2 * Copyright (C) 2009 Andre Noll <maan@systemlinux.org>
4 * Licensed under the GPL v2. For licencing details see COPYING.
7 /** \file oss_write.c Paraslash's oss output plugin. */
10 #include <sys/ioctl.h>
13 #include <sys/soundcard.h>
22 #include "buffer_tree.h"
24 #include "write_common.h"
25 #include "oss_write.cmdline.h"
28 /** Always use 16 bit little endian. */
29 #define FORMAT AFMT_S16_LE
31 /** Data specific to the oss writer. */
32 struct private_oss_write_data {
33 /** The file handle of the device. */
36 * The samplerate given by command line option or the decoder
37 * of the writer node group.
41 * The number of channels, given by command line option or the
42 * decoder of the writer node group.
45 /** Four bytes for stereo streams, two bytes for mono streams. */
49 static void oss_pre_select_btr(struct sched *s, struct task *t)
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);
62 para_fd_set(powd->fd, &s->wfds, &s->max_fileno);
65 s->timeout.tv_sec = 0;
66 s->timeout.tv_usec = 1;
69 static void oss_close(struct writer_node *wn)
71 struct private_oss_write_data *powd = wn->private_data;
74 oss_cmdline_parser_free(wn->conf);
79 * The Open Sound System Programmer's Guide sayeth:
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.
89 static int oss_init(struct writer_node *wn, unsigned samplerate, unsigned channels)
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;
95 PARA_INFO_LOG("opening %s\n", conf->device_arg);
96 ret = para_open(conf->device_arg, O_WRONLY, 0);
100 ret = mark_fd_nonblocking(powd->fd);
104 ret = ioctl(powd->fd, SNDCTL_DSP_SETFMT, &format);
106 ret = -ERRNO_TO_PARA_ERROR(errno);
109 ret = -E_BAD_SAMPLE_FORMAT;
110 if (format != FORMAT)
112 /* set number of channels */
113 if (!conf->channels_given && channels != 0)
116 ch = conf->channels_arg;
117 ret = -E_BAD_CHANNEL_COUNT;
121 ret = ioctl(powd->fd, SNDCTL_DSP_CHANNELS, &ch);
123 ret = -ERRNO_TO_PARA_ERROR(errno);
126 if (powd->channels != ch)
128 powd->bytes_per_frame = ch * 2;
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.
137 if (!conf->samplerate_given && samplerate != 0)
140 rate = conf->samplerate_arg;
141 powd->samplerate = rate;
142 ret = ioctl(powd->fd, SNDCTL_DSP_SPEED, &rate);
144 ret = -ERRNO_TO_PARA_ERROR(errno);
147 if (rate != powd->samplerate) {
148 int min = PARA_MIN(rate, powd->samplerate),
149 max = PARA_MAX(rate, powd->samplerate);
151 * Check whether the returned sample rate differs significantly
152 * from the requested one.
154 ret = -E_BAD_SAMPLERATE;
155 if (100 * max > 110 * min) /* more than 10% deviation */
157 PARA_NOTICE_LOG("using %dHz rather than %dHz\n", rate,
160 wn->min_iqs = powd->bytes_per_frame;
168 static void oss_post_select_btr(__a_unused struct sched *s,
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);
186 if (!conf->samplerate_given) /* config option trumps btr_exec */
187 ret = get_btr_samplerate(wn->btrn, &rate);
189 rate = conf->samplerate_arg;
191 if (!conf->channels_given)
192 ret = get_btr_channels(wn->btrn, &ch);
194 ch = conf->channels_arg;
195 ret = oss_init(wn, rate, ch);
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 */
207 if (!FD_ISSET(powd->fd, &s->wfds))
209 ret = write_nonblock(powd->fd, data, frames * powd->bytes_per_frame, 0);
212 btr_consume(btrn, ret);
217 btr_remove_node(btrn);
220 static int oss_open(struct writer_node *wn)
222 struct writer_node_group *wng;
223 struct private_oss_write_data *powd;
225 powd = para_calloc(sizeof(*powd));
226 wn->private_data = powd;
229 return oss_init(wn, wng->samplerate ? *wng->samplerate : 0,
230 wng->channels? *wng->channels : 0);
236 __malloc static void *oss_parse_config(const char *options)
239 struct oss_write_args_info *conf = para_calloc(sizeof(*conf));
241 PARA_INFO_LOG("options: %s, %zd\n", options, strcspn(options, " \t"));
242 ret = oss_cmdline_parser_string(options, conf, "oss_write");
251 static void oss_free_config(void *conf)
253 oss_cmdline_parser_free(conf);
257 * The init function of the oss writer.
259 * \param w Pointer to the writer to initialize.
263 void oss_write_init(struct writer *w)
265 struct oss_write_args_info dummy;
267 oss_cmdline_parser_init(&dummy);
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;
275 w->help = (struct ggo_help) {
276 .short_help = oss_write_args_info_help,
277 .detailed_help = oss_write_args_info_detailed_help
279 oss_cmdline_parser_free(&dummy);