advancedsettings: Add option to set cache size on libass

E.g to set total cache size in libass to 32M

<advancedsettings>
    <libasscache>32</libasscache>
</advancedsettings>

When unset it defaults to 192M

xbmc/cores/VideoPlayer/DVDSubtitles/DVDSubtitlesLibass.cpp

@@ -19,6 +19,7 @@
 #include "utils/URIUtils.h"
 #include "utils/log.h"
 #include "windowing/GraphicContext.h"
+#include "settings/AdvancedSettings.h"
 
 static void libass_log(int level, const char *fmt, va_list args, void *data)
 {
@@ -54,6 +55,8 @@ CDVDSubtitlesLibass::CDVDSubtitlesLibass()
   if(!m_renderer)
     return;
 
+  ass_set_cache_limits(m_renderer, 0, CServiceBroker::GetSettingsComponent()->GetAdvancedSettings()->m_libAssCache);
+
   //Setting default font to the Arial in \media\fonts (used if FontConfig fails)
   const std::shared_ptr<CSettings> settings = CServiceBroker::GetSettingsComponent()->GetSettings();
   strPath = URIUtils::AddFileToFolder("special://home/media/Fonts/", settings->GetString(CSettings::SETTING_SUBTITLES_FONT));

xbmc/settings/AdvancedSettings.cpp

@@ -392,6 +392,8 @@ void CAdvancedSettings::Initialize()
 #else
   m_cacheMemSize = 1024 * 1024 * 20; // 20 MiB
 #endif
+  m_libAssCache = 0;
+
   m_cacheBufferMode = CACHE_BUFFER_MODE_INTERNET; // Default (buffer all internet streams/filesystems)
   m_cacheChunkSize = 128 * 1024; // 128 KiB
   // the following setting determines the readRate of a player data
@@ -1044,6 +1046,10 @@ void CAdvancedSettings::ParseSettingsFile(const std::string &file)
 
   XMLUtils::GetUInt(pRootElement, "fanartres", m_fanartRes, 0, 9999);
   XMLUtils::GetUInt(pRootElement, "imageres", m_imageRes, 0, 9999);
+
+  XMLUtils::GetUInt(pRootElement, "libasscache", m_libAssCache, 0, 1024);
+
+
   if (XMLUtils::GetString(pRootElement, "imagescalingalgorithm", tmp))
     m_imageScalingAlgorithm = CPictureScalingAlgorithm::FromString(tmp);
   XMLUtils::GetBoolean(pRootElement, "playlistasfolders", m_playlistAsFolders);

xbmc/settings/AdvancedSettings.h

@@ -332,6 +332,8 @@ class CAdvancedSettings : public ISettingCallback, public ISettingsHandler
     unsigned int m_cacheChunkSize;
     float m_cacheReadFactor;
 
+    unsigned int m_libAssCache;
+
     bool m_jsonOutputCompact;
     unsigned int m_jsonTcpPort;