Missing subtitle streams metadata

Describe the issue
Metadata for subtitle streams are almost always missing.

Code snipppet

movies = plex.library.section('Movies')
for video in movies.search():
    print("[%s]" % video.title)
    video = video.reload()
    for subtitle in video.subtitleStreams():
        print("\t%s - %s | %s | %s | %s" % (subtitle,  subtitle.title, subtitle.key, subtitle.format, subtitle.forced))
print("done!")

Code snipppet output:

[#RealityHigh]
	<SubtitleStream:42643> - None | None | None | False
	<SubtitleStream:42644> - None | None | None | False
	<SubtitleStream:42645> - None | None | None | False
	<SubtitleStream:42646> - None | None | None | False
	<SubtitleStream:42647> - None | None | None | False
[The 'Burbs]
	<SubtitleStream:194791> - None | None | None | False
[0.0MHz]
	<SubtitleStream:216274:Simplified> - Simplified | None | None | False
	<SubtitleStream:216275:Traditional> - Traditional | None | None | False
	<SubtitleStream:/library/streams/146> - None | /library/streams/146237 | srt | False
[2 Fast 2 Furious]
	<SubtitleStream:210926> - None | None | None | False
	<SubtitleStream:210927> - None | None | None | False
[2 Guns]
	<SubtitleStream:270997> - None | None | None | False
[3 from Hell]
	<SubtitleStream:/library/streams/228> - None | /library/streams/228323 | srt | False
...
...
...
done!

Expected behavior
For example, looking at #RealityHigh via Plex site, I see English, Dutch, French, Spanish, and German non-forced SRT subtitles. I expected to see these information here alongside their key. That should be true for every movie and be mostly consistent.

subtitle.title, subtitle.key, subtitle.format, subtitle.forced shouldn't be nearly always 'None'

Enviroment:

• OS: Ubuntu; Plex is running in a docker container
• Plex version: 4.38.2
• Python Version: 3.8.2
• PlexAPI version: 3.5.0

[blacktwin]

Here is the content of a SubtitleStream

<SubtitleStream:318297> - None | None | None | False
{   '_data': <Element 'Stream' at 0x000002536F3226D8>,
    '_details_key': '',
    '_initpath': '/library/metadata/112676?checkFiles=1&includeExtras=1&includeRelated=1&includeOnDeck=1&includeChapters=1&includePopularLeaves=1&includeConcerts=1&includePreferences=1',
    '_server': <PlexServer:http://127.0.0.1:324>,
    'codec': 'vobsub',
    'codecID': None,
    'forced': False,
    'format': None,
    'id': 318297,
    'index': 2,
    'key': None,
    'language': 'English',
    'languageCode': 'eng',
    'selected': False,
    'streamType': 3,
    'title': None,
    'type': 3}

You are not pulling out the language information into your string. There is more information available than what you are outputting to you string. Also these are the attributes found in the XML so you can confirm that this information is accurate.

<Stream id="318297" streamType="3" default="1" codec="vobsub" index="2" bitrate="13" language="English" languageCode="eng" requiredBandwidths="15,15,15,15,15,15,15,15" streamIdentifier="3" displayTitle="English (VOBSUB)" extendedDisplayTitle="English (VOBSUB)"/>

Well looks like the SubtitleStream class needs an update. requiredBandwidths, streamIdentifier, displayTitle, extendedDisplayTitle will need to be added.

Ah... I didn't realize there was more information available to me in SubtitleStream. displayTitle & extendedDisplayTitle are precisely what I'm looking for.

[blacktwin]

updating the media.SubtitleStream class to the following should give you what you need.

@utils.registerPlexObject
class SubtitleStream(MediaPartStream):
    """ Respresents a audio stream within a :class:`~plexapi.media.MediaPart`.

        Attributes:
            TAG (str): 'Stream'
            STREAMTYPE (int): 3
            forced (bool): True if this is a forced subtitle
            format (str): Subtitle format (ex: srt).
            key (str): Key of this subtitle stream (ex: /library/streams/212284).
            title (str): Title of this subtitle stream.
    """
    TAG = 'Stream'
    STREAMTYPE = 3

    def _loadData(self, data):
        """ Load attribute values from Plex XML response. """
        super(SubtitleStream, self)._loadData(data)
        self.bitrate = data.attrib.get('bitrate')
        self.default = data.attrib.get('default')
        self.displayTitle = data.attrib.get('displayTitle')
        self.extendedDisplayTitle = data.attrib.get('extendedDisplayTitle')
        self.forced = cast(bool, data.attrib.get('forced', '0'))
        self.format = data.attrib.get('format')
        self.key = data.attrib.get('key')
        self.requiredBandwidths = data.attrib.get('requiredBandwidths')
        self.streamIdentifier = cast(int, data.attrib.get('streamIdentifier'))

Feel free to create a PR for this and please reference this Issue if you do. If not, I'll get around to it eventually.

Also you can always check the items XML to see what information is available and cross ref this project. If something is missing create an issue or a PR to fix it.

[JonnyWong16]

All subtitle attributes have been added in #590.