Android: Bitmap.compress poor quality with PNG format - android

My application captures video footage and saves it as .mp4 file. I would like to extract one frame from this video and also save it to file. Since I haven't found nothing better, I've decided to use MediaMetadataRetriever.getFrameAtTime() for that. It happens inside the class that inherits from AsyncTask. Here is how my code looks like my doInBackground():
Bitmap bitmap1 = null;
MediaMetadataRetriever retriever = new MediaMetadataRetriever();
try {
retriever.setDataSource(src);
bitmap1 = retriever.getFrameAtTime(timeUs, MediaMetadataRetriever.OPTION_CLOSEST_SYNC);
if (Utils.saveBitmap(bitmap1, dst)) {
Log.d(TAG, "doInBackground Image export OK");
} else {
Log.d(TAG, "doInBackground Image export FAILED");
}
} catch (RuntimeException ex) {
Log.d(TAG, "doInBackground Image export FAILED");
} finally {
retriever.release();
if (bitmap1 != null) {
bitmap1.recycle();
}
}
And the saveBitmap() method:
File file = new File(filepath);
boolean result;
try {
result = file.createNewFile();
if (!result) {
return false;
}
FileOutputStream ostream = new FileOutputStream(file);
bitmap.compress(Bitmap.CompressFormat.PNG, 100, ostream);
ostream.close();
return true;
} catch (Exception e) {
e.printStackTrace();
return false;
}
Now, the problem is that the quality of the exported image is noticeably worse then the video quality. I don't think that this should happen with PNG output format. You can see the difference below:
The first image was extracted from the video using ffmpeg on my desktop. The second one was extracted using the code above on Samsung Galaxy S6. The result looks pretty much the same on every Android device I was using.
Can someone tell how can I improve the quality of the exported picture?

I found other solution for the issue. You can use bigflake's example to build mechanism for extracting video frame. The one thing you will have to add is seeking mechanism. This works well, keeps the exact quality and does not require any third-party libraries. Only downside I've noticed so far is that it will result in longer execution time than the original idea.

Related

Not getting full length of bytes from the Video

I'm trying to save the frame of the image from the live stream video. So, I'm able to show live stream video from my android application as well as saving it in my local storage. Now, I want to use some sort of delay in my saveImage function so that images get saved after some specific time. I have used both Handler and TimerTask. The image is getting saved in my local directory after some delay but the length of the image that I get is sometimes very small, the other time normal. I want my saved image to exactly the length of the video stream that I am getting in my application.
I hope the question I asked is easy to understand. I am a beginner in both android and stack overflow.
P.S - I used mjpeg library for showing the video. The video I am getting is from an IP Camera.
Code for saving the images
public void saveImage(){
try {
photo =
new File(Environment.getExternalStorageDirectory(),
"Download/photos/photo" + Instant.now().getEpochSecond() + ".jpg");
if (photo.exists()) {
photo.delete();
}
System.out.println("Photo " + photo);
FileOutputStream fos = new FileOutputStream(photo.getPath());
System.out.println("Image_length" +image.length);
fos.write(image);
fos.close();
} catch (IOException e) {
Log.e("PictureDemo", "Exception in photoCallback", e);
}
}
Code where saveImage is called
final Bitmap outputImg = BitmapFactory.decodeByteArray(image, 0, image.length);
if (outputImg != null) {
if (run) {
newFrame(outputImg);
// Saving frames in internal Storage
new Timer().schedule(
new TimerTask() {
#Override
public void run() {
saveImage();
}
},5000
);
}
} else {
Log.e(tag, "Read image error");
}

Android - how to get frames from video file?

I want to extract frames from video file stored on the device. Every solution i found is to use FFmpegMediaMetadataRetriever or MediaMetadaraRetriever, but as I wrote here it's not working for me. Is there any other way to extract frames from video?
I admit I haven't used this method for a while, but if it still works with the current Android API, it should do the trick.
Please let me know if it still works. If not - I will delete this answer.
public static Bitmap getVideoFrame(Context context, Uri uri, long time) {
Bitmap bitmap = null;
MediaMetadataRetriever retriever = new MediaMetadataRetriever();
try {
retriever.setDataSource(context, uri);
bitmap = retriever.getFrameAtTime(time);
} catch (RuntimeException ex) {
ex.printStackTrace();
} finally {
try {
retriever.release();
} catch (RuntimeException ex) {
ex.printStackTrace();
}
}
return bitmap;
}
Hope this helps.

Display an image without saving it

My app can download an image from a raspberry. it works fine. This is the code
public void downloadFile() {
FTPClient ftpClient = new FTPClient();
try {
ftpClient.connect("******");
ftpClient.login("****","*****");
ftpClient.enterLocalPassiveMode();
ftpClient.setFileType(FTP.BINARY_FILE_TYPE);
String remoteFile1;
File downloadFile1 = new File(filePath);
OutputStream outputStream1 = new BufferedOutputStream(new FileOutputStream(downloadFile1));
boolean success = ftpClient.retrieveFile(remoteFile1, outputStream1);
outputStream1.close();
if (success) {
System.out.println("File #1 has been downloaded successfully.");
} else {
System.out.println("Error in downloading file !");
}
boolean logout = ftpClient.logout();
if (logout) {
System.out.println("Connection close...");
}
} catch (IOException ex) {
System.out.println("Error: " + ex.getMessage());
ex.printStackTrace();
} finally {
try {
ftpClient.disconnect();
} catch (IOException ex) {
ex.printStackTrace();
}
}
}
And then I can display it so the user of my app can see it. For the image loading, Im using this code and it works too.
private void loadImage(String imagePath) {
Uri imageUri;
String fullImagePath;
Drawable image;
ImageView imageDisplay;
imageUri = Uri.parse(imagePath);
fullImagePath = imageUri.getPath();
image = Drawable.createFromPath(fullImagePath);
imageDisplay=(ImageView) findViewById(R.id.imageDisplay);
imageDisplay.setImageDrawable(image);
}
Now I want to display the image without downloading it in my gallery. But I can't figure out how to do this.
Can someone help me please.
You cannot show an image without download it. Actually when you see something "remotely", you are downloading it.
If you mean that the image is too large and you don't want to download, but want a mechanism for the user can view it. One possible solution is make a thumbnail (reduced image) in server side and show that "preview" to the user. Then if the user want to download it to the gallery you could get the original image.
If you want to display an image without downloading it, it has to be uploaded in a image hosting site or alike so you will just use the link instead of the whole FTP Client.
Basically, you are using a code that is intended for saving an image. And the one you are using for loading the images fetches data from the Drawable. So you are in the wrong path.

