the SoundBlaster Pro which
66 * supports 44.1 kHz in mono but just 22.05 kHz in stereo. A program which
67 * selects 44.1 kHz speed and then sets the device to stereo mode will
68 * incorrectly believe that the device is still in 44.1 kHz mode when actually
69 * the speed is decreased to 22.05 kHz.
70 */
71 static int oss_init(struct writer_node *wn, unsigned samplerate, unsigned channels)
72 {
73 int ret, format = FORMAT;
74 unsigned ch, rate;
75 struct oss_write_args_info *conf = wn->conf;
76 struct private_oss_write_data *powd = wn->private_data;
77
78 PARA_INFO_LOG("opening %s\n", conf->device_arg);
79 ret = para_open(conf->device_arg, O_WRONLY, 0);
80 if (ret < 0)
81 return ret;
82 powd->fd = ret;
83 ret = mark_fd_nonblocking(powd->fd);
84 if (ret < 0)
85 goto err;
86 /* set PCM format */
87 ret = ioctl(powd->fd, SNDCTL_DSP_SETFMT, &format);
88 if (ret < 0) {
89 ret = -ERRNO_TO_PARA_ERROR(errno);
90 goto err;
91 }
92 ret = -E_BAD_SAMPLE_FORMAT;
93 if (format != FORMAT)
94 goto err;
95 /* set number of channels */
96 ret = -E_BAD_CHANNEL_COUNT;
97 if (channels == 0)
98 goto err;
99 ch = channels;
100 ret = ioctl(powd->fd, SNDCTL_DSP_CHANNELS, &ch);
101 if (ret < 0) {
102 ret = -ERRNO_TO_PARA_ERROR(errno);
103 goto err;
104 }
105 ret = -E_BAD_CHANNEL_COUNT;
106 if (ch != channels)
107 goto err;
108 powd->bytes_per_frame = ch * 2;
109
110 /*
111 * Set sampling rate
112 *
113 * If we request a higher sampling rate than is supported by the
114 * device, the the highest possible speed is automatically used. The
115 * value actually used is returned as the new value of the argument.
116 */
117 rate = samplerate;
118 ret = ioctl(powd->fd, SNDCTL_DSP_SPEED, &rate);
119 if (ret < 0) {
120 ret = -ERRNO_TO_PARA_ERROR(errno);
121 goto err;
122 }
123 if (rate != samplerate) {
124 unsigned min = PARA_MIN(rate, samplerate),
125 max = PARA_MAX(rate, samplerate);
126 /*
127 * Check whether the returned sample rate differs significantly
128 * from the requested one.
129 */
130 ret = -E_BAD_SAMPLERATE;
131 if (100 * max > 110 * min) /* more than 10% deviation */
132 goto err;
133 PARA_NOTICE_LOG("using %dHz rather than %dHz\n", rate,
134 samplerate);
135 }
136 wn->min_iqs = powd->bytes_per_frame;
137 return 1;
138 err:
139 close(powd->fd);
140 free(powd);
141 return ret;
142 }
143
144 static void oss_post_select(__a_unused struct sched *s,
145 struct task *t)
146 {
147 struct writer_node *wn = container_of(t, struct writer_node, task);
148 struct oss_write_args_info *conf = wn->conf;
149 struct private_oss_write_data *powd = wn->private_data;
150 struct btr_node *btrn = wn->btrn;
151 size_t frames, bytes;
152 int ret = btr_node_status(btrn, wn->min_iqs, BTR_NT_LEAF);
153 char *data;
154
155 if (ret < 0)
156 goto out;
157 if (ret == 0)
158 return;
159 if (powd->fd < 0) {
160 int32_t rate, ch;
161 ret = -1;
162 if (!conf->samplerate_given) /* config option trumps btr_exec */
163 ret = get_btr_samplerate(wn->btrn, &rate);
164 if (ret < 0)
165 rate = conf->samplerate_arg;
166 ret = -1;
167 if (!conf->channels_given)
168 ret = get_btr_channels(wn->btrn, &ch);
169 if (ret < 0)
170 ch = conf->channels_arg;
171 ret = oss_init(wn, rate, ch);
172 if (ret < 0)
173 goto out;
174 return;
175 }
176 bytes = btr_next_buffer(btrn, &data);
177 frames = bytes / powd->bytes_per_frame;
178 if (!frames) { /* eof and less than a single frame available */
179 ret = -E_OSS_EOF;
180 goto out;
181 }
182 ret = 0;
183 if (!FD_ISSET(powd->fd, &s->wfds))
184 goto out;
185 ret = write_nonblock(powd->fd, data, frames * powd->bytes_per_frame, 0);
186 if (ret < 0)
187 goto out;
188 btr_consume(btrn, ret);
189 ret = 0;
190 out:
191 t->error = ret;
192 if (ret < 0)
193 btr_remove_node(btrn);
194 }
195
196 static int oss_open(struct writer_node *wn)
197 {
198 struct private_oss_write_data *powd;
199
200 powd = para_calloc(sizeof(*powd));
201 wn->private_data = powd;
202 powd->fd = -1;
203 return 1;
204 }
205
206 __malloc static void *oss_parse_config(const char *options)
207 {
208 int ret;
209 struct oss_write_args_info *conf = para_calloc(sizeof(*conf));
210
211 ret = oss_cmdline_parser_string(options, conf, "oss_write");
212 if (ret)
213 goto err_out;
214 return conf;
215 err_out:
216 free(conf);
217 return NULL;
218 }
219
220 static void oss_free_config(void *conf)
221 {
222 oss_cmdline_parser_free(conf);
223 }
224
225 /**
226 * The init function of the oss writer.
227 *
228 * \param w Pointer to the writer to initialize.
229 *
230 * \sa struct writer.
231 */
232 void oss_write_init(struct writer *w)
233 {
234 struct oss_write_args_info dummy;
235
236 oss_cmdline_parser_init(&dummy);
237 w->open = oss_open;
238 w->close = oss_close;
239 w->pre_select = oss_pre_select;
240 w->post_select = oss_post_select;
241 w->parse_config = oss_parse_config;
242 w->free_config = oss_free_config;
243 w->shutdown = NULL;
244 w->help = (struct ggo_help) {
245 .short_help = oss_write_args_info_help,
246 .detailed_help = oss_write_args_info_detailed_help
247 };
248 oss_cmdline_parser_free(&dummy);
249 }