oss_write.c

   1 /*
   2  * Copyright (C) 2009-2012 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 <sys/soundcard.h>
  13
  14 #include "para.h"
  15 #include "fd.h"
  16 #include "string.h"
  17 #include "list.h"
  18 #include "sched.h"
  19 #include "ggo.h"
  20 #include "buffer_tree.h"
  21 #include "write.h"
  22 #include "write_common.h"
  23 #include "oss_write.cmdline.h"
  24 #include "error.h"
  25
  26 /** Data specific to the oss writer. */
  27 struct private_oss_write_data {
  28         /** The file handle of the device. */
  29         int fd;
  30         /** Four bytes for stereo streams, two bytes for mono streams. */
  31         int bytes_per_frame;
  32 };
  33
  34 static int get_oss_format(enum sample_format sf)
  35 {
  36         switch (sf) {
  37         case SF_S8: return AFMT_S8;
  38         case SF_U8: return AFMT_U8;
  39         case SF_S16_LE: return AFMT_S16_LE;
  40         case SF_S16_BE: return AFMT_S16_BE;
  41         case SF_U16_LE: return AFMT_U16_LE;
  42         case SF_U16_BE: return AFMT_U16_BE;
  43         default: return AFMT_S16_LE;
  44         }
  45 }
  46
  47 static void oss_pre_select(struct sched *s, struct task *t)
  48 {
  49         struct writer_node *wn = container_of(t, struct writer_node, task);
  50         struct private_oss_write_data *powd = wn->private_data;
  51         int ret = btr_node_status(wn->btrn, wn->min_iqs, BTR_NT_LEAF);
  52
  53         if (ret == 0)
  54                 return;
  55         if (ret < 0 || !powd)
  56                 return sched_min_delay(s);
  57         para_fd_set(powd->fd, &s->wfds, &s->max_fileno);
  58 }
  59
  60 static void oss_close(struct writer_node *wn)
  61 {
  62         struct private_oss_write_data *powd = wn->private_data;
  63
  64         if (!powd)
  65                 return;
  66         close(powd->fd);
  67         free(powd);
  68 }
  69
  70 /*
  71  * The Open Sound System Programmer's Guide sayeth:
  72  *
  73  * Set sampling parameters always so that number of channels (mono/stereo) is
  74  * set before selecting sampling rate (speed).  Failing to do this will make
  75  * your program incompatible with cards such as the SoundBlaster Pro which
  76  * supports 44.1 kHz in mono but just 22.05 kHz in stereo. A program which
  77  * selects 44.1 kHz speed and then sets the device to stereo mode will
  78  * incorrectly believe that the device is still in 44.1 kHz mode when actually
  79  * the speed is decreased to 22.05 kHz.
  80  */
  81 static int oss_init(struct writer_node *wn, unsigned sample_rate,
  82                 unsigned channels, int sample_format)
  83 {
  84         int ret, format;
  85         unsigned ch, rate;
  86         struct oss_write_args_info *conf = wn->conf;
  87         struct private_oss_write_data *powd = para_calloc(sizeof(*powd));
  88
  89         PARA_INFO_LOG("opening %s\n", conf->device_arg);
  90         ret = para_open(conf->device_arg, O_WRONLY, 0);
  91         if (ret < 0)
  92                 goto err_free;
  93         powd->fd = ret;
  94         ret = mark_fd_nonblocking(powd->fd);
  95         if (ret < 0)
  96                 goto err;
  97         /* set PCM format */
  98         sample_format = format = get_oss_format(sample_format);
  99         ret = ioctl(powd->fd, SNDCTL_DSP_SETFMT, &format);
 100         if (ret < 0) {
 101                 ret = -ERRNO_TO_PARA_ERROR(errno);
 102                 goto err;
 103         }
 104         ret = -E_BAD_SAMPLE_FORMAT;
 105         if (format != sample_format)
 106                 goto err;
 107         /* set number of channels */
 108         ch = channels;
 109         ret = ioctl(powd->fd, SNDCTL_DSP_CHANNELS, &ch);
 110         if (ret < 0) {
 111                 ret = -ERRNO_TO_PARA_ERROR(errno);
 112                 goto err;
 113         }
 114         ret = -E_BAD_CHANNEL_COUNT;
 115         if (ch != channels)
 116                 goto err;
 117         if (format == SF_U8 || format == SF_S8)
 118                 powd->bytes_per_frame = ch;
 119         else
 120                 powd->bytes_per_frame = ch * 2;
 121
 122         /*
 123          * Set sampling rate
 124          *
 125          * If we request a higher sampling rate than is supported by the
 126          * device, the the highest possible speed is automatically used. The
 127          * value actually used is returned as the new value of the argument.
