oss_write.c

   1 /*
   2  * Copyright (C) 2009 Andre Noll <maan@systemlinux.org>
   3  *
   4  * Licensed under the GPL v2. For licencing details see COPYING.
   5  */
   6
   7 /** \file oss_write.c Paraslash's oss output plugin. */
   8
   9 #include <regex.h>
  10 #include <sys/ioctl.h>
  11 #include <fcntl.h>
  12 #include <dirent.h>
  13 #include <sys/soundcard.h>
  14 #include <stdbool.h>
  15
  16 #include "para.h"
  17 #include "fd.h"
  18 #include "string.h"
  19 #include "list.h"
  20 #include "sched.h"
  21 #include "ggo.h"
  22 #include "buffer_tree.h"
  23 #include "write.h"
  24 #include "write_common.h"
  25 #include "oss_write.cmdline.h"
  26 #include "error.h"
  27
  28 /** Always use 16 bit little endian. */
  29 #define FORMAT AFMT_S16_LE
  30
  31 /** Data specific to the oss writer. */
  32 struct private_oss_write_data {
  33         /** The file handle of the device. */
  34         int fd;
  35         /**
  36          * The samplerate given by command line option or the decoder
  37          * of the writer node group.
  38          */
  39         int samplerate;
  40         /**
  41          * The number of channels, given by command line option or the
  42          * decoder of the writer node group.
  43          */
  44         int channels;
  45         /** Four bytes for stereo streams, two bytes for mono streams. */
  46         int bytes_per_frame;
  47 };
  48
  49 static int oss_pre_select(struct sched *s, struct writer_node *wn)
  50 {
  51         struct private_oss_write_data *powd = wn->private_data;
  52         struct writer_node_group *wng = wn->wng;
  53
  54         if (*wng->loaded - wn->written < powd->bytes_per_frame)
  55                 return 0;
  56         para_fd_set(powd->fd, &s->wfds, &s->max_fileno);
  57         return 1;
  58 }
  59
  60 static void oss_pre_select_btr(struct sched *s, struct task *t)
  61 {
  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);
  65
  66         t->error = 0;
  67         if (ret < 0)
  68                 goto min_delay;
  69         if (ret == 0)
  70                 return;
  71         if (!powd)
  72                 goto min_delay;
  73         para_fd_set(powd->fd, &s->wfds, &s->max_fileno);
  74         return;
  75 min_delay:
  76         s->timeout.tv_sec = 0;
  77         s->timeout.tv_usec = 1;
  78 }
  79
  80 static int oss_post_select(struct sched *s, struct writer_node *wn)
  81 {
  82         int ret;
  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;
  87
  88         if (*wng->input_error < 0 && bytes < powd->bytes_per_frame) {
  89                 wn->written = *wng->loaded;
  90                 return *wng->input_error;
  91         }
  92         frames = bytes / powd->bytes_per_frame;
  93         if (!frames) /* less than a single frame available */
  94                 goto out;
  95         if (!FD_ISSET(powd->fd, &s->wfds))
  96                 goto out;
  97         ret = write_nonblock(powd->fd, data, frames * powd->bytes_per_frame, 0);
  98         if (ret < 0)
  99                 return ret;
 100         wn->written += ret;
 101 out:
 102         return 1;
 103 }
 104
 105 static void oss_close(struct writer_node *wn)
 106 {
 107         struct private_oss_write_data *powd = wn->private_data;
 108
 109         close(powd->fd);
 110         oss_cmdline_parser_free(wn->conf);
 111         free(powd);
 112 }
 113
 114 /*
 115  * The Open Sound System Programmer's Guide sayeth:
 116  *
 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.
 124  */
 125 static int oss_init(struct writer_node *wn, unsigned samplerate, unsigned channels)
 126 {
 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;
 130
 131         PARA_INFO_LOG("opening %s\n", conf->device_arg);
 132         ret = para_open(conf->device_arg, O_WRONLY, 0);
 133         if (ret < 0)
 134                 return ret;
 135         powd->fd = ret;
 136         ret = mark_fd_nonblocking(powd->fd);
 137         if (ret < 0)
 138                 goto err;
 139         /* set PCM format */
 140         ret = ioctl(powd->fd, SNDCTL_DSP_SETFMT, &format);
 141         if (ret < 0) {
 142                 ret = -ERRNO_TO_PARA_ERROR(errno);
 143                 goto err;
 144         }
 145         ret = -E_BAD_SAMPLE_FORMAT;
 146         if (format != FORMAT)
 147                 goto err;
 148         /* set number of channels */
 149         if (!conf->channels_given && channels != 0)
 150                 ch = channels;
 151         else
 152                 ch = conf->channels_arg;
 153         ret = -E_BAD_CHANNEL_COUNT;
 154         if (ch == 0)
 155                 goto err;
 156         powd->channels = ch;
 157         ret = ioctl(powd->fd, SNDCTL_DSP_CHANNELS, &ch);
 158         if (ret < 0) {
 159                 ret = -ERRNO_TO_PARA_ERROR(errno);
 160                 goto err;
 161         }
 162         if (powd->channels != ch)
 163                 goto err;
 164         powd->bytes_per_frame = ch * 2;
 165
 166         /*
 167          * Set sampling rate
 168          *
 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.
