snatch/oss.c

   1 /* All the code for dealing with OSS */
   2
   3 #include <linux/soundcard.h>
   4
   5 static char *ossname;
   6 static int oss_fd=-1;
   7 static int oss_fd_fakeopen=0;
   8
   9 static int oss_fmt_translate(int format){
  10   int i;
  11   for(i=0;i<10;i++)
  12     if(format==((1<<i)>>1))return(i);
  13   return(0);
  14 }
  15
  16 static void oss_hook_init(void){
  17
  18   /* oss device? */
  19   ossname=nstrdup(getenv("SNATCH_OSS_DEVICE"));
  20   if(!ossname){
  21     if(debug)
  22       fprintf(stderr,
  23               "----env: SNATCH_OSS_DEVICE\n"
  24               "           not set. Using default (/dev/dsp*).\n");
  25     ossname=nstrdup("/dev/dsp*");
  26   }else{
  27     if(debug)
  28       fprintf(stderr,
  29               "----env: SNATCH_OSS_DEVICE\n"
  30               "           set (%s)\n",ossname);
  31   }
  32 }
  33
  34 /* The OSS audio device is subverted through open().  If we didn't
  35    care about allowing a fake audio open() to 'succeed' even when the
  36    real device is busy, then we could just watch for the ioctl(), grab
  37    the fd() then, and not need to bother with any silly string
  38    matching.  However, we *do* care, so we do this the more complex,
  39    slightly more error prone way. */
  40
  41 static int oss_identify(const char *pathname){
  42   if( (ossname[strlen(ossname)-1]=='*' &&
  43        !strncmp(pathname,ossname,strlen(ossname)-1)) ||
  44       (ossname[strlen(ossname)-1]!='*' &&
  45        !strcmp(pathname,ossname)))return(1);
  46   return(0);
  47 }
  48
  49 static int oss_open_hook(const char *pathname){
  50   int ret;
  51   if(oss_fd>-1){
  52     /* umm... an oss fd is already open.  report the problem and
  53        continue */
  54     fprintf(stderr,
  55             "\n"
  56             "WARNING: RealPlayer is attempting to open more than one\n"
  57             "         OSS audio device (in this case, %s).\n"
  58             "         This behavior is unexpected; ignoring this open()\n"
  59             "         request.\n",pathname);
  60     return(-1);
  61   }else{
  62
  63     /* are we faking the audio? */
  64     if(fake_audiop){
  65       ret=(*libc_open)("/dev/null",O_RDWR,0);
  66       oss_fd_fakeopen=1;
  67     }else{
  68       ret=(*libc_open)(pathname,O_RDWR,0);
  69       oss_fd_fakeopen=0;
  70     }
  71
  72     oss_fd=ret;
  73     audio_fd=ret;
  74     audio_channels=-1;
  75     audio_rate=-1;
  76     audio_format=-1;
  77     audio_samplepos=0;
  78     audio_timezero=bigtime(NULL,NULL);
  79
  80     if(debug)
  81       fprintf(stderr,
  82               "    ...: Caught RealPlayer opening OSS audio device "
  83               "%s (fd %d).\n",
  84               pathname,ret);
  85     if(debug && fake_audiop)
  86       fprintf(stderr,
  87               "    ...: Faking the audio open and writes as requested.\n");
  88   }
  89   return(ret);
  90 }
  91
  92 static void oss_close_hook(int fd){
  93   if(fd==oss_fd)oss_fd=-1;
  94 }
  95
  96 /* watch OSS audio ioctl()s to track playback rate/channels/depth */
  97
  98 static int oss_ioctl_hook_p(int fd){
  99   if(fd==oss_fd)return(1);
 100   return(0);
 101 }
 102
 103 static int oss_ioctl_hook(int fd,int rq,void *arg){
 104   int ret=0;
 105   if(!fake_audiop && !oss_fd_fakeopen)
 106     ret=(*libc_ioctl)(fd,rq,arg);
 107
 108   switch(rq){
 109   case SNDCTL_DSP_RESET:
 110     audio_timezero=0;
 111     audio_samplepos=0;
 112     break;
 113   case SNDCTL_DSP_SPEED:
 114     audio_rate=*(int *)arg;
 115     if(debug)
 116       fprintf(stderr,
 117               "    ...: Audio output sampling rate set to %dHz.\n",
 118               audio_rate);
 119     CloseOutputFile(0);
 120     break;
 121   case SNDCTL_DSP_CHANNELS:
 122     audio_channels=*(int *)arg;
 123     if(debug)
 124       fprintf(stderr,
 125               "    ...: Audio output set to %d channels.\n",
 126               audio_channels);
 127     CloseOutputFile(0);
 128     break;
 129   case SNDCTL_DSP_SETFMT:
 130     audio_format=oss_fmt_translate(*(int *)arg);
 131     if(debug)
 132       fprintf(stderr,
 133               "    ...: Audio output format set to %s.\n",
 134               audio_fmts[audio_format]);
 135     CloseOutputFile(0);
 136     break;
 137   case SNDCTL_DSP_GETOSPACE:
 138     if(fake_audiop){
 139       audio_buf_info *temp=arg;
 140       temp->fragments=32;
 141       temp->fragstotal=32;
 142       temp->fragsize=2048;
 143       temp->bytes=64*1024;
 144
 145       if(debug)
 146         fprintf(stderr,"    ...: OSS output buffer size requested; faking 64k\n");
 147       ret=0;
 148     }
 149     break;
 150   case SNDCTL_DSP_GETODELAY: /* Must reject the ODELAY if we're not going to
 151                                 properly simulate it! */
 152     if(fake_audiop){
 153       if(debug)
 154         fprintf(stderr,
 155                 "    ...: Rejecting SNDCTL_DSP_GETODELAY ioctl()\n");
 156       *(int *)arg=0;
 157       ret=-1;
 158     }
 159     break;
 160   }
 161
 162   return(ret);
 163 }