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Médias (1)
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Bug de détection d’ogg
22 mars 2013, par
Mis à jour : Avril 2013
Langue : français
Type : Video
Autres articles (57)
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Les autorisations surchargées par les plugins
27 avril 2010, parMediaspip core
autoriser_auteur_modifier() afin que les visiteurs soient capables de modifier leurs informations sur la page d’auteurs -
Publier sur MédiaSpip
13 juin 2013Puis-je poster des contenus à partir d’une tablette Ipad ?
Oui, si votre Médiaspip installé est à la version 0.2 ou supérieure. Contacter au besoin l’administrateur de votre MédiaSpip pour le savoir -
List of compatible distributions
26 avril 2011, parThe table below is the list of Linux distributions compatible with the automated installation script of MediaSPIP. Distribution nameVersion nameVersion number Debian Squeeze 6.x.x Debian Weezy 7.x.x Debian Jessie 8.x.x Ubuntu The Precise Pangolin 12.04 LTS Ubuntu The Trusty Tahr 14.04
If you want to help us improve this list, you can provide us access to a machine whose distribution is not mentioned above or send the necessary fixes to add (...)
Sur d’autres sites (7547)
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Audio & Video not synchronized properly if i merged more videos in mp4parser
1er octobre 2013, par maniyaI have used mp4parser for merging video with dynamic pause and record video capture for max 6 second recording. In preview its working fine when recorded video with minimum pause/record, If i tried with more than 3 pause/record mean the last video file not get merged properly with audio.At the start of the video the sync is ok but at the end the video hanged and audio playing in screen for the remaining file duration about 1sec.
My Recording manager
public class RecordingManager implements Camera.ErrorCallback, MediaRecorder.OnErrorListener, MediaRecorder.OnInfoListener {
private static final String TAG = RecordingManager.class.getSimpleName();
private static final int FOCUS_AREA_RADIUS = 32;
private static final int FOCUS_MAX_VALUE = 1000;
private static final int FOCUS_MIN_VALUE = -1000;
private static final long MINIMUM_RECORDING_TIME = 2000;
private static final int MAXIMUM_RECORDING_TIME = 70 * 1000;
private static final long LOW_STORAGE_THRESHOLD = 5 * 1024 * 1024;
private static final long RECORDING_FILE_LIMIT = 100 * 1024 * 1024;
private boolean paused = true;
private MediaRecorder mediaRecorder = null;
private boolean recording = false;
private FrameLayout previewFrame = null;
private boolean mPreviewing = false;
// private TextureView mTextureView = null;
// private SurfaceTexture mSurfaceTexture = null;
// private boolean mSurfaceTextureReady = false;
//
private SurfaceView surfaceView = null;
private SurfaceHolder surfaceHolder = null;
private boolean surfaceViewReady = false;
private Camera camera = null;
private Camera.Parameters cameraParameters = null;
private CamcorderProfile camcorderProfile = null;
private int mOrientation = -1;
private OrientationEventListener mOrientationEventListener = null;
private long mStartRecordingTime;
private int mVideoWidth;
private int mVideoHeight;
private long mStorageSpace;
private Handler mHandler = new Handler();
// private Runnable mUpdateRecordingTimeTask = new Runnable() {
// @Override
// public void run() {
// long recordingTime = System.currentTimeMillis() - mStartRecordingTime;
// Log.d(TAG, String.format("Recording time:%d", recordingTime));
// mHandler.postDelayed(this, CLIP_GRAPH_UPDATE_INTERVAL);
// }
// };
private Runnable mStopRecordingTask = new Runnable() {
@Override
public void run() {
stopRecording();
}
};
private static RecordingManager mInstance = null;
private Activity currentActivity = null;
private String destinationFilepath = "";
private String snapshotFilepath = "";
