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 int oss_pre_select(struct sched *s, struct writer_node *wn)
51 struct private_oss_write_data *powd = wn->private_data;
52 struct writer_node_group *wng = wn->wng;
54 if (*wng->loaded - wn->written < powd->bytes_per_frame)
56 para_fd_set(powd->fd, &s->wfds, &s->max_fileno);
60 static void oss_pre_select_btr(struct sched *s, struct task *t)
62 struct writer_node *wn = container_of(t, struct writer_node, task);
63 struct private_oss_write_data *powd = wn->private_data;
64 int ret = btr_node_status(wn->btrn, wn->min_iqs, BTR_NT_LEAF);
73 para_fd_set(powd->fd, &s->wfds, &s->max_fileno);
76 s->timeout.tv_sec = 0;
77 s->timeout.tv_usec = 1;
80 static int oss_post_select(struct sched *s, struct writer_node *wn)
83 struct private_oss_write_data *powd = wn->private_data;
84 struct writer_node_group *wng = wn->wng;
85 size_t frames, bytes = *wng->loaded - wn->written;
86 char *data = *wng->bufp + wn->written;
88 if (*wng->input_error < 0 && bytes < powd->bytes_per_frame) {
89 wn->written = *wng->loaded;
90 return *wng->input_error;
92 frames = bytes / powd->bytes_per_frame;
93 if (!frames) /* less than a single frame available */
95 if (!FD_ISSET(powd->fd, &s->wfds))
97 ret = write_nonblock(powd->fd, data, frames * powd->bytes_per_frame, 0);
105 static void oss_close(struct writer_node *wn)
107 struct private_oss_write_data *powd = wn->private_data;
110 oss_cmdline_parser_free(wn->conf);
115 * The Open Sound System Programmer's Guide sayeth:
117 * Set sampling parameters always so that number of channels (mono/stereo) is
118 * set before selecting sampling rate (speed). Failing to do this will make
119 * your program incompatible with cards such as the SoundBlaster Pro which
120 * supports 44.1 kHz in mono but just 22.05 kHz in stereo. A program which
121 * selects 44.1 kHz speed and then sets the device to stereo mode will
122 * incorrectly believe that the device is still in 44.1 kHz mode when actually
123 * the speed is decreased to 22.05 kHz.
125 static int oss_init(struct writer_node *wn, unsigned samplerate, unsigned channels)
127 int ret, format = FORMAT, ch, rate;
128 struct oss_write_args_info *conf = wn->conf;
129 struct private_oss_write_data *powd = wn->private_data;
131 PARA_INFO_LOG("opening %s\n", conf->device_arg);
132 ret = para_open(conf->device_arg, O_WRONLY, 0);
136 ret = mark_fd_nonblocking(powd->fd);
140 ret = ioctl(powd->fd, SNDCTL_DSP_SETFMT, &format);
142 ret = -ERRNO_TO_PARA_ERROR(errno);
145 ret = -E_BAD_SAMPLE_FORMAT;
146 if (format != FORMAT)
148 /* set number of channels */
149 if (!conf->channels_given && channels != 0)
152 ch = conf->channels_arg;
153 ret = -E_BAD_CHANNEL_COUNT;
157 ret = ioctl(powd->fd, SNDCTL_DSP_CHANNELS, &ch);
159 ret = -ERRNO_TO_PARA_ERROR(errno);
162 if (powd->channels != ch)
164 powd->bytes_per_frame = ch * 2;
169 * If we request a higher sampling rate than is supported by the
170 * device, the the highest possible speed is automatically used. The
171 * value actually used is returned as the new value of the argument.
173 if (!conf->samplerate_given && samplerate != 0)
176 rate = conf->samplerate_arg;
177 powd->samplerate = rate;
178 ret = ioctl(powd->fd, SNDCTL_DSP_SPEED, &rate);
180 ret = -ERRNO_TO_PARA_ERROR(errno);
183 if (rate != powd->samplerate) {
184 int min = PARA_MIN(rate, powd->samplerate),
185 max = PARA_MAX(rate, powd->samplerate);
187 * Check whether the returned sample rate differs significantly
188 * from the requested one.
190 ret = -E_BAD_SAMPLERATE;
191 if (100 * max > 110 * min) /* more than 10% deviation */
193 PARA_NOTICE_LOG("using %dHz rather than %dHz\n", rate,
196 wn->min_iqs = powd->bytes_per_frame;
204 static void oss_post_select_btr(__a_unused struct sched *s,
207 struct writer_node *wn = container_of(t, struct writer_node, task);
208 struct oss_write_args_info *conf = wn->conf;
209 struct private_oss_write_data *powd = wn->private_data;
210 struct btr_node *btrn = wn->btrn;
211 size_t frames, bytes;
212 int ret = btr_node_status(btrn, wn->min_iqs, BTR_NT_LEAF);
222 if (!conf->samplerate_given) /* config option trumps btr_exec */
223 ret = get_btr_samplerate(wn->btrn, &rate);
225 rate = conf->samplerate_arg;
227 if (!conf->channels_given)
228 ret = get_btr_channels(wn->btrn, &ch);
230 ch = conf->channels_arg;
231 ret = oss_init(wn, rate, ch);
236 bytes = btr_next_buffer(btrn, &data);
237 frames = bytes / powd->bytes_per_frame;
238 if (!frames) { /* eof and less than a single frame available */
243 if (!FD_ISSET(powd->fd, &s->wfds))
245 ret = write_nonblock(powd->fd, data, frames * powd->bytes_per_frame, 0);
248 btr_consume(btrn, ret);
254 static int oss_open(struct writer_node *wn)
256 struct writer_node_group *wng;
257 struct private_oss_write_data *powd;
259 powd = para_calloc(sizeof(*powd));
260 wn->private_data = powd;
263 return oss_init(wn, wng->samplerate ? *wng->samplerate : 0,
264 wng->channels? *wng->channels : 0);
270 __malloc static void *oss_parse_config(const char *options)
273 struct oss_write_args_info *conf = para_calloc(sizeof(*conf));
275 PARA_INFO_LOG("options: %s, %zd\n", options, strcspn(options, " \t"));
276 ret = oss_cmdline_parser_string(options, conf, "oss_write");
285 static void oss_free_config(void *conf)
287 oss_cmdline_parser_free(conf);
291 * The init function of the oss writer.
293 * \param w Pointer to the writer to initialize.
297 void oss_write_init(struct writer *w)
299 struct oss_write_args_info dummy;
301 oss_cmdline_parser_init(&dummy);
303 w->close = oss_close;
304 w->pre_select = oss_pre_select;
305 w->pre_select_btr = oss_pre_select_btr;
306 w->post_select = oss_post_select;
307 w->post_select_btr = oss_post_select_btr;
308 w->parse_config = oss_parse_config;
309 w->free_config = oss_free_config;
311 w->help = (struct ggo_help) {
312 .short_help = oss_write_args_info_help,
313 .detailed_help = oss_write_args_info_detailed_help
315 oss_cmdline_parser_free(&dummy);