There's a new version of YouTube out, and as usual, hidden inside its chocolaty center are hints at upcoming features and capabilities. We've seen information about a lot of this stuff before, some of which has even been confirmed by Google itself. Aside from the user interface changes we mentioned in the announcement post, there are framework elements for the upcoming YouTube subscription service, "Uninterrupted Playback," an offline video mode, and background music listening.

Take A Peek At Music Pass

The following strings in the 5.3 app look like they're intended to be used for a separate page or popup encouraging users to upgrade to "Music Pass," which we assume is the name for YouTube's upcoming subscription service. The text below describes several features in advertising bulletin fashion.

music_upsell_dialog.xml layout describes an upsell page/screen that uses these strings:

<string name="music_pass">Music Pass</string> <string name="offline_playback">Offline playback</string>

<string name="offline_playback_details">Take your music everywhere</string> <string name="background_listening">Background listening</string>

<string name="background_listening_details">Keep your music playing while using other apps</string> <string name="uninterrupted_music">Uninterrupted music</string>

<string name="uninterrupted_music_details">No ads on millions of songs</string>

Offline playback (music? video? both?), background listening, "uninterrupted music," and "no ads on millions of songs" are all mentioned. No ads is obviously a component of the paid service, just like Google Play Music and the premium versions of Pandora and Spotify. But notice that it doesn't simply say "no ads," it's "no ads on millions of songs." It's likely that Google needed to negotiate the rights for the YouTube Music Pass service separately from Google Play Music since music videos are legally and commercially distinct from their songs. So does that mean that the service is truly ad-free, or that a portion of the songs and/or music videos on offer will have ads that further benefit the music labels? There's no way to know at the moment.

Also note that the offline playback and background listening are specifically mentioned in the context of Music Pass. It's possible that these features might be limited to paid subscribers. Again, there's no way to confirm or deny that with the information here.

These icons are used in the above music_upsell_dialog.xml layout, one for each feature:

ic_airplane.png (offline playback), ic_headphone.png (background listening), ic_noads.png (uninterrupted music)

More Hints At Offline Video Playback

The following strings are further indications that offline video playback is headed for the YouTube app very soon. The interesting components are bolded below: it looks like entire playlists can be cached locally for offline playback (assuming you've got the storage space, of course), though YouTube uploaders may be able to specify that their videos cannot be saved locally.

<string name="offline_failed">Error adding to offline</string>

<string name="offline_video_not_playable">Video is not playable</string>

<string name="offline_failed_disk_full">Disk full</string>

<string name="offline_failed_network_error">Network error</string>

<string name="offline_expired">Offline version expired</string> <string name="video_already_added_to_offline">Video is already added to offline.</string>

<string name="cannot_watch_offline">This video can’t be watched offline</string>

<string name="add_to_offline_not_enough_space">Not enough space</string>

<string name="add_playlist_to_offline_start">Adding playlist to offline...</string>

<string name="playlist_already_added_to_offline">Playlist is already added to offline</string>

<string name="add_playlist_to_offline_error">Error adding playlist to offline</string> <string name="offline_waiting">Waiting... %1$d%%</string>

<string name="offline_waiting_for_network">Waiting for network...</string>

<string name="offline_video_deleted">Deleted</string>

<string name="offline_playlist_adding_progress">Adding... %1$d/%2$d</string>

<string name="retry_offline">Retry</string>

<string name="retry_offline_video_confirmation">Retry adding to offline?</string>

<string name="remove_offline_playlist_confirmation">Remove from offline?</string>

<string name="offline_video_expired_confirmation">Offline version expired. Reconnect to check availability.</string>

The last string reinforces the 48-hour limitation on saved videos. There's an XML file labeled "pref_offline_storage_widget.xml," but we don't think it's a conventional homescreen widget, it's just a part of the upcoming user interface adjustments. Notice the references to a display for used and free storage space, and the option to save offline videos in 360p or 720p HD.

<string name="pref_offline_category">Offline</string>

<string name="pref_offline_quality_title">Quality</string>

<string name="pref_offline_network_policy_title">Add over Wifi only</string>

<string name="pref_offline_storage_title">Storage</string>

<string name="pref_offline_storage_used">%1$s used</string>

<string name="pref_offline_storage_free">%1$s free</string> <string name="offline_video_quality_360p">Standard (360p)</string>

<string name="offline_video_quality_720p">HD (720dp)</string>

Other Bits And Pieces

We found a few other icons that we can't exactly place, but an educated guess says that the "ic_offline_error.png" is for problems stemming from saved videos, and "ic_offline_retry.png" lets you try the operation again.

"in_set_mix_pressed" looks like an icon for a YouTube playlist, either a pre-made playlist (like YouTube has now) or an auto-populated genre/style/artist playlist, like the radio stations in Google Play Music. "ic_set_shuffle_off.png" is self-explanatory.

One last thing: a string reference to something called the "exo player." We've got no idea what this is - it might be the term for the background play function, or it could just be some internal reference for the app developers.

<string name="pref_developer_exo_player_title">ExoPlayer</string>

If you're still waiting on the YouTube 5.3 app to roll out to your device, we've got the APK right here.

Thanks to Artem Russakovskii and Santiago Rosales for putting in the legwork for this post.