From 7ab6a2c4c9c88c73f416946625b411e3579f4245 Mon Sep 17 00:00:00 2001
From: Gustavo Trott <gustavo@trott.com.br>
Date: Wed, 28 Apr 2021 15:47:55 -0300
Subject: [PATCH] Detects if PDF contains font Type 3 and rasterize
automatically
---
.../handlers/AbstractCommandHandler.java | 4 ++
.../handlers/PdfFontType3DetectorHandler.java | 42 ++++++++++++++++++
.../presentation/imp/SvgImageCreatorImp.java | 43 +++++++++++++++++--
3 files changed, 86 insertions(+), 3 deletions(-)
create mode 100644 bbb-common-web/src/main/java/org/bigbluebutton/presentation/handlers/PdfFontType3DetectorHandler.java
diff --git a/bbb-common-web/src/main/java/org/bigbluebutton/presentation/handlers/AbstractCommandHandler.java b/bbb-common-web/src/main/java/org/bigbluebutton/presentation/handlers/AbstractCommandHandler.java
index d15172569b..fe0e8c95d9 100755
--- a/bbb-common-web/src/main/java/org/bigbluebutton/presentation/handlers/AbstractCommandHandler.java
+++ b/bbb-common-web/src/main/java/org/bigbluebutton/presentation/handlers/AbstractCommandHandler.java
@@ -82,6 +82,10 @@ public abstract class AbstractCommandHandler extends
return stdoutBuilder.indexOf(value) > -1;
}
+ protected Boolean stdoutEquals(String value) {
+ return stdoutBuilder.toString().trim().equals(value);
+ }
+
protected Boolean stderrContains(String value) {
return stderrBuilder.indexOf(value) > -1;
}
diff --git a/bbb-common-web/src/main/java/org/bigbluebutton/presentation/handlers/PdfFontType3DetectorHandler.java b/bbb-common-web/src/main/java/org/bigbluebutton/presentation/handlers/PdfFontType3DetectorHandler.java
new file mode 100644
index 0000000000..5d3e04750f
--- /dev/null
+++ b/bbb-common-web/src/main/java/org/bigbluebutton/presentation/handlers/PdfFontType3DetectorHandler.java
@@ -0,0 +1,42 @@
+/**
+ * BigBlueButton open source conferencing system - http://www.bigbluebutton.org/
+ *
+ * Copyright (c) 2015 BigBlueButton Inc. and by respective authors (see below).
+ *
+ * This program is free software; you can redistribute it and/or modify it under the
+ * terms of the GNU Lesser General Public License as published by the Free Software
+ * Foundation; either version 3.0 of the License, or (at your option) any later
+ * version.
+ *
+ * BigBlueButton 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License along
+ * with BigBlueButton; if not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+package org.bigbluebutton.presentation.handlers;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class PdfFontType3DetectorHandler extends AbstractCommandHandler {
+
+ private static Logger log = LoggerFactory
+ .getLogger(PdfFontType3DetectorHandler.class);
+
+ /**
+ *
+ * @return If pdf page contains one or more texts with font Type 3.
