script for get container infos of mp4 video file

mp4Info.py

#!/usr/bin/python
#
# m4aInfo.py - script for get container info of mp4 video file
#
# originally written by gioshe
# part of eighttrak, http://code.google.com/p/eighttrak/
#
# This work is released under the GNU GPL, version 2 or later.
#
import struct

_mapping = {
    '\xa9day':'Year',
    '\xa9gen':'Genre Name',
    '\xa9nam':'Title',
    '\xa9ART':'Artist',
    '\xa9alb':'Album',
    '\xa9wrt':'Composer',
    '\xa9too':'Encoder',
    '\xa9cmt':'Comment',
    '\xa9grp':'Grouping',
    'trkn':'Track Number',
    'disk':'Disc Number',
    'gnre':'Genre',
    'cpil':'Compilation',
    'covr':'Cover Art',
    'tmpo':'Tempo',
    'apid':'Apple ID',
    'cprt':'Copyright',
    'rtng':'Rating'
    }

class MP4Info:
    def __init__(self,fd, includeArt = False):
        self.fd = fd
        self.movieInfo = {'MPEG Version':4,'Layer':1}
        self.includeArt = includeArt
        self.macEpochOffset = 2082844800L
        self.scan()
        try:
            self.movieInfo['Bit Rate'] = int(0.5+self.movieInfo['Size']/self.movieInfo['Duration']*8)
        except: pass
    
    def atom(self):
        sizeTag = self.fd.read(8)
        (size,tag) = struct.unpack('!I4s',sizeTag)
        #print size,tag
        nextatom = self.fd.tell()+size-8
        return (tag,nextatom)
    
    def scan(self):
        try:
            while True:
                (tag,ends) = self.atom()
                #print "file",tag
                if tag=='moov': self.scanMoov(ends)
                if tag=='mdat': self.scanMdat(ends)
                self.fd.seek(ends)
        except: pass

    def scanMoov(self,moovEnds):
        while True:
            (tag,ends) = self.atom()
            #print "moov",tag
            if tag=='mvhd': self.scanMvhd(ends)
            if tag=='udta': self.scanUdta(ends)
            if tag=='trak': self.scanTrak(ends)
            self.fd.seek(ends)
            if ends>=moovEnds: break

    def scanMdat(self,mdatEnds):
        if not self.movieInfo.has_key('Size'):
            self.movieInfo['Size'] = 0
        self.movieInfo['Size'] = self.movieInfo['Size']+mdatEnds-self.fd.tell()

    def scanMvhd(self,mvhdEnds):
        size = mvhdEnds-self.fd.tell()
        mvhd = self.fd.read(24)
        (version,flags,creationTime,modTime,timeScale,duration,rate) = struct.unpack("!c3s5I",mvhd)
        self.movieInfo['Version'] = ord(version)
        self.movieInfo['Flags'] = (ord(flags[0])<<16)+(ord(flags[1])<<8)+ord(flags[2])
        self.movieInfo['Creation Time'] = creationTime - self.macEpochOffset
        self.movieInfo['Modification Time'] = modTime- self.macEpochOffset
        self.movieInfo['Time Scale'] = timeScale
        self.movieInfo['Duration'] = duration/(1.0*timeScale)
        self.movieInfo['Rate'] = rate/65536.0
    
    def scanUdta(self,udtaEnds):
        while True:
            (tag,ends) = self.atom()
            #print "udta",tag
            if tag=='meta': self.scanMeta(ends)
            self.fd.seek(ends)
            if ends>=udtaEnds: break

    def scanMeta(self,metaEnds):
        self.fd.seek(self.fd.tell()+4)
        while True:
            (tag,ends) = self.atom()
            #print "meta",tag
            if tag=='ilst': self.scanIlst(ends)
            self.fd.seek(ends)
            if ends>=metaEnds: break

    def scanIlst(self,ilstEnds):
        while True:
            (tag,ends) = self.atom()
            (payloadTag,payloadEnds) = self.atom()
            #print "ilst",tag,payloadTag
            if payloadTag=='data': self.scanData(tag,ends)
            self.fd.seek(ends)
            if ends>=ilstEnds: break

    def scanData(self,tag,dataEnds):
        size = dataEnds-self.fd.tell()
        long1 = struct.unpack("!I",self.fd.read(4))
        long2 = struct.unpack("!I",self.fd.read(4))
        #print tag,long1,long2
        s = self.fd.read(size-8)
        try:
            if tag=='trkn': s = struct.unpack("!IHxx",s)
        except: pass
        try:
            if tag=='disk': s = struct.unpack("!IH",s)
        except: pass
        try:
            if tag=='cpil': s = (ord(s)!=0)
        except: pass
        try:
            if tag=='tmpo': s = struct.unpack("!H",s)[0]
        except: pass
        try:
            if tag=='gnre': s = struct.unpack("!H",s)[0]
        except: pass
        try:
            if tag=='rtng': s = ord(s[0])
        except: pass
        try:
            if tag=='\xa9day': s = int(s[:4])
        except: pass
        if tag!='covr' or self.includeArt:
            self.movieInfo[_mapping.get(tag,tag)] = s
        
    def scanTrak(self,trakEnds):
        while True:
            (tag,ends) = self.atom()
            #print "trak",tag
            if tag=='mdia': self.scanMdia(ends)
            self.fd.seek(ends)
            if ends>=trakEnds: break

    def scanMdia(self,mdiaEnds):
        while True:
            (tag,ends) = self.atom()
            #print "mdia",tag
            if tag=='minf': self.scanMinf(ends)
            self.fd.seek(ends)
            if ends>=mdiaEnds: break

    def scanMinf(self,minfEnds):
        while True:
            (tag,ends) = self.atom()
            #print "minf",tag
            if tag=='stbl': self.scanStbl(ends)
            self.fd.seek(ends)
            if ends>=minfEnds: break

    def scanStbl(self,stblEnds):
        while True:
            (tag,ends) = self.atom()
            #print "stbl",tag
            if tag=='stsd': self.scanStsd(ends)
            self.fd.seek(ends)
            if ends>=stblEnds: break

    def scanStsd(self,stsdEnds):
        size = stsdEnds-self.fd.tell()
        #print 'stsd size',size
        data = self.fd.read(size)
        format = data[12:16]
        #print format
        if format=='mp4a' or format=='drms' or format=='samr':
            self.movieInfo['Sample Rate'] = struct.unpack("!I",data[40:44])[0]>>16
            self.movieInfo['Channels'] = struct.unpack("!H",data[32:34])[0]
            self.movieInfo['Bits Per Sample'] = struct.unpack('!H',data[34:36])[0]
            self.movieInfo['VBR'] = struct.unpack("!H",data[36:38])[0]==-2
        #print data.lower()

    def info(self):
        return self.movieInfo

if __name__=='__main__':
    import sys
    import pprint
    pp = pprint.PrettyPrinter(indent=4)
    filePath = sys.argv[1]
    i = MP4Info(open(filePath,"rb"))
    pp.pprint(i.info())