2 * Copyright (C) 2009-2011 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 /** Data specific to the oss writer. */
29 struct private_oss_write_data {
30 /** The file handle of the device. */
32 /** Four bytes for stereo streams, two bytes for mono streams. */
36 static int get_oss_format(enum sample_format sf)
39 case SF_S8: return AFMT_S8;
40 case SF_U8: return AFMT_U8;
41 case SF_S16_LE: return AFMT_S16_LE;
42 case SF_S16_BE: return AFMT_S16_BE;
43 case SF_U16_LE: return AFMT_U16_LE;
44 case SF_U16_BE: return AFMT_U16_BE;
45 default: return AFMT_S16_LE;
49 static void oss_pre_select(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);
58 return sched_min_delay(s);
59 para_fd_set(powd->fd, &s->wfds, &s->max_fileno);
62 static void oss_close(struct writer_node *wn)
64 struct private_oss_write_data *powd = wn->private_data;
73 * The Open Sound System Programmer's Guide sayeth:
75 * Set sampling parameters always so that number of channels (mono/stereo) is
76 * set before selecting sampling rate (speed). Failing to do this will make
77 * your program incompatible with cards such as the SoundBlaster Pro which
78 * supports 44.1 kHz in mono but just 22.05 kHz in stereo. A program which
79 * selects 44.1 kHz speed and then sets the device to stereo mode will
80 * incorrectly believe that the device is still in 44.1 kHz mode when actually
81 * the speed is decreased to 22.05 kHz.
83 static int oss_init(struct writer_node *wn, unsigned sample_rate,
84 unsigned channels, int sample_format)
88 struct oss_write_args_info *conf = wn->conf;
89 struct private_oss_write_data *powd = para_calloc(sizeof(*powd));
91 PARA_INFO_LOG("opening %s\n", conf->device_arg);
92 ret = para_open(conf->device_arg, O_WRONLY, 0);
96 ret = mark_fd_nonblocking(powd->fd);
100 sample_format = format = get_oss_format(sample_format);
101 ret = ioctl(powd->fd, SNDCTL_DSP_SETFMT, &format);
103 ret = -ERRNO_TO_PARA_ERROR(errno);
106 ret = -E_BAD_SAMPLE_FORMAT;
107 if (format != sample_format)
109 /* set number of channels */
111 ret = ioctl(powd->fd, SNDCTL_DSP_CHANNELS, &ch);
113 ret = -ERRNO_TO_PARA_ERROR(errno);
116 ret = -E_BAD_CHANNEL_COUNT;
119 if (format == SF_U8 || format == SF_S8)
120 powd->bytes_per_frame = ch;
122 powd->bytes_per_frame = ch * 2;
127 * If we request a higher sampling rate than is supported by the
128 * device, the the highest possible speed is automatically used. The
129 * value actually used is returned as the new value of the argument.
132 ret = ioctl(powd->fd, SNDCTL_DSP_SPEED, &rate);
134 ret = -ERRNO_TO_PARA_ERROR(errno);
137 if (rate != sample_rate) {
138 unsigned min = PARA_MIN(rate, sample_rate),
139 max = PARA_MAX(rate, sample_rate);
141 * Check whether the returned sample rate differs significantly
142 * from the requested one.
144 ret = -E_BAD_SAMPLERATE;
145 if (100 * max > 110 * min) /* more than 10% deviation */
147 PARA_NOTICE_LOG("using %dHz rather than %dHz\n", rate,
150 wn->min_iqs = powd->bytes_per_frame;
151 wn->private_data = powd;
160 static void oss_post_select(__a_unused struct sched *s,
163 struct writer_node *wn = container_of(t, struct writer_node, task);
164 struct private_oss_write_data *powd = wn->private_data;
165 struct btr_node *btrn = wn->btrn;
166 size_t frames, bytes;
167 int ret = btr_node_status(btrn, wn->min_iqs, BTR_NT_LEAF);
175 int32_t rate, ch, format;
176 get_btr_sample_rate(btrn, &rate);
177 get_btr_channels(btrn, &ch);
178 get_btr_sample_format(btrn, &format);
179 ret = oss_init(wn, rate, ch, format);
184 btr_merge(btrn, wn->min_iqs);
185 bytes = btr_next_buffer(btrn, &data);
186 frames = bytes / powd->bytes_per_frame;
187 if (!frames) { /* eof and less than a single frame available */
188 ret = -E_WRITE_COMMON_EOF;
192 if (!FD_ISSET(powd->fd, &s->wfds))
194 ret = write_nonblock(powd->fd, data, frames * powd->bytes_per_frame);
197 btr_consume(btrn, ret);
202 btr_remove_node(btrn);
205 __malloc static void *oss_parse_config_or_die(const char *options)
207 struct oss_write_args_info *conf = para_calloc(sizeof(*conf));
209 /* exits on errors */
210 oss_cmdline_parser_string(options, conf, "oss_write");
214 static void oss_free_config(void *conf)
216 oss_cmdline_parser_free(conf);
220 * The init function of the oss writer.
222 * \param w Pointer to the writer to initialize.
226 void oss_write_init(struct writer *w)
228 struct oss_write_args_info dummy;
230 oss_cmdline_parser_init(&dummy);
231 w->close = oss_close;
232 w->pre_select = oss_pre_select;
233 w->post_select = oss_post_select;
234 w->parse_config_or_die = oss_parse_config_or_die;
235 w->free_config = oss_free_config;
237 w->help = (struct ggo_help) {
238 .short_help = oss_write_args_info_help,
239 .detailed_help = oss_write_args_info_detailed_help
241 oss_cmdline_parser_free(&dummy);