Examples with Mpeg7CatalogImpl org.opencastproject.metadata.mpeg7.Mpeg7CatalogImpl used on opensource projects

Example 6 with Mpeg7CatalogImpl

use of org.opencastproject.metadata.mpeg7.Mpeg7CatalogImpl in project opencast by opencast.

the class TextAnalyzerServiceImpl method extract.

/**
 * Starts text extraction on the image and returns a receipt containing the final result in the form of an
 * Mpeg7Catalog.
 *
 * @param image
 *          the element to analyze
 * @param block
 *          <code>true</code> to make this operation synchronous
 * @return a receipt containing the resulting mpeg-7 catalog
 * @throws TextAnalyzerException
 */
private Catalog extract(Job job, Attachment image) throws TextAnalyzerException, MediaPackageException {
    final Attachment attachment = image;
    final URI imageUrl = attachment.getURI();
    File imageFile = null;
    try {
        Mpeg7CatalogImpl mpeg7 = Mpeg7CatalogImpl.newInstance();
        logger.info("Starting text extraction from {}", imageUrl);
        try {
            imageFile = workspace.get(imageUrl);
        } catch (NotFoundException e) {
            throw new TextAnalyzerException("Image " + imageUrl + " not found in workspace", e);
        } catch (IOException e) {
            throw new TextAnalyzerException("Unable to access " + imageUrl + " in workspace", e);
        }
        VideoText[] videoTexts = analyze(imageFile, image.getIdentifier());
        // Create a temporal decomposition
        MediaTime mediaTime = new MediaTimeImpl(0, 0);
        Video avContent = mpeg7.addVideoContent(image.getIdentifier(), mediaTime, null);
        TemporalDecomposition<VideoSegment> temporalDecomposition = (TemporalDecomposition<VideoSegment>) avContent.getTemporalDecomposition();
        // Add a segment
        VideoSegment videoSegment = temporalDecomposition.createSegment("segment-0");
        videoSegment.setMediaTime(mediaTime);
        // Add the video text to the spacio temporal decomposition of the segment
        SpatioTemporalDecomposition spatioTemporalDecomposition = videoSegment.createSpatioTemporalDecomposition(true, false);
        for (VideoText videoText : videoTexts) {
            spatioTemporalDecomposition.addVideoText(videoText);
        }
        logger.info("Text extraction of {} finished, {} lines found", attachment.getURI(), videoTexts.length);
        URI uri;
        InputStream in;
        try {
            in = mpeg7CatalogService.serialize(mpeg7);
        } catch (IOException e) {
            throw new TextAnalyzerException("Error serializing mpeg7", e);
        }
        try {
            uri = workspace.putInCollection(COLLECTION_ID, job.getId() + ".xml", in);
        } catch (IOException e) {
            throw new TextAnalyzerException("Unable to put mpeg7 into the workspace", e);
        }
        Catalog catalog = (Catalog) MediaPackageElementBuilderFactory.newInstance().newElementBuilder().newElement(Catalog.TYPE, MediaPackageElements.TEXTS);
        catalog.setURI(uri);
        logger.debug("Created MPEG7 catalog for {}", imageUrl);
        return catalog;
    } catch (Exception e) {
        logger.warn("Error extracting text from " + imageUrl, e);
        if (e instanceof TextAnalyzerException) {
            throw (TextAnalyzerException) e;
        } else {
            throw new TextAnalyzerException(e);
        }
    } finally {
        try {
            workspace.delete(imageUrl);
        } catch (Exception e) {
            logger.warn("Unable to delete temporary text analysis image {}: {}", imageUrl, e);
        }
    }
}