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

   1
   2 /*
   3  * This file is part of DisOrder.
   4  * Copyright (C) 2005 Richard Kettlewell
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  19  * USA
  20  */
  21
  22 #include <config.h>
  23
  24 #include <string.h>
  25 #include <stdlib.h>
  26 #include <errno.h>
  27 #include <unistd.h>
  28 #include <poll.h>
  29 #include <ao/ao.h>
  30 #include <ao/plugin.h>
  31
  32 /* extra declarations to help out lazy <ao/plugin.h> */
  33 int ao_plugin_test(void);
  34 ao_info *ao_plugin_driver_info(void);
  35 char *ao_plugin_file_extension(void);
  36
  37 /* private data structure for this driver */
  38 struct internal {
  39   int fd;                               /* output file descriptor */
  40   int exit_on_error;                    /* exit on write error */
  41 };
  42
  43 /* like write() but never returns EINTR/EAGAIN or short */
  44 static int do_write(int fd, const void *ptr, size_t n) {
  45   size_t written = 0;
  46   int ret;
  47   struct pollfd ufd;
  48
  49   memset(&ufd, 0, sizeof ufd);
  50   ufd.fd = fd;
  51   ufd.events = POLLOUT;
  52   while(written < n) {
  53     ret = write(fd, (const char *)ptr + written, n - written);
  54     if(ret < 0) {
  55       switch(errno) {
  56       case EINTR: break;
  57       case EAGAIN:
  58         /* Someone sneakily gave us a nonblocking file descriptor, wait until
  59          * we can write again */
  60         ret = poll(&ufd, 1, -1);
  61         if(ret < 0 && errno != EINTR) return -1;
  62         break;
  63       default:
  64         return -1;
  65       }
  66     } else
  67       written += ret;
  68   }
  69   return written;
  70 }
  71
  72 /* return 1 if this driver can be opened */
  73 int ao_plugin_test(void) {
  74   return 1;
  75 }
  76
  77 /* return info about this driver */
  78 ao_info *ao_plugin_driver_info(void) {
  79   static const char *options[] = { "fd" };
  80   static const ao_info info = {
  81     AO_TYPE_LIVE,                       /* type */
  82     (char *)"DisOrder format driver",   /* name */
  83     (char *)"disorder",                 /* short_name */
  84     (char *)"http://www.greenend.org.uk/rjk/disorder/", /* comment */
  85     (char *)"Richard Kettlewell",       /* author */
  86     AO_FMT_NATIVE,                      /* preferred_byte_format */
  87     0,                                  /* priority */
  88     (char **)options,                   /* options */
  89     1,                                  /* option_count */
  90   };
  91   return (ao_info *)&info;
  92 }
  93
  94 /* initialize the private data structure */
  95 int ao_plugin_device_init(ao_device *device) {
  96   struct internal *i = malloc(sizeof (struct internal));
  97   const char *e;
  98
  99   if(!i) return 0;
 100   memset(i, 0, sizeof *i);
 101   if((e = getenv("DISORDER_RAW_FD")))
 102     i->fd = atoi(e);
 103   else
 104     i->fd = 1;
 105   device->internal = i;
 106   return 1;
 107 }
 108
 109 /* set an option */
 110 int ao_plugin_set_option(ao_device *device,
 111                          const char *key,
 112                          const char *value) {
 113   struct internal *i = device->internal;
 114
 115   if(!strcmp(key, "fd"))
 116     i->fd = atoi(value);
 117   else if(!strcmp(key, "fragile"))
 118     i->exit_on_error = atoi(value);
 119   /* unknown options are required to be ignored */
 120   return 1;
 121 }
 122
 123 /* open the device */
 124 int ao_plugin_open(ao_device *device, ao_sample_format *format) {
 125   struct internal *i = device->internal;
 126
 127   /* we would like native-order samples */
 128   device->driver_byte_format = AO_FMT_NATIVE;
 129   if(do_write(i->fd, format, sizeof *format) < 0) {
 130     if(i->exit_on_error) exit(-1);
 131     return 0;
 132   }
 133   return 1;
 134 }
 135
 136 /* play some samples */
 137 int ao_plugin_play(ao_device *device, const char *output_samples,
 138                    uint_32 num_bytes) {
 139   struct internal *i = device->internal;
 140
 141   if(do_write(i->fd, output_samples, num_bytes) < 0) {
 142     if(i->exit_on_error) _exit(-1);
 143     return 0;
 144   }
 145   return 1;
 146 }
 147
 148 /* close the device */
 149 int ao_plugin_close(ao_device attribute((unused)) *device) {
 150   return 1;
 151 }
 152
 153 /* delete private data structures */
 154 void ao_plugin_device_clear(ao_device *device) {
 155   free(device->internal);
 156   device->internal = 0;
 157 }
 158
 159 /* report preferred filename extension */
 160 char *ao_plugin_file_extension(void) {
 161   return 0;
 162 }
 163
 164 /*
 165 Local Variables:
 166 c-basic-offset:2
 167 comment-column:40
 168 End:
 169 */
 170 /* arch-tag:ru/Jqo0hseWMoSt/ba4Xlw */