Grab video thumbnail and show it in a Gridview in android

I am developing a module for which i want to show all the user's videos from sd card into a Gridview. I have grabbed video file paths in usual way (Checking if file or directory and save if its a file) in a arraylist and grabbed its bitmap thumbnail with following code:
Bitmap bmThumbnail = ThumbnailUtils.createVideoThumbnail(VideoValues.get(position).getAbsolutePath(),
Thumbnails.MINI_KIND);
Obviously this code runs in a background thread. But the only problem is that the gribview still freezes a lot while scrolling. According to me the main problem is extracting the bitmap from video, which takes a lot of time. Can anyone suggest me a different way to get bitmap from video and how it in a grid ? I have seen the smooth behavior in other apps like Facebook, etc. But I cannot figure out as to how that can be done.
please use below method for retrive video thumbnail from video
#SuppressLint("NewApi")
public static Bitmap retriveVideoFrameFromVideo(String videoPath)
throws Throwable
{
Bitmap bitmap = null;
MediaMetadataRetriever mediaMetadataRetriever = null;
try
{
mediaMetadataRetriever = new MediaMetadataRetriever();
mediaMetadataRetriever.setDataSource(videoPath);
bitmap = mediaMetadataRetriever.getFrameAtTime();
}
catch (Exception e)
{
throw new Throwable(
"Exception in retriveVideoFrameFromVideo(String videoPath)"
+ e.getMessage());
}
finally
{
if (mediaMetadataRetriever != null)
{
mediaMetadataRetriever.release();
}
}
return bitmap;
}

Android Create Video Thumbnail at specific time

I already got it to create a thumbnail from my video.
The code looks like this:
videoGalleryThumbnails.add(ThumbnailUtils.extractThumbnail(ThumbnailUtils.createVideoThumbnail(
videoFile.getAbsolutePath(), MediaStore.Images.Thumbnails.MINI_KIND), 500, 200));
But the thumbnail created is at a really bad time. It is exactly when the video is black. Now i have no use of a completely black Thumbnail.
How can i take a Thumbnail of my video at a specific time? E.g. at 00:31 or at 01:44?
Or is it not possible?
I tried also to use MediaMetadataRetriever, but i get only a white image. Code looks like this
File tempVideoList[] = (Environment.getExternalStoragePublicDirectory(PATH_VIDEO_GALLERY))
.listFiles();
MediaMetadataRetriever retriever = new MediaMetadataRetriever();
Bitmap myBitmap=null;
for (File videoFile : tempVideoList) {
if (videoFile.isFile()) {
//from here
try {
retriever.setDataSource(videoFile.getAbsolutePath());
myBitmap = retriever.getFrameAtTime(11); //at 11th second
} catch (Exception ex) {
Log.i("MyDebugCode", "MediaMetadataRetriever got exception:" + ex);
}
videoGalleryThumbnails.add(myBitmap);
//to here
}
If i replace the code marked as "from here" to "to here" with the top first code, it works.
I also tried MediaMetadataRetriever.OPTION_CLOSEST and OPTION_CLOSEST_SYNC and OPTION_NEXT_SYNC.
Ok i got it.
The MediaMetadataRetriever was absolutely the right way to go. The problem is, that it counts the time in microseconds and not in seconds. Solution looks like this:
try {
retriever.setDataSource(videoFile.getAbsolutePath());
int timeInSeconds = 30;
myBitmap = retriever.getFrameAtTime(timeInSeconds * 1000000,
MediaMetadataRetriever.OPTION_CLOSEST_SYNC);
} catch (Exception ex) {
Log.i("MyDebugCode", "MediaMetadataRetriever got exception:" + ex);
}
videoGalleryThumbnails.add(myBitmap);
I don't know, if OPTION_CLOSEST_SYNC is actually needed, but it looks like this is the better way for programming.
Thanks to William Riley for pointing me in the right direction.
need little changes for this code:
try {
MediaMetadataRetriever retriever = new MediaMetadataRetriever();
//have to control the version for the setDataSource
if (Build.VERSION.SDK_INT >= 14)
retriever.setDataSource(video_path, new HashMap<String, String>());
else
retriever.setDataSource(video_path);
int timeInSeconds = 5;
Bitmap thumb = retriever.getFrameAtTime(timeInSeconds * 1000000,
MediaMetadataRetriever.OPTION_CLOSEST_SYNC);
imageViewThumb.setImageBitmap(thumb);
} catch (Exception ex) {
ex.printStackTrace();
}
if we don't control the version for "setDataSource" then we will get exceptions. for me it was not working until version controlling.

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