public static RecordingManager getInstance(Activity activity, FrameLayout previewFrame) {
if (mInstance == null || mInstance.currentActivity != activity) {
mInstance = new RecordingManager(activity, previewFrame);
}
return mInstance;
}
private RecordingManager(Activity activity, FrameLayout previewFrame) {
currentActivity = activity;
this.previewFrame = previewFrame;
}
public int getVideoWidth() {
return this.mVideoWidth;
}
public int getVideoHeight() {
return this.mVideoHeight;
}
public void setDestinationFilepath(String filepath) {
this.destinationFilepath = filepath;
}
public String getDestinationFilepath() {
return this.destinationFilepath;
}
public void setSnapshotFilepath(String filepath) {
this.snapshotFilepath = filepath;
}
public String getSnapshotFilepath() {
return this.snapshotFilepath;
}
public void init(String videoPath, String snapshotPath) {
Log.v(TAG, "init.");
setDestinationFilepath(videoPath);
setSnapshotFilepath(snapshotPath);
if (!Utils.isExternalStorageAvailable()) {
showStorageErrorAndFinish();
return;
}
openCamera();
if (camera == null) {
showCameraErrorAndFinish();
return;
}
public void onResume() {
Log.v(TAG, "onResume.");
paused = false;
// Open the camera
if (camera == null) {
openCamera();
if (camera == null) {
showCameraErrorAndFinish();
return;
}
}
// Initialize the surface texture or surface view
// if (useTexture() && mTextureView == null) {
// initTextureView();
// mTextureView.setVisibility(View.VISIBLE);
// } else if (!useTexture() && mSurfaceView == null) {
initSurfaceView();
surfaceView.setVisibility(View.VISIBLE);
// }
// Start the preview
if (!mPreviewing) {
startPreview();
}
}
private void openCamera() {
Log.v(TAG, "openCamera");
try {
camera = Camera.open();
camera.setErrorCallback(this);
camera.setDisplayOrientation(90); // Since we only support portrait mode
cameraParameters = camera.getParameters();
} catch (RuntimeException e) {
e.printStackTrace();
camera = null;
}
}
private void closeCamera() {
Log.v(TAG, "closeCamera");
if (camera == null) {
Log.d(TAG, "Already stopped.");
return;
}
camera.setErrorCallback(null);
if (mPreviewing) {
stopPreview();
}
camera.release();
camera = null;
}
private void initSurfaceView() {
surfaceView = new SurfaceView(currentActivity);
surfaceView.getHolder().addCallback(new SurfaceViewCallback());
surfaceView.setVisibility(View.GONE);
FrameLayout.LayoutParams params = new LayoutParams(
LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT, Gravity.CENTER);
surfaceView.setLayoutParams(params);
Log.d(TAG, "add surface view to preview frame");
previewFrame.addView(surfaceView);
}
private void releaseSurfaceView() {
if (surfaceView != null) {
previewFrame.removeAllViews();
surfaceView = null;
surfaceHolder = null;
surfaceViewReady = false;
}
}
private void startPreview() {
// if ((useTexture() && !mSurfaceTextureReady) || (!useTexture() && !mSurfaceViewReady)) {
// return;
// }
Log.v(TAG, "startPreview.");
if (mPreviewing) {
stopPreview();
}
setCameraParameters();
resizePreview();
try {
// if (useTexture()) {
// mCamera.setPreviewTexture(mSurfaceTexture);
// } else {
camera.setPreviewDisplay(surfaceHolder);
// }
camera.startPreview();
mPreviewing = true;
} catch (Exception e) {
closeCamera();
e.printStackTrace();
Log.e(TAG, "startPreview failed.");
}
}
private void stopPreview() {
Log.v(TAG, "stopPreview");
if (camera != null) {
camera.stopPreview();
mPreviewing = false;
}
}
public void onPause() {
paused = true;
if (recording) {
stopRecording();
}
closeCamera();
// if (useTexture()) {
// releaseSurfaceTexture();
// } else {
releaseSurfaceView();
// }
}
private void setCameraParameters() {
if (CamcorderProfile.hasProfile(CamcorderProfile.QUALITY_720P)) {
camcorderProfile = CamcorderProfile.get(CamcorderProfile.QUALITY_720P);
} else if (CamcorderProfile.hasProfile(CamcorderProfile.QUALITY_480P)) {
camcorderProfile = CamcorderProfile.get(CamcorderProfile.QUALITY_480P);
} else {
