TV input services let the user pause and resume channel playback via time-shifting APIs. Android 7.0 expands on time-shifting by letting the user save multiple recorded sessions.
Users can schedule recordings in advance, or start a recording as they watch a program. Once the system has saved a recording, the user can browse, manage, and play back the recording using the system TV app.
If you want to provide recording functionality for your TV input service, you must indicate to the system that your app supports recording, implement the ability to record programs, handle and communicate any errors that occur during recording, and manage your recorded sessions.
Indicating Support for Recording
To tell the system that your TV input service supports recording, set
android:canRecord attribute in your service metadata XML file
<tv-input xmlns:android="http://schemas.android.com/apk/res/android" android:canRecord="true" android:setupActivity="com.example.sampletvinput.SampleTvInputSetupActivity" />
For more information on the service metadata file, see Declare Your TV Input Service in the Manifest.
Alternatively, you can indicate recording support in your code using these steps:
- In your TV input service
onCreate()method, create a new
TvInputInfoobject using the
- When creating the new
build()to indicate your service supports recording.
- Register your
TvInputInfoobject with the system by calling
Recording a Session
After your TV input service registers that it supports recording
functionality, the system calls your
TvInputService.onCreateRecordingSession() method when it needs to access
your app's recording implementation. Implement your own
TvInputService.RecordingSession subclass and return it
onCreateRecordingSession() callback fires. This subclass is responsible
for switching to the correct channel data, recording the requested data,
and communicating recording status and errors to the system.
When the system calls
RecordingSession.onTune(), passing in a channel URI, tune to the channel
that the URI specifies. Notify the system that your app has tuned to the
desired channel by calling
notifyTuned() or, if your app could not tune to the proper channel, call
The system next invokes the
RecordingSession.onStartRecording() callback. Your app must start recording
immediately. When the system invokes this callback, it may provide a URI
that contains information about the program that is about to be recorded.
When the recording is done, you'll copy this data to the
Finally, the system calls
RecordingSession.onStopRecording(). At this point, your app must stop
recording immediately. You also need to create an entry in the
table. This entry should include the recorded session data URI in the
RecordedPrograms.COLUMN_RECORDING_DATA_URI column, and any program
information that the system provided in the initial call to
Handling Recording Errors
If an error occurs during recording, resulting in unusable recorded data,
notify the system by calling
notifyError(). Similarly, you can call
notifyError() after a recording session is created to let the system know
that your app can no longer record sessions.
If an error occurs during recording, but you'd like to provide a
partial recording to users for playback, call
notifyRecordingStopped() to enable the system to
use the partial session.
Managing Recorded Sessions
The system maintains information for all recorded sessions from all
recording-capable channel apps in the
content provider table. This information is accessible via the
content recording URIs. Use content provider APIs to
read, add, and delete entries from this table.
For more information on working with content provider data see Content Provider Basics.
TV devices may have limited storage, so use your best judgment when
allocating storage to save recorded sessions. Use
there isn't enough space to save a recorded session.
When the user initiates recording, you should start recording data as soon
as possible. To facilitate this, complete any up-front time-consuming tasks,
like accessing and allocating storage space, when the system invokes the
onCreateRecordingSession() callback. Doing so lets you start
recording immediately when the
onStartRecording() callback fires.