MCR-3836 Generate an iView image from a video frame

mycore-iview2/pom.xml

@@ -124,6 +124,11 @@
       <artifactId>junit-jupiter-params</artifactId>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>org.mockito</groupId>
+      <artifactId>mockito-core</artifactId>
+      <scope>test</scope>
+    </dependency>
     <dependency>
       <groupId>org.mycore</groupId>
       <artifactId>mycore-base</artifactId>

mycore-iview2/src/main/java/org/mycore/iview2/backend/MCRVideoFrameJobAction.java

@@ -0,0 +1,112 @@
+/*
+ * This file is part of ***  M y C o R e  ***
+ * See https://www.mycore.de/ for details.
+ *
+ * MyCoRe is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * MyCoRe is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with MyCoRe.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package org.mycore.iview2.backend;
+
+import java.awt.image.BufferedImage;
+import java.io.IOException;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+import javax.imageio.ImageIO;
+
+import org.mycore.common.MCRException;
+import org.mycore.common.config.MCRConfiguration2;
+import org.mycore.common.digest.MCRDigest;
+import org.mycore.datamodel.niofs.MCRContentTypes;
+import org.mycore.datamodel.niofs.MCRFileAttributes;
+import org.mycore.datamodel.niofs.MCRPath;
+import org.mycore.imagetiler.MCRImage;
+import org.mycore.iview2.frontend.MCRIView2Commands;
+import org.mycore.iview2.services.MCRIView2Tools;
+import org.mycore.media.services.MCRVideoFrameGenerator;
+import org.mycore.services.queuedjob.MCRJob;
+import org.mycore.services.queuedjob.MCRJobAction;
+
+/** Stores a full-resolution video frame as an iView image under the video's path. */
+public class MCRVideoFrameJobAction extends MCRJobAction {
+
+    public static final String DERIVATE_PARAMETER = "derivate";
+
+    public static final String PATH_PARAMETER = "path";
+
+    public MCRVideoFrameJobAction(MCRJob job) {
+        super(job);
+    }
+
+    @Override
+    public boolean isActivated() {
+        return true;
+    }
+
+    @Override
+    public String name() {
+        return getClass().getName();
+    }
+
+    @Override
+    public void execute() {
+        MCRPath video = MCRPath.getPath(job.getParameter(DERIVATE_PARAMETER), job.getParameter(PATH_PARAMETER));
+        try {
+            if (!Files.isRegularFile(video)) {
+                return;
+            }
+            String contentType = MCRContentTypes.probeContentType(video);
+            if (contentType == null || !contentType.startsWith("video/")) {
+                return;
+            }
+            MCRVideoFrameGenerator generator = MCRConfiguration2.getInstanceOfOrThrow(
+                MCRVideoFrameGenerator.class, "MCR.Media.VideoFrameGenerator");
+            if (!generator.checkRequirements(video)) {
+                return;
+            }
+            // A replaced video changes its digest. The job of the new content then creates the frame.
+            MCRDigest digest = digest(video);
+            BufferedImage frame = generator.generateFrame(video);
+            Path image = Files.createTempFile("MyCoRe-Video-Frame-", ".png");
+            try {
+                if (!ImageIO.write(frame, "png", image.toFile())) {
+                    throw new IOException("No PNG writer available");
+                }
+                // A queued video may have been deleted or replaced while FFmpeg was running.
+                if (!Files.isRegularFile(video) || !digest.equals(digest(video))) {
+                    return;
+                }
+                MCRImage tiledImage = MCRImage.getInstance(image, video.getOwner(), video.getOwnerRelativePath());
+                tiledImage.setTileDir(MCRIView2Tools.getTileDir());
+                tiledImage.tile();
+                if (!Files.isRegularFile(video)) {
+                    MCRIView2Commands.deleteImageTiles(video.getOwner(), video.getOwnerRelativePath());
+                }
+            } finally {
+                Files.deleteIfExists(image);
+            }
+        } catch (IOException e) {
+            throw new MCRException("Could not generate iView image for video " + video, e);
+        }
+    }
+
+    private static MCRDigest digest(MCRPath video) throws IOException {
+        return Files.readAttributes(video, MCRFileAttributes.class).digest();
+    }
+
+    @Override
+    public void rollback() {
+        // Files are cleaned up in execute(); a retry regenerates the frame.
+    }
+}

mycore-iview2/src/main/java/org/mycore/iview2/events/MCRVideoFrameEventHandler.java

