{"id":781,"date":"2015-07-29T04:46:20","date_gmt":"2015-07-29T04:46:20","guid":{"rendered":"http:\/\/editspecialists.com\/pr\/?p=781"},"modified":"2016-12-19T02:00:19","modified_gmt":"2016-12-19T02:00:19","slug":"all-about-pr-media-cache-files","status":"publish","type":"post","link":"https:\/\/editspecialists.com\/pr\/index.php\/all-about-pr-media-cache-files\/","title":{"rendered":"All about Pr Media Cache Files"},"content":{"rendered":"

The Mercury playback\u00a0engine’s\u00a0workings are\u00a0kept secret\u00a0by Adobe’s marketers.\u00a0Recommended RAM is about three gigs\u00a0<\/span>per core you have on your system. Click here for Adobe’s official\u00a0rendering & exporting\u00a0notes.<\/a><\/span>
\n<\/a>While both Avid and FCPX support editing\u00a0with native media, Premiere is\u00a0designed\u00a0<\/em>around it. Adobe has not developed\u00a0its own\u00a0mezzanine, or intermediate, codec; while you can transcode media to, say, Apple\u2019s ProRes or Avid\u2019s DNxHD, it\u2019s not necessary they say…
\nPlaying\u00a0anything without stutters from source or timeline\u00a0depends on these four\u00a0things:<\/p>\n

1.<\/strong> Media has to be on a fast, local media drive (the faster the better, like 1000 MB\/S \u00a0or better)
\n2.<\/strong> In Software-only\u00a0a fast CPU with 8 cores or more.
\nOr in GPU Acceleration mode:
\nA combination of fast CPU\u00a0& GPU with\u00a01000+ cores & at least 4GB VRAM
\n3.<\/strong> Cache files & Database on a local, fast drive. (1000 MB\/S or better)
\n4. <\/strong>Sequence settings have to match files on Timeline<\/a> or Previews have to match delivery format.<\/p>\n

When you bring in any footage that can’t be used as it’s own preview or cache file, Pr creates cache files in the background on import.\u00a0After import playback is usually stuttery and audio drops out, but if you let it sit for a while, playback becomes smoother.
\nIf you can use the media file as the preview file<\/a>\u00a0then Pr will not create cache files.
\n\"nocolor\"<\/a>
\nThis is indicated by NO color in the Timeline.<\/strong><\/p>\n

This is the list of preferred I-Frame codecs that play without generating cache files:
\nDVCPRO-HD in MXF<\/a> wrapper (the file structure on P2 cards)
\nDVCPRO-HD in Quicktime wrapper
\nPRORES >Any flavor\u00a0(Mac only)
\nAVID DNxHD MXF<\/a> (Adobe licensed for both Mac & PC)
\nAVID DNxHD in Quicktime wrapper
\nAVC-intra MXF<\/a> (Mac & PC)
\nAVI (windows only)
\nAny other file will generate Cache files on import for both Video & Audio<\/strong><\/p>\n

WARNING:<\/strong>
\nBy default both the cache files and the database are stored\u00a0here:
\nMac:<\/strong> \/Users\/\/Library\/Application Support\/Adobe\/Common
\n<\/em>Windows:<\/strong> \\Users\\<username>\\AppData\\Roaming\\Adobe\\Common<\/em>
\nDO NOT LEAVE THEM THERE<\/strong> or you will run your editing system into the ground! The cache files can easily\u00a0grow\u00a0to 100GB\u00a0or more.\u00a0You have to manually delete them when a project is done and they also have to get rebuild in a multi-user-environment, because adobe does not support database or cache on shared storage.<\/a>
\n
\nVIDEO\u00a0<\/strong>files in Media cache folder:
\n.ims \u2013 Importer State files. These files refer to the sta- tus of an imported file.
\n.mxfassoc – MXF associations. Some flavors of MXF have media attached; some don\u2019t. This cache keeps track of the associations.
\n.prmdc \u2013 Premiere Metadata Database Cache. This is a cache for the database.
\n.mpegindex \u2013 MPEG Index Files. Some types of MPEG files require their own index, like XDCAM.<\/p>\n

AUDIO <\/strong>files in\u00a0Media Cache folder:
\n.cfa \u2013 Conformed Audio. Most\u00a0compressed formats have compressed audio, Pr\u00a0builds an uncompressed version for them.
\n.pek \u2013 PEaK files. These PEaK files are a picture of the peaks that are turned into waveforms.
\nFrom Adobe >These rules determine which types of audio get conformed:<\/a><\/p>\n