Develop Reference

Android camera2 preview image disorder when saved using ImageReader

I am taking a series of pictures using Android Camera2 API for real time pose estimation and environment reconstruction (the SLAM problem). Currently I simply save all of these pictures in my SD card for off-line processing.
I setup the processing pipeline according to google's Camera2Basic using a TextureView as well as an ImageReader, where they are both set as target surfaces for a repeat preview request.
mButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(mIsShooting){
try {
mCaptureSession.stopRepeating();
mPreviewRequestBuilder.removeTarget(mImageReader.getSurface());
mCaptureSession.setRepeatingRequest(mPreviewRequestBuilder.build(), mCaptureCallback, mBackgroundHandler);
mIsShooting = false;
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
else{
try {
mCaptureSession.stopRepeating();
mPreviewRequestBuilder.addTarget(mImageReader.getSurface());
mCaptureSession.setRepeatingRequest(mPreviewRequestBuilder.build(), mCaptureCallback, mBackgroundHandler);
mIsShooting = true;
} catch (CameraAccessException e) {
e.printStackTrace();
}
}
}
});
The ImageReader is added/removed when pressing the button. The ImageReader's OnImageAvailableListener is implemented as follow:
private ImageReader.OnImageAvailableListener mOnImageAvailableListener = new ImageReader.OnImageAvailableListener() {
#Override
public void onImageAvailable(ImageReader reader) {
Image img = reader.acquireLatestImage();
if(null == img){
return;
}
if(img.getTimestamp() <= mLatestFrameTime){
Log.i(Tag, "disorder detected!");
return;
}
mLatestFrameTime = img.getTimestamp();
ImageSaver saver = new ImageSaver(img, img.getTimestamp());
saver.run();
}
};
I use acquireLatestImage (with buffer size set to 2) to discard old frames and have also checked the image's timestamp to make sure they are monotonously increasing.
The reader does receive images at an acceptable rate (about 25fps). However a closer look at the saved image sequence show they are not
always saved in chronological order.
The following pictures come from a long sequence shot by the program (sorry for not being able to post pictures directly :( ):
Image 1:
Image 2:
Image 3:
Such disorder does not occur very often but they can occur any time and seems not to be an initialization problem. I suppose it has something to do with the ImageReader's buffer size as with larger buffer less "flash backs" are occurred. Does anyone have the same problem?

I finally find that such disorder disappears when setting ImageReader's format to be YUV_420_888 in its constructor. Originally I set this field as JPEG.
Using JPEG format incurs not only large processing delay but also disorder. I guess the conversion from image sensor data to desired format utilizes other hardware such as DSP or GPU which does not guarantee chronological order.

Are you using TEMPLATE_STILL_CAPTURE for the capture requests when you enable the ImageReader, or just TEMPLATE_PREVIEW? What devices are you seeing issues with?
If you're using STILL_CAPTURE, make sure you check if the device supports the ENABLE_ZSL flag, and set it to false. When it is set to true (generally the default on devices that support it, for the STILL_CAPTURE template), images may be returned out of order since there's a zero-shutter-lag queue in place within the camera device.

Reading Binary Picture Data from exiftool?

I'm working on a .opus music library software which converts audio/video files to .opus files and tags them with metadata automatically.
Previous versions of the program have saved the album art as binary data apparently as revealed by exiftool.
The thing is that when I run the command to output data as binary using the -b option, the entire thing is in binary seemingly. I'm not sure how to get the program to parse it. I was kind of expecting an entry like Picture : 11010010101101101011....
The output looks similar to this though:
How can I parse the picture data so I can reconstruct the image for newer versions of the program? (I'm using Java8_171 on Kubuntu 18.04)

It looks like you're trying to open the raw bytes in a text editor, which will of course give you gobble-dee-gook since those raw bytes do not represent characters that can be displayed by any text editor. I can see from your output from exiftool that you are able to know the length of the image in bytes. Providing you know the beginning byte position in the file, this should make your task relatively easy with a little bit of Java code. If you can get the starting position of the image inside your file, you should be able to do something like:
import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.*;
public class SaveImage {
public static void main(String[] args) throws IOException {
byte[] imageBytes;
try (RandomAccessFile binaryReader =
new RandomAccessFile("your-file.xxx", "r")) {
int dataLength = 0; // Assign this the byte length shown in your
// post instead of zero
int startPos = 0; // I assume you can find this somehow.
// If it's not at the beginning
// change it accordingly.
imageBytes = new byte[dataLength];
binaryReader.read(imageBytes, startPos, dataLength);
}
try (InputStream in = new ByteArrayInputStream(imageBytes)) {
BufferedImage bImageFromConvert = ImageIO.read(in);
ImageIO.write(bImageFromConvert,
"jpg", // or whatever file format is appropriate
new File("/path/to/your/file.jpg"));
}
}
}

