我需要以每秒不同的帧数显示图像，最大FPS为30.图像来自SD卡，并且都具有相同的尺寸：480 x 640。 我创建了3个可能的解决方案，但每个解决方案都存在问题：
以下结果为30 FPS。
予。不重复使用位图
CPU负载：达到 92％
private Bitmap bitmap;
private void startAnimation1() {
TimerTask updateImage = new UpdateImage1();
timer.scheduleAtFixedRate(updateImage, 0, 1000 / FPS);
}
class UpdateImage1 extends TimerTask {
@Override
public void run() {
try {
if (i == IMAGES_NR) {
i = 0;
}
bitmap = BitmapFactory.decodeStream(new FileInputStream(framesFiles[i]), null, null);
i++;
} catch (FileNotFoundException e) {
System.out.println("Exception 1: " + e.getMessage());
}
runOnUiThread(new Runnable() {
@Override
public void run() {
imgView.setImageBitmap(bitmap);
}
});
}
}
II。通过BitmapFactory.Options.inBitmap
重用位图运行动画后，应用程序崩溃了：
06-20 15:08:58.158: WARN/System.err(7880): java.lang.ArrayIndexOutOfBoundsException: length=-5131855; regionStart=0; regionLength=1024
06-20 15:08:58.158: WARN/System.err(7880): at java.util.Arrays.checkOffsetAndCount(Arrays.java:1731)
06-20 15:08:58.158: WARN/System.err(7880): at java.io.BufferedInputStream.read(BufferedInputStream.java:273)
06-20 15:08:58.158: WARN/System.err(7880): at android.graphics.BitmapFactory.nativeDecodeStream(Native Method)
06-20 15:08:58.158: WARN/System.err(7880): at android.graphics.BitmapFactory.decodeStream(BitmapFactory.java:587)
06-20 15:08:58.158: WARN/System.err(7880): at com.example.SendPreviewOptimization.MyActivity$UpdateImage2.run(MyActivity.java:148)
06-20 15:08:58.158: WARN/System.err(7880): at java.util.Timer$TimerImpl.run(Timer.java:284)
06-20 15:08:58.168: DEBUG/skia(7880): ---- read threw an exception
06-20 15:08:58.168: DEBUG/skia(7880): --- decoder->decode returned false
06-20 15:08:58.168: WARN/System.err(7880): java.lang.IllegalArgumentException: Problem decoding into existing bitmap
06-20 15:08:58.168: WARN/System.err(7880): at android.graphics.BitmapFactory.decodeStream(BitmapFactory.java:590)
06-20 15:08:58.168: WARN/System.err(7880): at com.example.SendPreviewOptimization.MyActivity$UpdateImage2.run(MyActivity.java:148)
06-20 15:08:58.168: WARN/System.err(7880): at java.util.Timer$TimerImpl.run(Timer.java:284)
06-20 15:08:58.178: ERROR/msm8960.hwcomposer(330): prepareBypass: Unable to setup bypass due to non-pmem memory
06-20 15:08:58.198: ASSERT/libc(7880): Fatal signal 11 (SIGSEGV) at 0xffd1d447 (code=1)
06-20 15:08:58.238: ERROR/msm8960.hwcomposer(330): prepareBypass: Unable to setup bypass due to non-pmem memory
06-20 15:08:58.498: ERROR/MP-Decision(1448): DOWN Ld:25 Ns:1.100000 Ts:190 rq:0.000000 seq:194.000000
06-20 15:08:58.708: INFO/DEBUG(27660): *** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
private static BitmapFactory.Options bitmapOptions;
private FileInputStream in;
private void startAnimation2() {
bitmapOptions = new BitmapFactory.Options();
// setup bitmap reuse options:
bitmapOptions.inPurgeable = true;
bitmapOptions.inInputShareable = true;
bitmapOptions.inBitmap = reusableBitmap;
bitmapOptions.inMutable = true;
bitmapOptions.inSampleSize = 1;
TimerTask updateImage = new UpdateImage2();
timer.scheduleAtFixedRate(updateImage, 0, 1000 / FPS);
}
class UpdateImage2 extends TimerTask {
@Override
public void run() {
try {
if (i == IMAGES_NR) {
i = 0;
}
//** version 1:
in = new FileInputStream(framesFiles[i]);
//decode into existing bitmap
BitmapFactory.decodeStream(in, null, bitmapOptions);
in.close();
//** version 2:
//BitmapFactory.decodeFile(framesFiles[i].getAbsolutePath(), bitmapOptions);
i++;
} catch (Exception e) {
System.out.println("Exception 2: " + e.getMessage());
}
runOnUiThread(new Runnable() {
@Override
public void run() {
imgView.setImageBitmap(reusableBitmap);
}
});
}
}
III。选项III：使用缓冲区（使Bytebuffer更高效的一件事是使用直接内存。）
这个选项让我无法工作:(
private ByteBuffer buffer;
private byte[] b;
private IntBuffer mPixels;
private void startAnimation3() {
buffer = ByteBuffer.allocate(480 * 640 * 6);
b = new byte[480 * 640 * 6];
TimerTask updateImage = new UpdateImage3();
timer.scheduleAtFixedRate(updateImage, 0, 1000 / FPS);
}
class UpdateImage3 extends TimerTask {
public void run() {
try {
if (i == IMAGES_NR) {
i = 0;
}
FileInputStream frameInputStream = new FileInputStream(framesFiles[i]);
frameInputStream.read(b);
buffer.wrap(b);
buffer.position(0);
reusableBitmap.copyPixelsFromBuffer(buffer);
frameInputStream.close();
i++;
} catch (Exception e) {
System.out.println("Exception 3: " + e.getMessage());
}
runOnUiThread(new Runnable() {
@Override
public void run() {
imgView.setImageBitmap(reusableBitmap);
}
});
}
}
private ByteBuffer copyToBuffer(Bitmap bitmap) {
int size = bitmap.getHeight() * bitmap.getRowBytes();
ByteBuffer buffer = ByteBuffer.allocateDirect(size);
bitmap.copyPixelsToBuffer(buffer);
return buffer;
}
在上述每个解决方案中，我都会收到logcat的
ERROR/msm8960.hwcomposer(330): prepareBypass: Unable to setup bypass due to non-pmem memory
我不知道究竟意味着什么。
我以前没有使用Bitmap重用，也不知道哪个是最好的解决方案。
我添加了我在这里创建的项目：https://www.dropbox.com/sh/3xov369u1bmjpd1/qBQax4t48D以及2帧/图像。
回答Neron T
我试过那个图书馆：
//Option IV:
private AQuery aquery;
private void startAnimation4() {
aquery = new AQuery(this);
aquery.id(R.id.imgView);
TimerTask updateImage = new UpdateImage4();
timer.scheduleAtFixedRate(updateImage, 0, 1000 / FPS);
}
class UpdateImage4 extends TimerTask {
public void run() {
try {
if (i == 29) {
i = 0;
}
runOnUiThread(new Runnable() {
@Override
public void run() {
//load image from file, down sample to target width of 300 pixels
aquery.image(framesFiles[i],300);
}
});
i++;
} catch (Exception e) {
System.out.println("Exception 4: " + e.getMessage());
}
}
}
它不能像我预期的那样工作 - 我在每张照片之前都有一个闪烁的效果。我认为首先它会清除图片，然后添加一个新图片:(