13 Replies Latest reply: Aug 5, 2013 8:40 AM by the_wine_snob RSS

    Intermediate Files - Maintaining Ultimate Quality

    the_wine_snob CommunityMVP

      Once, most people were shooting to miniDV tape, and then capturing from that to a DV-AVI file for editing. In that Capture, it was a byte for byte transfer of data, and then written to a DV-AVI file, with very light compression.

       

      Now, nearly everyone is editing some form of highly-compressed Video file. At some point, after the image being recorded strikes the sensor, and the final file on the camera's memory card, or similar, there is compression being applied to the data, and it's much more significant. Often, it's a form of the H.264 CODEC, but not always. Still, some compression is being applied. This compression goes pretty much unnoticed, since the material is HD to begin with, but it is there.

       

      Once edited, if one then goes directly to BD (Blu-ray Disc), there will be one more layer of compression, either to H.264, or HD MPEG-2. Still, quality is quite high, and seldom calls attention to itself.

       

      What does one do, if they need to edit, then output to an intermediate file, work on that in another program, like Adobe AfterEffects, and then will need to do additional editing to the output file from AE, before going to that BD? If one continues to do a succession of heavy compressions, quality will go down, and rather quickly. The degrading will most likely be seen where there is rapid motion (either camera or subject) and also in the form of artifacts, which will grow with each generation of compression. It's like looking at a FAX, of a FAX, or a FAX.

       

      This is where using a lossless CODEC to create an intermediate file, can be very useful.

       

      If you are in need of an intermediate file, to do more editing on, about the best that you can do is use one of the lossless CODEC's, like Lagarith Lossless, or UT Lossless. Both are free, and both are good, but the file sizes WILL be large. Prepare for that. One would just download and install one of those CODEC's, and reboot. Then in Export/Share, they would choose MS AVI, and under Compressor, would look in the drop-down list for the Lagarith, or the UT Lossless CODEC. The file format will be .AVI, and contain the lossless CODEC. Those files will then Import into the video-editing program, or compositing program, with no loss in quality. This will eliminate one compression stage, and improve overall quality. The fewer compression steps, the better the final output.

       

      Note: if one is sharing the .AVI's with either of those lossless CODEC's, then the recipient will need to have that CODEC installed, as well, or they will not be able to even play the file, much less edit it. Remember, these CODEC's are for intermediate files, and are not ideal as final delivery formats.

       

      Both of those lossless CODEC's are fairly quick to both Encode and Decode, but there IS some processing necessary, so they might not Import, or edit as quickly as the original material, and certainly not as quickly as using a DV-AVI in an SD Project was - but still fairly fast.

       

      If you are in need of intermediate files, give either the Lagarith Lossless, or the UT Lossless a try. Remember, after installation, and rebooting, they will then be found in the MS AVI (not DV-AVI), and then under the Compression/Compressor choices for the CODEC inside the AVI wrapper.

       

      Hunt