2 * Copyright (C) 2009-2010 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 wn
->private_data
= powd
;
92 PARA_INFO_LOG("opening %s\n", conf
->device_arg
);
93 ret
= para_open(conf
->device_arg
, O_WRONLY
, 0);
97 ret
= mark_fd_nonblocking(powd
->fd
);
101 sample_format
= format
= get_oss_format(sample_format
);
102 ret
= ioctl(powd
->fd
, SNDCTL_DSP_SETFMT
, &format
);
104 ret
= -ERRNO_TO_PARA_ERROR(errno
);
107 ret
= -E_BAD_SAMPLE_FORMAT
;
108 if (format
!= sample_format
)
110 /* set number of channels */
112 ret
= ioctl(powd
->fd
, SNDCTL_DSP_CHANNELS
, &ch
);
114 ret
= -ERRNO_TO_PARA_ERROR(errno
);
117 ret
= -E_BAD_CHANNEL_COUNT
;
120 if (format
== SF_U8
|| format
== SF_S8
)
121 powd
->bytes_per_frame
= ch
;
123 powd
->bytes_per_frame
= ch
* 2;
128 * If we request a higher sampling rate than is supported by the
129 * device, the the highest possible speed is automatically used. The
130 * value actually used is returned as the new value of the argument.
133 ret
= ioctl(powd
->fd
, SNDCTL_DSP_SPEED
, &rate
);
135 ret
= -ERRNO_TO_PARA_ERROR(errno
);
138 if (rate
!= sample_rate
) {
139 unsigned min
= PARA_MIN(rate
, sample_rate
),
140 max
= PARA_MAX(rate
, sample_rate
);
142 * Check whether the returned sample rate differs significantly
143 * from the requested one.
145 ret
= -E_BAD_SAMPLERATE
;
146 if (100 * max
> 110 * min
) /* more than 10% deviation */
148 PARA_NOTICE_LOG("using %dHz rather than %dHz\n", rate
,
151 wn
->min_iqs
= powd
->bytes_per_frame
;
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 */
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
);