Examples with MediaLocatorImpl org.opencastproject.metadata.mpeg7.MediaLocatorImpl used on opensource projects

Example 1 with MediaLocatorImpl

use of org.opencastproject.metadata.mpeg7.MediaLocatorImpl 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);
        }
    }
}

Example 2 with MediaLocatorImpl

use of org.opencastproject.metadata.mpeg7.MediaLocatorImpl in project opencast by opencast.

the class VideoSegmenterTest method testAnalyzeSegmentMerging.

@Test
public void testAnalyzeSegmentMerging() {
    Mpeg7CatalogService mpeg7catalogService = vsegmenter.mpeg7CatalogService;
    MediaTime contentTime = new MediaRelTimeImpl(0, track.getDuration());
    MediaLocator contentLocator = new MediaLocatorImpl(track.getURI());
    Mpeg7Catalog mpeg7 = mpeg7catalogService.newInstance();
    Video videoContent = mpeg7.addVideoContent("videosegment", contentTime, contentLocator);
    LinkedList<Segment> segments;
    LinkedList<Segment> result;
    int segmentcount = 1;
    track.setDuration(47000L);
    // list of segment durations (starttimes can be calculated from those)
    int[] segmentArray1 = { 3000, 2000, 8000, 3000, 1000, 6000, 3000, 2000, 4000, 11000, 2000, 2000 };
    int[] segmentArray2 = { 1000, 2000, 8000, 3000, 1000, 6000, 3000, 2000, 4000, 11000, 2000, 4000 };
    int[] segmentArray3 = { 1000, 2000, 4000, 3000, 1000, 2000, 3000, 2000, 4000, 1000, 2000, 4000 };
    int[] segmentArray4 = { 6000, 7000, 13000, 9000, 8000, 11000, 5000, 16000 };
    // predicted outcome of filtering the segmentation
    int[] prediction1 = { 5000, 10000, 8000, 9000, 15000 };
    int[] prediction2 = { 13000, 8000, 9000, 11000, 6000 };
    int[] prediction3 = { 29000 };
    int[] prediction4 = { 6000, 7000, 13000, 9000, 8000, 11000, 5000, 16000 };
    // total duration of respective segment arrays
    long duration1 = 47000L;
    long duration2 = 47000L;
    long duration3 = 29000L;
    long duration4 = 75000L;
    int[][] segmentArray = { segmentArray1, segmentArray2, segmentArray3, segmentArray4 };
    int[][] prediction = { prediction1, prediction2, prediction3, prediction4 };
    long[] durations = { duration1, duration2, duration3, duration4 };
    // check for all test segmentations if "filterSegmentation" yields the expected result
    for (int k = 0; k < segmentArray.length; k++) {
        segments = new LinkedList<Segment>();
        result = new LinkedList<Segment>();
        track.setDuration(durations[k]);
        int previous = 0;
        for (int i = 0; i < segmentArray[k].length; i++) {
            Segment s = videoContent.getTemporalDecomposition().createSegment("segment-" + segmentcount++);
            s.setMediaTime(new MediaRelTimeImpl(previous, segmentArray[k][i]));
            segments.add(s);
            previous += segmentArray[k][i];
        }
        vsegmenter.filterSegmentation(segments, track, result, 5000);
        assertEquals("segment merging yields wrong number of segments", prediction[k].length, result.size());
        previous = 0;
        for (int i = 0; i < prediction[k].length; i++) {
            String message = "segment " + i + " in set " + k + " has the wrong start time.";
            String message1 = "segment " + i + " in set " + k + " has the wrong duration.";
            assertEquals(message, previous, result.get(i).getMediaTime().getMediaTimePoint().getTimeInMilliseconds());
            assertEquals(message1, prediction[k][i], result.get(i).getMediaTime().getMediaDuration().getDurationInMilliseconds());
            previous += prediction[k][i];
        }
    }
}

Example 3 with MediaLocatorImpl

use of org.opencastproject.metadata.mpeg7.MediaLocatorImpl in project opencast by opencast.

the class VideoSegmenterServiceImpl method uniformSegmentation.

/**
 * Creates a uniform segmentation for a given track, with prefNumber as the number of segments
 * which will all have the same length
 *
 * @param track the track that is segmented
 * @param segmentsNew will be set to list of new segments (pass null if not required)
 * @param prefNumber number of generated segments
 * @return Mpeg7Catalog that can later be saved in a Catalog as endresult
 */
protected Mpeg7Catalog uniformSegmentation(Track track, LinkedList<Segment> segmentsNew, int prefNumber) {
    if (segmentsNew == null) {
        segmentsNew = new LinkedList<Segment>();
    }
    MediaTime contentTime = new MediaRelTimeImpl(0, track.getDuration());
    MediaLocator contentLocator = new MediaLocatorImpl(track.getURI());
    Mpeg7Catalog mpeg7 = mpeg7CatalogService.newInstance();
    Video videoContent = mpeg7.addVideoContent("videosegment", contentTime, contentLocator);
    long segmentDuration = track.getDuration() / prefNumber;
    long currentSegStart = 0;
    // create "prefNumber"-many segments that all have the same length
    for (int i = 1; i < prefNumber; i++) {
        Segment s = videoContent.getTemporalDecomposition().createSegment("segment-" + i);
        s.setMediaTime(new MediaRelTimeImpl(currentSegStart, segmentDuration));
        segmentsNew.add(s);
        currentSegStart += segmentDuration;
    }
    // add last segment separately to make sure the last segment ends exactly at the end of the track
    Segment s = videoContent.getTemporalDecomposition().createSegment("segment-" + prefNumber);
    s.setMediaTime(new MediaRelTimeImpl(currentSegStart, track.getDuration() - currentSegStart));
    segmentsNew.add(s);
    return mpeg7;
}

Example 4 with MediaLocatorImpl

use of org.opencastproject.metadata.mpeg7.MediaLocatorImpl in project opencast by opencast.

the class VideoSegmenterServiceImpl method filterSegmentation.

