/*
* Copyright 2021 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package androidx.camera.video;
import android.Manifest;
import android.content.Context;
import androidx.annotation.CheckResult;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.annotation.RequiresApi;
import androidx.annotation.RequiresPermission;
import androidx.camera.core.impl.utils.ContextUtil;
import androidx.core.content.PermissionChecker;
import androidx.core.util.Consumer;
import androidx.core.util.Preconditions;
import java.util.concurrent.Executor;
/**
* A recording that can be started at a future time.
*
* <p>A pending recording allows for configuration of a recording before it is started. Once a
* pending recording is started with {@link #start(Executor, Consumer)}, any changes to the pending
* recording will not affect the actual recording; any modifications to the recording will need
* to occur through the controls of the {@link Recording} class returned by
* {@link #start(Executor, Consumer)}.
*
* <p>A pending recording can be created using one of the {@link Recorder} methods for starting a
* recording such as {@link Recorder#prepareRecording(Context, MediaStoreOutputOptions)}.
* <p>There may be more settings that can only be changed per-recorder instead of per-recording,
* because it requires expensive operations like reconfiguring the camera. For those settings, use
* the {@link Recorder.Builder} methods to configure before creating the {@link Recorder}
* instance, then create the pending recording with it.
*/
@RequiresApi(21) // TODO(b/200306659): Remove and replace with annotation on package-info.java
public final class PendingRecording {
private final Context mContext;
private final Recorder mRecorder;
private final OutputOptions mOutputOptions;
private Consumer<VideoRecordEvent> mEventListener;
private Executor mListenerExecutor;
private boolean mAudioEnabled = false;
private boolean mIsPersistent = false;
PendingRecording(@NonNull Context context, @NonNull Recorder recorder,
@NonNull OutputOptions options) {
// Application context is sufficient for all our needs, so store that to avoid leaking
// unused resources. For attribution, ContextUtil.getApplicationContext() will retain the
// attribution tag from the original context.
mContext = ContextUtil.getApplicationContext(context);
mRecorder = recorder;
mOutputOptions = options;
}
/**
* Returns an application context which was retrieved from the {@link Context} used to
* create this object.
*/
@NonNull
Context getApplicationContext() {
return mContext;
}
@NonNull
Recorder getRecorder() {
return mRecorder;
}
@NonNull
OutputOptions getOutputOptions() {
return mOutputOptions;
}
@Nullable
Executor getListenerExecutor() {
return mListenerExecutor;
}
@Nullable
Consumer<VideoRecordEvent> getEventListener() {
return mEventListener;
}
boolean isAudioEnabled() {
return mAudioEnabled;
}
boolean isPersistent() {
return mIsPersistent;
}
/**
* Enables audio to be recorded for this recording.
*
* <p>This method must be called prior to {@link #start(Executor, Consumer)} to enable audio
* in the recording. If this method is not called, the {@link Recording} generated by
* {@link #start(Executor, Consumer)} will not contain audio, and
* {@link AudioStats#getAudioState()} will always return
* {@link AudioStats#AUDIO_STATE_DISABLED} for all {@link RecordingStats} send to the listener
* set passed to {@link #start(Executor, Consumer)}.
*
* <p>Recording with audio requires the {@link android.Manifest.permission#RECORD_AUDIO}
* permission; without it, recording will fail at {@link #start(Executor, Consumer)} with an
* {@link IllegalStateException}.
*
* @return this pending recording
* @throws IllegalStateException if the {@link Recorder} this recording is associated to
* doesn't support audio.
* @throws SecurityException if the {@link Manifest.permission#RECORD_AUDIO} permission
* is denied for the current application.
*/
@RequiresPermission(Manifest.permission.RECORD_AUDIO)
@NonNull
public PendingRecording withAudioEnabled() {
// Check permissions and throw a security exception if RECORD_AUDIO is not granted.
if (PermissionChecker.checkSelfPermission(mContext, Manifest.permission.RECORD_AUDIO)
== PermissionChecker.PERMISSION_DENIED) {
throw new SecurityException("Attempted to enable audio for recording but application "
+ "does not have RECORD_AUDIO permission granted.");
}
Preconditions.checkState(mRecorder.isAudioSupported(), "The Recorder this recording is "
+ "associated to doesn't support audio.");
mAudioEnabled = true;
return this;
}
/**
* Configures the recording to be a persistent recording.
*
* <p>A persistent recording will only be stopped by explicitly calling
* {@link Recording#stop()} or {@link Recording#close()} and will ignore events that would
* normally cause recording to stop, such as lifecycle events or explicit unbinding of a
* {@link VideoCapture} use case that the recording's {@link Recorder} is attached to.
