Down Conversions

Down conversion is the process of converting hi-definition video into standard-definition. As virtually all video today is shot in hi-def (pending the full scale arrival of UHD: Ultra hi-def, or 4K) there are times when standard def files need to be created from a movie or show that was only shot in Hi-def. Many clients at television post houses still use SD tape, and movie distributors often will request DVD as a film submission.

The downconversion process can be tape to tape, file to file, or file to tape. It involves taking a 1920 x 1080 16:9 file and making it into a NTSC or PAL 525 or 625 File. The 16: 9 aspect ratio native to HD can be kept in standard def, or the hi-definition file can be converted to the SD 4:3 aspect ratio. If the new file stays 16:9 it can be in letterbox format, or matted. If the new SD file is 4:3 it will be side-matted.

Down conversion can be achieved using either a software, or hardware conversion process. Software conversions can be done on a computer with a myriad of different programs; it can also be done by re-exporting a file in Final Cut Pro to the format and standard needed. Software downconversions are cheaper but you will most likely run into issues that will be flagged in QC and depending on your distribution or network specifications, cause the program to be rejected. Issues that can occur in software conversions include freeze frames. This is where the picture will “freeze” for one frame, a duplicate frame will be shown on consecutive frames. Video formats usually have movement in every frame so the freeze frame will cause the picture to visibly freeze. Conversion errors typically will cause a freeze frame in every 5th frame of video making the picture appear to stutter. Another software conversion issue is frame blending. This is where you can see an outline around an image such as a face or body as it is moving. Many distributors, television networks and producers will not allow frame blending, freeze frames and other down conversion errors.

The better way to downconvert is the hardware conversion using a machine such as a Teranex. Teranex conversions are done at the highest quality on machines that are designed for this purpose and use specific algorithms for conversions that eliminate the freeze frames, frame blending, motion lag and other visible artifacts that would be present through software conversion. The Teranex allows you to input any hi-def source whether it is 1080i (interlaced) 1080p (progressive); and any time code (23.98, 29.97, 50) and output the signal to any standard def format (NTSC or PAL.) It can also do the opposite and up convert files as well as do cross conversions within the HD or SD realm.

If after down conversion, a standard def file is still too large, say for a DVD which holds a maximum of 4.7gb for single layer & 8.5gb for dual layer the SD file can be compressed to fit on a DVD while still maintaining good quality.

Call us for more info 323-316-8298
Email: laposthouse@gmail.com






Full Service Television Video Post Production & QC:
HDCAM SR, Quicktime, Digitizing, Conversions, Blu-Ray

Services Include:
  • 4K, 2K, HD, SD
  • Digitizing from Tape to Pro Res Files
  • HDCAM SR, HDCAM, Digibeta, IMX, NTSC/PAL
  • 100% Quality Control of Tape or File with Complete QC Reports
  • Post Production Consulting
  • Video & Audio Finishing Services
  • Up, Down, & Cross Conversions Clones or Dubs (Analog/Digital/NTSC/PAL)
  • Subtitle Encoding & Closed Captioning Files and Encoing
  • Editing & Color Correction w/ Final Cut Pro, Adobe Premiere, Avid & Pro Tools
  • Quicktime video output & mastering production to: HDCAM SR, HDCAM, DIGIBETA, IMX, BETA SP, DVCAM, DV
  • 5.1 Surround, Voice-Overs, Narration, Dialogue Replacement
  • Blu-Ray/DVD mastering, CD/DVD face printing
  • Digital Cinema Package (DCP) Encoding and Delivery
  • Reel compilations, screener versions, cutdowns, slates, pulled blacks