oss_write.c

   1 /*
   2  * Copyright (C) 2009-2010 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 /** Data specific to the oss writer. */
  29 struct private_oss_write_data {
  30         /** The file handle of the device. */
  31         int fd;
  32         /** Four bytes for stereo streams, two bytes for mono streams. */
  33         int bytes_per_frame;
  34 };
  35
  36 static int get_oss_format(enum sample_format sf)
  37 {
  38         switch (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;
  46         }
  47 }
  48
  49 static void oss_pre_select(struct sched *s, struct task *t)
  50 {
  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);
  54
  55         t->error = 0;
  56         if (ret < 0)
  57                 sched_min_delay(s);
  58         else if (ret > 0)
  59                 para_fd_set(powd->fd, &s->wfds, &s->max_fileno);
  60 }
  61
  62 static void oss_close(struct writer_node *wn)
  63 {
  64         struct private_oss_write_data *powd = wn->private_data;
  65
  66         if (powd->fd >= 0)
  67                 close(powd->fd);
  68         free(powd);
  69 }
  70
  71 /*
  72  * The Open Sound System Programmer's Guide sayeth:
  73  *
  74  * Set sampling parameters always so that number of channels (mono/stereo) is
  75  * set before selecting sampling rate (speed).  Failing to do this will make
  76  * your program incompatible with cards such as the SoundBlaster Pro which
  77  * supports 44.1 kHz in mono but just 22.05 kHz in stereo. A program which
  78  * selects 44.1 kHz speed and then sets the device to stereo mode will
  79  * incorrectly believe that the device is still in 44.1 kHz mode when actually
  80  * the speed is decreased to 22.05 kHz.
  81  */
  82 static int oss_init(struct writer_node *wn, unsigned sample_rate,
  83                 unsigned channels, int sample_format)
  84 {
  85         int ret, format;
  86         unsigned ch, rate;
  87         struct oss_write_args_info *conf = wn->conf;
  88         struct private_oss_write_data *powd = wn->private_data;
  89
  90         PARA_INFO_LOG("opening %s\n", conf->device_arg);
  91         ret = para_open(conf->device_arg, O_WRONLY, 0);
  92         if (ret < 0)
  93                 return ret;
  94         powd->fd = ret;
  95         ret = mark_fd_nonblocking(powd->fd);
  96         if (ret < 0)
  97                 goto err;
  98         /* set PCM format */
  99         sample_format = format = get_oss_format(sample_format);
 100         ret = ioctl(powd->fd, SNDCTL_DSP_SETFMT, &format);
 101         if (ret < 0) {
 102                 ret = -ERRNO_TO_PARA_ERROR(errno);
 103                 goto err;
 104         }
 105         ret = -E_BAD_SAMPLE_FORMAT;
 106         if (format != sample_format)
 107                 goto err;
 108         /* set number of channels */
 109         ch = channels;
 110         ret = ioctl(powd->fd, SNDCTL_DSP_CHANNELS, &ch);
 111         if (ret < 0) {
 112                 ret = -ERRNO_TO_PARA_ERROR(errno);
 113                 goto err;
 114         }
 115         ret = -E_BAD_CHANNEL_COUNT;
 116         if (ch != channels)
 117                 goto err;
 118         if (format == SF_U8 || format == SF_S8)
 119                 powd->bytes_per_frame = ch;
 120         else
 121                 powd->bytes_per_frame = ch * 2;
 122
 123         /*
 124          * Set sampling rate
 125          *
 126          * If we request a higher sampling rate than is supported by the
 127          * device, the the highest possible speed is automatically used. The
 128          * value actually used is returned as the new value of the argument.
 129          */
 130         rate = sample_rate;
 131         ret = ioctl(powd->fd, SNDCTL_DSP_SPEED, &rate);
 132         if (ret < 0) {
 133                 ret = -ERRNO_TO_PARA_ERROR(errno);
 134                 goto err;
 135         }
 136         if (rate != sample_rate) {
 137                 unsigned min = PARA_MIN(rate, sample_rate),
 138                         max = PARA_MAX(rate, sample_rate);
 139                 /*
 140                  * Check whether the returned sample rate differs significantly
 141                  * from the requested one.