+ */
+ public boolean hasFontType3() {
+ if (stdoutEquals("1")) {
+ return true;
+ }
+
+ return false;
+ }
+
+}
diff --git a/bbb-common-web/src/main/java/org/bigbluebutton/presentation/imp/SvgImageCreatorImp.java b/bbb-common-web/src/main/java/org/bigbluebutton/presentation/imp/SvgImageCreatorImp.java
index 50e654e902..5cb07b8ffb 100755
--- a/bbb-common-web/src/main/java/org/bigbluebutton/presentation/imp/SvgImageCreatorImp.java
+++ b/bbb-common-web/src/main/java/org/bigbluebutton/presentation/imp/SvgImageCreatorImp.java
@@ -16,6 +16,7 @@ import org.bigbluebutton.presentation.handlers.AddNamespaceToSvgHandler;
import org.bigbluebutton.presentation.handlers.Pdf2PngPageConverterHandler;
import org.bigbluebutton.presentation.handlers.Png2SvgConversionHandler;
import org.bigbluebutton.presentation.handlers.SvgConversionHandler;
+import org.bigbluebutton.presentation.handlers.PdfFontType3DetectorHandler;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
@@ -59,6 +60,7 @@ public class SvgImageCreatorImp implements SvgImageCreator {
int numSlides = 1;
boolean done = false;
+ Boolean rasterizeCurrSlide = this.forceRasterizeSlides;
// Convert single image file
if (SupportedFileTypes.isImageFile(pres.getFileType())) {
@@ -93,11 +95,38 @@ public class SvgImageCreatorImp implements SvgImageCreator {
// Continue image processing
long startConv = System.currentTimeMillis();
+
+ //Detect if PDF contains text with font Type 3
+ //Pdftocairo has problem to convert Pdf to Svg when text contains font Type 3
+ //Case detects type 3, rasterize will be forced to avoid the problem
+ NuProcessBuilder detectFontType3Process = this.createDetectFontType3Process(source,page);
+ PdfFontType3DetectorHandler detectFontType3tHandler = new PdfFontType3DetectorHandler();
+ detectFontType3Process.setProcessListener(detectFontType3tHandler);
+
+ NuProcess processDetectFontType3 = detectFontType3Process.start();
+ try {
+ processDetectFontType3.waitFor(convPdfToSvgTimeout + 1, TimeUnit.SECONDS);
+ done = true;
+ } catch (InterruptedException e) {
+ done = false;
+ log.error("InterruptedException while verifing font type 3 on {} page {}: {}", pres.getName(), page, e);
+ }
+
+ if(detectFontType3tHandler.isCommandTimeout()) {
+ log.error("Command execution (detectFontType3) exceeded the {} secs timeout for {} page {}.", convPdfToSvgTimeout, pres.getName(), page);
+ }
+
+ if(detectFontType3tHandler.hasFontType3()) {
+ log.info("Font Type 3 identified on {} page {}, slide will be rasterized.", pres.getName(), page);
+ rasterizeCurrSlide = true;
+ }
+
+
File destsvg = new File(imagePresentationDir.getAbsolutePath() + File.separatorChar + "slide" + page + ".svg");
SvgConversionHandler pHandler = new SvgConversionHandler();
- if(this.forceRasterizeSlides == false) {
+ if(rasterizeCurrSlide == false) {
NuProcessBuilder convertPdfToSvg = createConversionProcess("-svg", page, source, destsvg.getAbsolutePath(),
true);
@@ -124,7 +153,7 @@ public class SvgImageCreatorImp implements SvgImageCreator {
if (destsvg.length() == 0 ||
pHandler.numberOfImageTags() > imageTagThreshold ||
pHandler.numberOfPaths() > pathsThreshold ||
- this.forceRasterizeSlides) {
+ rasterizeCurrSlide) {
// We need t delete the destination file as we are starting a
// new conversion process
@@ -134,7 +163,7 @@ public class SvgImageCreatorImp implements SvgImageCreator {
done = false;
- if(!this.forceRasterizeSlides) {
+ if(!rasterizeCurrSlide) {
Map<String, Object> logData = new HashMap<String, Object>();
logData.put("meetingId", pres.getMeetingId());
logData.put("presId", pres.getId());
@@ -282,6 +311,14 @@ public class SvgImageCreatorImp implements SvgImageCreator {
return new NuProcessBuilder(Arrays.asList("timeout", convPdfToSvgTimeout + "s", "/bin/sh", "-c", rawCommand));
}
+ private NuProcessBuilder createDetectFontType3Process(String source, int page) {
+ String rawCommand = "pdffonts -f " + String.valueOf(page) + " -l " + String.valueOf(page) + " " + source;
+ rawCommand += " | grep -m 1 'Type 3'";
+ rawCommand += " | wc -l";
+
+ return new NuProcessBuilder(Arrays.asList("timeout", convPdfToSvgTimeout + "s", "/bin/sh", "-c", rawCommand));
+ }
+
private File determineSvgImagesDirectory(File presentationFile) {
return new File(presentationFile.getParent() + File.separatorChar + "svgs");
}
--
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