 172          */
 173         if (!conf->samplerate_given && samplerate != 0)
 174                 rate = samplerate;
 175         else
 176                 rate = conf->samplerate_arg;
 177         powd->samplerate = rate;
 178         ret = ioctl(powd->fd, SNDCTL_DSP_SPEED, &rate);
 179         if (ret < 0) {
 180                 ret = -ERRNO_TO_PARA_ERROR(errno);
 181                 goto err;
 182         }
 183         if (rate != powd->samplerate) {
 184                 int min = PARA_MIN(rate, powd->samplerate),
 185                         max = PARA_MAX(rate, powd->samplerate);
 186                 /*
 187                  * Check whether the returned sample rate differs significantly
 188                  * from the requested one.
 189                  */
 190                 ret = -E_BAD_SAMPLERATE;
 191                 if (100 * max > 110 * min) /* more than 10% deviation */
 192                         goto err;
 193                 PARA_NOTICE_LOG("using %dHz rather than %dHz\n", rate,
 194                         powd->samplerate);
 195         }
 196         wn->min_iqs = powd->bytes_per_frame;
 197         return 1;
 198 err:
 199         close(powd->fd);
 200         free(powd);
 201         return ret;
 202 }
 203
 204 static void oss_post_select_btr(__a_unused struct sched *s,
 205                 struct task *t)
 206 {
 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);
 213         char *data;
 214
 215         if (ret < 0)
 216                 goto out;
 217         if (ret == 0)
 218                 return;
 219         if (powd->fd < 0) {
 220                 int32_t rate, ch;
 221                 ret = -1;
 222                 if (!conf->samplerate_given) /* config option trumps btr_exec */
 223                         ret = get_btr_samplerate(wn->btrn, &rate);
 224                 if (ret < 0)
 225                         rate = conf->samplerate_arg;
 226                 ret = -1;
 227                 if (!conf->channels_given)
 228                         ret = get_btr_channels(wn->btrn, &ch);
 229                 if (ret < 0)
 230                         ch = conf->channels_arg;
 231                 ret = oss_init(wn, rate, ch);
 232                 if (ret < 0)
 233                         goto out;
 234                 return;
 235         }
 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 */
 239                 ret = -E_OSS_EOF;
 240                 goto out;
 241         }
 242         ret = 0;
 243         if (!FD_ISSET(powd->fd, &s->wfds))
 244                 goto out;
 245         ret = write_nonblock(powd->fd, data, frames * powd->bytes_per_frame, 0);
 246         if (ret < 0)
 247                 goto out;
 248         btr_consume(btrn, ret);
 249         ret = 0;
 250 out:
 251         t->error = ret;
 252 }
 253
 254 static int oss_open(struct writer_node *wn)
 255 {
 256         struct writer_node_group *wng;
 257         struct private_oss_write_data *powd;
 258
 259         powd = para_calloc(sizeof(*powd));
 260         wn->private_data = powd;
 261         if (!wn->btrn) {
 262                 wng = wn->wng;
 263                 return oss_init(wn, wng->samplerate ? *wng->samplerate : 0,
 264                         wng->channels? *wng->channels : 0);
 265         }
 266         powd->fd = -1;
 267         return 1;
 268 }
 269
 270 __malloc static void *oss_parse_config(const char *options)
 271 {
 272         int ret;
 273         struct oss_write_args_info *conf = para_calloc(sizeof(*conf));
 274
 275         PARA_INFO_LOG("options: %s, %zd\n", options, strcspn(options, " \t"));
 276         ret = oss_cmdline_parser_string(options, conf, "oss_write");
 277         if (ret)
 278                 goto err_out;
 279         return conf;
 280 err_out:
 281         free(conf);
 282         return NULL;
 283 }
 284
 285 static void oss_free_config(void *conf)
 286 {
 287         oss_cmdline_parser_free(conf);
 288 }
 289
 290 /**
 291  * The init function of the oss writer.
 292  *
 293  * \param w Pointer to the writer to initialize.
 294  *
 295  * \sa struct writer.
 296  */
 297 void oss_write_init(struct writer *w)
 298 {
 299         struct oss_write_args_info dummy;
 300
 301         oss_cmdline_parser_init(&dummy);
 302         w->open = oss_open;
 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;
 310         w->shutdown = NULL;
 311         w->help = (struct ggo_help) {
 312                 .short_help = oss_write_args_info_help,
 313                 .detailed_help = oss_write_args_info_detailed_help
 314         };
 315         oss_cmdline_parser_free(&dummy);
 316 }