server: Fix return value of com_ff().
[paraslash.git] / oss_write.c
1 /*
2 * Copyright (C) 2009 Andre Noll <maan@tuebingen.mpg.de>
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 <sys/soundcard.h>
12
13 #include "para.h"
14 #include "fd.h"
15 #include "string.h"
16 #include "list.h"
17 #include "sched.h"
18 #include "ggo.h"
19 #include "buffer_tree.h"
20 #include "write.h"
21 #include "write_common.h"
22 #include "oss_write.cmdline.h"
23 #include "error.h"
24
25 /** Data specific to the oss writer. */
26 struct private_oss_write_data {
27 /** The file handle of the device. */
28 int fd;
29 /** Four bytes for stereo streams, two bytes for mono streams. */
30 int bytes_per_frame;
31 };
32
33 /*
34 * We keep one bit of static storage to make sure only one instance of the oss
35 * writer is running at any given time.
36 */
37 static bool sound_device_busy;
38
39 static bool sound_device_is_busy(void)
40 {
41 return sound_device_busy;
42 }
43
44 static void set_sound_device_busy(void)
45 {
46 assert(!sound_device_busy);
47 sound_device_busy = true;
48 }
49
50 static void set_sound_device_idle(void)
51 {
52 assert(sound_device_busy);
53 sound_device_busy = false;
54 }
55
56 static int get_oss_format(enum sample_format sf)
57 {
58 switch (sf) {
59 case SF_S8: return AFMT_S8;
60 case SF_U8: return AFMT_U8;
61 case SF_S16_LE: return AFMT_S16_LE;
62 case SF_S16_BE: return AFMT_S16_BE;
63 case SF_U16_LE: return AFMT_U16_LE;
64 case SF_U16_BE: return AFMT_U16_BE;
65 default: return AFMT_S16_LE;
66 }
67 }
68
69 static void oss_pre_select(struct sched *s, void *context)
70 {
71 struct writer_node *wn = context;
72 struct private_oss_write_data *powd = wn->private_data;
73 int ret = btr_node_status(wn->btrn, wn->min_iqs, BTR_NT_LEAF);
74
75 if (ret == 0 || (sound_device_is_busy() && !powd))
76 return;
77 if (ret < 0 || !powd)
78 return sched_min_delay(s);
79 para_fd_set(powd->fd, &s->wfds, &s->max_fileno);
80 }
81
82 static void oss_close(struct writer_node *wn)
83 {
84 struct private_oss_write_data *powd = wn->private_data;
85
86 if (!powd)
87 return;
88 close(powd->fd);
89 free(powd);
90 set_sound_device_idle();
91 }
92
93 /*
94 * The Open Sound System Programmer's Guide sayeth:
95 *
96 * Set sampling parameters always so that number of channels (mono/stereo) is
97 * set before selecting sampling rate (speed). Failing to do this will make
98 * your program incompatible with cards such as the SoundBlaster Pro which
99 * supports 44.1 kHz in mono but just 22.05 kHz in stereo. A program which
100 * selects 44.1 kHz speed and then sets the device to stereo mode will
101 * incorrectly believe that the device is still in 44.1 kHz mode when actually
102 * the speed is decreased to 22.05 kHz.
103 */
104 static int oss_init(struct writer_node *wn, unsigned sample_rate,
105 unsigned channels, int sample_format)
106 {
107 int ret, format;
108 unsigned ch, rate;
109 struct oss_write_args_info *conf = wn->conf;
110 struct private_oss_write_data *powd = para_calloc(sizeof(*powd));
111
112 PARA_INFO_LOG("opening %s\n", conf->device_arg);
113 ret = para_open(conf->device_arg, O_WRONLY, 0);
114 if (ret < 0)
115 goto err_free;
116 powd->fd = ret;
117 ret = mark_fd_nonblocking(powd->fd);
118 if (ret < 0)
119 goto err;
120 /* set PCM format */
121 sample_format = format = get_oss_format(sample_format);
122 ret = ioctl(powd->fd, SNDCTL_DSP_SETFMT, &format);
123 if (ret < 0) {
124 ret = -ERRNO_TO_PARA_ERROR(errno);
125 goto err;
126 }
127 ret = -E_BAD_SAMPLE_FORMAT;
128 if (format != sample_format)
129 goto err;
130 /* set number of channels */
131 ch = channels;
132 ret = ioctl(powd->fd, SNDCTL_DSP_CHANNELS, &ch);
133 if (ret < 0) {
134 ret = -ERRNO_TO_PARA_ERROR(errno);
135 goto err;
136 }
137 ret = -E_BAD_CHANNEL_COUNT;
138 if (ch != channels)
139 goto err;
140 if (format == SF_U8 || format == SF_S8)
141 powd->bytes_per_frame = ch;
142 else
143 powd->bytes_per_frame = ch * 2;
144
145 /*
146 * Set sampling rate
147 *
148 * If we request a higher sampling rate than is supported by the
149 * device, the highest possible speed is automatically used. The
150 * value actually used is returned as the new value of the argument.
