Re: Detect CD Media Type?

[scdbackup@gmx.net]

> have some method to detect media type? I mean CD, like CD-R, CD-RW..?

Interesting topic.


> I try to use dvd+rw-mediainfo. but it just can detect dvd media, not
> include cd. am I right?
>  
> If I am wrong, can some body help me?..thanks very much

To my knowledge  dvd+rw-mediainfo  is unwilling to detect CD media types :
 "non-DVD media mounted, exiting"

For CD types, i grep the output of cdrecord option -atip.

If you use contemporary cdrecord-ProDVD (under the command name cdrecord),
then this shell code might do the trick for DVD and CD. 
cdrecord without DVD support will only detect types "CD-R" and "CD-RW".

  media_type="unknown-media"
  infotext=$(cdrecord dev=$scsi_adr -atip 2>&1)
  if echo "$infotext" | \
     grep 'book type:.*DVD+RW' >/dev/null 2>&1
  then
    media_type="DVD+RW" 
  elif echo "$infotext" | \
       grep 'book type:.*DVD-RW' >/dev/null 2>&1
  then
    media_type="DVD-RW"
  elif echo "$infotext" | \
       grep 'book type:.*DVD+R' >/dev/null 2>&1
  then
    media_type="DVD+R"
  elif echo "$infotext" | \
       grep 'book type:.*DVD-R' >/dev/null 2>&1
  then
    media_type="DVD-R"
  elif echo "$infotext" | \
       grep '^  Is erasable' >/dev/null 2>&1
  then
    media_type="CD-RW"
  elif echo "$infotext" | \
       grep '^  Is not erasable' >/dev/null 2>&1
  then
    media_type="CD-R"
  fi
  echo "Detected media type     : $media_type"


I myself use alternatively growisofs , cdrecord or cdrecord-ProDVD .

growisofs is accessed via a wrapper which reacts on cdrecord option -atip
and produces a sparse emulation of cdrecord's -atip output :

  infotext=$(dvd+rw-mediainfo "$growisofs_target" 2>&1)
  if echo "$infotext" |
     grep 'Mounted Media:.*DVD+RW' >/dev/null 2>&1
  then
    media_type="DVD+RW"
  elif echo "$infotext" |
       grep 'Mounted Media:.*DVD+R' >/dev/null 2>&1
  then
    media_type="DVD+R"
  elif echo "$infotext" |
       grep 'Mounted Media:.*DVD-RW' >/dev/null 2>&1
  then
    media_type="DVD-RW"
    if echo "$infotext" |
       grep 'Mounted Media:.*Restricted Overwrite' >/dev/null 2>&1
    then
      media_type="$media_type (growisofs mode Restricted Overwrite)"
    fi
  elif echo "$infotext" |
       grep 'Mounted Media:.*DVD-R' >/dev/null 2>&1
  then
    media_type="DVD-R"
  elif echo "$infotext" |
       grep 'non-DVD media mounted, exiting' >/dev/null 2>&1
  then
    media_type="growisofs:non-DVD"
  fi
  echo "book type: $media_type  (-atip reply emulated by growisofs_wrapper)"  


The following code interprets the output of any of the programs.

Variable  cdrecord_prog  points either to  growisofs_wrapper  or to
one of the cdrecord programs. 

  help_reply=$($cdrecord_prog -help 2>&1)
  cdrecord_is_prodvd=0
  if echo " $help_reply" | \
     grep 'Usage:.*cdrecord-ProDVD.*trackn' >/dev/null 2>&1
  then
    cdrecord_is_prodvd=1
  fi

  media_type="scdbackup:unknown-media"
  infotext=$($cdrecord_prog dev=$scsi_adr -atip 2>&1)

  if echo "$infotext" | \
     grep 'book type:.*DVD+RW' >/dev/null 2>&1
  then
    media_type="DVD+RW" 
  elif echo "$infotext" | \
       grep 'book type:.*DVD-RW' >/dev/null 2>&1
  then
    media_type="DVD-RW"
    if echo "$infotext" |
       grep '(growisofs mode Restricted Overwrite)' >/dev/null 2>&1
    then
#       echo 'Note: DVD-RW in mode "Restricted Overwrite" needs no blanking'
      if test "$blanken" = "all" -o "$blanken" = "full" \
           -o "$blanken" = "sequential"
      then
        dummy=dummy
      else
        growisofs_rov_keep=1
      fi
    fi
  elif echo "$infotext" | \
       grep 'book type:.*DVD+R' >/dev/null 2>&1
  then
    media_type="DVD+R"
  elif echo "$infotext" | \
       grep 'book type:.*DVD-R' >/dev/null 2>&1
  then
    media_type="DVD-R"
  elif echo "$infotext" | \
       grep '^  Is erasable' >/dev/null 2>&1
  then
    media_type="CD-RW"
  elif echo "$infotext" | \
       grep '^  Is not erasable' >/dev/null 2>&1
  then
    media_type="CD-R"
  elif echo "$infotext" | \
       grep 'growisofs:non-DVD' >/dev/null 2>&1
  then
    media_type="growisofs:non-DVD"
  elif test "$cdrecord_is_prodvd" = "0"
  then
    media_type="$media_type (not cdrecord-ProDVD ?)"
  fi

  echo "Detected media type     : $media_type"


Well, that is far from elegant but allows me to use quite arbitrary
writer programs and at least detect those media types which are suitable
for the particular program.

I do not know any documents which explain or standardize the output formats of
cdrecord -atip , cdrecord-ProDVD -atip ot dvd+rw-mediainfo. Therefore
the next revision of either program might render this code invalid. 
I count on Joerg and Andy not fiddling with these output formats
without a good reason.

Trustworthy documentation about the output of  cdrecord -atip  respectively
 dvd+rw-mediainfo  would be highly appreciated, of course. (Yes, i already
did read man cdrecord.)


Have a nice day :)

Thomas