shairport-metadata.py

import re, sys
import base64
import json

def start_item(line):
    regex = r"<item><type>(([A-Fa-f0-9]{2}){4})</type><code>(([A-Fa-f0-9]{2}){4})</code><length>(\d*)</length>"
    matches = re.findall(regex, line)
    typ = matches[0][0].decode('hex')
    code = matches[0][2].decode('hex')
    length = int(matches[0][4])
    return (typ, code, length)

def start_data(line):
    try:
        assert line == '<data encoding="base64">\n'
    except AssertionError:
        if line.startswith("<data"):
            return 0
        return -1
    return 0

def read_data(line, length):
    b64size = 4*((length+2)/3);
    try:
        data = base64.b64decode(line[:b64size])
    except TypeError:
        data = ""
        pass
    return data

def guessImageMime(magic):

    if magic.startswith('\xff\xd8'):
        return 'image/jpeg'
    elif magic.startswith('\x89PNG\r\n\x1a\r'):
        return 'image/png'
    else:
        return "image/jpg"

if __name__ == "__main__":

    metadata = {}
    fi = sys.stdin
    while True:
        line = sys.stdin.readline()
        if not line:    #EOF
            break
        sys.stdout.flush()
        if not line.startswith("<item>"):
            continue
        typ, code, length = start_item(line)

        data = ""
        if (length > 0):
            r = start_data(sys.stdin.readline())
            if (r == -1):
                continue
            data = read_data(sys.stdin.readline(), length)

        # Everything read
        if (typ == "core"):
            if (code == "asal"):
                metadata['Album Name'] = data
            elif (code == "asar"):
                metadata['Artist'] = data
            #elif (code == "ascm"):
            #    metadata['Comment'] = data
            #elif (code == "asgn"):
            #    metadata['Genre'] = data
            elif (code == "minm"):
                metadata['Title'] = data
            #elif (code == "ascp"):
            #    metadata['Composer'] = data
            #elif (code == "asdt"):
            #    metadata['File Kind'] = data
            #elif (code == "assn"):
            #    metadata['Sort as'] = data
            #elif (code == "clip"):
            #    metadata['IP'] = data
        if (typ == "ssnc" and code == "snam"):
            metadata['snam'] = data
        if (typ == "ssnc" and code == "prgr"):
            metadata['prgr'] = data
        if (typ == "ssnc" and code == "pfls"):
            metadata = {}
            print json.dumps({})
            sys.stdout.flush()
        if (typ == "ssnc" and code == "pend"):
            metadata = {}
            print json.dumps({})
            sys.stdout.flush()
        if (typ == "ssnc" and code == "prsm"):
            metadata['pause'] = False
        if (typ == "ssnc" and code == "pbeg"):
            metadata['pause'] = False
        if (typ == "ssnc" and code == "PICT"):
            if (len(data) == 0):
                print json.dumps({"image": ""})
            else:
                mime = guessImageMime(data)
                print json.dumps({"image": "data:" + mime + ";base64," + base64.b64encode(data)})
            sys.stdout.flush()
        if (typ == "ssnc" and code == "mden"):
            print json.dumps(metadata)
            sys.stdout.flush()
            metadata = {}