 128          */
 129         rate = sample_rate;
 130         ret = ioctl(powd->fd, SNDCTL_DSP_SPEED, &rate);
 131         if (ret < 0) {
 132                 ret = -ERRNO_TO_PARA_ERROR(errno);
 133                 goto err;
 134         }
 135         if (rate != sample_rate) {
 136                 unsigned min = PARA_MIN(rate, sample_rate),
 137                         max = PARA_MAX(rate, sample_rate);
 138                 /*
 139                  * Check whether the returned sample rate differs significantly
 140                  * from the requested one.
 141                  */
 142                 ret = -E_BAD_SAMPLERATE;
 143                 if (100 * max > 110 * min) /* more than 10% deviation */
 144                         goto err;
 145                 PARA_NOTICE_LOG("using %dHz rather than %dHz\n", rate,
 146                         sample_rate);
 147         }
 148         wn->min_iqs = powd->bytes_per_frame;
 149         wn->private_data = powd;
 150         return 1;
 151 err:
 152         close(powd->fd);
 153 err_free:
 154         free(powd);
 155         return ret;
 156 }
 157
 158 static void oss_post_select(__a_unused struct sched *s,
 159                 struct task *t)
 160 {
 161         struct writer_node *wn = container_of(t, struct writer_node, task);
 162         struct private_oss_write_data *powd = wn->private_data;
 163         struct btr_node *btrn = wn->btrn;
 164         size_t frames, bytes;
 165         int ret = btr_node_status(btrn, wn->min_iqs, BTR_NT_LEAF);
 166         char *data;
 167
 168         if (ret < 0)
 169                 goto out;
 170         if (ret == 0)
 171                 return;
 172         if (!powd) {
 173                 int32_t rate, ch, format;
 174                 get_btr_sample_rate(btrn, &rate);
 175                 get_btr_channels(btrn, &ch);
 176                 get_btr_sample_format(btrn, &format);
 177                 ret = oss_init(wn, rate, ch, format);
 178                 if (ret < 0)
 179                         goto out;
 180                 return;
 181         }
 182         btr_merge(btrn, wn->min_iqs);
 183         bytes = btr_next_buffer(btrn, &data);
 184         frames = bytes / powd->bytes_per_frame;
 185         if (!frames) { /* eof and less than a single frame available */
 186                 ret = -E_WRITE_COMMON_EOF;
 187                 goto out;
 188         }
 189         ret = 0;
 190         if (!FD_ISSET(powd->fd, &s->wfds))
 191                 goto out;
 192         ret = xwrite(powd->fd, data, frames * powd->bytes_per_frame);
 193         if (ret < 0)
 194                 goto out;
 195         btr_consume(btrn, ret);
 196         ret = 0;
 197 out:
 198         t->error = ret;
 199         if (ret < 0)
 200                 btr_remove_node(btrn);
 201 }
 202
 203 __malloc static void *oss_parse_config_or_die(const char *options)
 204 {
 205         struct oss_write_args_info *conf = para_calloc(sizeof(*conf));
 206
 207         /* exits on errors */
 208         oss_cmdline_parser_string(options, conf, "oss_write");
 209         return conf;
 210 }
 211
 212 static void oss_free_config(void *conf)
 213 {
 214         oss_cmdline_parser_free(conf);
 215 }
 216
 217 /**
 218  * The init function of the oss writer.
 219  *
 220  * \param w Pointer to the writer to initialize.
 221  *
 222  * \sa struct writer.
 223  */
 224 void oss_write_init(struct writer *w)
 225 {
 226         struct oss_write_args_info dummy;
 227
 228         oss_cmdline_parser_init(&dummy);
 229         w->close = oss_close;
 230         w->pre_select = oss_pre_select;
 231         w->post_select = oss_post_select;
 232         w->parse_config_or_die = oss_parse_config_or_die;
 233         w->free_config = oss_free_config;
 234         w->shutdown = NULL;
 235         w->help = (struct ggo_help) {
 236                 .short_help = oss_write_args_info_help,
 237                 .detailed_help = oss_write_args_info_detailed_help
 238         };
 239         oss_cmdline_parser_free(&dummy);
 240 }