mediaReader.readPacket() blocks while trying to read rtsp stream in Xuggler

I am trying to download a video (with a Xuggler 5.4 library) from rtsp stream to a file using the code below.
String inputSource = "rtsp://[ip-address]:[port]/user=[username]&[password]=password&channel=1&stream=1.sdp";
String outputFilename = "d:/downloadedrtsp.flv";
try {
IContainerFormat inFormat = IContainerFormat.make();
inFormat.setInputFormat("h246");
IMediaReader mediaReader = ToolFactory.makeReader(inputSource);
mediaReader.setQueryMetaData(false);
IMediaWriter mediaWriter = ToolFactory.makeWriter(outputFilename, mediaReader);
mediaReader.addListener(mediaWriter);
logger.info("before reading");
IError error;
while ((error = mediaReader.readPacket()) == null) {
logger.info("reading packet");
}
logger.info("error: " + error.getDescription());
logger.info(error.getType());
logger.info(error.toString());
} catch (Exception e) {
e.printStackTrace();
}
The problem is that after printing "before reading" the code just stop executing, and after a long time it prints me three lines from logger:
error: Unknown error
ERROR_EOF
Unknown error
Stream works great when i am opening it in the VLC media player. I am shure there is some mistake in my mediaReader configuration, but i don't know where exactly as i have a very little experience working with videos. Here is some information about video, taken from VLC:

It seems like everything works as expected.
The error type ERROR_EOF marks the end of the input stream (see the documentation).
The long time you program "stop executing" is the time it takes for Xuggler to convert the video frames (it actually doesn't "stop", just iterate through the while loop).

How to properly detect, decode and play a radio stream?

I am currently trying to write a jukebox-like application in Java that is able to play any audio source possible, but encountered some difficulties when trying to play radio streams.
For playback I use JLayer from JavaZoom, that works fine as long as the target is a direct media file or a direct media stream (I can play PCM, MP3 and OGG just fine). However I encounter difficulties when trying to play radio streams which either contain pre-media data like a m3u/pls file (which I could fix by adding a detection beforehand), or data that is streamed on port 80 while a web-page exists at the same location and the media transmitted depends on the type of request. In the later case, whenever I try to stream the media, I instead get the HTML data.
Example link of a stream that is hidden behind a web-page: http://stream.t-n-media.de:8030
This is playable in VLC, but if you put it into a browser or my application you'll receive an HTML file.
Is there:
A ready-made, free solution that I could use in place of JLayer? Preferably open source so I can study it?
A tutorial that can help me to write a solution on my own?
Or can someone give me an example on how to properly detect/request a media stream?
Thanks in advance!