camcorderProfile = CamcorderProfile.get(CamcorderProfile.QUALITY_HIGH);
}
mVideoWidth = camcorderProfile.videoFrameWidth;
mVideoHeight = camcorderProfile.videoFrameHeight;
camcorderProfile.fileFormat = MediaRecorder.OutputFormat.MPEG_4;
camcorderProfile.videoFrameRate = 30;
Log.v(TAG, "mVideoWidth=" + mVideoWidth + " mVideoHeight=" + mVideoHeight);
cameraParameters.setPreviewSize(mVideoWidth, mVideoHeight);
if (cameraParameters.getSupportedWhiteBalance().contains(Camera.Parameters.WHITE_BALANCE_AUTO)) {
cameraParameters.setWhiteBalance(Camera.Parameters.WHITE_BALANCE_AUTO);
}
if (cameraParameters.getSupportedFocusModes().contains(Camera.Parameters.FOCUS_MODE_CONTINUOUS_VIDEO)) {
cameraParameters.setFocusMode(Camera.Parameters.FOCUS_MODE_CONTINUOUS_VIDEO);
}
cameraParameters.setRecordingHint(true);
cameraParameters.set("cam_mode", 1);
camera.setParameters(cameraParameters);
cameraParameters = camera.getParameters();
camera.setDisplayOrientation(90);
android.hardware.Camera.CameraInfo info = new android.hardware.Camera.CameraInfo();
Log.d(TAG, info.orientation + " degree");
}
private void resizePreview() {
Log.d(TAG, String.format("Video size:%d|%d", mVideoWidth, mVideoHeight));
Point optimizedSize = getOptimizedPreviewSize(mVideoWidth, mVideoHeight);
Log.d(TAG, String.format("Optimized size:%d|%d", optimizedSize.x, optimizedSize.y));
ViewGroup.LayoutParams params = (ViewGroup.LayoutParams) previewFrame.getLayoutParams();
params.width = optimizedSize.x;
params.height = optimizedSize.y;
previewFrame.setLayoutParams(params);
}
public void setOrientation(int ori) {
this.mOrientation = ori;
}
public void setOrientationEventListener(OrientationEventListener listener) {
this.mOrientationEventListener = listener;
}
public Camera getCamera() {
return camera;
}
@SuppressWarnings("serial")
public void setFocusArea(float x, float y) {
if (camera != null) {
int viewWidth = surfaceView.getWidth();
int viewHeight = surfaceView.getHeight();
int focusCenterX = FOCUS_MAX_VALUE - (int) (x / viewWidth * (FOCUS_MAX_VALUE - FOCUS_MIN_VALUE));
int focusCenterY = FOCUS_MIN_VALUE + (int) (y / viewHeight * (FOCUS_MAX_VALUE - FOCUS_MIN_VALUE));
final int left = focusCenterY - FOCUS_AREA_RADIUS < FOCUS_MIN_VALUE ? FOCUS_MIN_VALUE : focusCenterY - FOCUS_AREA_RADIUS;
final int top = focusCenterX - FOCUS_AREA_RADIUS < FOCUS_MIN_VALUE ? FOCUS_MIN_VALUE : focusCenterX - FOCUS_AREA_RADIUS;
final int right = focusCenterY + FOCUS_AREA_RADIUS > FOCUS_MAX_VALUE ? FOCUS_MAX_VALUE : focusCenterY + FOCUS_AREA_RADIUS;
final int bottom = focusCenterX + FOCUS_AREA_RADIUS > FOCUS_MAX_VALUE ? FOCUS_MAX_VALUE : focusCenterX + FOCUS_AREA_RADIUS;
Camera.Parameters params = camera.getParameters();
params.setFocusAreas(new ArrayList() {
{
add(new Camera.Area(new Rect(left, top, right, bottom), 1000));
}
});
camera.setParameters(params);
camera.autoFocus(new AutoFocusCallback() {
@Override
public void onAutoFocus(boolean success, Camera camera) {
Log.d(TAG, "onAutoFocus");
}
});
}
}
public void startRecording(String destinationFilepath) {
if (!recording) {
updateStorageSpace();
setDestinationFilepath(destinationFilepath);
if (mStorageSpace <= LOW_STORAGE_THRESHOLD) {
Log.v(TAG, "Storage issue, ignore the start request");
Toast.makeText(currentActivity, "Storage issue, ignore the recording request", Toast.LENGTH_LONG).show();
return;
}
if (!prepareMediaRecorder()) {
Toast.makeText(currentActivity, "prepareMediaRecorder failed.", Toast.LENGTH_LONG).show();
return;
}
Log.d(TAG, "Successfully prepare media recorder.");
try {
mediaRecorder.start();
} catch (RuntimeException e) {
Log.e(TAG, "MediaRecorder start failed.");
releaseMediaRecorder();
return;
}
mStartRecordingTime = System.currentTimeMillis();
if (mOrientationEventListener != null) {
mOrientationEventListener.disable();
}
recording = true;
}
}
public void stopRecording() {
if (recording) {
if (!paused) {
// Capture at least 1 second video
