flac.icl

   1 implementation module flac
   2
   3 import StdEnv
   4
   5 import Data.Error
   6 import Data.Func
   7 import Control.Monad => qualified join
   8 import System.FilePath
   9 import System._Pointer
  10 import System._Posix
  11 import Text
  12
  13 import StdDebug
  14
  15 NUM_COMMENT_OFFSET :== 32
  16 COMMENTS_OFFSET :== 40
  17 COMMENT_SIZE :== 16
  18
  19 getTags :: FilePath !*World -> *(MaybeErrorString [(String, String)], !*World)
  20 getTags fp w
  21         #! (mdp, w) = mallocSt 8 w
  22         #! (ok, w) = FLAC__metadata_get_tags (packString fp) mdp w
  23         | not ok
  24                 #! w = freeSt mdp w
  25                 = (Error "Error getting tags", w)
  26         #! md = derefInt mdp
  27         #! num_comments = readInt md NUM_COMMENT_OFFSET
  28         #! comments = readInt md COMMENTS_OFFSET
  29         #! comments = mapM (makeComment o derefString)
  30                 [readInt comments (COMMENT_SIZE*i+8)\\i<-[0..num_comments-1]]
  31         #! w = FLAC__metadata_object_delete md w
  32         #! w = freeSt mdp w
  33         = (comments, w)
  34 where
  35         makeComment :: !String -> MaybeErrorString (String, String)
  36         makeComment s = case indexOf "=" s of
  37                 -1 = Error "No = in the tag"
  38                 i = Ok (s % (0, i-1), s % (i+1, size s))
  39
  40 FLAC__metadata_get_tags :: !String !Pointer !*env -> (!Bool, !*env)
  41 FLAC__metadata_get_tags _ _ _ = code {
  42         ccall FLAC__metadata_get_tags "sp:I:A"
  43 }
  44
  45 FLAC__metadata_object_delete :: !Pointer !*env -> *env
  46 FLAC__metadata_object_delete _ _ = code {
  47         ccall FLAC__metadata_object_delete "p:V:A"
  48 }
  49
  50 Start w = getTags
  51         "/mnt/data/music/Ahab/The Divinity of Oceans/01 Yet Another Raft of the Medusa (Pollard's Weakness).flac"
  52         w