151 */
152 rate = sample_rate;
153 ret = ioctl(powd->fd, SNDCTL_DSP_SPEED, &rate);
154 if (ret < 0) {
155 ret = -ERRNO_TO_PARA_ERROR(errno);
156 goto err;
157 }
158 if (rate != sample_rate) {
159 unsigned min = PARA_MIN(rate, sample_rate),
160 max = PARA_MAX(rate, sample_rate);
161 /*
162 * Check whether the returned sample rate differs significantly
163 * from the requested one.
164 */
165 ret = -E_BAD_SAMPLERATE;
166 if (100 * max > 110 * min) /* more than 10% deviation */
167 goto err;
168 PARA_NOTICE_LOG("using %uHz rather than %uHz\n", rate,
169 sample_rate);
170 }
171 wn->min_iqs = powd->bytes_per_frame;
172 wn->private_data = powd;
173 return 1;
174 err:
175 close(powd->fd);
176 err_free:
177 free(powd);
178 PARA_ERROR_LOG("failed to init %s: %s\n", conf->device_arg,
179 para_strerror(-ret));
180 return ret;
181 }
182
183 static int oss_post_select(__a_unused struct sched *s, void *context)
184 {
185 struct writer_node *wn = context;
186 struct private_oss_write_data *powd = wn->private_data;
187 struct btr_node *btrn = wn->btrn;
188 size_t frames, bytes;
189 int ret;
190 char *data;
191 audio_buf_info abi;
192
193 ret = task_get_notification(wn->task);
194 if (ret < 0)
195 goto out;
196 ret = btr_node_status(btrn, wn->min_iqs, BTR_NT_LEAF);
197 if (ret <= 0)
198 goto out;
199 if (!powd) {
200 int32_t rate, ch, format;
201
202 if (sound_device_is_busy())
203 return 0;
204 get_btr_sample_rate(btrn, &rate);
205 get_btr_channels(btrn, &ch);
206 get_btr_sample_format(btrn, &format);
207 ret = oss_init(wn, rate, ch, format);
208 if (ret < 0)
209 goto out;
210 set_sound_device_busy();
211 return 0;
212 }
213 btr_merge(btrn, wn->min_iqs);
214 bytes = btr_next_buffer(btrn, &data);
215 frames = bytes / powd->bytes_per_frame;
216 if (!frames) { /* eof and less than a single frame available */
217 ret = -E_WRITE_COMMON_EOF;
218 goto out;
219 }
220 ret = 0;
221 if (!FD_ISSET(powd->fd, &s->wfds))
222 goto out;
223 /* get maximal number of bytes that can be written */
224 ret = ioctl(powd->fd, SNDCTL_DSP_GETOSPACE, &abi);
225 if (ret >= 0) {
226 size_t max_frames = abi.bytes / powd->bytes_per_frame;
227 if (max_frames == 0)
228 goto out;
229 /* cap number of frames to avoid sound artefacts */
230 frames = PARA_MIN(frames, max_frames);
231 }
232 ret = xwrite(powd->fd, data, frames * powd->bytes_per_frame);
233 if (ret < 0)
234 goto out;
235 btr_consume(btrn, ret);
236 ret = 0;
237 out:
238 if (ret < 0)
239 btr_remove_node(&wn->btrn);
240 return ret;
241 }
242
243 __malloc static void *oss_parse_config_or_die(int argc, char **argv)
244 {
245 struct oss_write_args_info *conf = para_calloc(sizeof(*conf));
246
247 /* exits on errors */
248 oss_write_cmdline_parser(argc, argv, conf);
249 return conf;
250 }
251
252 static void oss_free_config(void *conf)
253 {
254 oss_write_cmdline_parser_free(conf);
255 }
256
257 /**
258 * The init function of the oss writer.
259 *
260 * \param w Pointer to the writer to initialize.
261 *
262 * \sa struct writer.
263 */
264 void oss_write_init(struct writer *w)
265 {
266 struct oss_write_args_info dummy;
267
268 oss_write_cmdline_parser_init(&dummy);
269 w->close = oss_close;
270 w->pre_select = oss_pre_select;
271 w->post_select = oss_post_select;
272 w->parse_config_or_die = oss_parse_config_or_die;
273 w->free_config = oss_free_config;
274 w->help = (struct ggo_help)DEFINE_GGO_HELP(oss_write);
275 oss_write_cmdline_parser_free(&dummy);
276 }