long currentTime = System.currentTimeMillis();
if (currentTime - mStartRecordingTime < MINIMUM_RECORDING_TIME) {
mHandler.postDelayed(mStopRecordingTask, MINIMUM_RECORDING_TIME - (currentTime - mStartRecordingTime));
return;
}
}
if (mOrientationEventListener != null) {
mOrientationEventListener.enable();
}
// mHandler.removeCallbacks(mUpdateRecordingTimeTask);
try {
mediaRecorder.setOnErrorListener(null);
mediaRecorder.setOnInfoListener(null);
mediaRecorder.stop(); // stop the recording
Toast.makeText(currentActivity, "Video file saved.", Toast.LENGTH_LONG).show();
long stopRecordingTime = System.currentTimeMillis();
Log.d(TAG, String.format("stopRecording. file:%s duration:%d", destinationFilepath, stopRecordingTime - mStartRecordingTime));
// Calculate the duration of video
MediaMetadataRetriever mmr = new MediaMetadataRetriever();
mmr.setDataSource(this.destinationFilepath);
String _length = mmr.extractMetadata(MediaMetadataRetriever.METADATA_KEY_DURATION);
if (_length != null) {
Log.d(TAG, String.format("clip duration:%d", Long.parseLong(_length)));
}
// Taking the snapshot of video
Bitmap snapshot = ThumbnailUtils.createVideoThumbnail(this.destinationFilepath, Thumbnails.MICRO_KIND);
try {
FileOutputStream out = new FileOutputStream(this.snapshotFilepath);
snapshot.compress(Bitmap.CompressFormat.JPEG, 70, out);
out.close();
} catch (Exception e) {
e.printStackTrace();
}
// mActivity.showPlayButton();
} catch (RuntimeException e) {
e.printStackTrace();
Log.e(TAG, e.getMessage());
// if no valid audio/video data has been received when stop() is
// called
} finally {
//
releaseMediaRecorder(); // release the MediaRecorder object
if (!paused) {
cameraParameters = camera.getParameters();
}
recording = false;
}
}
}
public void setRecorderOrientation(int orientation) {
// For back camera only
if (orientation != -1) {
Log.d(TAG, "set orientationHint:" + (orientation + 135) % 360 / 90 * 90);
mediaRecorder.setOrientationHint((orientation + 135) % 360 / 90 * 90);
}else {
Log.d(TAG, "not set orientationHint to mediaRecorder");
}
}
private boolean prepareMediaRecorder() {
mediaRecorder = new MediaRecorder();
camera.unlock();
mediaRecorder.setCamera(camera);
mediaRecorder.setAudioSource(MediaRecorder.AudioSource.CAMCORDER);
mediaRecorder.setVideoSource(MediaRecorder.VideoSource.CAMERA);
mediaRecorder.setProfile(camcorderProfile);
mediaRecorder.setMaxDuration(MAXIMUM_RECORDING_TIME);
mediaRecorder.setOutputFile(this.destinationFilepath);
try {
mediaRecorder.setMaxFileSize(Math.min(RECORDING_FILE_LIMIT, mStorageSpace - LOW_STORAGE_THRESHOLD));
} catch (RuntimeException exception) {
}
setRecorderOrientation(mOrientation);
if (!useTexture()) {
mediaRecorder.setPreviewDisplay(surfaceHolder.getSurface());
}
try {
mediaRecorder.prepare();
} catch (IllegalStateException e) {
releaseMediaRecorder();
return false;
} catch (IOException e) {
releaseMediaRecorder();
return false;
}
mediaRecorder.setOnErrorListener(this);
mediaRecorder.setOnInfoListener(this);
return true;
}
private void releaseMediaRecorder() {
if (mediaRecorder != null) {
mediaRecorder.reset(); // clear recorder configuration
mediaRecorder.release(); // release the recorder object
mediaRecorder = null;
camera.lock(); // lock camera for later use
}
}
private Point getOptimizedPreviewSize(int videoWidth, int videoHeight) {
Display display = currentActivity.getWindowManager().getDefaultDisplay();
Point size = new Point();
display.getSize(size);
Point optimizedSize = new Point();
optimizedSize.x = size.x;
optimizedSize.y = (int) ((float) videoWidth / (float) videoHeight * size.x);
return optimizedSize;
}
private void showCameraErrorAndFinish() {
DialogInterface.OnClickListener buttonListener = new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
currentActivity.finish();
}
};
new AlertDialog.Builder(currentActivity).setCancelable(false)
.setTitle("Camera error")
.setMessage("Cannot connect to the camera.")
