CDLow.py

   1 """
   2         CDLow - Low level CDROM interface
   3         Written to replace CDAudio, CDDB and PyGAME.CD and
   4                 add functionality (skipping)
   5         Originally from the Gryphon CD player (http://gryphon.sourceforge.net/)
   6
   7         Copyright 2001 (c) Christian Storgaard.
   8         Changes made by Ron Kuslak <rds@rdsarts.com>, 2003-2004
   9
  10         This program is free software; you can redistribute it and/or modify
  11         it under the terms of the GNU General Public License as published by
  12         the Free Software Foundation; either version 2 of the License, or
  13         (at your option) any later version.
  14
  15         This program is distributed in the hope that it will be useful
  16         but WITHOUT ANY WARRANTY; without even the implied warranty of
  17         MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18         GNU General Public License for more details.
  19
  20         You should have received a copy of the GNU General Public License
  21         along with this program; if not, write to the Free Software
  22         Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  23 """
  24
  25 from fcntl import ioctl
  26 from CDROM import *
  27 import os, struct
  28
  29 debug = 0
  30
  31 trayopen  = 0
  32
  33 NOSTATUS  = 0
  34 PAUSED    = 1
  35 STOPPED   = 2
  36 NODISC    = 3
  37 PLAYING   = 4
  38 ERROR     = 5
  39
  40 tochdr_fmt   = "BB"
  41 tocentry_fmt = "BBBix"
  42 addr_fmt     = "BBB"+"x"*(struct.calcsize('i')-3)
  43 region_fmt   = "BBBBBB"
  44 subchnl_fmt  = "BBxBBiBBB"
  45
  46 class cd:
  47         path = "/dev/cdrom"
  48         start = end = None
  49         open = cd = 0
  50         last = (0,0,0)
  51         skip = 3        # In seconds
  52         data = 0        # Display Data-tracks
  53
  54 """ ####        Internal functions      ####
  55     ####            -- start --         ####"""
  56 def cd_open():
  57         if cd.cd > 0:
  58                 cd.open = 1
  59                 return 0
  60         else:
  61                 try:
  62                         cd.cd = os.open(cd.path, os.O_RDONLY|os.O_NONBLOCK)
  63                         trayopen = 0
  64                         return 0
  65                 except:
  66                         cd.status = NODISC
  67                         trayopen = 1
  68                         return 1
  69
  70 def cd_close():
  71         if cd.cd < 1:
  72                 cd.open = 0
  73                 return 0
  74         os.close(cd.cd)
  75         cd.cd   = 0
  76         cd.open = 0
  77         return 0
  78
  79 """exit function"""
  80 import atexit
  81 atexit.register(cd_close)
  82
  83 """ ####        Internal functions      ####
  84     ####             -- end --          ####"""
  85
  86 def stop():
  87 #       cd_open()
  88         """ We don't care if there's a CD in or not, we're just stopping ;)"""
  89         if get_status() == PAUSED:
  90                 try:
  91                         ioctl(cd.cd, CDROMRESUME)
  92                 except:
  93                         pass
  94 #       cd_open()
  95         try:
  96                 ioctl(cd.cd, CDROMSTOP)
  97         except:
  98                 pass
  99 #       cd_close()
 100
 101 def pause():
 102         status = get_status()
 103 #       cd_open()
 104         if status == PLAYING:
 105                 ioctl(cd.cd, CDROMPAUSE)
 106         elif status == PAUSED:
 107                 ioctl(cd.cd, CDROMRESUME)
 108 #       cd_close()
 109
 110 def forward(val=None):
 111         if val!=None: skip(0,val,1)
 112         else: skip(0)
 113
 114 def rewind(val=None):
