use of org.opencastproject.videosegmenter.api.VideoSegmenterException in project opencast by opencast.
the class VideoSegmenterServiceImpl method segment.
/**
* Starts segmentation on the video track identified by
* <code>mediapackageId</code> and <code>elementId</code> and returns a
* receipt containing the final result in the form of anMpeg7Catalog.
*
* @param track
* the element to analyze
* @return a receipt containing the resulting mpeg-7 catalog
* @throws VideoSegmenterException
*/
protected Catalog segment(Job job, Track track) throws VideoSegmenterException, MediaPackageException {
// implementation
if (!track.hasVideo()) {
logger.warn("Element {} is not a video track", track);
throw new VideoSegmenterException("Element is not a video track");
}
try {
Mpeg7Catalog mpeg7;
File mediaFile = null;
URL mediaUrl = null;
try {
mediaFile = workspace.get(track.getURI());
mediaUrl = mediaFile.toURI().toURL();
} catch (NotFoundException e) {
throw new VideoSegmenterException("Error finding the video file in the workspace", e);
} catch (IOException e) {
throw new VideoSegmenterException("Error reading the video file in the workspace", e);
}
if (track.getDuration() == null)
throw new MediaPackageException("Track " + track + " does not have a duration");
logger.info("Track {} loaded, duration is {} s", mediaUrl, track.getDuration() / 1000);
MediaTime contentTime = new MediaRelTimeImpl(0, track.getDuration());
MediaLocator contentLocator = new MediaLocatorImpl(track.getURI());
Video videoContent;
logger.debug("changesThreshold: {}, stabilityThreshold: {}", changesThreshold, stabilityThreshold);
logger.debug("prefNumber: {}, maxCycles: {}", prefNumber, maxCycles);
boolean endOptimization = false;
int cycleCount = 0;
LinkedList<Segment> segments;
LinkedList<OptimizationStep> optimizationList = new LinkedList<OptimizationStep>();
LinkedList<OptimizationStep> unusedResultsList = new LinkedList<OptimizationStep>();
OptimizationStep stepBest = new OptimizationStep();
// local copy of changesThreshold, that can safely be changed over optimization iterations
float changesThresholdLocal = changesThreshold;
// local copies of prefNumber, absoluteMin and absoluteMax, to make a dependency on track length possible
int prefNumberLocal = prefNumber;
int absoluteMaxLocal = absoluteMax;
int absoluteMinLocal = absoluteMin;
// absoluteMax and absoluteMin with the duration of the track
if (durationDependent) {
double trackDurationInHours = track.getDuration() / 3600000.0;
prefNumberLocal = (int) Math.round(trackDurationInHours * prefNumberLocal);
absoluteMaxLocal = (int) Math.round(trackDurationInHours * absoluteMax);
absoluteMinLocal = (int) Math.round(trackDurationInHours * absoluteMin);
// make sure prefNumberLocal will never be 0 or negative
if (prefNumberLocal <= 0) {
prefNumberLocal = 1;
}
logger.info("Numbers of segments are set to be relative to track duration. Therefore for {} the preferred " + "number of segments is {}", mediaUrl, prefNumberLocal);
}
logger.info("Starting video segmentation of {}", mediaUrl);
// to the desired number of segments
while (!endOptimization) {
mpeg7 = mpeg7CatalogService.newInstance();
videoContent = mpeg7.addVideoContent("videosegment", contentTime, contentLocator);
// run the segmentation with FFmpeg
segments = runSegmentationFFmpeg(track, videoContent, mediaFile, changesThresholdLocal);
// calculate errors for "normal" and filtered segmentation
// and compare them to find better optimization.
