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 /** 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. */
35 /** Four bytes for stereo streams, two bytes for mono streams. */
39 static void oss_pre_select(struct sched
*s
, struct task
*t
)
41 struct writer_node
*wn
= container_of(t
, struct writer_node
, task
);
42 struct private_oss_write_data
*powd
= wn
->private_data
;
43 int ret
= btr_node_status(wn
->btrn
, wn
->min_iqs
, BTR_NT_LEAF
);
49 para_fd_set(powd
->fd
, &s
->wfds
, &s
->max_fileno
);
52 static void oss_close(struct writer_node
*wn
)
54 struct private_oss_write_data
*powd
= wn
->private_data
;
62 * The Open Sound System Programmer's Guide sayeth:
64 * Set sampling parameters always so that number of channels (mono/stereo) is
65 * set before selecting sampling rate (speed). Failing to do this will make
66 * your program incompatible with cards such as the SoundBlaster Pro which
67 * supports 44.1 kHz in mono but just 22.05 kHz in stereo. A program which
68 * selects 44.1 kHz speed and then sets the device to stereo mode will
69 * incorrectly believe that the device is still in 44.1 kHz mode when actually
70 * the speed is decreased to 22.05 kHz.
72 static int oss_init(struct writer_node
*wn
, unsigned sample_rate
, unsigned channels
)
74 int ret
, format
= FORMAT
;
76 struct oss_write_args_info
*conf
= wn
->conf
;
77 struct private_oss_write_data
*powd
= wn
->private_data
;
79 PARA_INFO_LOG("opening %s\n", conf
->device_arg
);
80 ret
= para_open(conf
->device_arg
, O_WRONLY
, 0);
84 ret
= mark_fd_nonblocking(powd
->fd
);
88 ret
= ioctl(powd
->fd
, SNDCTL_DSP_SETFMT
, &format
);
90 ret
= -ERRNO_TO_PARA_ERROR(errno
);
93 ret
= -E_BAD_SAMPLE_FORMAT
;
96 /* set number of channels */
97 ret
= -E_BAD_CHANNEL_COUNT
;
101 ret
= ioctl(powd
->fd
, SNDCTL_DSP_CHANNELS
, &ch
);
103 ret
= -ERRNO_TO_PARA_ERROR(errno
);
106 ret
= -E_BAD_CHANNEL_COUNT
;
109 powd
->bytes_per_frame
= ch
* 2;
114 * If we request a higher sampling rate than is supported by the
115 * device, the the highest possible speed is automatically used. The
116 * value actually used is returned as the new value of the argument.
119 ret
= ioctl(powd
->fd
, SNDCTL_DSP_SPEED
, &rate
);
121 ret
= -ERRNO_TO_PARA_ERROR(errno
);
124 if (rate
!= sample_rate
) {
125 unsigned min
= PARA_MIN(rate
, sample_rate
),
126 max
= PARA_MAX(rate
, sample_rate
);
128 * Check whether the returned sample rate differs significantly
129 * from the requested one.
131 ret
= -E_BAD_SAMPLERATE
;
132 if (100 * max
> 110 * min
) /* more than 10% deviation */
134 PARA_NOTICE_LOG("using %dHz rather than %dHz\n", rate
,
137 wn
->min_iqs
= powd
->bytes_per_frame
;
145 static void oss_post_select(__a_unused
struct sched
*s
,
148 struct writer_node
*wn
= container_of(t
, struct writer_node
, task
);
149 struct oss_write_args_info
*conf
= wn
->conf
;
150 struct private_oss_write_data
*powd
= wn
->private_data
;
151 struct btr_node
*btrn
= wn
->btrn
;
152 size_t frames
, bytes
;
153 int ret
= btr_node_status(btrn
, wn
->min_iqs
, BTR_NT_LEAF
);
163 if (!conf
->sample_rate_given
) /* config option trumps btr_exec */
164 ret
= get_btr_sample_rate(wn
->btrn
, &rate
);
166 rate
= conf
->sample_rate_arg
;
168 if (!conf
->channels_given
)
169 ret
= get_btr_channels(wn
->btrn
, &ch
);
171 ch
= conf
->channels_arg
;
172 ret
= oss_init(wn
, rate
, ch
);
177 btr_merge(btrn
, wn
->min_iqs
);
178 bytes
= btr_next_buffer(btrn
, &data
);
179 frames
= bytes
/ powd
->bytes_per_frame
;
180 if (!frames
) { /* eof and less than a single frame available */
185 if (!FD_ISSET(powd
->fd
, &s
->wfds
))
187 ret
= write_nonblock(powd
->fd
, data
, frames
* powd
->bytes_per_frame
);
190 btr_consume(btrn
, ret
);
195 btr_remove_node(btrn
);
198 static int oss_open(struct writer_node
*wn
)
200 struct private_oss_write_data
*powd
;
202 powd
= para_calloc(sizeof(*powd
));
203 wn
->private_data
= powd
;
208 __malloc
static void *oss_parse_config(const char *options
)
211 struct oss_write_args_info
*conf
= para_calloc(sizeof(*conf
));
213 ret
= oss_cmdline_parser_string(options
, conf
, "oss_write");
222 static void oss_free_config(void *conf
)
224 oss_cmdline_parser_free(conf
);
228 * The init function of the oss writer.
230 * \param w Pointer to the writer to initialize.
234 void oss_write_init(struct writer
*w
)
236 struct oss_write_args_info dummy
;
238 oss_cmdline_parser_init(&dummy
);
240 w
->close
= oss_close
;
241 w
->pre_select
= oss_pre_select
;
242 w
->post_select
= oss_post_select
;
243 w
->parse_config
= oss_parse_config
;
244 w
->free_config
= oss_free_config
;
246 w
->help
= (struct ggo_help
) {
247 .short_help
= oss_write_args_info_help
,
248 .detailed_help
= oss_write_args_info_detailed_help
250 oss_cmdline_parser_free(&dummy
);