Some more aacdec cleanups
[paraslash.git] / alsa_writer.c
1 /*
2 * Copyright (C) 2005-2006 Andre Noll <maan@systemlinux.org>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
17 */
18
19 /** \file alsa_writer.c paraslash's alsa output plugin */
20
21 /*
22 * Based in parts on aplay.c from the alsa-utils-1.0.8 package,
23 * Copyright (c) by Jaroslav Kysela <perex@suse.cz>, which is
24 * based on the vplay program by Michael Beck.
25 */
26
27 #include "para.h"
28 #include "fd.h"
29 #include "string.h"
30 #include "write.h"
31
32 #include <alsa/asoundlib.h>
33
34 #include "write.cmdline.h"
35 #include "error.h"
36
37 extern struct gengetopt_args_info conf;
38
39 #define FORMAT SND_PCM_FORMAT_S16_LE
40
41 /** data specific to the alsa writer */
42 struct private_alsa_data {
43 /** the alsa handle */
44 snd_pcm_t *handle;
45 /** determined and set by alsa_open() */
46 size_t bytes_per_frame;
47 };
48
49 /*
50 * open and prepare the PCM handle for writing
51 *
52 * Install PCM software and hardware configuration. Exit on errors.
53 */
54 static int alsa_open(struct writer_node *w)
55 {
56 snd_pcm_hw_params_t *hwparams;
57 snd_pcm_sw_params_t *swparams;
58 snd_pcm_uframes_t buffer_size, xfer_align, start_threshold,
59 stop_threshold;
60 unsigned buffer_time = 0;
61 int err;
62 snd_pcm_info_t *info;
63 snd_output_t *log;
64 snd_pcm_uframes_t period_size;
65 struct private_alsa_data *pad = para_malloc(sizeof(struct private_alsa_data));
66 w->private_data = pad;
67
68 snd_pcm_info_alloca(&info);
69 if (snd_output_stdio_attach(&log, stderr, 0) < 0)
70 return -E_ALSA_LOG;
71 err = snd_pcm_open(&pad->handle, conf.device_arg,
72 SND_PCM_STREAM_PLAYBACK, 0);
73 if (err < 0)
74 return -E_PCM_OPEN;
75 if ((err = snd_pcm_info(pad->handle, info)) < 0)
76 return -E_SND_PCM_INFO;
77
78 snd_pcm_hw_params_alloca(&hwparams);
79 snd_pcm_sw_params_alloca(&swparams);
80 if (snd_pcm_hw_params_any(pad->handle, hwparams) < 0)
81 return -E_BROKEN_CONF;
82 if (snd_pcm_hw_params_set_access(pad->handle, hwparams,
83 SND_PCM_ACCESS_RW_INTERLEAVED) < 0)
84 return -E_ACCESS_TYPE;
85 if (snd_pcm_hw_params_set_format(pad->handle, hwparams, FORMAT) < 0)
86 return -E_SAMPLE_FORMAT;
87 if (snd_pcm_hw_params_set_channels(pad->handle, hwparams,
88 conf.channels_arg) < 0)
89 return -E_CHANNEL_COUNT;
90 if (snd_pcm_hw_params_set_rate_near(pad->handle, hwparams,
91 (unsigned int*) &conf.sample_rate_arg, 0) < 0)
92 return -E_SET_RATE;
93 err = snd_pcm_hw_params_get_buffer_time_max(hwparams, &buffer_time, 0);
94 if (err < 0 || !buffer_time)
95 return -E_GET_BUFFER_TIME;
96 PARA_DEBUG_LOG("buffer time: %d\n", buffer_time);
97 if (snd_pcm_hw_params_set_buffer_time_near(pad->handle, hwparams,
98 &buffer_time, 0) < 0)
99 return -E_SET_BUFFER_TIME;
100 if (snd_pcm_hw_params(pad->handle, hwparams) < 0)
101 return -E_HW_PARAMS;
102 snd_pcm_hw_params_get_period_size(hwparams, &period_size, 0);
103 snd_pcm_hw_params_get_buffer_size(hwparams, &buffer_size);
104 PARA_DEBUG_LOG("buffer size: %lu, period_size: %lu\n", buffer_size,
105 period_size);
106 if (period_size == buffer_size)
107 return -E_BAD_PERIOD;
108 snd_pcm_sw_params_current(pad->handle, swparams);
109 err = snd_pcm_sw_params_get_xfer_align(swparams, &xfer_align);
110 if (err < 0 || !xfer_align)
111 return -E_GET_XFER;
112 snd_pcm_sw_params_set_avail_min(pad->handle, swparams, period_size);
113 /* round to closest transfer boundary */
114 start_threshold = (buffer_size / xfer_align) * xfer_align;
115 if (start_threshold < 1)
116 start_threshold = 1;
117 if (snd_pcm_sw_params_set_start_threshold(pad->handle, swparams,
118 start_threshold) < 0)
119 return -E_START_THRESHOLD;
120 stop_threshold = buffer_size;
121 if (snd_pcm_sw_params_set_stop_threshold(pad->handle, swparams,
122 stop_threshold) < 0)
123 return -E_STOP_THRESHOLD;
124 if (snd_pcm_sw_params_set_xfer_align(pad->handle, swparams,
125 xfer_align) < 0)
126 return -E_SET_XFER;
127 if (snd_pcm_sw_params(pad->handle, swparams) < 0)
128 return -E_SW_PARAMS;
129 pad->bytes_per_frame = snd_pcm_format_physical_width(FORMAT)
130 * conf.channels_arg / 8;
131 return period_size * pad->bytes_per_frame;
132 }
133
134 /**
135 * push out pcm frames
136 * \param data pointer do data to be written
137 * \param nbytes number of bytes (not frames)
138 *
139 * \return Number of bytes written, -E_ALSA_WRITE on errors.
140 */
141 static int alsa_write(char *data, size_t nbytes, struct writer_node *wn)
142 {
143 struct private_alsa_data *pad = wn->private_data;
144 size_t frames = nbytes / pad->bytes_per_frame;
145 unsigned char *d = (unsigned char*)data;
146 snd_pcm_sframes_t r, result = 0;
147
148 while (frames > 0) {
149 /* write interleaved frames */
150 r = snd_pcm_writei(pad->handle, d, frames);
151 if (r < 0)
152 PARA_ERROR_LOG("write error: %s\n", snd_strerror(r));
153 if (r == -EAGAIN || (r >= 0 && r < frames))
154 snd_pcm_wait(pad->handle, 1);
155 else if (r == -EPIPE)
156 snd_pcm_prepare(pad->handle);
157 else if (r < 0)
158 return -E_ALSA_WRITE;
159 if (r > 0) {
160 result += r;
161 frames -= r;
162 d += r * pad->bytes_per_frame;
163 }
164 }
165 return result * pad->bytes_per_frame;
166 }
167
168 static void alsa_close(struct writer_node *wn)
169 {
170 struct private_alsa_data *pad = wn->private_data;
171 snd_pcm_drain(pad->handle);
172 snd_pcm_close(pad->handle);
173 snd_config_update_free_global();
174 free(pad);
175 }
176
177 /** the init function of the alsa writer */
178 void alsa_writer_init(struct writer *w)
179 {
180 w->open = alsa_open;
181 w->write = alsa_write;
182 w->close = alsa_close;
183 w->shutdown = NULL; /* nothing to do */
184 }