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

   1 /*
   2  * This file is part of DisOrder.
   3  * Copyright (C) 2005, 2007, 2010 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  * @attention This driver will not build with libao 1.0.0.  libao has
  25  * taken away half the plugin API and not provided any replacement.
  26  */
  27
  28 #include "common.h"
  29
  30 #include <errno.h>
  31 #include <unistd.h>
  32 #include <poll.h>
  33 #include <ao/ao.h>
  34 #include <ao/plugin.h>
  35
  36 #include "speaker-protocol.h"
  37
  38 /* extra declarations to help out lazy <ao/plugin.h> */
  39 int ao_plugin_test(void);
  40 ao_info *ao_plugin_driver_info(void);
  41 char *ao_plugin_file_extension(void);
  42
  43 /** @brief Private data structure for this driver */
  44 struct internal {
  45   int fd;                               /* output file descriptor */
  46   int exit_on_error;                    /* exit on write error */
  47
  48   /** @brief Record of sample format */
  49   struct stream_header header;
  50
  51 };
  52
  53 /* like write() but never returns EINTR/EAGAIN or short */
  54 static int do_write(int fd, const void *ptr, size_t n) {
  55   size_t written = 0;
  56   int ret;
  57   struct pollfd ufd;
  58
  59   memset(&ufd, 0, sizeof ufd);
  60   ufd.fd = fd;
  61   ufd.events = POLLOUT;
  62   while(written < n) {
  63     ret = write(fd, (const char *)ptr + written, n - written);
  64     if(ret < 0) {
  65       switch(errno) {
  66       case EINTR: break;
  67       case EAGAIN:
  68         /* Someone sneakily gave us a nonblocking file descriptor, wait until
  69          * we can write again */
  70         ret = poll(&ufd, 1, -1);
  71         if(ret < 0 && errno != EINTR) return -1;
  72         break;
  73       default:
  74         return -1;
  75       }
  76     } else
  77       written += ret;
  78   }
  79   return written;
  80 }
  81
  82 /* return 1 if this driver can be opened */
  83 int ao_plugin_test(void) {
  84   return 1;
  85 }
  86
  87 /* return info about this driver */
  88 ao_info *ao_plugin_driver_info(void) {
  89   static const char *options[] = { "fd" };
  90   static const ao_info info = {
  91     AO_TYPE_LIVE,                       /* type */
  92     (char *)"DisOrder format driver",   /* name */
  93     (char *)"disorder",                 /* short_name */
  94     (char *)"http://www.greenend.org.uk/rjk/disorder/", /* comment */
  95     (char *)"Richard Kettlewell",       /* author */
  96     AO_FMT_NATIVE,                      /* preferred_byte_format */
  97     0,                                  /* priority */
  98     (char **)options,                   /* options */
  99     1,                                  /* option_count */
 100   };
 101   return (ao_info *)&info;
 102 }
 103
 104 /* initialize the private data structure */
 105 int ao_plugin_device_init(ao_device *device) {
 106   struct internal *i = malloc(sizeof (struct internal));
 107   const char *e;
 108
 109   if(!i) return 0;
 110   memset(i, 0, sizeof *i);
 111   if((e = getenv("DISORDER_RAW_FD")))
 112     i->fd = atoi(e);
 113   else
 114     i->fd = 1;
 115   device->internal = i;
 116   return 1;
 117 }
 118
 119 /* set an option */
 120 int ao_plugin_set_option(ao_device *device,
 121                          const char *key,
 122                          const char *value) {
 123   struct internal *i = device->internal;
 124
 125   if(!strcmp(key, "fd"))
 126     i->fd = atoi(value);
 127   else if(!strcmp(key, "fragile"))
 128     i->exit_on_error = atoi(value);
 129   /* unknown options are required to be ignored */
 130   return 1;
 131 }
 132
 133 /* open the device */
 134 int ao_plugin_open(ao_device *device, ao_sample_format *format) {
 135   struct internal *i = device->internal;
 136
 137   /* we would like native-order samples */
 138   device->driver_byte_format = AO_FMT_NATIVE;
 139   i->header.rate = format->rate;
 140   i->header.channels = format->channels;
 141   i->header.bits = format->bits;
 142   i->header.endian = ENDIAN_NATIVE;
 143   return 1;
 144 }
 145
 146 /* play some samples */
 147 int ao_plugin_play(ao_device *device, const char *output_samples,
 148                    uint_32 num_bytes) {
 149   struct internal *i = device->internal;
 150
 151   /* Fill in and write the header */
 152   i->header.nbytes = num_bytes;
 153   if(do_write(i->fd, &i->header, sizeof i->header) < 0) {
 154     if(i->exit_on_error) _exit(-1);
 155     return 0;
 156   }
 157
 158   /* Write the sample data */
 159   if(do_write(i->fd, output_samples, num_bytes) < 0) {
 160     if(i->exit_on_error) _exit(-1);
 161     return 0;
 162   }
 163   return 1;
 164 }
 165
 166 /* close the device */
 167 int ao_plugin_close(ao_device attribute((unused)) *device) {
 168   return 1;
 169 }
 170
 171 /* delete private data structures */
 172 void ao_plugin_device_clear(ao_device *device) {
 173   free(device->internal);
 174   device->internal = 0;
 175 }
 176
 177 /* report preferred filename extension */
 178 char *ao_plugin_file_extension(void) {
 179   return 0;
 180 }
 181
 182 /*
 183 Local Variables:
 184 c-basic-offset:2
 185 comment-column:40
 186 End:
 187 */