// "normal"
OptimizationStep currentStep = new OptimizationStep(stabilityThreshold, changesThresholdLocal, segments.size(), prefNumberLocal, mpeg7, segments);
// filtered
LinkedList<Segment> segmentsNew = new LinkedList<Segment>();
OptimizationStep currentStepFiltered = new OptimizationStep(stabilityThreshold, changesThresholdLocal, 0, prefNumberLocal, filterSegmentation(segments, track, segmentsNew, stabilityThreshold * 1000), segments);
currentStepFiltered.setSegmentNumAndRecalcErrors(segmentsNew.size());
logger.info("Segmentation yields {} segments after filtering", segmentsNew.size());
OptimizationStep currentStepBest;
// - and the filtered segmentation is not already better than the maximum error
if (currentStep.getErrorAbs() <= currentStepFiltered.getErrorAbs() || (segmentsNew.size() < prefNumberLocal && currentStep.getSegmentNum() > (track.getDuration() / 1000.0f) / (stabilityThreshold / 2) && !(currentStepFiltered.getErrorAbs() <= maxError))) {
optimizationList.add(currentStep);
Collections.sort(optimizationList);
currentStepBest = currentStep;
unusedResultsList.add(currentStepFiltered);
} else {
optimizationList.add(currentStepFiltered);
Collections.sort(optimizationList);
currentStepBest = currentStepFiltered;
}
cycleCount++;
logger.debug("errorAbs = {}, error = {}", currentStep.getErrorAbs(), currentStep.getError());
logger.debug("changesThreshold = {}", changesThresholdLocal);
logger.debug("cycleCount = {}", cycleCount);
// end optimization if maximum number of cycles is reached or if the segmentation is good enough
if (cycleCount >= maxCycles || currentStepBest.getErrorAbs() <= maxError) {
endOptimization = true;
if (optimizationList.size() > 0) {
if (optimizationList.getFirst().getErrorAbs() <= optimizationList.getLast().getErrorAbs() && optimizationList.getFirst().getError() >= 0) {
stepBest = optimizationList.getFirst();
} else {
stepBest = optimizationList.getLast();
}
}
// just to be sure, check if one of the unused results was better
for (OptimizationStep currentUnusedStep : unusedResultsList) {
if (currentUnusedStep.getErrorAbs() < stepBest.getErrorAbs()) {
stepBest = unusedResultsList.getFirst();
}
}
// continue optimization, calculate new changes threshold for next iteration of optimization
} else {
OptimizationStep first = optimizationList.getFirst();
OptimizationStep last = optimizationList.getLast();
// estimate a new changesThreshold based on the one yielding the smallest error
if (optimizationList.size() == 1 || first.getError() < 0 || last.getError() > 0) {
if (currentStepBest.getError() >= 0) {
// if the error is smaller or equal to 1, increase changes threshold weighted with the error
if (currentStepBest.getError() <= 1) {
changesThresholdLocal += changesThresholdLocal * currentStepBest.getError();
} else {
// to faster reach reasonable segment numbers
if (cycleCount <= 1 && currentStep.getSegmentNum() > 2000) {
changesThresholdLocal = 0.2f;
// if the error is bigger than one, double the changes threshold, because multiplying
// with a large error can yield a much too high changes threshold
} else {
changesThresholdLocal *= 2;
}
}
} else {
changesThresholdLocal /= 2;
}
logger.debug("onesided optimization yields new changesThreshold = {}", changesThresholdLocal);
// if there are already iterations with positive and negative errors, choose a changesThreshold between those
} else {
// for simplicity a linear relationship between the changesThreshold
// and the number of generated segments is assumed and based on that
// the expected correct changesThreshold is calculated
// the new changesThreshold is calculated by averaging the the mean and the mean weighted with errors
// because this seemed to yield better results in several cases
float x = (first.getSegmentNum() - prefNumberLocal) / (float) (first.getSegmentNum() - last.getSegmentNum());
float newX = ((x + 0.5f) * 0.5f);
changesThresholdLocal = first.getChangesThreshold() * (1 - newX) + last.getChangesThreshold() * newX;
logger.debug("doublesided optimization yields new changesThreshold = {}", changesThresholdLocal);
}
}
}