/**
 * Merges small subsequent segments (with high difference) into a bigger one
 *
 * @param segments list of segments to be filtered
 * @param track the track that is segmented
 * @param segmentsNew will be set to list of new segments (pass null if not required)
 * @param mergeThresh minimum duration for a segment in milliseconds
 * @return Mpeg7Catalog that can later be saved in a Catalog as endresult
 */
protected Mpeg7Catalog filterSegmentation(LinkedList<Segment> segments, Track track, LinkedList<Segment> segmentsNew, int mergeThresh) {
    if (segmentsNew == null) {
        segmentsNew = new LinkedList<Segment>();
    }
    boolean merging = false;
    MediaTime contentTime = new MediaRelTimeImpl(0, track.getDuration());
    MediaLocator contentLocator = new MediaLocatorImpl(track.getURI());
    Mpeg7Catalog mpeg7 = mpeg7CatalogService.newInstance();
    Video videoContent = mpeg7.addVideoContent("videosegment", contentTime, contentLocator);
    int segmentcount = 1;
    MediaTimePoint currentSegStart = new MediaTimePointImpl();
    for (Segment o : segments) {
        // if the current segment is shorter than merge treshold start merging
        if (o.getMediaTime().getMediaDuration().getDurationInMilliseconds() <= mergeThresh) {
            // start merging and save beginning of new segment that will be generated
            if (!merging) {
                currentSegStart = o.getMediaTime().getMediaTimePoint();
                merging = true;
            }
        // current segment is longer than merge threshold
        } else {
            long currentSegDuration = o.getMediaTime().getMediaDuration().getDurationInMilliseconds();
            long currentSegEnd = o.getMediaTime().getMediaTimePoint().getTimeInMilliseconds() + currentSegDuration;
            if (merging) {
                long newDuration = o.getMediaTime().getMediaTimePoint().getTimeInMilliseconds() - currentSegStart.getTimeInMilliseconds();
                // save new segment that merges all previously skipped short segments
                if (newDuration >= mergeThresh) {
                    Segment s = videoContent.getTemporalDecomposition().createSegment("segment-" + segmentcount++);
                    s.setMediaTime(new MediaRelTimeImpl(currentSegStart.getTimeInMilliseconds(), newDuration));
                    segmentsNew.add(s);
                    // copy the following long segment to new list
                    Segment s2 = videoContent.getTemporalDecomposition().createSegment("segment-" + segmentcount++);
                    s2.setMediaTime(o.getMediaTime());
                    segmentsNew.add(s2);
                // if too short split new segment in middle and merge halves to
                // previous and following segments
                } else {
                    long followingStartOld = o.getMediaTime().getMediaTimePoint().getTimeInMilliseconds();
                    long newSplit = (currentSegStart.getTimeInMilliseconds() + followingStartOld) / 2;
                    long followingEnd = followingStartOld + o.getMediaTime().getMediaDuration().getDurationInMilliseconds();
                    long followingDuration = followingEnd - newSplit;
                    // if at beginning, don't split, just merge to first large segment
                    if (segmentsNew.isEmpty()) {
                        Segment s = videoContent.getTemporalDecomposition().createSegment("segment-" + segmentcount++);
                        s.setMediaTime(new MediaRelTimeImpl(0, followingEnd));
                        segmentsNew.add(s);
                    } else {
                        long previousStart = segmentsNew.getLast().getMediaTime().getMediaTimePoint().getTimeInMilliseconds();
                        // adjust end time of previous segment to split time
                        segmentsNew.getLast().setMediaTime(new MediaRelTimeImpl(previousStart, newSplit - previousStart));
                        // create new segment starting at split time
                        Segment s = videoContent.getTemporalDecomposition().createSegment("segment-" + segmentcount++);
                        s.setMediaTime(new MediaRelTimeImpl(newSplit, followingDuration));
                        segmentsNew.add(s);
                    }
                }
                merging = false;
            // copy segments that are long enough to new list (with corrected number)
            } else {
                Segment s = videoContent.getTemporalDecomposition().createSegment("segment-" + segmentcount++);
                s.setMediaTime(o.getMediaTime());
                segmentsNew.add(s);
            }
        }
    }
    // if there is an unfinished merging process after going through all segments
    if (merging && !segmentsNew.isEmpty()) {
        long newDuration = track.getDuration() - currentSegStart.getTimeInMilliseconds();
        // if merged segment is long enough, create new segment
        if (newDuration >= mergeThresh) {
            Segment s = videoContent.getTemporalDecomposition().createSegment("segment-" + segmentcount);
            s.setMediaTime(new MediaRelTimeImpl(currentSegStart.getTimeInMilliseconds(), newDuration));
            segmentsNew.add(s);
        // if not long enough, merge with previous segment
        } else {
            newDuration = track.getDuration() - segmentsNew.getLast().getMediaTime().getMediaTimePoint().getTimeInMilliseconds();
            segmentsNew.getLast().setMediaTime(new MediaRelTimeImpl(segmentsNew.getLast().getMediaTime().getMediaTimePoint().getTimeInMilliseconds(), newDuration));
        }
    }
    // segment spanning the whole video
    if (segmentsNew.isEmpty()) {
        Segment s = videoContent.getTemporalDecomposition().createSegment("segment-" + segmentcount);
        s.setMediaTime(new MediaRelTimeImpl(0, track.getDuration()));
        segmentsNew.add(s);
    }
    return mpeg7;
}