*
* <p>Even though lifecycle events or explicit unbinding use cases won't stop a persistent
* recording, it will still stop the camera from producing data, resulting in the in-progress
* persistent recording stopping getting data until the camera stream is activated again. For
* example, when the activity goes into background, the recording will keep waiting for new
* data to be recorded until the activity is back to foreground.
*
* <p>A {@link Recorder} instance is recommended to be associated with a single
* {@link VideoCapture} instance, especially when using persistent recording. Otherwise, there
* might be unexpected behavior. Any in-progress persistent recording created from the same
* {@link Recorder} should be stopped before starting a new recording, even if the
* {@link Recorder} is associated with a different {@link VideoCapture}.
*
* <p>To switch to a different camera stream while a recording is in progress, first create
* the recording as persistent recording, then rebind the {@link VideoCapture} it's
* associated with to a different camera. The implementation may be like:
* <pre>{@code
* // Prepare the Recorder and VideoCapture, then bind the VideoCapture to the back camera.
* Recorder recorder = Recorder.Builder().build();
* VideoCapture videoCapture = VideoCapture.withOutput(recorder);
* cameraProvider.bindToLifecycle(
* lifecycleOwner, CameraSelector.DEFAULT_BACK_CAMERA, videoCapture);
*
* // Prepare the persistent recording and start it.
* Recording recording = recorder
* .prepareRecording(context, outputOptions)
* .asPersistentRecording()
* .start(eventExecutor, eventListener);
*
* // Record from the back camera for a period of time.
*
* // Rebind the VideoCapture to the front camera.
* cameraProvider.unbindAll();
* cameraProvider.bindToLifecycle(
* lifecycleOwner, CameraSelector.DEFAULT_FRONT_CAMERA, videoCapture);
*
* // Record from the front camera for a period of time.
*
* // Stop the recording explicitly.
* recording.stop();
* }</pre>
*
* <p>The audio data will still be recorded after the {@link VideoCapture} is unbound.
* {@link Recording#pause() Pause} the recording first and {@link Recording#resume() resume} it
* later to stop recording audio while rebinding use cases.
*
* <p>If the recording is unable to receive data from the new camera, possibly because of
* incompatible surface combination, an exception will be thrown when binding to lifecycle.
*/
@ExperimentalPersistentRecording
@NonNull
public PendingRecording asPersistentRecording() {
mIsPersistent = true;
return this;
}
/**
* Starts the recording, making it an active recording.
*
* <p>Only a single recording can be active at a time, so if another recording is active,
* this will throw an {@link IllegalStateException}.
*
* <p>If there are no errors starting the recording, the returned {@link Recording}
* can be used to {@link Recording#pause() pause}, {@link Recording#resume() resume},
* or {@link Recording#stop() stop} the recording.
*
* <p>Upon successfully starting the recording, a {@link VideoRecordEvent.Start} event will
* be the first event sent to the provided event listener.
*
* <p>If errors occur while starting the recording, a {@link VideoRecordEvent.Finalize} event
* will be the first event sent to the provided listener, and information about the error can
* be found in that event's {@link VideoRecordEvent.Finalize#getError()} method. The returned
* {@link Recording} will be in a finalized state, and all controls will be no-ops.
*
* <p>If the returned {@link Recording} is garbage collected, the recording will be
* automatically stopped. A reference to the active recording must be maintained as long as
* the recording needs to be active. If the recording is garbage collected, the
* {@link VideoRecordEvent.Finalize} event will contain error
* {@link VideoRecordEvent.Finalize#ERROR_RECORDING_GARBAGE_COLLECTED}.
*
* <p>The {@link Recording} will be stopped automatically if the {@link VideoCapture} its
* {@link Recorder} is attached to is unbound unless it's created
* {@link #asPersistentRecording() as a persistent recording}.
*
* @throws IllegalStateException if the associated Recorder currently has an unfinished
* active recording.
* @param listenerExecutor the executor that the event listener will be run on.
* @param listener the event listener to handle video record events.
*/
@NonNull
@CheckResult
public Recording start(
@NonNull Executor listenerExecutor,
@NonNull Consumer<VideoRecordEvent> listener) {
Preconditions.checkNotNull(listenerExecutor, "Listener Executor can't be null.");
Preconditions.checkNotNull(listener, "Event listener can't be null");
mListenerExecutor = listenerExecutor;
mEventListener = listener;
return mRecorder.start(this);
}
}