我需要降低某些mp4文件的视频分辨率,我决定使用jcodec。我试图搜索一些示例如何执行此操作,但没有找到任何示例。任何有关此信息都将非常有用。
答案 0 :(得分:2)
我也在寻找答案,但没有找到任何答案。
所以我查看了代码并意识到在将Bitmap传递给JCodec之前对其进行缩放可以解决问题。
这是我使用的课程。请注意,这是Android的代码,它使用最新的JCodec for Android。
public class DDVideoEncoder {
private static final String TAG = DDVideoEncoder.class.getSimpleName();
private SequenceEncoder encoder;
public DDVideoEncoder(String filepath) throws IOException, OutOfMemoryError {
File out = new File(filepath);
encoder = new SequenceEncoder(out);
}
// returns false on out of memory error.
public Boolean addFrame(String filePath, int newSize) throws IOException {
// newSize indicates size of bitmap in percent
Bitmap bi = getResizedBitmap(filePath, newSize);
try { encoder.encodeImage(bi); }
catch (OutOfMemoryError outOfMemoryError) { Log.d(TAG, "encodeImage:" + outOfMemoryError); return false; }
catch (NullPointerException nil) { Log.d(TAG, "encodeImage:"+nil); return false; }
return true;
}
public void finishEncoding(){
try { encoder.finish(); }
catch (IOException io) {
Log.d("DDVideoEncoder", "IOException"); }
}
// newSize indicates size of bitmap in percent of original.
//decodes image and scales it to reduce memory consumption
private Bitmap getResizedBitmap(String filePath, int newSize) {
//Decode image size
BitmapFactory.Options o = new BitmapFactory.Options();
o.inJustDecodeBounds = true;
//BitmapFactory.decodeStream(new FileInputStream(f),null,o);
BitmapFactory.decodeFile(filePath, o);
//The new size we want to scale to
final int REQUIRED_SIZE=newSize*10;
//Find the correct scale value. It should be the power of 2.
int scale=1;
while(o.outWidth/scale/2>=REQUIRED_SIZE && o.outHeight/scale/2>=REQUIRED_SIZE)
scale*=2;
//Decode with inSampleSize
BitmapFactory.Options o2 = new BitmapFactory.Options();
o2.inSampleSize=scale;
//return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
return BitmapFactory.decodeFile(filePath, o2);
}
}
然后你可以使用这样的类:
try {
DDVideoEncoder tmpEncoder = new DDVideoEncoder(dir+vidName);
// write x frames
Log.d("test", "adding frame");
try { tmpEncoder.addFrame(path, 50); }
catch (OutOfMemoryError outOfMemoryError){ Log.d("test", "oom"); break; }
catch (IOException io) { Log.d("CactusMemChecker", io.getMessage()); break; }
catch (IndexOutOfBoundsException oob) { Log.d("test", "oob"); break; }
// finish up
tmpEncoder.finishEncoding();
} catch (IOException e) {
Log.d("test", e.getMessage());
testResult = false;
} catch (OutOfMemoryError e) {
Log.d("test", e.getMessage());
testResult = false;
} catch (IndexOutOfBoundsException e) {
Log.d("test", e.getMessage());
testResult = false;
}