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 3 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,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU 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, see <http://www.gnu.org/licenses/>.
  17  */
  18 /** @file driver/disorder.c
  19  * @brief libao driver used by DisOrder
  20  *
  21  * The output from this driver is expected to be fed to @c
  22  * disorder-normalize to convert to the confnigured target format.
  23  */
  24
  25 #include "common.h"
  26
  27 #include <errno.h>
  28 #include <unistd.h>
  29 #include <poll.h>
  30 #include <ao/ao.h>
  31 #include <ao/plugin.h>
  32
  33 #include "speaker-protocol.h"
  34
  35 /* extra declarations to help out lazy <ao/plugin.h> */
  36 int ao_plugin_test(void);
  37 ao_info *ao_plugin_driver_info(void);
  38 char *ao_plugin_file_extension(void);
  39
  40 /** @brief Private data structure for this driver */
  41 struct internal {
  42   int fd;                               /* output file descriptor */
  43   int exit_on_error;                    /* exit on write error */
  44
  45   /** @brief Record of sample format */
  46   struct stream_header header;
  47
  48 };
  49
  50 /* like write() but never returns EINTR/EAGAIN or short */
  51 static int do_write(int fd, const void *ptr, size_t n) {
  52   size_t written = 0;
  53   int ret;
  54   struct pollfd ufd;
  55
  56   memset(&ufd, 0, sizeof ufd);
  57   ufd.fd = fd;
  58   ufd.events = POLLOUT;
  59   while(written < n) {
  60     ret = write(fd, (const char *)ptr + written, n - written);
  61     if(ret < 0) {
  62       switch(errno) {
  63       case EINTR: break;
  64       case EAGAIN:
  65         /* Someone sneakily gave us a nonblocking file descriptor, wait until
  66          * we can write again */
  67         ret = poll(&ufd, 1, -1);
  68         if(ret < 0 && errno != EINTR) return -1;
  69         break;
  70       default:
  71         return -1;
  72       }
  73     } else
  74       written += ret;
  75   }
  76   return written;
  77 }
  78
  79 /* return 1 if this driver can be opened */
  80 int ao_plugin_test(void) {
  81   return 1;
  82 }
  83
  84 /* return info about this driver */
  85 ao_info *ao_plugin_driver_info(void) {
  86   static const char *options[] = { "fd" };
  87   static const ao_info info = {
  88     AO_TYPE_LIVE,                       /* type */
  89     (char *)"DisOrder format driver",   /* name */
  90     (char *)"disorder",                 /* short_name */
  91     (char *)"http://www.greenend.org.uk/rjk/disorder/", /* comment */
  92     (char *)"Richard Kettlewell",       /* author */
  93     AO_FMT_NATIVE,                      /* preferred_byte_format */
  94     0,                                  /* priority */
  95     (char **)options,                   /* options */
  96     1,                                  /* option_count */
  97   };
  98   return (ao_info *)&info;
  99 }
 100
 101 /* initialize the private data structure */
 102 int ao_plugin_device_init(ao_device *device) {
 103   struct internal *i = malloc(sizeof (struct internal));
 104   const char *e;
 105
 106   if(!i) return 0;
 107   memset(i, 0, sizeof *i);
 108   if((e = getenv("DISORDER_RAW_FD")))
 109     i->fd = atoi(e);
 110   else
 111     i->fd = 1;
 112   device->internal = i;
 113   return 1;
 114 }
 115
 116 /* set an option */
 117 int ao_plugin_set_option(ao_device *device,
 118                          const char *key,
 119                          const char *value) {
 120   struct internal *i = device->internal;
 121
 122   if(!strcmp(key, "fd"))
 123     i->fd = atoi(value);
 124   else if(!strcmp(key, "fragile"))
 125     i->exit_on_error = atoi(value);
 126   /* unknown options are required to be ignored */
 127   return 1;
 128 }
 129
 130 /* open the device */
 131 int ao_plugin_open(ao_device *device, ao_sample_format *format) {
 132   struct internal *i = device->internal;
 133
 134   /* we would like native-order samples */
 135   device->driver_byte_format = AO_FMT_NATIVE;
 136   i->header.rate = format->rate;
 137   i->header.channels = format->channels;
 138   i->header.bits = format->bits;
 139   i->header.endian = ENDIAN_NATIVE;
 140   return 1;
 141 }
 142
 143 /* play some samples */
 144 int ao_plugin_play(ao_device *device, const char *output_samples,
 145                    uint_32 num_bytes) {
 146   struct internal *i = device->internal;
 147
 148   /* Fill in and write the header */
 149   i->header.nbytes = num_bytes;
 150   if(do_write(i->fd, &i->header, sizeof i->header) < 0) {
 151     if(i->exit_on_error) _exit(-1);
 152     return 0;
 153   }
 154
 155   /* Write the sample data */
 156   if(do_write(i->fd, output_samples, num_bytes) < 0) {
 157     if(i->exit_on_error) _exit(-1);
 158     return 0;
 159   }
 160   return 1;
 161 }
 162
 163 /* close the device */
 164 int ao_plugin_close(ao_device attribute((unused)) *device) {
 165   return 1;
 166 }
 167
 168 /* delete private data structures */
 169 void ao_plugin_device_clear(ao_device *device) {
 170   free(device->internal);
 171   device->internal = 0;
 172 }
 173
 174 /* report preferred filename extension */
 175 char *ao_plugin_file_extension(void) {
 176   return 0;
 177 }
 178
 179 /*
 180 Local Variables:
 181 c-basic-offset:2
 182 comment-column:40
 183 End:
 184 */