.setNeutralButton("OK", buttonListener)
.show();
}
private void showStorageErrorAndFinish() {
DialogInterface.OnClickListener buttonListener = new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
currentActivity.finish();
}
};
new AlertDialog.Builder(currentActivity).setCancelable(false)
.setTitle("Storage error")
.setMessage("Cannot read external storage.")
.setNeutralButton("OK", buttonListener)
.show();
}
private void updateStorageSpace() {
mStorageSpace = getAvailableSpace();
Log.v(TAG, "updateStorageSpace mStorageSpace=" + mStorageSpace);
}
private long getAvailableSpace() {
String state = Environment.getExternalStorageState();
Log.d(TAG, "External storage state=" + state);
if (Environment.MEDIA_CHECKING.equals(state)) {
return -1;
}
if (!Environment.MEDIA_MOUNTED.equals(state)) {
return -1;
}
File directory = currentActivity.getExternalFilesDir("vine");
directory.mkdirs();
if (!directory.isDirectory() || !directory.canWrite()) {
return -1;
}
try {
StatFs stat = new StatFs(directory.getAbsolutePath());
return stat.getAvailableBlocks() * (long) stat.getBlockSize();
} catch (Exception e) {
Log.i(TAG, "Fail to access external storage", e);
}
return -1;
}
private boolean useTexture() {
return false;
// return Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR1;
}
private class SurfaceViewCallback implements SurfaceHolder.Callback {
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
Log.v(TAG, "surfaceChanged. width=" + width + ". height=" + height);
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
Log.v(TAG, "surfaceCreated");
surfaceViewReady = true;
surfaceHolder = holder;
startPreview();
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
Log.d(TAG, "surfaceDestroyed");
surfaceViewReady = false;
}
}
@Override
public void onError(int error, Camera camera) {
Log.e(TAG, "Camera onError. what=" + error + ".");
if (error == Camera.CAMERA_ERROR_SERVER_DIED) {
} else if (error == Camera.CAMERA_ERROR_UNKNOWN) {
}
}
@Override
public void onInfo(MediaRecorder mr, int what, int extra) {
if (what == MediaRecorder.MEDIA_RECORDER_INFO_MAX_DURATION_REACHED) {
stopRecording();
} else if (what == MediaRecorder.MEDIA_RECORDER_INFO_MAX_FILESIZE_REACHED) {
stopRecording();
Toast.makeText(currentActivity, "Size limit reached", Toast.LENGTH_LONG).show();
}
}
@Override
public void onError(MediaRecorder mr, int what, int extra) {
Log.e(TAG, "MediaRecorder onError. what=" + what + ". extra=" + extra);
if (what == MediaRecorder.MEDIA_RECORDER_ERROR_UNKNOWN) {
stopRecording();
}
}
}VideoUtils
public class VideoUtils {
private static final String TAG = VideoUtils.class.getSimpleName();
static double[] matrix = new double[] { 0.0, 1.0, 0.0, -1.0, 0.0, 0.0, 0.0,
0.0, 1.0 };
public static boolean MergeFiles(String speratedDirPath,
String targetFileName) {
File videoSourceDirFile = new File(speratedDirPath);
String[] videoList = videoSourceDirFile.list();
List<track> videoTracks = new LinkedList<track>();
List<track> audioTracks = new LinkedList<track>();
for (String file : videoList) {
Log.d(TAG, "source files" + speratedDirPath
+ File.separator + file);
try {
FileChannel fc = new FileInputStream(speratedDirPath
+ File.separator + file).getChannel();
Movie movie = MovieCreator.build(fc);
for (Track t : movie.getTracks()) {
if (t.getHandler().equals("soun")) {
audioTracks.add(t);
}
if (t.getHandler().equals("vide")) {
videoTracks.add(t);
}
}
} catch (FileNotFoundException e) {
e.printStackTrace();
return false;
} catch (IOException e) {
e.printStackTrace();
return false;
}
}
Movie result = new Movie();
try {
if (audioTracks.size() > 0) {
result.addTrack(new AppendTrack(audioTracks
.toArray(new Track[audioTracks.size()])));
}
