How Python modifies the MP3 file

The example in this article describes how Python modifies the MP3 file. Share to everyone for your reference. Specific as follows:

With this program modified MP3 than the original is smaller, because a picture was deleted, played to MP3 "thin body" role. In some MP3, each has a picture of more than 400 K, 10 a few MP3, quite a common MP3 file size.

#-*-coding:cp936-*-"" "Removes the id3v2.3 portion of the MP3 file for playback on the MP3 machine usage: mp3lcear [source mp3 directory] [generated MP3 directory]" "Import sysimport Osimport Stringimport shutilimport structimport threadimport threadingimport timemp3suffix = ' mp3 ' Class Process (threading. Thread): "" Simply displays the progress "" "Def __init__ (self,msg,sleeptime): threading in the process of running. Thread.__init__ (self) self.msg = msgself.running = Trueself.sleeptime = Sleeptimedef setpause (self,pause): Self.pause = Pausedef setrunning (self,running): self.running = Runningdef run (self): while (self.running): self.pause.wait () print Self.msg,time.sleep (self.sleeptime) def usage (code, msg= "):" "" Program Usage "" "Print >> Sys.stderr, __doc__if msg: Print >> Sys.stderr, Msgsys.exit (code) def checkdir (argdir,create=false): "" "Check whether the directory exists, if Create is ture, create a new directory" " TempDir = Noneif (not Os.path.isdir (Argdir)): Currentdir = Os.path.abspath (os.curdir) tempdir = Os.path.join (Currentdir, Argdir) if (not Os.path.isdir (tempdir) and create): Os.mkdir (TempDir) else:usage (1, "directory" +argdir+ "not Present") Else:tempdir = os.path.abspAth (argdir) return tempdirdef clearMp3 (srcfile,destfile): "" "Modify the MP3 file and create it to destfile the address specified by" "" Global PROCESSSRCFP = Nonefilesize = Os.path.getsize (srcfile) TRY:SRCFP = open (Srcfile, ' rb ') head = Srcfp.read (3) if (head== ' ID3 '): Srcfp.seek ( 3,1) size = Srcfp.read (4) if (not Len (size) ==4):p rint srcfile+ ' file format error ' ELSE:SIZE0 = struct.unpack (' B ', size[0]) [0]SIZE1 = Struct.unpack (' B ', size[1]) [0]size2 = Struct.unpack (' B ', size[2]) [0]SIZE3 = Struct.unpack (' B ', size[3]) [0]headsize = (( (size0&0x7f) <<21) | ((size1&0x7f) <<14) | ((size2&0x7f) <<7) | (size3&0x7f)) FileSize = FILESIZE-HEADSIZEDESTFP = Nonetry:datalen = 0DESTFP = Open (DestFile, ' WB ') Srcfp.seek (headsize,1) data= Srcfp.read (1024x768) while (data!= "):d estfp.write (data) Data=srcfp.read (1024x768) Except Exception,e:print ' Create file ' +destfile+ ' Error ', etry:if (destfp! = None):d estfp.closeexcept exception,de:print deelse:print srcfile+ ' No need to modify copy ', try: Shutil.copyfile (srcfile,destfile) except Exception, Ce:print ceexcept exception,oe:print ' Error in modification ', oetry: if (SRCFP! = None): Srcfp.close () except exception,se:print deif __name__ = = "__main__": if (len (SYS.ARGV) <3): Usage (1) Global Processsourcedir = Checkdir (sys.argv[1]) DestDir = Checkdir (sys.argv[2],true) print ' Mp3 source directory ', Sourcedirprint ' Mp3 destination directory ', destdirprocess = Process (' ... ', 1) pause = Threading. Event () process.setpause (pause) Process.Start () for filename in Os.listdir (sourcedir): Srcpath = Os.path.join (sourcedir , filename) DestPath = os.path.join (destDir, filename) if Os.path.isfile (srcpath):p rint ' start processing ' +filename,tempfilename = Filename.lower () if (not Tempfilename.endswith (mp3suffix)):p rint filename+ ' is not a mp3 file \ n ' else:pause.set () clearMp3 ( Srcpath,destpath) pause.clear () print ' End \ n ' pause.set () process.running = falsesys.exit (0)

Hopefully this article will help you with Python programming.

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