@@ -0,0 +1,108 @@
+/*
+ * This file is part of ***  M y C o R e  ***
+ * See https://www.mycore.de/ for details.
+ *
+ * MyCoRe is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * MyCoRe is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with MyCoRe.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package org.mycore.iview2.events;
+
+import java.io.IOException;
+import java.nio.file.Path;
+import java.nio.file.attribute.BasicFileAttributes;
+import java.util.List;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.mycore.common.MCRException;
+import org.mycore.common.config.MCRConfiguration2;
+import org.mycore.common.events.MCREvent;
+import org.mycore.common.events.MCREventHandlerBase;
+import org.mycore.datamodel.niofs.MCRContentTypes;
+import org.mycore.datamodel.niofs.MCRPath;
+import org.mycore.iview2.backend.MCRVideoFrameJobAction;
+import org.mycore.iview2.frontend.MCRIView2Commands;
+import org.mycore.iview2.services.MCRIView2Tools;
+import org.mycore.media.services.MCRVideoFrameGenerator;
+import org.mycore.services.queuedjob.MCRJob;
+import org.mycore.services.queuedjob.MCRJobQueueManager;
+import org.mycore.services.queuedjob.MCRJobStatus;
+
+/** Creates iView images for every video file, independent of the derivate's main document. */
+public class MCRVideoFrameEventHandler extends MCREventHandlerBase {
+
+    private static final Logger LOGGER = LogManager.getLogger();
+
+    private static final String VIDEO_FRAME_GENERATOR_PROPERTY = "MCR.Media.VideoFrameGenerator";
+
+    @Override
+    public void handlePathCreated(MCREvent evt, Path file, BasicFileAttributes attrs) {
+        if (!(file instanceof MCRPath path) || !attrs.isRegularFile()) {
+            return;
+        }
+        try {
+            String contentType = MCRContentTypes.probeContentType(path);
+            if (contentType != null && contentType.startsWith("video/") && checkRequirements(path)) {
+                MCRJob job = new MCRJob(MCRVideoFrameJobAction.class);
+                job.setParameter(MCRVideoFrameJobAction.DERIVATE_PARAMETER, path.getOwner());
+                job.setParameter(MCRVideoFrameJobAction.PATH_PARAMETER, path.getOwnerRelativePath());
+                MCRJobQueueManager manager = MCRJobQueueManager.getInstance();
+                if (manager.getJobDAO().getJobCount(MCRVideoFrameJobAction.class, job.getParameters(),
+                    List.of(MCRJobStatus.NEW, MCRJobStatus.ERROR)) > 0) {
+                    LOGGER.info("There is already a video frame job for {}. Skipping.", file);
+                } else if (!manager.getJobQueue(MCRVideoFrameJobAction.class).offer(job)) {
+                    LOGGER.warn("Video frame job queue did not accept job for {}", file);
+                }
+            }
+        } catch (IOException | RuntimeException e) {
+            // The poster is optional and must not abort the file event.
+            LOGGER.warn("Could not enqueue video frame generation for {}", file, e);
+        }
+    }
+
+    private boolean checkRequirements(MCRPath path) {
+        return MCRConfiguration2.getInstanceOfOrThrow(MCRVideoFrameGenerator.class,
+            VIDEO_FRAME_GENERATOR_PROPERTY).checkRequirements(path);
+    }
+
+    @Override
+    public void handlePathUpdated(MCREvent evt, Path file, BasicFileAttributes attrs) {
+        handlePathCreated(evt, file, attrs);
+    }
+
+    @Override
+    public void handlePathRepaired(MCREvent evt, Path file, BasicFileAttributes attrs) {
+        // A repair only generates missing frames. Delete the tiles to force a new frame.
+        if (file instanceof MCRPath path && hasTiles(path)) {
+            return;
+        }
+        handlePathCreated(evt, file, attrs);
+    }
+
+    boolean hasTiles(MCRPath path) {
+        return MCRIView2Tools.hasTiles(path.getOwner(), path.getOwnerRelativePath());
+    }
+
+    @Override
+    public void handlePathDeleted(MCREvent evt, Path file, BasicFileAttributes attrs) {
+        if (file instanceof MCRPath path) {
+            // MIME detection need not work after deletion. The tiling handler also uses this cleanup.
+            try {
+                MCRIView2Commands.deleteImageTiles(path.getOwner(), path.getOwnerRelativePath());
+            } catch (IOException e) {
+                throw new MCRException("Could not delete video frame tiles for " + file, e);
+            }
+        }
+    }
+}

mycore-iview2/src/main/java/org/mycore/iview2/services/MCRIView2Tools.java

@@ -56,6 +56,8 @@
 import org.mycore.datamodel.niofs.MCRPath;
 import org.mycore.imagetiler.MCRImage;
 import org.mycore.imagetiler.MCRTiledPictureProps;
+import org.mycore.iview2.backend.MCRTileFileProvider;
+import org.mycore.iview2.backend.MCRTileInfo;
 
 import jakarta.activation.FileTypeMap;
 import jakarta.persistence.EntityManager;
@@ -152,6 +154,20 @@ public static boolean isFileSupported(String filename) {
             filename.toLowerCase(Locale.ROOT)));
     }
 
