mdw@git.distorted.org.uk Git - disorder/blob - driver/disorder.c

   1 /*
   2  * This file is part of DisOrder.
   3  * Copyright (C) 2005, 2007 Richard Kettlewell
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  18  * USA
  19  */
  20 /** @file driver/disorder.c
  21  * @brief libao driver used by DisOrder
  22  *
  23  * The output from this driver is expected to be fed to @c
  24  * disorder-normalize to convert to the confnigured target format.
  25  */
  26
  27 #include <config.h>
  28 #include "types.h"
  29
  30 #include <string.h>
  31 #include <stdlib.h>
  32 #include <errno.h>
  33 #include <unistd.h>
  34 #include <poll.h>
  35 #include <ao/ao.h>
  36 #include <ao/plugin.h>
  37
  38 #include "speaker-protocol.h"
  39
  40 /* extra declarations to help out lazy <ao/plugin.h> */
  41 int ao_plugin_test(void);
  42 ao_info *ao_plugin_driver_info(void);
  43 char *ao_plugin_file_extension(void);
  44
  45 /** @brief Private data structure for this driver */
  46 struct internal {
  47   int fd;                               /* output file descriptor */
  48   int exit_on_error;                    /* exit on write error */
  49
  50   /** @brief Record of sample format */
  51   struct stream_header header;
  52
  53 };
  54
  55 /* like write() but never returns EINTR/EAGAIN or short */
  56 static int do_write(int fd, const void *ptr, size_t n) {
  57   size_t written = 0;
  58   int ret;
  59   struct pollfd ufd;
  60
  61   memset(&ufd, 0, sizeof ufd);
  62   ufd.fd = fd;
  63   ufd.events = POLLOUT;
  64   while(written < n) {
  65     ret = write(fd, (const char *)ptr + written, n - written);
  66     if(ret < 0) {
  67       switch(errno) {
  68       case EINTR: break;
  69       case EAGAIN:
  70         /* Someone sneakily gave us a nonblocking file descriptor, wait until
  71          * we can write again */
  72         ret = poll(&ufd, 1, -1);
  73         if(ret < 0 && errno != EINTR) return -1;
  74         break;
  75       default:
  76         return -1;
  77       }
  78     } else
  79       written += ret;
  80   }
  81   return written;
  82 }
  83
  84 /* return 1 if this driver can be opened */
  85 int ao_plugin_test(void) {
  86   return 1;
  87 }
  88
  89 /* return info about this driver */
  90 ao_info *ao_plugin_driver_info(void) {
  91   static const char *options[] = { "fd" };
  92   static const ao_info info = {
  93     AO_TYPE_LIVE,                       /* type */
  94     (char *)"DisOrder format driver",   /* name */
  95     (char *)"disorder",                 /* short_name */
  96     (char *)"http://www.greenend.org.uk/rjk/disorder/", /* comment */
  97     (char *)"Richard Kettlewell",       /* author */
  98     AO_FMT_NATIVE,                      /* preferred_byte_format */
  99     0,                                  /* priority */
 100     (char **)options,                   /* options */
 101     1,                                  /* option_count */
 102   };
 103   return (ao_info *)&info;
 104 }
 105
 106 /* initialize the private data structure */
 107 int ao_plugin_device_init(ao_device *device) {
 108   struct internal *i = malloc(sizeof (struct internal));
 109   const char *e;
 110
 111   if(!i) return 0;
 112   memset(i, 0, sizeof *i);
 113   if((e = getenv("DISORDER_RAW_FD")))
 114     i->fd = atoi(e);
 115   else
 116     i->fd = 1;
 117   device->internal = i;
 118   return 1;
 119 }
 120
 121 /* set an option */
 122 int ao_plugin_set_option(ao_device *device,
 123                          const char *key,
 124                          const char *value) {
 125   struct internal *i = device->internal;
 126
 127   if(!strcmp(key, "fd"))
 128     i->fd = atoi(value);
 129   else if(!strcmp(key, "fragile"))
 130     i->exit_on_error = atoi(value);
 131   /* unknown options are required to be ignored */
 132   return 1;
 133 }
 134
 135 /* open the device */
 136 int ao_plugin_open(ao_device *device, ao_sample_format *format) {
 137   struct internal *i = device->internal;
 138
 139   /* we would like native-order samples */
 140   device->driver_byte_format = AO_FMT_NATIVE;
 141   i->header.rate = format->rate;
 142   i->header.channels = format->channels;
 143   i->header.bits = format->bits;
 144   i->header.endian = ENDIAN_NATIVE;
 145   return 1;
 146 }
 147
 148 /* play some samples */
 149 int ao_plugin_play(ao_device *device, const char *output_samples,
 150                    uint_32 num_bytes) {
 151   struct internal *i = device->internal;
 152
 153   /* Fill in and write the header */
 154   i->header.nbytes = num_bytes;
 155   if(do_write(i->fd, &i->header, sizeof i->header) < 0) {
 156     if(i->exit_on_error) _exit(-1);
 157     return 0;
 158   }
 159
 160   /* Write the sample data */
 161   if(do_write(i->fd, output_samples, num_bytes) < 0) {
 162     if(i->exit_on_error) _exit(-1);
 163     return 0;
 164   }
 165   return 1;
 166 }
 167
 168 /* close the device */
 169 int ao_plugin_close(ao_device attribute((unused)) *device) {
 170   return 1;
 171 }
 172
 173 /* delete private data structures */
 174 void ao_plugin_device_clear(ao_device *device) {
 175   free(device->internal);
 176   device->internal = 0;
 177 }
 178
 179 /* report preferred filename extension */
 180 char *ao_plugin_file_extension(void) {
 181   return 0;
 182 }
 183
 184 /*
 185 Local Variables:
 186 c-basic-offset:2
 187 comment-column:40
 188 End:
 189 */