import java.io.*;
import java.net.*;
import javax.sound.sampled.*;
import javax.sound.midi.*;
/**
* This class plays sounds streaming from a URL: it does not have to preload
* the entire sound into memory before playing it. It is a command-line
* application with no gui. It includes code to convert ULAW and ALAW
* audio formats to PCM so they can be played. Use the -m command-line option
* before MIDI files.
*/
public class PlaySoundStream {
// Create a URL from the command-line argument and pass it to the
// right static method depending on the presence of the -m (MIDI) option.
public static void main(String[ ] args) throws Exception {
if (args[0].equals("-m")) streamMidiSequence(new URL(args[1]));
else streamSampledAudio(new URL(args[0]));
// Exit explicitly.
// This is needed because the audio system starts background threads.
System.exit(0);
}
/** Read sampled audio data from the specified URL and play it */
public static void streamSampledAudio(URL url)
throws IOException, UnsupportedAudioFileException,
LineUnavailableException
{
AudioInputStream ain = null; // We read audio data from here
SourceDataLine line = null; // And write it here.
try {
// Get an audio input stream from the URL
ain=AudioSystem.getAudioInputStream(url);
// Get information about the format of the stream
AudioFormat format = ain.getFormat( );
DataLine.Info info=new DataLine.Info(SourceDataLine.class,format);
// If the format is not supported directly (i.e. if it is not PCM
// encoded), then try to transcode it to PCM.
if (!AudioSystem.isLineSupported(info)) {
// This is the PCM format we want to transcode to.
// The parameters here are audio format details that you
// shouldn't need to understand for casual use.
AudioFormat pcm =
new AudioFormat(format.getSampleRate( ), 16,
format.getChannels( ), true, false);
// Get a wrapper stream around the input stream that does the
// transcoding for us.
ain = AudioSystem.getAudioInputStream(pcm, ain);
// Update the format and info variables for the transcoded data
format = ain.getFormat( );
info = new DataLine.Info(SourceDataLine.class, format);
}
// Open the line through which we'll play the streaming audio.
line = (SourceDataLine) AudioSystem.getLine(info);
line.open(format);
// Allocate a buffer for reading from the input stream and writing
// to the line. Make it large enough to hold 4k audio frames.
// Note that the SourceDataLine also has its own internal buffer.
int framesize = format.getFrameSize( );
byte[ ] buffer = new byte[4 * 1024 * framesize]; // the buffer
int numbytes = 0; // how many bytes
// We haven't started the line yet.
boolean started = false;
for(;;) { // We'll exit the loop when we reach the end of stream
// First, read some bytes from the input stream.
int bytesread=ain.read(buffer,numbytes,buffer.length-numbytes);
// If there were no more bytes to read, we're done.
if (bytesread == -1) break;
numbytes += bytesread;
// Now that we've got some audio data to write to the line,
// start the line, so it will play that data as we write it.
if (!started) {
line.start( );
started = true;
}
// We must write bytes to the line in an integer multiple of
// the framesize. So figure out how many bytes we'll write.
int bytestowrite = (numbytes/framesize)*framesize;
// Now write the bytes. The line will buffer them and play
// them. This call will block until all bytes are written.
line.write(buffer, 0, bytestowrite);
// If we didn't have an integer multiple of the frame size,
// then copy the remaining bytes to the start of the buffer.
int remaining = numbytes - bytestowrite;
if (remaining > 0)
System.arraycopy(buffer,bytestowrite,buffer,0,remaining);
numbytes = remaining;
}
// Now block until all buffered sound finishes playing.
line.drain( );
}
finally { // Always relinquish the resources we use
if (line != null) line.close( );
if (ain != null) ain.close( );
}
}
// A MIDI protocol constant that isn't defined by javax.sound.midi
public static final int END_OF_TRACK = 47;
/* MIDI or RMF data from the specified URL and play it */
public static void streamMidiSequence(URL url)
throws IOException, InvalidMidiDataException, MidiUnavailableException
{
Sequencer sequencer=null; // Converts a Sequence to MIDI events
Synthesizer synthesizer=null; // Plays notes in response to MIDI events
try {
// Create, open, and connect a Sequencer and Synthesizer
// They are closed in the finally block at the end of this method.
sequencer = MidiSystem.getSequencer( );
sequencer.open( );
synthesizer = MidiSystem.getSynthesizer( );
synthesizer.open( );
sequencer.getTransmitter( ).setReceiver(synthesizer.getReceiver( ));
// Specify the InputStream to stream the sequence from
sequencer.setSequence(url.openStream( ));
// This is an arbitrary object used with wait and notify to
// prevent the method from returning before the music finishes
final Object lock = new Object( );
// Register a listener to make the method exit when the stream is
// done. See Object.wait( ) and Object.notify( )
sequencer.addMetaEventListener(new MetaEventListener( ) {
public void meta(MetaMessage e) {
if (e.getType( ) == END_OF_TRACK) {
synchronized(lock) {
lock.notify( );
}
}
}
});
// Start playing the music
sequencer.start( );
// Now block until the listener above notifies us that we're done.
synchronized(lock) {
while(sequencer.isRunning( )) {
try { lock.wait( ); } catch(InterruptedException e) { }
}
}
}
finally {
// Always relinquish the sequencer, so others can use it.
if (sequencer != null) sequencer.close( );
if (synthesizer != null) synthesizer.close( );
}
}
}
I have used this piece of code in one of my projects that deal with Audio streaming and was working just fine.
Furthermore, you can see similar examples here:
Java Audio Example

Just reading the javadoc of AudioSystem give me an idea.
There is an other signature for getAudioInputStream: you can give it an InputStream instead of a URL.
So, try to manage to get the input stream by yourself and add the needed headers so that you get the stream instead the html content:
URLConnection uc = url.openConnection();
uc.setRequestProperty("<header name here>", "<header value here>");
InputStream in = uc.getInputStream();
ain=AudioSystem.getAudioInputStream(in);
Hope this help.