if (videoTracks.size() > 0) {
result.addTrack(new AppendTrack(videoTracks
.toArray(new Track[videoTracks.size()])));
}
IsoFile out = new DefaultMp4Builder().build(result);
FileChannel fc = new RandomAccessFile(
String.format(targetFileName), "rw").getChannel();
Log.d(TAG, "target file:" + targetFileName);
TrackBox tb = out.getMovieBox().getBoxes(TrackBox.class).get(1);
TrackHeaderBox tkhd = tb.getTrackHeaderBox();
double[] b = tb.getTrackHeaderBox().getMatrix();
tkhd.setMatrix(matrix);
fc.position(0);
out.getBox(fc);
fc.close();
for (String file : videoList) {
File TBRFile = new File(speratedDirPath + File.separator + file);
TBRFile.delete();
}
boolean a = videoSourceDirFile.delete();
Log.d(TAG, "try to delete dir:" + a);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
return false;
}
return true;
}
public static boolean clearFiles(String speratedDirPath) {
File videoSourceDirFile = new File(speratedDirPath);
if (videoSourceDirFile != null
&& videoSourceDirFile.listFiles() != null) {
File[] videoList = videoSourceDirFile.listFiles();
for (File video : videoList) {
video.delete();
}
videoSourceDirFile.delete();
}
return true;
}
public static int createSnapshot(String videoFile, int kind, String snapshotFilepath) {
return 0;
};
public static int createSnapshot(String videoFile, int width, int height, String snapshotFilepath) {
return 0;
}
}
</track></track></track></track>my reference code project link is
-
Perspective transformations
Finally (after a long break) I managed to force myself to update the PHP documentation and this time it was distortImage code example. Things have been hectic lately but that does not quite explain the 6 months(?) break between this and the previous post. As a matter of a fact there is no excuse for such a long silence so I will try to update this blog a bit more often from now on.
Back in the day I used to blog the examples and update the documentation if I remembered but I am trying to fix this bad habit. Most of the latest examples have been updated in to the manual. In the case of the two last examples I updated the documentation first and then blogged on the subject.
I took some time to actually understand the perspective transformations properly using the excellent ImageMagick examples (mainly created by Anthony Thyssen) as a reference. The basic idea of perspective distortion seems simple : to distort the control points to new locations. Grabbing the syntax for Imagick was easy, an array of control point pairs in the form of :
-
array(source_x, source_y, dest_x, dest_y ... )
The following example uses the built-in checkerboard pattern to demonstrate perspective distortion :
-
< ?php
-
/* Create new object */
-
$im = new Imagick() ;
-
-
/* Create new checkerboard pattern */
-
$im->newPseudoImage(100, 100, "pattern:checkerboard") ;
-
-
/* Set the image format to png */
-
$im->setImageFormat(’png’) ;
-
-
/* Fill background area with transparent */
-
$im->setImageVirtualPixelMethod(Imagick: :VIRTUALPIXELMETHOD_TRANSPARENT) ;
-
-
/* Activate matte */
-
$im->setImageMatte(true) ;
-
-
/* Control points for the distortion */
-
$controlPoints = array( 10, 10,
-
10, 5,
-
-
10, $im->getImageHeight() - 20,
-
10, $im->getImageHeight() - 5,
-
-
$im->getImageWidth() - 10, 10,
-
$im->getImageWidth() - 10, 20,
-
-
$im->getImageWidth() - 10, $im->getImageHeight() - 10,
-
$im->getImageWidth() - 10, $im->getImageHeight() - 30) ;
-
-
/* Perform the distortion */
-
$im->distortImage(Imagick: :DISTORTION_PERSPECTIVE, $controlPoints, true) ;
-
-
/* Ouput the image */
-
header("Content-Type : image/png") ;
-
echo $im ;
-
?>
Here is the source image :
And the result :
-
-
What is “interoperable TTML” ?
