/*
* Copyright 2014 Google Inc. All rights reserved.
*
* 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 com.android.grafika;
import android.os.Bundle;
import android.app.Activity;
import android.graphics.SurfaceTexture;
import android.util.Log;
import android.view.Surface;
import android.view.TextureView;
import java.io.File;
import java.io.IOException;
/**
* Decodes two video streams simultaneously to two TextureViews.
* <p>
* One key feature is that the video decoders do not stop when the activity is restarted due
* to an orientation change. This is to simulate playback of a real-time video stream. If
* the Activity is pausing because it's "finished" (indicating that we're leaving the Activity
* for a nontrivial amount of time), the video decoders are shut down.
* <p>
* TODO: consider shutting down when the screen is turned off, to preserve battery.
*/
public class DoubleDecodeActivity extends Activity {
private static final String TAG = MainActivity.TAG;
private static final int VIDEO_COUNT = 2;
// Must be static storage so they'll survive Activity restart.
private static boolean sVideoRunning = false;
private static VideoBlob[] sBlob = new VideoBlob[VIDEO_COUNT];
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_double_decode);
if (!sVideoRunning) {
sBlob[0] = new VideoBlob((TextureView) findViewById(R.id.double1_texture_view),
ContentManager.MOVIE_SLIDERS, 0);
sBlob[1] = new VideoBlob((TextureView) findViewById(R.id.double2_texture_view),
ContentManager.MOVIE_EIGHT_RECTS, 1);
sVideoRunning = true;
} else {
sBlob[0].recreateView((TextureView) findViewById(R.id.double1_texture_view));
sBlob[1].recreateView((TextureView) findViewById(R.id.double2_texture_view));
}
}
@Override
protected void onPause() {
super.onPause();
boolean finishing = isFinishing();
Log.d(TAG, "isFinishing: " + finishing);
for (int i = 0; i < VIDEO_COUNT; i++) {
if (finishing) {
sBlob[i].stopPlayback();
sBlob[i] = null;
}
}
sVideoRunning = !finishing;
Log.d(TAG, "onPause complete");
}
/**
* Video playback blob.
* <p>
* Encapsulates the video decoder and playback surface.
* <p>
* We want to avoid tearing down and recreating the video decoder on orientation changes,
* because it can be expensive to do so. That means keeping the decoder's output Surface
* around, which means keeping the SurfaceTexture around.
* <p>
* It's possible that the orientation change will cause the UI thread's EGL context to be
* torn down and recreated (the app framework docs don't seem to make any guarantees here),
* so we need to detach the SurfaceTexture from EGL on destroy, and reattach it when
* the new SurfaceTexture becomes available. Happily, TextureView does this for us.
*/
private static class VideoBlob implements TextureView.SurfaceTextureListener {
private final String LTAG;
private TextureView mTextureView;
private int mMovieTag;
private SurfaceTexture mSavedSurfaceTexture;
private PlayMovieThread mPlayThread;
private SpeedControlCallback mCallback;
/**
* Constructs the VideoBlob.
*
* @param view The TextureView object we want to draw into.
* @param movieTag Which movie to play.
* @param ordinal The blob's ordinal (only used for log messages).
*/
public VideoBlob(TextureView view, int movieTag, int ordinal) {
LTAG = TAG + ordinal;
Log.d(LTAG, "VideoBlob: tag=" + movieTag + " view=" + view);
mMovieTag = movieTag;
mCallback = new SpeedControlCallback();
recreateView(view);
}
/**
* Performs partial construction. The VideoBlob is already created, but the Activity
* was recreated, so we need to update our view.
*/
public void recreateView(TextureView view) {
Log.d(LTAG, "recreateView: " + view);
mTextureView = view;
mTextureView.setSurfaceTextureListener(this);
if (mSavedSurfaceTexture != null) {
Log.d(LTAG, "using saved st=" + mSavedSurfaceTexture);
view.setSurfaceTexture(mSavedSurfaceTexture);
}
}
/**
* Stop playback and shut everything down.
*/
public void stopPlayback() {
Log.d(LTAG, "stopPlayback");
mPlayThread.requestStop();
// TODO: wait for the playback thread to stop so we don't kill the Surface
// before the video stops
// We don't need this any more, so null it out. This also serves as a signal
// to let onSurfaceTextureDestroyed() know that it can tell TextureView to
// free the SurfaceTexture.
mSavedSurfaceTexture = null;
}
@Override
public void onSurfaceTextureAvailable(SurfaceTexture st, int width, int height) {
Log.d(LTAG, "onSurfaceTextureAvailable size=" + width + "x" + height + ", st=" + st);
// If this is our first time though, we're going to use the SurfaceTexture that
// the TextureView provided. If not, we're going to replace the current one with
// the original.
if (mSavedSurfaceTexture == null) {
mSavedSurfaceTexture = st;
File sliders = ContentManager.getInstance().getPath(mMovieTag);
mPlayThread = new PlayMovieThread(sliders, new Surface(st), mCallback);
} else {
// Can't do it here in Android <= 4.4. The TextureView doesn't add a
// listener on the new SurfaceTexture, so it never sees any updates.
// Needs to happen from activity onCreate() -- see recreateView().
//Log.d(LTAG, "using saved st=" + mSavedSurfaceTexture);
//mTextureView.setSurfaceTexture(mSavedSurfaceTexture);
}
}
@Override
public void onSurfaceTextureSizeChanged(SurfaceTexture st, int width, int height) {
Log.d(LTAG, "onSurfaceTextureSizeChanged size=" + width + "x" + height + ", st=" + st);
}
@Override
public boolean onSurfaceTextureDestroyed(SurfaceTexture st) {
Log.d(LTAG, "onSurfaceTextureDestroyed st=" + st);
// The SurfaceTexture is already detached from the EGL context at this point, so
// we don't need to do that.
//
// The saved SurfaceTexture will be null if we're shutting down, so we want to
// return "true" in that case (indicating that TextureView can release the ST).
return (mSavedSurfaceTexture == null);
}
@Override
public void onSurfaceTextureUpdated(SurfaceTexture st) {
//Log.d(TAG, "onSurfaceTextureUpdated st=" + st);
}
}
/**
* Thread object that plays a movie from a file to a surface.
* <p>
* Currently loops until told to stop.
*/
private static class PlayMovieThread extends Thread {
private final File mFile;
private final Surface mSurface;
private final SpeedControlCallback mCallback;
private MoviePlayer mMoviePlayer;
/**
* Creates thread and starts execution.
* <p>
* The object takes ownership of the Surface, and will access it from the new thread.
* When playback completes, the Surface will be released.
*/
public PlayMovieThread(File file, Surface surface, SpeedControlCallback callback) {
mFile = file;
mSurface = surface;
mCallback = callback;
start();
}
/**
* Asks MoviePlayer to halt playback. Returns without waiting for playback to halt.
* <p>
* Call from UI thread.
*/
public void requestStop() {
mMoviePlayer.requestStop();
}
@Override
public void run() {
try {
mMoviePlayer = new MoviePlayer(mFile, mSurface, mCallback);
mMoviePlayer.setLoopMode(true);
mMoviePlayer.play();
} catch (IOException ioe) {
Log.e(TAG, "movie playback failed", ioe);
} finally {
mSurface.release();
Log.d(TAG, "PlayMovieThread stopping");
}
}
}
}