I know this answer comes late, but I had the same issue: I wanted to play MP3 and AAC audio and also wanted the user to insert PLS/M3U links. Here is what I did:
First I tried to parse the type by using the simple file name:
import de.webradio.enumerations.FileExtension;
import java.net.URL;
public class FileExtensionParser {
/**
*Parses a file extension
* #param filenameUrl the url
* #return the filename. if filename cannot be determined by file extension, Apache Tika parses by live detection
*/
public FileExtension parseFileExtension(URL filenameUrl) {
String filename = filenameUrl.toString();
if (filename.endsWith(".mp3")) {
return FileExtension.MP3;
} else if (filename.endsWith(".m3u") || filename.endsWith(".m3u8")) {
return FileExtension.M3U;
} else if (filename.endsWith(".aac")) {
return FileExtension.AAC;
} else if(filename.endsWith((".pls"))) {
return FileExtension.PLS;
}
URLTypeParser parser = new URLTypeParser();
return parser.parseByContentDetection(filenameUrl);
}
}
If that fails, I use Apache Tika to do a kind of live detection:
public class URLTypeParser {
/** This class uses Apache Tika to parse an URL using her content
*
* #param url the webstream url
* #return the detected file encoding: MP3, AAC or unsupported
*/
public FileExtension parseByContentDetection(URL url) {
try {
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
InputStream in = connection.getInputStream();
BodyContentHandler handler = new BodyContentHandler();
AudioParser parser = new AudioParser();
Metadata metadata = new Metadata();
parser.parse(in, handler, metadata);
return parseMediaType(metadata);
} catch (IOException e) {
e.printStackTrace();
} catch (TikaException e) {
e.printStackTrace();
} catch (SAXException e) {
e.printStackTrace();
}
return FileExtension.UNSUPPORTED_TYPE;
}
private FileExtension parseMediaType(Metadata metadata) {
String parsedMediaType = metadata.get("encoding");
if (parsedMediaType.equalsIgnoreCase("aac")) {
return FileExtension.AAC;
} else if (parsedMediaType.equalsIgnoreCase("mpeg1l3")) {
return FileExtension.MP3;
}
return FileExtension.UNSUPPORTED_TYPE;
}
}
This will also solve the HTML problem, since the method will return FileExtension.UNSUPPORTED for HTML content.
I combined this classes together with a factory pattern and it works fine. The live detection takes only about two seconds.
I don't think that this will help you anymore but since I struggled almost three weeks I wanted to provide a working answer. You can see the whole project at github: https://github.com/Seppl2202/webradio

Android Mediarecorder: Getting 3GP instead of MPEG4

I want to record video only in android with MPEG4 format. I want the container and codec to be MPEG4. So here is what I have done for that.
Thread video = new Thread(new Runnable() {
public void run() {
videoRecorder = new MediaRecorder();
videoRecorder.setPreviewDisplay(surfaceView.getHolder().getSurface());
videoRecorder.setVideoSource(MediaRecorder.VideoSource.DEFAULT);
videoRecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);
videoRecorder.setVideoEncodingBitRate(56 * 8 * 1024);
videoRecorder.setVideoSize(176, 144);
videoRecorder.setVideoFrameRate(12);
videoRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.MPEG_4_SP);
videoRecorder.setOutputFile("/sdcard/video.m4e");
try {
videoRecorder.prepare();
} catch (IllegalStateException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
videoRecorder.start();
}
});
video.start();
Now, after recording, I got the video recorded into video.m4e file. But when I check its information, I got the following:
At the same time I used the following to record audio:
Thread audio = new Thread(new Runnable() {
public void run() {
audioRecorder = new MediaRecorder();
audioRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
audioRecorder.setOutputFormat(MediaRecorder.OutputFormat.RAW_AMR);
audioRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
audioRecorder.setOutputFile("/sdcard/audio.amr");
try {
audioRecorder.prepare();
} catch (IllegalStateException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
audioRecorder.start();
}
});
audio.start();
and I got the container format and codec as AMR as I intended:
So, what causes MediaRecorder to record video in 3GP format? I haven't specified 3GP anywhere in my program. I am testing this code on my Samsung Galaxy tab running Android 2.2

MPEG-4 is a method of defining compression of audio and visual (AV) digital data.A file format for storing time-based media content. It is a general format forming the basis for a number of other more specific file formats (e.g. 3GP, Motion JPEG 2000, MPEG-4 Part 14).So there is no conspiracy in the result you got, the compression method (OR "Codec") you used was MPEG4 and the video format generated by your phone is 3gp, which in actual is a part of the video formats of the suite of the MPEG4 compression scheme for the media.

This is defined by the frameworks. Specifically it has a set of parameters that are found in the MediaRecorder class that define what all is supported.

I do not understand akkilis's explanation.
In the official Android tutorial "MediaRecorder.OutputFormat",
MPEG_4 is one of options of "media file formats", parallel to THREE_GPP.
int AAC_ADTS AAC ADTS file format
int AMR_NB AMR NB file format
int AMR_WB AMR WB file format
int DEFAULT
int MPEG_4 MPEG4 media file format
int RAW_AMR This constant was deprecated in API level 16. Deprecated in favor of MediaRecorder.OutputFormat.AMR_NB
int THREE_GPP 3GPP media file format
There is another parameter to specify the encoding format:
"MediaRecorder.VideoEncoder"
int DEFAULT
int H263
int H264
int MPEG_4_SP
In OP's code, he specified both file format and encoding format.
videoRecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);
videoRecorder.setVideoEncoder(MediaRecorder.VideoEncoder.MPEG_4_SP);
So it seems akkilis's explanation does not work for this example.