 115         if val!=None: skip(1,val,1)
 116         skip(1)
 117
 118 def goto(min, sec, frm=0):
 119         """See if we have the last track to play in cache, else set to last on disc"""
 120         if cd.last == (0,0,0):
 121                 if cd.end == None: get_header()
 122                 cd.last = get_track_time(cd.end)
 123         try: play_msf(min, sec, frm, cd.last[0], cd.last[1], cd.last[2])
 124         except: pass
 125
 126 def skip(direction, amount=None, frames=0):
 127         if amount == None: amount = cd.skip
 128         if not frames: amount = amount*CD_FRAMES
 129         curmin, cursec, curfrm = get_current_timing()['abs']
 130         start = msf2frm(curmin,cursec,curfrm)
 131         """Apply according to which direction we are skipping"""
 132         if direction == 1:start=start-amount
 133         else:start=start+amount
 134         startmin,startsec,startfrm=frm2msf(start)
 135         """See if we have the last track to play in cache, else set to last on disc"""
 136         if cd.last == (0,0,0):
 137                 if cd.end == None: get_header()
 138                 cd.last = get_track_time(cd.end)
 139         try: play_msf(startmin, startsec, startfrm, cd.last[0], cd.last[1], cd.last[2])
 140         except: pass
 141
 142 def play(first,last=None):
 143         if last == None:last=first
 144         i=get_track_time(first)
 145         cd.last = get_track_time(last+1)
 146         play_msf(i[0],i[1],i[2],cd.last[0],cd.last[1],cd.last[2])
 147
 148 def play_msf(startmin, startsec, startfrm, endmin, endsec, endfrm):
 149 #       cd_open()
 150         cd.last=(endmin,endsec,endfrm)
 151         region = struct.pack(region_fmt,startmin,startsec,startfrm,endmin,endsec,endfrm)
 152         ioctl(cd.cd, CDROMPLAYMSF, region)
 153 #       cd_close()
 154
 155 def eject():
 156         cd_open()
 157         try:
 158                 ioctl(cd.cd, CDROMSTOP)
 159                 # Always unlock door before eject, in case something else locked it
 160                 ioctl(cd.cd, CDROM_LOCKDOOR, 0)
 161         except:
 162                 # ioctl(cd.cd, CDROMRESET)
 163                 ioctl(cd.cd, CDROMSTOP)
 164                 # Always unlock door before eject, in case something else locked it
 165                 ioctl(cd.cd, CDROM_LOCKDOOR, 0)
 166         try:
 167                 ioctl(cd.cd, CDROMEJECT_SW, 0)
 168                 ioctl(cd.cd, CDROMEJECT)
 169         except:
 170                 ioctl(cd.cd, CDROMEJECT_SW, 0)
 171                 ioctl(cd.cd, CDROMEJECT)
 172 #       cd_close()
 173
 174 def close():
 175 #       cd_open()
 176         try:
 177                 ioctl(cd.cd, CDROMCLOSETRAY)
 178         except:
 179                 pass
 180 #       cd_close()
 181
 182 def do_eject():
 183         if debug: print "Activated:\tCDLow.do_eject"
 184         cd_close()
 185         cd_open()
 186         global trayopen
 187         if debug: print "\tStatus:",trayopen
 188         ioctl(cd.cd, CDROMEJECT_SW, 0)
 189         if not trayopen:
 190                 try:
 191                         stop()
 192                         if debug: print "\tStopped"
 193                 except:
 194                         pass
 195                 eject()
 196                 if debug: print "\tEjected Tray"
 197                 cd.cd = 0
 198                 cd.status = NODISC
 199                 trayopen = 1
 200         else:
 201                 close()
 202                 if debug: print "\tClosed Tray"
 203                 trayopen = 0
 204                 cd_close()
 205                 if debug: print "\tClosed CD"
 206                 cd_open()
 207                 if debug: print "\tOpened CD"