 142                  */
 143                 ret = -E_BAD_SAMPLERATE;
 144                 if (100 * max > 110 * min) /* more than 10% deviation */
 145                         goto err;
 146                 PARA_NOTICE_LOG("using %dHz rather than %dHz\n", rate,
 147                         sample_rate);
 148         }
 149         wn->min_iqs = powd->bytes_per_frame;
 150         return 1;
 151 err:
 152         close(powd->fd);
 153         powd->fd = -1;
 154         return ret;
 155 }
 156
 157 static void oss_post_select(__a_unused struct sched *s,
 158                 struct task *t)
 159 {
 160         struct writer_node *wn = container_of(t, struct writer_node, task);
 161         struct private_oss_write_data *powd = wn->private_data;
 162         struct btr_node *btrn = wn->btrn;
 163         size_t frames, bytes;
 164         int ret = btr_node_status(btrn, wn->min_iqs, BTR_NT_LEAF);
 165         char *data;
 166
 167         if (ret < 0)
 168                 goto out;
 169         if (ret == 0)
 170                 return;
 171         if (powd->fd < 0) {
 172                 int32_t rate, ch, format;
 173                 get_btr_sample_rate(btrn, &rate);
 174                 get_btr_channels(btrn, &ch);
 175                 get_btr_sample_format(btrn, &format);
 176                 ret = oss_init(wn, rate, ch, format);
 177                 if (ret < 0)
 178                         goto out;
 179                 return;
 180         }
 181         btr_merge(btrn, wn->min_iqs);
 182         bytes = btr_next_buffer(btrn, &data);
 183         frames = bytes / powd->bytes_per_frame;
 184         if (!frames) { /* eof and less than a single frame available */
 185                 ret = -E_OSS_EOF;
 186                 goto out;
 187         }
 188         ret = 0;
 189         if (!FD_ISSET(powd->fd, &s->wfds))
 190                 goto out;
 191         ret = write_nonblock(powd->fd, data, frames * powd->bytes_per_frame);
 192         if (ret < 0)
 193                 goto out;
 194         btr_consume(btrn, ret);
 195         ret = 0;
 196 out:
 197         t->error = ret;
 198         if (ret < 0)
 199                 btr_remove_node(btrn);
 200 }
 201
 202 static int oss_open(struct writer_node *wn)
 203 {
 204         struct private_oss_write_data *powd;
 205
 206         powd = para_calloc(sizeof(*powd));
 207         wn->private_data = powd;
 208         powd->fd = -1;
 209         return 1;
 210 }
 211
 212 __malloc static void *oss_parse_config(const char *options)
 213 {
 214         int ret;
 215         struct oss_write_args_info *conf = para_calloc(sizeof(*conf));
 216
 217         ret = oss_cmdline_parser_string(options, conf, "oss_write");
 218         if (ret)
 219                 goto err_out;
 220         return conf;
 221 err_out:
 222         free(conf);
 223         return NULL;
 224 }
 225
 226 static void oss_free_config(void *conf)
 227 {
 228         oss_cmdline_parser_free(conf);
 229 }
 230
 231 /**
 232  * The init function of the oss writer.
 233  *
 234  * \param w Pointer to the writer to initialize.
 235  *
 236  * \sa struct writer.
 237  */
 238 void oss_write_init(struct writer *w)
 239 {
 240         struct oss_write_args_info dummy;
 241
 242         oss_cmdline_parser_init(&dummy);
 243         w->open = oss_open;
 244         w->close = oss_close;
 245         w->pre_select = oss_pre_select;
 246         w->post_select = oss_post_select;
 247         w->parse_config = oss_parse_config;
 248         w->free_config = oss_free_config;
 249         w->shutdown = NULL;
 250         w->help = (struct ggo_help) {
 251                 .short_help = oss_write_args_info_help,
 252                 .detailed_help = oss_write_args_info_detailed_help
 253         };
 254         oss_cmdline_parser_free(&dummy);
 255 }