19 septembre 2012, par silviaI’ve just tried to come to terms with the latest state of TTML, the Timed Text Markup Language.
TTML has been specified by the W3C Timed Text Working Group and released as a RECommendation v1.0 in November 2010. Since then, several organisations have tried to adopt it as their caption file format. This includes the SMPTE, the EBU (European Broadcasting Union), and Microsoft.
Both, Microsoft and the EBU actually looked at TTML in detail and decided that in order to make it usable for their use cases, a restriction of its functionalities is needed.
EBU-TT
The EBU released EBU-TT, which restricts the set of valid attributes and feature. “The EBU-TT format is intended to constrain the features provided by TTML, especially to make EBU-TT more suitable for the use with broadcast video and web video applications.” (see EBU-TT).
In addition, EBU-specific namespaces were introduce to extend TTML with EBU-specific data types, e.g. ebuttdt:frameRateMultiplierType or ebuttdt:smpteTimingType. Similarly, a bunch of metadata elements were introduced, e.g. ebuttm:documentMetadata, ebuttm:documentEbuttVersion, or ebuttm:documentIdentifier.
The use of namespaces as an extensibility mechanism will ascertain that EBU-TT files continue to be valid TTML files. However, any vanilla TTML parser will not know what to do with these custom extensions and will drop them on the floor.
Simple Delivery Profile
With the intention to make TTML ready for “internet delivery of Captions originated in the United States”, Microsoft proposed a “Simple Delivery Profile for Closed Captions (US)” (see Simple Profile). The Simple Profile is also a restriction of TTML.
Unfortunately, the Microsoft profile is not the same as the EBU-TT profile : for example, it contains the “set” element, which is not conformant in EBU-TT. Similarly, the supported style features are different, e.g. Simple Profile supports “display-region”, while EBU-TT does not. On the other hand, EBU-TT supports monospace, sans-serif and serif fonts, while the Simple profile does not.
Thus files created for the Simple Delivery Profile will not work on players that expect EBU-TT and the reverse.
Fortunately, the Simple Delivery Profile does not introduce any new namespaces and new features, so at least it is an explicit subpart of TTML and not both a restriction and extension like EBU-TT.
SMPTE-TT
SMPTE also created a version of the TTML standard called SMPTE-TT. SMPTE did not decide on a subset of TTML for their purposes – it was simply adopted as a complete set. “This Standard provides a framework for timed text to be supported for content delivered via broadband means,…” (see SMPTE-TT).
However, SMPTE extended TTML in SMPTE-TT with an ability to store a binary blob with captions in another format. This allows using SMPTE-TT as a transport format for any caption format and is deemed to help with “backwards compatibility”.
Now, instead of specifying a profile, SMPTE decided to define how to convert CEA-608 captions to SMPTE-TT. Even if it’s not called a “profile”, that’s actually what it is. It even has its own namespace : “m608 :”.
Conclusion
With all these different versions of TTML, I ask myself what a video player that claims support for TTML will do to get something working. The only chance it has is to implement all the extensions defined in all the different profiles. I pity the player that has to deal with a SMPTE-TT file that has a binary blob in it and is expected to be able to decode this.
Now, what is a caption author supposed to do when creating TTML ? They obviously cannot expect all players to be able to play back all TTML versions. Should they create different files depending on what platform they are targeting, i.e. a EBU-TT version, a SMPTE-TT version, a vanilla TTML version, and a Simple Delivery Profile version ? Should they by throwing all the features of all the versions into one TTML file and hope that the players will pick out the right things that they require and drop the rest on the floor ?
Maybe the best way to progress would be to make a list of the “safe” features : those features that every TTML profile supports. That may be the best way to get an “interoperable TTML” file. Here’s me hoping that this minimal set of features doesn’t just end up being the usual (starttime, endtime, text) triple.
UPDATE :
I just found out that UltraViolet have their own profile of SMPTE-TT called CFF-TT (see UltraViolet FAQ and spec). They are making some SMPTE-TT fields optional, but introduce a new @forcedDisplayMode attribute under their own namespace “cff :”.
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