File Check-whether-a-frame-could-be-decoded-before-seeking.patch of Package ffmpegthumbs4

From 6fa26cddeff42831a6c6bf885bd8c905a413d3e4 Mon Sep 17 00:00:00 2001
From: Kai Uwe Broulik <kde@privat.broulik.de>
Date: Wed, 26 Sep 2018 10:24:42 +0200
Subject: [PATCH] Check whether a frame could be decoded before seeking

Otherwise crashes when trying to generate thumbnail for a video file without actual video data.

CHANGELOG: Fixed video thumbnailer crashing when trying to decode files without video stream

Differential Revision: https://phabricator.kde.org/D15752
---
 ffmpegthumbnailer/moviedecoder.cpp     | 5 +++--
 ffmpegthumbnailer/moviedecoder.h       | 2 +-
 ffmpegthumbnailer/videothumbnailer.cpp | 4 +++-
 3 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/ffmpegthumbnailer/moviedecoder.cpp b/ffmpegthumbnailer/moviedecoder.cpp
index b2e7551..6d1a79c 100644
--- a/ffmpegthumbnailer/moviedecoder.cpp
+++ b/ffmpegthumbnailer/moviedecoder.cpp
@@ -227,7 +227,7 @@ void MovieDecoder::seek(int timeInSeconds)
 }
 
 
-void MovieDecoder::decodeVideoFrame()
+bool MovieDecoder::decodeVideoFrame()
 {
     bool frameFinished = false;
 
@@ -237,8 +237,9 @@ void MovieDecoder::decodeVideoFrame()
 
     if (!frameFinished) {
         kDebug() << "decodeVideoFrame() failed: frame not finished";
-        return;
     }
+
+    return frameFinished;
 }
 
 bool MovieDecoder::decodeVideoPacket()
diff --git a/ffmpegthumbnailer/moviedecoder.h b/ffmpegthumbnailer/moviedecoder.h
index 788ce43..060c02e 100644
--- a/ffmpegthumbnailer/moviedecoder.h
+++ b/ffmpegthumbnailer/moviedecoder.h
@@ -39,7 +39,7 @@ public:
 
     QString getCodec();
     void seek(int timeInSeconds);
-    void decodeVideoFrame();
+    bool decodeVideoFrame();
     void getScaledVideoFrame(int scaledSize, bool maintainAspectRatio, VideoFrame& videoFrame);
 
     int getWidth();
diff --git a/ffmpegthumbnailer/videothumbnailer.cpp b/ffmpegthumbnailer/videothumbnailer.cpp
index 97218c8..c3fd1c4 100644
--- a/ffmpegthumbnailer/videothumbnailer.cpp
+++ b/ffmpegthumbnailer/videothumbnailer.cpp
@@ -98,7 +98,9 @@ void VideoThumbnailer::generateThumbnail(const QString& videoFile, ImageWriter&
 {
     MovieDecoder movieDecoder(videoFile, NULL);
     if (movieDecoder.getInitialized()) {
-        movieDecoder.decodeVideoFrame(); //before seeking, a frame has to be decoded
+        if (!movieDecoder.decodeVideoFrame()) { //before seeking, a frame has to be decoded
+            return;
+        }
         
         if ((!m_WorkAroundIssues) || (movieDecoder.getCodec() != QLatin1String("h264"))) { //workaround for bug in older ffmpeg (100% cpu usage when seeking in h264 files)
             int secondToSeekTo = m_SeekTime.isEmpty() ? movieDecoder.getDuration() * m_SeekPercentage / 100 : timeToSeconds(m_SeekTime);
-- 
GitLab