 208         return trayopen
 209
 210 def get_volume():
 211 #       cd_open()
 212         try:
 213                 return struct.unpack("BBBB",ioctl(cd.cd, CDROMVOLREAD, struct.pack("BBBB",0,0,0,0)))
 214
 215         except:
 216                 return (0,0,0,0)
 217 #       cd_close()
 218
 219 def set_volume(frontleft,frontright=None,backleft=0,backright=0):
 220 #       cd_open()
 221         if frontright == None: frontright = frontleft
 222         try:
 223                 return struct.unpack("BBBB",ioctl(cd.cd, CDROMVOLCTRL, struct.pack("BBBB",frontleft,frontright,backleft,backright)))
 224
 225         except:
 226                 return 1
 227 #       cd_close()
 228
 229 def get_status(time=0, all=0):
 230 #       cd_open()
 231         result = 0
 232         i = 1
 233         while result == 0 and i < 5:
 234                 try:    # If this fails then it's because it's happening too fast, just retry
 235                         info = ioctl(cd.cd, CDROMSUBCHNL, struct.pack(subchnl_fmt, CDROM_MSF,0,0,0,0,0,0,0))
 236                         drvstatus = get_drive_status()
 237                         result = 1
 238                 except:
 239                         i = i +1
 240 #       cd_close()
 241         format, status, track, something, absaddr, relmin, relsec, relfrm = struct.unpack(subchnl_fmt, info)
 242         absmin, abssec, absfrm = struct.unpack(addr_fmt, struct.pack("i", absaddr))
 243         zero = (1, 0,0,0, 0,0,0)
 244         if   status == CDROM_AUDIO_PLAY      : cd.status = PLAYING
 245         elif status == CDROM_AUDIO_PAUSED    : cd.status = PAUSED
 246         elif status == CDROM_AUDIO_COMPLETED :
 247                 cd.status = STOPPED
 248                 track,relmin,relsec,relfrm,absmin,abssec,absfrm = zero
 249         elif status == CDROM_AUDIO_ERROR     :
 250                 cd.status = ERROR
 251                 track,relmin,relsec,relfrm,absmin,abssec,absfrm = zero
 252         elif status == CDROM_AUDIO_INVALID   :
 253                 cd.status = ERROR
 254                 track,relmin,relsec,relfrm,absmin,abssec,absfrm = zero
 255         elif status == CDROM_AUDIO_NO_STATUS :
 256                 cd.status = NOSTATUS
 257                 track,relmin,relsec,relfrm,absmin,abssec,absfrm = zero
 258         if   drvstatus == CDS_NO_DISC :
 259                 cd.status = NODISC
 260                 track,relmin,relsec,relfrm,absmin,abssec,absfrm = zero
 261         if all: return {'status': drvstatus, 'format': format, 'status': status, 'track': track, 'something': something, 'absaddr': absaddr, 'relmin': relmin, 'relsec': relsec, 'relfrm': relfrm}
 262         elif time: return {'cur_t': track,'rel':(relmin,relsec,relfrm),'abs':(absmin,abssec,absfrm)}
 263         else: return cd.status
 264
 265 def get_disc_type():
 266 #       cd_open()
 267         ret = ioctl(cd.cd, CDROM_DRIVE_STATUS)
 268 #       cd_close()
 269         return ret
 270
 271 def get_drive_status():
 272 #       cd_open()
 273         ret = 999
 274         ret = ioctl(cd.cd, CDROM_DRIVE_STATUS)
 275 #       cd_close()
 276         return ret
 277
 278 def get_header():
 279 #       cd_open()
 280         tochdr = struct.pack(tochdr_fmt, 0, 0)
 281         tochdr = ioctl(cd.cd, CDROMREADTOCHDR, tochdr)
 282         cd.start, cd.end = struct.unpack(tochdr_fmt, tochdr)
 283 #       cd_close()
 284
 285 def get_track_time(trk):
 286         if cd.start == None:
 287                 get_header()
 288         if   trk < 1: trk = 1
 289         elif trk > cd.end: trk = CDROM_LEADOUT
 290 #       cd_open()
 291         toc = struct.pack(tocentry_fmt, trk, 0, CDROM_MSF, 0)