// after optimization of the changes threshold, the minimum duration for a segment
// (stability threshold) is optimized if the result is still not good enough
int threshLow = stabilityThreshold * 1000;
int threshHigh = threshLow + (threshLow / 2);
LinkedList<Segment> tmpSegments;
float smallestError = Float.MAX_VALUE;
int bestI = threshLow;
segments = stepBest.getSegments();
// is smaller than the maximum error, the stability threshold will not be optimized
if (stepBest.getError() <= maxError) {
threshHigh = stabilityThreshold * 1000;
}
for (int i = threshLow; i <= threshHigh; i = i + 1000) {
tmpSegments = new LinkedList<Segment>();
filterSegmentation(segments, track, tmpSegments, i);
float newError = OptimizationStep.calculateErrorAbs(tmpSegments.size(), prefNumberLocal);
if (newError < smallestError) {
smallestError = newError;
bestI = i;
}
}
tmpSegments = new LinkedList<Segment>();
mpeg7 = filterSegmentation(segments, track, tmpSegments, bestI);
// for debugging: output of final segmentation after optimization
logger.debug("result segments:");
for (int i = 0; i < tmpSegments.size(); i++) {
int[] tmpLog2 = new int[7];
tmpLog2[0] = tmpSegments.get(i).getMediaTime().getMediaTimePoint().getHour();
tmpLog2[1] = tmpSegments.get(i).getMediaTime().getMediaTimePoint().getMinutes();
tmpLog2[2] = tmpSegments.get(i).getMediaTime().getMediaTimePoint().getSeconds();
tmpLog2[3] = tmpSegments.get(i).getMediaTime().getMediaDuration().getHours();
tmpLog2[4] = tmpSegments.get(i).getMediaTime().getMediaDuration().getMinutes();
tmpLog2[5] = tmpSegments.get(i).getMediaTime().getMediaDuration().getSeconds();
Object[] tmpLog1 = { tmpLog2[0], tmpLog2[1], tmpLog2[2], tmpLog2[3], tmpLog2[4], tmpLog2[5], tmpLog2[6] };
tmpLog1[6] = tmpSegments.get(i).getIdentifier();
logger.debug("s:{}:{}:{}, d:{}:{}:{}, {}", tmpLog1);
}
logger.info("Optimized Segmentation yields (after {} iteration" + (cycleCount == 1 ? "" : "s") + ") {} segments", cycleCount, tmpSegments.size());
// if no reasonable segmentation could be found, instead return a uniform segmentation
if (tmpSegments.size() < absoluteMinLocal || tmpSegments.size() > absoluteMaxLocal) {
mpeg7 = uniformSegmentation(track, tmpSegments, prefNumberLocal);
logger.info("Since no reasonable segmentation could be found, a uniform segmentation was created");
}
Catalog mpeg7Catalog = (Catalog) MediaPackageElementBuilderFactory.newInstance().newElementBuilder().newElement(Catalog.TYPE, MediaPackageElements.SEGMENTS);
URI uri;
try {
uri = workspace.putInCollection(COLLECTION_ID, job.getId() + ".xml", mpeg7CatalogService.serialize(mpeg7));
} catch (IOException e) {
throw new VideoSegmenterException("Unable to put the mpeg7 catalog into the workspace", e);
}
mpeg7Catalog.setURI(uri);
logger.info("Finished video segmentation of {}", mediaUrl);
return mpeg7Catalog;
} catch (Exception e) {
logger.warn("Error segmenting " + track, e);
if (e instanceof VideoSegmenterException) {
throw (VideoSegmenterException) e;
} else {
throw new VideoSegmenterException(e);
}
}
}
use of org.opencastproject.videosegmenter.api.VideoSegmenterException in project opencast by opencast.
the class VideoSegmenterRemoteImpl method segment.
@Override
public Job segment(Track track) throws VideoSegmenterException {
HttpPost post = new HttpPost();
try {
List<BasicNameValuePair> params = new ArrayList<BasicNameValuePair>();
params.add(new BasicNameValuePair("track", MediaPackageElementParser.getAsXml(track)));
post.setEntity(new UrlEncodedFormEntity(params));
} catch (Exception e) {
throw new VideoSegmenterException(e);
}
HttpResponse response = null;
try {
response = getResponse(post);
if (response != null) {
try {
Job receipt = JobParser.parseJob(response.getEntity().getContent());
logger.info("Analyzing {} on a remote analysis server", track);
return receipt;
} catch (Exception e) {
throw new VideoSegmenterException("Unable to analyze element '" + track + "' using a remote analysis service", e);
}
}
} finally {
closeConnection(response);
}
throw new VideoSegmenterException("Unable to analyze element '" + track + "' using a remote analysis service");
}
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