+    /**
+     * Checks whether an iView tile file exists for a file in a derivate.
+     *
+     * @param derivateId the derivate ID
+     * @param path the file path within the derivate
+     * @return true if a regular tile file exists
+     */
+    public static boolean hasTiles(String derivateId, String path) {
+        MCRTileFileProvider provider = MCRConfiguration2
+            .getSingleInstanceOfOrThrow(MCRTileFileProvider.class, "MCR.IIIFImage.Iview.TileFileProvider");
+        return provider.getTileFile(new MCRTileInfo(derivateId, path, null))
+            .filter(Files::isRegularFile).isPresent();
+    }
+
     /**
      * Checks for a given derivate id whether all files in that derivate are tiled.
      *

mycore-iview2/src/main/java/org/mycore/iview2/services/MCRIview2URIResolver.java

@@ -18,6 +18,9 @@
 
 package org.mycore.iview2.services;
 
+import java.net.URLDecoder;
+import java.nio.charset.StandardCharsets;
+
 import javax.xml.transform.Source;
 import javax.xml.transform.TransformerException;
 import javax.xml.transform.URIResolver;
@@ -59,13 +62,26 @@ public class MCRIview2URIResolver implements URIResolver {
      */
     @Override
     public Source resolve(String href, String base) throws TransformerException {
-        String[] params = href.split(":");
+        String[] params = href.split(":", 3);
 
         if (params.length != 3) {
             throw new TransformerException("Invalid href: " + href);
         }
 
         switch (params[1]) {
+            case "hasTiles" -> {
+                int separator = params[2].indexOf('/');
+                if (separator <= 0 || separator == params[2].length() - 1) {
+                    throw new TransformerException("Invalid href: " + href);
+                }
+                String derivateId = params[2].substring(0, separator);
+                try {
+                    String path = URLDecoder.decode(params[2].substring(separator + 1), StandardCharsets.UTF_8);
+                    return new JDOMSource(new Element(String.valueOf(MCRIView2Tools.hasTiles(derivateId, path))));
+                } catch (IllegalArgumentException e) {
+                    throw new TransformerException("Invalid encoded path in href: " + href, e);
+                }
+            }
             case "isCompletelyTiled" -> {
                 boolean completelyTiled = MCRIView2Tools.isCompletelyTiled(params[2]);
                 return new JDOMSource(new Element(String.valueOf(completelyTiled)));

mycore-iview2/src/main/resources/components/iview2/config/mycore.properties

@@ -56,7 +56,10 @@ MCR.IIIFImage.Iview.ThumbnailForPdfEventHandler.Derivate.Types=derivate_types:co
 MCR.EventHandler.MCRDerivate.080.Class=org.mycore.iview2.events.MCRThumbnailForPdfEventHandler
 MCR.Media.Thumbnail.Generators=%MCR.Media.Thumbnail.Generators%,org.mycore.iview2.services.MCRImageThumbnailGenerator
 
-MCR.QueuedJob.OrdinaryJobs=%MCR.QueuedJob.OrdinaryJobs%,org.mycore.iview2.backend.MCRPDFThumbnailJobAction
+MCR.QueuedJob.OrdinaryJobs=%MCR.QueuedJob.OrdinaryJobs%,org.mycore.iview2.backend.MCRPDFThumbnailJobAction,org.mycore.iview2.backend.MCRVideoFrameJobAction
 
 # Maximum input file size in bytes for PDF thumbnail generation. If empty, no limit is applied.
 MCR.IView2.PDF.Thumbnail.MaxInputFileSize=
+
+# Generate an iView image from an embedded cover or representative full-resolution frame of every video file.
+MCR.EventHandler.MCRPath.025.Class=org.mycore.iview2.events.MCRVideoFrameEventHandler

mycore-iview2/src/main/resources/xslt/functions/iview2.xsl

@@ -11,4 +11,12 @@
         <xsl:value-of select="count($isCompletelyTiled/true)&gt;0" />
     </xsl:function>
 
+    <!-- Checks availability only; IIIF enforces permissions when serving the image. -->
+    <xsl:function name="mcriview2:has-tiles" as="xs:boolean">
+        <xsl:param name="derivateID" as="xs:string"/>
+        <xsl:param name="path" as="xs:string"/>
+        <xsl:sequence select="exists(document(concat('iview2:hasTiles:', $derivateID, '/',
+            encode-for-uri($path)))/true)"/>
+    </xsl:function>
+
 </xsl:stylesheet>