 292         toc = ioctl(cd.cd, CDROMREADTOCENTRY, toc)
 293
 294         track, adrctrl, format, addr = struct.unpack(tocentry_fmt, toc)
 295         m, s, f = struct.unpack(addr_fmt, struct.pack("i", addr))
 296
 297         adr = adrctrl & 0xf
 298         ctrl = (adrctrl & 0xf0) >> 4
 299
 300         start = (m * CD_SECS + s) * CD_FRAMES + f       # 60 and 75
 301         data = 0
 302         if ctrl & CDROM_DATA_TRACK:
 303                 data = 1
 304 #       cd_close()
 305         return m,s,f,start,data
 306
 307 def get_track_length(first,last=None):
 308         if last==None: last=first+1
 309         off1min, off1sec, off1frm, off1, data1 = get_track_time(first)
 310         off2min, off2sec, off2frm, off2, data2 = get_track_time(last)
 311
 312         lenmin,lensec,lenfrm=frm2msf(off2-off1)
 313
 314         return off1min,off1sec,off1frm,lenmin,lensec,lenfrm,off1,data1
 315
 316 def get_tracks_id():
 317         get_header()
 318         offset = []
 319         data = []
 320         length = []
 321         tracklist = range(cd.start,cd.end+1)
 322         tracklist.append(CDROM_LEADOUT)
 323         for i in tracklist:
 324                 m,s,f,lenm,lens,lenf,start,tdata = get_track_length(i)
 325                 offset.append((m, s, f))
 326                 data.append(tdata)
 327                 if i <= cd.end:         # We don't want length of CDROM_LEADOUT ;)
 328                         length.append((lenm, lens, lenf))#0))   # 0 is CDAudio's way
 329         tracks = {'start_t':cd.start, 'end_t':cd.end, 'offset': offset, 'length': length, 'id': disc_id(offset, cd.start, cd.end), 'data': data}
 330         tracks['cddb'] = get_cddb_id(tracks['id'][2:-1], tracks['id'][-1])
 331         return tracks
 332
 333 def get_current_timing():       # Wrapper for get_status(1)
 334         return get_status(1)
 335
 336 def disc_id(offset, first, last):
 337         track_frames = []
 338         checksum = long(0)
 339         for i in range(first-1, last):
 340                 (min, sec, frame) = offset[i]
 341                 checksum = checksum + id_sum(min*CD_SECS + sec)
 342                 track_frames.append(min*CD_SECS*CD_FRAMES + sec*CD_FRAMES + frame)
 343         (min, sec, frame) = offset[last]
 344         track_frames.append(min*CD_SECS*CD_FRAMES + sec*CD_FRAMES + frame)
 345
 346         total_time = (track_frames[-1] / CD_FRAMES) - (track_frames[0] / CD_FRAMES)
 347
 348         discid = (int((checksum % 0xff) << 24) | total_time << 8 | last)
 349
 350         return [discid,last]+track_frames[:-1]+[track_frames[-1]/CD_FRAMES]
 351
 352 def id_sum(s):
 353         sum = 0
 354         while s > 0:
 355                 sum = sum + (s % 10)
 356                 s = s / 10
 357         return sum
 358
 359 def frm2msf(frm):
 360         min = (frm / CD_FRAMES) / CD_SECS
 361         sec = (frm / CD_FRAMES) - (min * CD_SECS)
 362         frm = frm - ((min * CD_SECS) * CD_FRAMES + sec * CD_FRAMES)
 363         return min,sec,frm
 364
 365 def msf2frm(min,sec,frm):
 366         return min*CD_SECS*CD_FRAMES+sec*CD_FRAMES+frm
 367
 368 def get_cddb_id(tracks, disclen):
 369         checksum = long(0)
 370         for i in tracks:
 371                 sum = 0
 372                 mfs = (i / CD_FRAMES)
 373                 while mfs > 0:
 374                         sum = sum + (mfs % 10)
 375                         mfs = mfs / 10
 376                 checksum = checksum + sum
 377         tot_time = disclen - tracks[0] / CD_FRAMES
 378         return "%08x" % ((checksum % 0xff) << 24 | tot_time << 8 | len(tracks))
 379
 380
 381 """ ####        Startup code    ####
 382     ####                        ####"""
 383
 384 cd_open()