7acde1dacc42bcef0af94380109fc14f6ea55287
[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 /** 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 if (powd->fd >= 0)
57 close(powd->fd);
58 free(powd);
59 }
60
61 /*
62 * The Open Sound System Programmer's Guide sayeth:
63 *
64 * Set sampling parameters always so that number of channels (mono/stereo) is
65 * set before selecting sampling rate (speed). Failing to do this will make
66 * your program incompatible with cards such as the SoundBlaster Pro which
67 * supports 44.1 kHz in mono but just 22.05 kHz in stereo. A program which
68 * selects 44.1 kHz speed and then sets the device to stereo mode will
69 * incorrectly believe that the device is still in 44.1 kHz mode when actually
70 * the speed is decreased to 22.05 kHz.
71 */
72 static int oss_init(struct writer_node *wn, unsigned sample_rate, unsigned channels)
73 {
74 int ret, format = FORMAT;
75 unsigned ch, rate;
76 struct oss_write_args_info *conf = wn->conf;
77 struct private_oss_write_data *powd = wn->private_data;
78
79 PARA_INFO_LOG("opening %s\n", conf->device_arg);
80 ret = para_open(conf->device_arg, O_WRONLY, 0);
81 if (ret < 0)
82 return ret;
83 powd->fd = ret;
84 ret = mark_fd_nonblocking(powd->fd);
85 if (ret < 0)
86 goto err;
87 /* set PCM format */
88 ret = ioctl(powd->fd, SNDCTL_DSP_SETFMT, &format);
89 if (ret < 0) {
90 ret = -ERRNO_TO_PARA_ERROR(errno);
91 goto err;
92 }
93 ret = -E_BAD_SAMPLE_FORMAT;
94 if (format != FORMAT)
95 goto err;
96 /* set number of channels */
97 ret = -E_BAD_CHANNEL_COUNT;
98 if (channels == 0)
99 goto err;
100 ch = channels;
101 ret = ioctl(powd->fd, SNDCTL_DSP_CHANNELS, &ch);
102 if (ret < 0) {
103 ret = -ERRNO_TO_PARA_ERROR(errno);
104 goto err;
105 }
106 ret = -E_BAD_CHANNEL_COUNT;
107 if (ch != channels)
108 goto err;
109 powd->bytes_per_frame = ch * 2;
110
111 /*
112 * Set sampling rate
113 *
114 * If we request a higher sampling rate than is supported by the
115 * device, the the highest possible speed is automatically used. The
116 * value actually used is returned as the new value of the argument.
117 */
118 rate = sample_rate;
119 ret = ioctl(powd->fd, SNDCTL_DSP_SPEED, &rate);
120 if (ret < 0) {
121 ret = -ERRNO_TO_PARA_ERROR(errno);
122 goto err;
123 }
124 if (rate != sample_rate) {
125 unsigned min = PARA_MIN(rate, sample_rate),
126 max = PARA_MAX(rate, sample_rate);
127 /*
128 * Check whether the returned sample rate differs significantly
129 * from the requested one.
130 */
131 ret = -E_BAD_SAMPLERATE;
132 if (100 * max > 110 * min) /* more than 10% deviation */
133 goto err;
134 PARA_NOTICE_LOG("using %dHz rather than %dHz\n", rate,
135 sample_rate);
136 }
137 wn->min_iqs = powd->bytes_per_frame;
138 return 1;
139 err:
140 close(powd->fd);
141 powd->fd = -1;
142 return ret;
143 }
144
145 static void oss_post_select(__a_unused struct sched *s,
146 struct task *t)
147 {
148 struct writer_node *wn = container_of(t, struct writer_node, task);
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 = get_btr_sample_rate(btrn, &rate);
162 if (ret < 0)
163 goto out;
164 ret = get_btr_channels(btrn, &ch);
165 if (ret < 0)
166 goto out;
167 ret = oss_init(wn, rate, ch);
168 if (ret < 0)
169 goto out;
170 return;
171 }
172 btr_merge(btrn, wn->min_iqs);
173 bytes = btr_next_buffer(btrn, &data);
174 frames = bytes / powd->bytes_per_frame;
175 if (!frames) { /* eof and less than a single frame available */
176 ret = -E_OSS_EOF;
177 goto out;
178 }
179 ret = 0;
180 if (!FD_ISSET(powd->fd, &s->wfds))
181 goto out;
182 ret = write_nonblock(powd->fd, data, frames * powd->bytes_per_frame);
183 if (ret < 0)
184 goto out;
185 btr_consume(btrn, ret);
186 ret = 0;
187 out:
188 t->error = ret;
189 if (ret < 0)
190 btr_remove_node(btrn);
191 }
192
193 static int oss_open(struct writer_node *wn)
194 {
195 struct private_oss_write_data *powd;
196
197 powd = para_calloc(sizeof(*powd));
198 wn->private_data = powd;
199 powd->fd = -1;
200 return 1;
201 }
202
203 __malloc static void *oss_parse_config(const char *options)
204 {
205 int ret;
206 struct oss_write_args_info *conf = para_calloc(sizeof(*conf));
207
208 ret = oss_cmdline_parser_string(options, conf, "oss_write");
209 if (ret)
210 goto err_out;
211 return conf;
212 err_out:
213 free(conf);
214 return NULL;
215 }
216
217 static void oss_free_config(void *conf)
218 {
219 oss_cmdline_parser_free(conf);
220 }
221
222 /**
223 * The init function of the oss writer.
224 *
225 * \param w Pointer to the writer to initialize.
226 *
227 * \sa struct writer.
228 */
229 void oss_write_init(struct writer *w)
230 {
231 struct oss_write_args_info dummy;
232
233 oss_cmdline_parser_init(&dummy);
234 w->open = oss_open;
235 w->close = oss_close;
236 w->pre_select = oss_pre_select;
237 w->post_select = oss_post_select;
238 w->parse_config = oss_parse_config;
239 w->free_config = oss_free_config;
240 w->shutdown = NULL;
241 w->help = (struct ggo_help) {
242 .short_help = oss_write_args_info_help,
243 .detailed_help = oss_write_args_info_detailed_help
244 };
245 oss_cmdline_parser_free(&dummy);
246 }